CA1123814A

CA1123814A - Aluminosilicate sols and powders

Info

Publication number: CA1123814A
Application number: CA297,488A
Authority: CA
Inventors: Horacio E. Bergna
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1977-06-24
Filing date: 1978-02-22
Publication date: 1982-05-18
Also published as: GB1601250A

Abstract

(IC 6287-B) ALUMINOSILICATE SOLS AND POWDERS

ABSTRACT OF THE DISCLOSURE

An amorphous aluminosilicate sol with uniform size particles and a porous amorphous aluminosilicate powder composition useful as a catalyst in petroleum cracking is prepared by a process comprising (1) preparing a sol of discrete colloidal particles of uniform size within the range of from 2 to 87 nanometers, the surface of the particles consisting of a coating of an aluminosilicate at least 0.5 nanometer in thickness, by separately and simul-taneously adding a sol of silica or a solution of sodium or potassium silicate and a solution of sodium or potassium aluminate to a heel sol of uniform-sized colloidal particles of aluminosilicate, silica, or one or more refractory metal oxides at a certain rate of addition and at a constant pH
in the range of 9 to 12 and a temperature of 50° to 100°C
to deposit or coat aluminosilicate onto the surface of the heel sol particles, (2) ion exchanging the sodium or potassium ions of the sol from (1) for ammonium ions, (3) optionally removing the ammonium ions partially or com-pletely with one or more metal ions described herein selected from Groups I to VIII of the Periodic Table, and (4) remov-ing water from the sol without gelling so that the particles become uniformly packed into aggregates having pores of substantially uniform size and coating said powder with a surface layer 0 to 15% by weight of a metal or metal oxide, said powder having a specific surface area of 30 to 750 m2/g, a bulk density of 0.5 g/cc or more and substantially uni-form size pore diameters of from 20 .ANG. to 250 .ANG., with pore diameters of 20 .ANG. to 45 .ANG. having a uniformity such that at least 90% of the pore volume is made up of pores of from 0.6D to 1.4D and pore diameters of 45 .ANG. to 250 .ANG. having a uniformity such that at least 80% of the pore volume is made up of pores of from 0.6D to 1.4D, where D is the median pore diameter.

Description

BAC KGROUND OF THE I NVE NTI ON
___ _ _ _ ~_ _ 1. Field of the Invention This invention relates to porous amor.phous alumino-silicate powders having uniform pore sizes and uniform particl~ size aluminosilicate aquasols. More specifically, this invention relates to porous amorphous aluminosilicate powders having a uniform pore size,precursor aluminosilicate aquasols with uniform particle size and their preparation by drying said aquasols to a powder without gelling.

2. Prior Art Silica gels which are dried to porous silica powd~rs are considered to be masses of spheres of SiO2 ranging from a few Angstroms up t~ several hundred ~n~stroms in diameter, which are aggregated together in a three-dimensional mass. Vysotskii ["Adsorption and ~dsorbents"
(No. 1), John t1iley & Sons, N.Y., 1973, p. 101] states that globular particles of silica form the skeleton of gels and that the cavities between the spherical particles consti-tute the pores in silica gels. This structure of silica gels is further d2scribed in detail by R. K. Iler, "The Colloid Chemistry of Silica and Silicates", Cornell Uni-~crsity Prcss, Ithaca, N.Y., 1955, p. 129. The pore size nnd pore uniformity of silica is related to the particle si7e and particle uniformity.

.S, Patent 3,782,075 disclos~s a silica packin~
.ltcrial for chromato~raphic columns havin~ uniform-sized porou~ mi.crosphereS havin~ su~stantially all of the micro-r.plleres ln the ran~e of from 0.5D to 1.5D whel-e D is the n~era~Je di.~m~ter.

.

3~14 It is known to react sodium silicate, sodium aluminate, and an acid, or sodium silicate, aluminum sul-fate, and an acid to form a gel or precipitate of alumino-silicate directly However, the prior art does not teach any method for controlling the ultimate size of alumino-silicate particles which eventually aggregate to form the gel structure or the preparation of the ultimate particles of uniform si7.e. The control of the pore size aistribution, namely the size distribution of spaces between these pri-mary globules or aluminosilicate particles is likewise not known.
The difficulty of making aluminosilicate solparticles from which uniformly porous gels and powders can be formed is exemplified by Kontorovich, et al., J. of Colloid Chemistry, USSR (English translation), Vol. 35, p. 864, 1973 (Kolloyd, zhur, p. 935). Aluminosilicate particles,made simply by mixing sodium silicate, sulfuric acid, and aluminosulfate,showed a wide distribution of radii such that, for example, where the commonest particle radius was 20 A, a large fraction of the particles were also as large as 60 ~ radius. He further points out that even when the gels are aged for growth, the particles grow only to about 35 A, even after long exposure in water at 70C. He states definitely that the presence of aluminum in the globules hinders the increase in the size of the particles. This puts a limit in the ~1 contcnt for certain particle sizes.
The nonuniformit~ of porcs of amorphous alumino-sili.cates is exemplified in U.S. Patcnt 3,346,509 which dis-closcs the prcparation of silica-~lumina compositions with

- 4 -1:~23~:14 a preponderance of the pore volume in pores of small radii.
The pore radii are disclosed as ranging from above 200 A
to less than 10 A with up to about 60% in the range of O O
10 A to 20 A.
U.S. Patent 3,766,057 discloses an alumino-silica gel dried to a powder having a mean pore radius of 40 A to 100 A and 15~ of the pore volume in a 10 A section with a wide distribution of particles in the adjacent particle sizes.

Making aluminosilicate sols of particles of 3 to 150 millimicrons in diameter which are uniform in chemical CQmposition was described by G. B. Alexander in U.S. Patent 2,974,108, issued March 7, 1961. In U.S. Patent 2,913,419, issued November 17, 1959, Alexander discloses the prepara-tion of gels and particles having a skin or outer surface of alumi~osilicate composition. The gels have a coarse structure to permit coating with aluminosilicate without closing the pores in the gel. There is no disclosure of the need for uniform pores or for the preparation of uni-form pore sizes or the control of the pH at a constant value between 9 and 12. Alexander's particles are used as filters while his gels are used as catalysts.
In porous catalyst powders, the uniformity in pore size is a definite advantage in affording specificity of reaction by avoiding side reactions and preventing the deposition of carbonaceous residues. Heretofore, it has not been possible to produce amorphous aluminosilicatc catalysts Wit]l a uniform pore size.
SI~MJ~ R~' OE TIIE IN~7EN'rION
Now it has bcen found that aluminosilicatc porous powders witll uniform porc sizc distribution comprisi ~2~38~L4 spheroidal colloidal partieles of uniform size ean be pre-pared by first growing uniform size particles at a con-stant pH to prepare a uniform partiele size amorphous aluminosilicate sol and then drying said uniform particle size sol to a powder without gelling the sol.
The eompositionsof this invention, which are particularly useful as a eatalyst, consist essentially of uniformly porous powders comprising spheroidal colloidal particles of uniform size packed into porous aggre~ates 10. having a uniform pore diameter between the particles, a bulk density of 0.5 g/cc or more, preferably from 0.5 to D.9 g/ce and a specific surface area of 30 to 750 m2/g of said particles having a surface of amorphous aluminosilicate.
The uniform spheroidal discrete eolloidal particles of the sol to be dried have particle diameters which range from 3 to 90 nanometers.
The spheroidal particles have a coating that con-sists of an amorphous aluminosilicate. Said aluminosilicate is coated or deposited on a pre-formed core of more or less spheroidal colloidal particles which may or may not have the same composition as the deposited aluminosilicate. For eatalytie activity it is only essential that the required eolloidal particles have a coating or surface of cataly-tieally active amorphous aluminosilicate. This coating eomposition extends witnin the surface to a depth of at least 0.5 nanometer, preferably 0.5 to 1.5 nanometers.
~lthough tllis composition can extend to a depth o~ ~reater than 1.5 nanomcters, ~epths ~rcater than 1.5 nanometers are seldom req~lired.
The spheroidal particles are coatcd with an amor-phous hydrous alumino~ilicatc compound compri.siny onc or more cations selected from the group consisting of sodium, potassium, hydrogen, ammonium and Group I to;VIII metals selected from the group consisting of Cs, Li, Mg, Ca, Sr, Ra, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb. The interior of the spheroidal particles is also composed of said aluminosili~
cate except to the extent that the nuclei or core may be a refractory metal oxide or silica.
The aluminosilicate chemical composition may be defined by the following formula:
x ~(A102)X(siO2)y]n~wH2o v where x and y are the number of moles of A102 and SiO~
r~specti~tely, the molar ratio of y:x being from 1:1 to 19:1 ~f Si:Al, and ~ is the moles of bound water, M is one or m6re metal cations selected from the group consisting of Li, Na, K, H, ~H4, ~s, Ru, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, ~, zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, ~0 r~re ea~th metals, ~f, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; and v is the valence of M. It is understood that where there are, e.g., three metals, the term Mx would v include each metal and its valence. The cations represented ~y M are preferably selected from one or more of the group consisting of amm~nium, hydrogen, Cs, Li, Mg, Ca, Sr, Ba, Sc, ~i, V, Cr, Mn, Fe, Co, Ni, Cu, Yl Zr, Nb, Mo, Tc, Ru, I~h, Pd, Ag, La, Ce, rare earth metals, l~f, Ta, W, Re, Os, Ir, Pt, ~u, Sn, Cd, Bi and Sb. Wllat is meant by one or more is 3~ that in the replacemellt o~ sodium or potassium with one or ~Z38i~

more mctal cations listed, there will be replaceme~nt to the extent the sodium or potassium is replaceable with one or more metal cations. Thus in addition to the one or more metal cations, some unreplaced sodium or potassium will remain.
Cenerally the aluminosilicate of this invention is produced in the form where M is sodium or potassium.
The sodium or potassium aluminosilicate is ion exchanged so that it is largely ammonium aluminosilicate although L0 some sodium or potassium aluminosilicate still remains.
The ammonium aluminosilicate can be heated to drive off the ammonium to give hydrogen aluminosilicate. The final form of the powder is generally ammonium or hydrogen alumino-silicate. However, where it is desired to replace the ammonium or hydrogen with one or more metals indicated above for M, t~e sol before drying may be ion exchanged to yield the aluminosilicate with the desired metal or metals. In such a case, a small amount of ammonium and/or hydrogen aluminosilicate also remains.
The powder compositions of this invention may also have a surface layer over the aforesaid aluminosilicate coating of one or more of the following metal or metal oxides which may be in the cationic form, partially replac-ing M: Li, Cs, Rb, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, La, Ce, the rare eath metals, Hf, Ta, W, Re, Os, Ir, Pt, Cu, ~g and Au. The most prt-~ferred aluminosilicate chemical composition is whcre M is ammonium or hydrot3cn or mixtures thereof.
Thus, in accordance witll thc invcntion, a uni~
3n formly porous powtlcr composition has becn found which com-priscs porous ag~l-c~atcs of spllcroida] particlcs which are 3 to 90 nanometers in size and nonporous to nitrogen and contain:
(a) a core of silica, aluminosilicate or one or more refractory metal oxides selected from alumina, zir-conia, titania, thoria and rare earth oxides (b) a coating around said core of at least 0.5 na~ometer in depth of an amorphous hydrous aluminosilicate - compound having a molar ratio of Si:Al of from 1:1 to 19:1 and comprising one or more cations selected from sodium, potassium, ammonium, hydrogen and Groups I to VIII metals selected from Cs, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, ~e, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; and (c) a surface layer over said coating of 0 to 15~ by weight of a metal or metal oxide selected from Cs, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; said powder composition having a specific surface area of 30 to 750 m2~g, a bulk density of 0.5 g/cc or more and substan~
tially uniform size pore diameters of from 20 A to 250 A, O O
with pore diameters of 20 A to 45 A having a uniformity such that at least 90% of the pore volume is made up of pores of from 0.6D to 1.4D and pore diameters of 45 A to 250 A
having a uniformity such that at least 80% o the pore volume is made up of pores of from 0.6D to 1.4D, where D
is the median pore diameter. A particularly useful powder is one with pore diameters of 20A to 150 A with a uniformity such that at least 90~ of the pore volume is made up of pores of from 0.6D to 1.4D. An even more uniform powder within the scope of the aluminosilicate powders of this invention is one with pore diameters of 20 A to 150 A with a uniformity such that at least 90% of the pore volume is made up of pores of from 0. 7D to 1.3D. The porous aggre-gates of this invention may range in size from 2 to 500 microns.
The aluminosilicates of this invention are pre-pared by a process comprising:
(a) preparing a heel sol of discrete colloidal particles selected from sodium, potassium or ammonium aluminosilicate, silica and one or more refractory metal oxides selected from the group consisting of titania, alumina, zirconia, lanthana, thoria and rare earth metal oxides, said heel sol comprising `particles o~ a substantially uniform diameter within the range of 2 to about 85 nano-meters, the initial concentration in the heel sol of sodium, potassium, ammonium aluminosilicate or total refractory metal oxide being at least 0.2.~ by weight with the particles stabilized against aggregation in the pH range 9 to 12;
~ b) addin~ to said heel, separately but simul-taneously, two feed solutions, one being a solution of sodium or potassium silicate having from 1 to 36 grams of silica per 100 cc, or a sol of silicic acid containing from 1 to 12% silica, the other being a solution of sodium or potassium aluminate containing from 1 to 15Q~ alumina, said feed solutions being added in rclati~e rates and proportions to maintain a constant molar ratio of Si:~l in the feed streams of from 1:1 to 19:1 with the rate of addition of silica not 3~ to exceed 10 grams of SiO2 per 1000 squarc mc~ers o~ total surface area of particlcs in thc hccl sol per hour;

~.Z3~

~ c) maintaining the pl~ of the heel sol at a constant value between 9 and 12 by adding a cation exchange resin in the hydrogen or ammonium form until the particles in the heel sol have attained an increase in diameter of at least 1 nanometer and a maximum size of 90 nanometers;

(d) filtering the sol from (c) to remove the cation exchange resin and optionally adjusting the concen-tration of the resulting aluminosilicate sol to a solids content of uo to 60% by weiqht: an~
(e) drying the resulting substantially gel-free sol of particles having an aluminosilicate surface to a powder by removing water at a rate at which no gelling will occur.
Accordingly, the uniform size amorphous alumino-silicate particle sols of this invention are produced by steps a, b and c of the aforesaid process followed by re-moval of the exchange resin. The uniformity of said parti-cles is such that the maximum standard deviation of the particle size is 0.37d where d isweighted avera~e particle size diameter.
Thus, the amorphous aluminosilicate sols of this invention have uniform particles of from 3 to 90 nanometers in diameter with a molar ratio of Si/Al of 1:1 to 19:1, said uniformity defined by particles having a maximum stan-dard deviation of 0.37d, where d is the weighted average particle size diameter.
The sol from (d) may be ion exchanged to remove the sodium or potassium ions by contacting it with a strong acid type of cation exchange resin in the ammonium form, after which the solids concentration may be adjusted to the 31~L4 range of 10 to 60% by wei~ht before drying the substantially gel-free aluminosilicate sol to a powder by removing the water at a rate at which no gelling will occur.
In the process of making the sol of this invention, the silica reacting with the aluminate ions is either largely monomeric or polymeric. When the silica is monomeric, most of the individual silicon atoms become associated directly with the A102 ions forming SiA104 ions in the colloidal particles r accompanied in the colloidal particle by the alkali ion present in the reaction such as Na+. On the other hand, in conventional gel processes, substantially more of the silica is polymerized before it can be linked to alumina, therefore less silica units are directly associated with alumina. For these reasons the aluminosilicate compositions of this invention are believed to have a more uniform SiO2 to A102 distribution than the conventional silica-alumina gels. This kind of uniformity at a submicron range scale combined with narrow pore size distribution is of great importance in determining the performance of this composition as catalysts and catalyst supports, for example when mixed with active zeolite catalysts.
It will be understood that even when the heel sol is a refractory oxide or silica or aluminosilicate, the particles in the final sol product will have a coating of alùminosilicate and are referred to herein as an al,umino-silicate sol.
The powders of this invention have substantially uniform pore sizes becausc the particles in,tne alumino-silicate sol beforc dryin~ are substantially uniform in diametc?r. The uniform p~rticle size of thc sol rcsults 11~38:~L4 because the two individual species, the aluminat~ ions and silica or silicate ions, are not allowe~ to react to form new particles or precipitate. The aluminate ions and silica or silicate ions are converted to.soluble forms of alumina and silica or silicate which are deposi~ed on the substantially uniform sized nuclei or initial particles in - the heel. When the alkaline solutions of silicate and aluminate are added, the plI of the mixture, but for the addi-tion of ion exchange resin,would rise. The addition of ion exchange resin is regulated to maintain the pI~ constant in the range of 9 to 12. This control of pH and the maxi-mum addition rate of silicate and aluminate de~cribed herein after (10 g of SiO2 per 1000 sq. meters of surface area per hour) results in the aluminosilicate particles being of ~ ~3~

The powders of this invention have an average pore size which dep~nds on the average particle size of the precursor aluminosilicate aquasol. The aquasol is in turn obtained by deposition of sodium or potassium alumino-silicate on colloidal nuclei particles in the heel sol.
For these reasons the selection of the heel sol has to be made on the basis of what properties are required in the final powder and on the amount of aluminosilicate that is -. to be deposited.
In the process of the present invention what is meant by constant pH is maintaining the pH within ~ 0.2.
The addition of a cation exchange resin in the hydrogen or ammonium form removes sodium ions and prevents the accumu-lation of sodium salt in the reaction medium that would cause coagulation of the colloidal particles.
Once the required spheroidal particles have been formed containing cations of sodium or potassium, there are the following ways in which the final powder of the in-vention can be made, depending on what cations are desired in the final product:
(a) The sodium or potassium ions in the sol may be ion exchanged, e.g., by hydrogen or ammonium ions and then the sol converted to powder by removing water.
(b) One or more cations of metals describcd herein to enhance catalytic activity may ~e added in limited amounts to the sol to partially replace hydrogen or ammonium ions be~ore formillg th~ powder.
(c) The sol containinc3 thc ori~inal sodium or potassium ions may be convert~d to powder and then the sodium or potassium iOIl cxchanged for ammonium or one or ~ ~38~

more of thc metal cations described herein. In this in-stance, removal of all sodium or potassium from thc powder is substantially attained only ~here the pores of the pow-der ~re large and only the outer surface of the ~pheroidal particles consists of aluminosilicate.
(d) In carrying out alternative (b) and (c), more cation metal may be used than required for ion exchange if it is desired to leave a thin film of metal on the alumino-silicate surface. Said metal deposited on the aluminosilicate is converted to hydroxide and oxide when the aluminosilicate is dried and calcined.
The metal cations of Groups I to VIII of the Periodic Table referred to herein include Group 1~ except for Fr, (;roup lB, Group 2A, Group 2B, except for Hg, Group 3B, exceljt actinium, Group 4B, Group 5B, Group 6B, Group 7B, Group 8 and Sn, Sb and Bi.
The aluminosilicate powders of the present in-vention are made by drying sols of spheroidal discrete colloidal uniform sized particles to obtain dried aggre-gates of said particles in which the spheroidal particlesare closely packed to~ethcr. The narrow pore size distri-bution of the powder of this invention is attainable with porous aggregates ranging in size from 2 to 500 microns, preferably 10 to 200 microns, althougll considerably larger powdcr grains can be obtained, depcndin~ on the method of drying. The uniform individual particlcs that compactly ag~lomcrate to form the powdcrs of this invention ~re selectecl from thc rang2 from 3 to 90 nanomcters in diamctcr, depcndi~l~ on the dcsi1-cd rcsulting porc siæe.

3~

It is most important that loose a~gregation of the particles or formation of gel networks of linked particles does not occur before water is removed. Otherwise, par-ticles become linked together in open three-dimensional networks in the sol. These open networks do not completely collapse upon removal of water and drying, thus leaving some pores appreciably wider than those remaining when the spheroidal particles are closely packed together upon being dried.
Most simply stated, drying should occur ~efore aggregation or gellin~ occurs in the sol. One way to obtain a mass of close-packed colloidal particles is to force the water under pressure out of a sol through microporous membrane against which the silica particles become packed, and then drying the water fro~ the wet solid ~iltercake.
~owever, the most convenient way is to concentrate the sol as much as possible, such as to a solids content of 10 to 60% by weight, without aggregating the particles and then to dry suddenly as ~y spray drying. In this case, the sol is concentrated rapidly in spheroidal droplets and the sur-face tension of the water compresses the mass of particles, orcing them together in spite of the mutualrepulsion due to the ionic charge on the surface, until they are randomly closely packed.
Fi~ure 1 is an illustration of the dried particle structure of the aquasol o~ this invention in contrast to structures after ~elation, coagulation or flocculation.
Figurc 2 is a drawing of a spray dricd porous a~gregatc of this invcntion.
~ ~igurc 3 is a cross sectioll of a particlc rna!ci ng ~.~.23~4 up the aggregate where the particle is homogeneous and where there is a core of a refractory o~ide.
Figure 4 illustrates the pore volume formed by the spheroidal particles of this invention.
Referring now to Figure 1, the gel s-tructure formed after drying is shown after (a) gelation or (b) coagulation or flocculation of the a~uasol of this in-vention. The dried structure of this invention with uniform - pore size distribution is also shown after drying without gelation.
Referring now to Figure 2, the spray dried aggregates of Particles of this invention is shown in a spheroidal shape to illustrate the uniform packing of -the particles to form the aggregate. The individual particles ma~ing up the aggregate may be homogeneously an amorphous aluminosilicate or may have a core of silica, aluminosilicate or one or more refractory metal oxides with a coating of said aluminosilicate as illustrated by Figure 3.
Figure 4 was merely included to illustrate the pore volume of this invention and its formation by the particles.
The theory of the shrinkage orces in dryin~
water from wet masses or ~els of colloidal silica has been described by R.K. Iler in "Colloid Chemistry of Silica and Silicates" (Cornel University Press) 1955, pages 140 to 143. The nature of the resulting ~el or aggregate masses has been discussed by R.K. Iler in a monograph on "Colloidal Silica" in Surface and Colloid Science, Vol. 6, edited by F. Matijevic (John Wiley & Sons, Inc.) 1973, pages 65 to 70. The principles relating to colloidal silica also apply to the present sols which are converted to powders.

~ ., 3~314 The colloidal particles which bear the highest ionic charge and which exert the greatest mutual repulsion in the end, form the most clos~ly packed aggregates. The reason is that as the sol becomes concentrated the particles still repel each other and do not join together even when they are ~uchcloser to each other than their own diameter.
Thus, the uniform spheroids remain uniformly distributed as further water is removed, un~il the concentration reaches the point where all the particles are ~orced into ~ontact at about the same time so that the spaces or pores be~ween them are uniform in size.
" If, however, the particies in the soi begi'n 'to form open three-dimensional aggregates, or i'gei phasei' as described by Iler in "Colloidal Siiicai', 'page 45, the'n these particles are no longer freè to move toge'the'r 'ù'nifor'ml'y as the sol l~ecomes very concentrated and 'when d'ried sùch particles are not fully closely packed and la'rger ~r`regular pores then remain in the powder.
Since aggregation of the particles i`n a sol to form a gel is not an instantaneous process bù't generally occurs over a period of hours or dàys, thè sol o'f t'his i'n-vention must be dried as rapidly as possible or bè'fo're gelling at as low a temperature as consistent'w`i`th `ra`p'i~
drying. Generally speaXing, the sols suitable 'for d`ry:in~
do not ~el in less than about an hoùr so that d'ry`ing 'w'ithin one hour is desirable.
Spray drying is a prc~errcd procedu'r~ `not o'nly because drying is rai~id, but bccausc thc powdcr `product is obtaincd as porous spllercs typically 5 to 200'mi`crons iil diamctcr which arc cspccially useful as catalysts.

~P~3~

Thc surface of the powder consists of an alumino-silicate at least to the dcpth of about 0.5 nanometer of the formula indicated above or it may contain a surface layer of the metal cations described in the following par-agraph and amounting to 0 to 15% by weight.
In the general formula, the hydrogen or ammonium ions may be wholly or in part substituted by cesium, rubidium, lithium or metal cations selected from the group magnesium, ealcium, strontium, barium, scandium, titanium, vanadium, chromium, manganese, iron, niekel, cobalt, copper, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, lanthanum and elements of the rare earth lanthanide series numbers 58 to 71 in the periodic system, thorium, uranium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, bismuth, eadmium, tin and antimony.
The core of the spheroidal particles eonsists of the pre-formed colloidal particles on whi~h the alumino-silicate is deposited. The chemical nature of the interior of the particles plays no direct role in catalysis, since the particles are nonporous to or~anic molecules. Ho~ever, the pre-formed particles must be thermally stable and pro-vide a suitable physical substrate for the aluminosilicate on the sur ace. Thus, the core may consist of aluminosili-cate,of any ratio of Si:~l from 1:1 to 99:1, and prefcrably 1:1 to 19:1, silica or one or more refractory o~ides having a meltin~ point over 1600C, which can be prc-~ormcd as an aqueous sol o~ rclatively uniform, morc or lcss sphcroi~al colloical particlcs from ~ to ~7 nanometcrs in diametcr.
Ty~ical re~ractory oxidcs arc alumina, zirconia, titania, ~2~4 lanthana, thoria and rare earth oxides. ~lowever, such pre-formed particles must be of such uniform size that after the aluminosilicate has becn dcposited, the final particles will meet the above requirement of uniformity. It will be noted that even if the pre~formed colloidal particles are cubic crystals of a refractory oxide, the shape becomes more rounded as amorphous aluminosilicate is deposited as an increasingly thick coating. If ~he pre-formed particles are the same as the aluminosilicate being deposited, then the particles are homogeneous and are simply grown in size.
The core material is supplied in the form of an aquasol, the preparatlon of which is known in ~he art~ The size of the particles in the aquasol comprising the heel or core of the particles making up the powders of this in-vention can vary rather widely in view of the particle size range of 2 to 87 nanometers. The powder of this invention with large pores, would have, for example, large colloidal particles of 50 nanometers in diameter. These large particles may have an aluminosilicate surface or coating as little as 0.5 nanometer in thic~ness. Thus 83-~- of the volume of such particles may consist of a core material which may be a refractory oxide such as silica or alumina.
Thus in this case, aluminosilicate comprises only a minor part of the weight of the powder. On the otllcr hand, the ultimate colloidal spheroidal particles ma~ing up the powder grains may consist throughout of aluminosilicate.
The powders of this invention with cores of a very stable rcfractory are more rcsistant to sintexin(3 than when they consist entircly of ~]uminosilicate. T}-us, whell tho cores o~ spll~roidal particles of this inv~ntion 3~1~

comprise more than 50~ of the volume of ~ractory par-tieles, the powders of this invention are more resistant to sintering which would close the pores thereof. The aluminosilicate surface may sinter and flow to some ext~nt, but the thermally stable cores prevent collapse of th~
structure and closing of the pores. Thus, high surface area can be retained and by suitable partial rehydration of the aluminosilicate surface catalytic activity can be restored.
The colloidal particles in the heel or starting sol whieh constitute the core on which aluminosilicate is to be deposited must meet a number of requirements:
- (a) The particles must be of generally spheroidal or equidimensional in width, thickness and breadth, with an average diameter of 2 to about 87 nanometers. Thus in making aluminosilic~te-coated particles 3 nanometers in diameter, if the thickness of the aluminosilicate coating is 0.5 nanometer and the diameter of the heel sol particle is 2 nanometers, the final diameter will be 3 nanometers.
If it is l.5 nanometers in thic~ness ~nd the heel particles are 87 nanometers in diameter, the final particles will be 90 nanometers in diameter. As will be explained, the thic~ness of the deposited aluminosilicate should be greater when the particles of the heel sol are of a different com-position from the coating.
(b) The heel sol particlcs must be physically and chcn1ically stablc at high tempcrature. The rcfractory mctal particles of the hcel are charactcrize~ c~s having a melting point in e~cess of 3600C.

~ (c) Tl~e hcel sol particlcs must bc Or a subst.~ncc?

38~4 that ean be made in the form of an aqueous sol of colloidal partieles of uniform size.
The heel sol partieles eonstitutinq thc eore of the partieles making up the powders of this invention are seleeted from siliea, a sodium or potassium aluminosilieate having a ~i:Al molar ratio of from 1:1 to 99:1, preferably 1:1 to 19:1 and one or more refraetory metal oxides seleeted from the group consisting of alumina, zireonia, titania, thoria and rare earth oxides~ The preferred refraetory metal oxide is seleeted from alumina, zireonia and titania.
The preferred heel particles are selected from siliea, - sodium or potassium aluminosilieate having a Si:Al molar ratio of from 1:1 to 19:1, alumina, zireonia and titania.
- The preparation of sueh heel sol particles in the form of an aqueous sol is known in the art. Colloidal siliea of uniform size has been deseribed by R. K. Iler in "Colloidal Silica", in Surface and Colloid Seienee, Volume 6, E. Ilatijevie Editor (John Wiley & Sons, Ine.) 1973, page 1. U.S. Patent 3,370,017 diseloses the prepara-tion of aluminasols of man~ types. U.. S. Patent 2,974,108 diseloses aluminosilicate sols. U.S. Patents3,111,681 and 2,984,628 diselose zireonia sols. U.~. Patent 3,024,199 discloses sols of the rare earth oxides. Most refraetory oxides ean be made in the form of a stable aqucous sol cxeept those such as ealeium oxide, barium oxide or magnesium oxidc, which tend to hydrate or dissolve to an undesirable extcnt in water. It should be understood that eolloidal hyclrous oxidcs, in which tlle oxide in the eolloidal particle is el-cmically hydrated with some bound watcr that e.-nnot bc remo~c?d by vacuum at ordinary tempcr~~
turc, is satisf.~ctory for thc prcsellt purposc, unlcss thc .238~L~

.
loss of water at elevated tem~erature results in a gross shrinkage of the core within the aluminosilicate particle.
Even if the small heel particles initially have a cubic or other approximately equidimensional shape, they become rounded when enough aluminosilicate coatin~ has been deposited to form the spheroidal shape of the final sol particles.
~ f the available refractory oxide sol is not of sufficient uniform particle size, a fraction of suitable uniformity must be isolated by means known to those skilled in the art of colloid chemistry, such as fractional sedi-mentation or centrifugation.
The refractory oxide sols must be so constituted that the particles remain nonaggregated in a pH range wider than that at which the aluminosilicate is deposited, namely g to 12. Many refractory oxides including alumina, ~irconia and thoria are stable by virtue of a positive charge on the particles with nitrate or chloride counter-ions at a pH below 5 or 6. Ordinarily, when the pH of such ~0 a sol is raised to 7 or 8 or higher, the particles coagu-late or gel.
To stabilize such sols at pH above 7, those skilled in the art are familiar with tèchniques for re-~ersing the charge on the particles by adding an excess of ~ultivalent ions that are strongly adsorbed on the oxide particles at low pll and put a negative charge on the - particles. Then the pH can be raised to the alkaline side with ammonia or sodium hydroxidc. Citric or tartaric acid is often uscd ~or this purposc. Enough of said acid is added, to thc o~idc sol which is bclow pll 6, to furnisl ~J23~3~4 one or two acid moleculcs per square nanometer of colloid ~xide surface, before the pl~ is raised to the desired range.
In some instances, the charge of a positive oxide sol can be reversed by adding it in a thin stream at a point of in-tense agitation in a solution of sodium polym~taphosphate or sodium silicate. When the aluminosilicate deposition of this invention begins,it can displace the organic cations from the oxide particles, but generally not polymetaphos-phat~, which remains in the product. For this reason, the phosphate is less preferred.
Where very small particles are required in the heel, e.g., an aluminosilicate sol of particles less than

5 or 10 nanometers in diameter, it is preferable to pre-pare the particles as a heel just before the aluminosili-cate is deposited. Where very small silica particles are wanted as nuclei, sodium silicate is added to water to obtain a silica concentration of 0.5 to 1.0% and the pH
is adjusted to 8 to 10.5 with ion exchange resin at a temperature of 30 to 50C. Initially, colloidal particles as small as 1 nanometer are formed an~ these grow in size spontaneously while diminishillg in numbers. When the desired size is reached, the temperature is raised to at least 50~C and deposition of the aluminosilicate according to the process of the invention is begun.
Similarly, small particles of sodium aluminosili-cate can be attained in the heel by adding to watcr sodium silicate and sodium aluminate solutions to acllicve the de--sired ratio of Si:~l and thc combined conccntration of SiO2 plus ~12O3 of 0.2 to 0.5~. The pll is adjusted to ~ to 12, and the solution warmed to 50~C bcfor~ the dcpositio 38~

of aluminosilicate according to the process o~ the in-vention is begun.
Initially in sueh heel solutions, polym~rization of the oxide occurs with initial equilibrium formation of elusters containing various numbers of molecules. Clusters that are smaller than a certain critieal size have a ten-dency to redissolve, while elusters that are larger than this critical si~e will have a tendency to grow. Such eritical size clusters of moleeules are referred to in the art and herein as nuclei. In general, the term nuelei im-plies elusters of molecules or very small eolloidal partieles which are not in equilibrium with the dispersing medium and have a strong tendeney to grow into larger particles.
Thus to ma~e the smallest aluminosilicate particles the heel in the process of the invention can consist of wat~r dispersions of nuclei of silica or aluminosilicate, said nuclei being ~reshly formed clusters of small particles having a tendency to grow and form larger particles. For some~hat larger particl~s, the heel can eonsist of a water dispersion of silica or aluminosilicate particles rather than nuelci, in equilibrium with the ~ater.
For very small nuclei of refractory oxide around 2 nanometers in diameter, certain basic salts may be used providinc3 they are suitably converted to stable negativel~
eharged particles. Thus, basie aluminum ehloride having the cmpirical formula ~12(O~I)5Cl actually consists of hydrated alumina units eontaining about 13 aluminum atoms bearinc~ positivc eharges, surroundcd by ehloride ions in solution, as discloscd by Gcorg Johansson, ~cta Chonlica Scandinavica, Volume 14, pa(~c 771, 19G0. By addincJ a dilu~e .23i314 .

s~lu-tion of the basic aluminum chloride, containin~, ~or ex~mple, 0.3% by weight of equivalent A1203, to a very strongly agitated solution of ammonium citrate so as to have present at least one citrate ion per chloride ion, a negativ~ly charged complex is obtained. To this a dilute s~d-iùm silicate solution can then be added in an amount such that there are several silicate ions present per alumi-~- ae-om. When the sodium is removed by exchange with a ~tion ex-change resin in ammonium form and the solution he~ted to 50C, there is obtained a sol of silica coated ~lumina nuclei on which aluminosilicate may then be de-posited by the process of this invention until a particle ~i~e o 3 or 4 nanometers has been attained suitable for mak:ing a powder having very fine uniform pores.
C~mmercially available ~quasols with particle dl~metèrs from about 4 to 60 nanometers may be used as a ~eel i~ the process of the present invention. Silica ~quas-~ls are used as nuclei where the silica composition ~f th~ core is not déleterious to the properties, most notably the thermal stability and the catalytic activity, of the final product.
As a general statement about forming very small particles of refractory oxides by hydrolysis of salts, the process of nucleation is influenced by several factors, especially those.that affect the solubility of the nùcléi.
The rate of formation of nuclei of a solid in water dèpends on the degree of supersaturation. The less soluble the su~stance formed, the hi~her will be the supcrsaturation, ~nd thus there will be present more and smaller iluclei.
Sir.ce solubility in ~vater increases with tempcratul-e, the ~L23~

~upe~saturation levcl decrcascs with incxeasing temperature.
Thus, the lower the temperature, the more nuclei present ahd ~he smaller the nuclei for a given heel and the higher the temperature the fewer nuclei and the larger the nuclei for a given heel.
Generally, the range of temperature at which sil-ica nuclei àre formed by deionization of sodium silicate ~s ~0 to ioooC. In this case silica nuclei of about 1 to

6 naiiometers in diameter are obtained. In the case of ~10 a-iuminosilicate sols the nuclei are formed at temperatures between 3bo and about 50C. At higher temperatures there may be some forma~ion of coarse precipitates instead of aiscrete particies. However, although it is necessary in the casê of the aluminosilicate to effect the deionization o the added soluble silicate and soluble aluminate at a ~elatively low temperature to obtain very small but discre.e aiuminosilicate nuclei, once a sufficiently large number of nuciei of said aluminosilicate have been formed, the tem`peratùre can be increased to as much as 10~C to accel-~0 érate the build-up or growth of the particles, ~ he desired final particle size of the sol is de`penàent on the initial particle size nuclei o~ the heel ahd the amount of aluminosilicate to bc deposited. When the final powder pore size desired requires small final `pa`rticles of alùminosilicate, the initial hcel should con-tain smaller particles. When small particles are used in ~he initial heel and the reactants build-up the nuclei to a lar~er particlc, the corc that constitutcs the ori~lnal nuclei has a ne~ iblc efcct on thc catalytically active surfacc of the ~inal par1:ic]cs or powder. Thus, whcrc thc Z38~L~

nuclei are silica and the build-up or deposit constitutes a substantial part of the final particle, the product i5 essen-tially a homogeneous aluminosilicate particle. In such cases the volume of original silica of the nuclei is ne~li-gible compared to the volume of the final particle and this small amount of silica has very little effect on the pro-perties of the final aluminosilicate solution.
When the nuclei are larger, relatively smaller ~mounts of aluminosilicate may be built up around the nuclei, depending on the finally desired particle size and pore diameter. When these larger nuclei are alumina, some overall physical properties of the final product will be somewhat different from those where the ~articles are homogeneous aluminosilicate, for example, density, refractive index and thermal properties will be different. However, the surface properties will be the same.
Particle size and concentration of the nuclei in - the heel have an effect on the desired or practical build-up ratio. Build-up ratio (BR) is the ratio between the total weight of solids in the product sol and the total weight of the nuclei in the heel, assuming all the added ~lumina and silica has been deposited upon the nuclei.
It is possible to calculate the build-up ratio on the basis of rclative volumes, assumin~ densities for the h~el nuclei and the deposited aluminosilicate. When the ratio is calculatcd as total volume of solids in the final sol particles divided by the total volume of solids in the hccl sol, it is possibl~ to calculatc the average particle c1iamcter in thc fin~ sol from thc bui]d-up ratio 3~ and the particlc sizc of thc hcel sol.

38~

As an example of build-up ratio by weight, if we start with a one-liter heel with a concentration of 1 g/100 ml of aluminosilicate (total mass of nuclei 10 g) and during the process we add a total of one liter of sodium silicate solution with a concentration of 20 g SiO2/100 ml and one liter of sodium/~luminate solution with a concentration of 5 g NaAlO2/100 ml (total mass of SiO2 NaAlO2 250 g), the result is about 3 liters of a sol containing 260 g of solids. The build-up ration in this case will be 260/10, or 26.
Assuming that all the silica and aluminate accrete or are deposited uniformly on the aluminosilicate nuclei, there will be a relationship between the build-up ratio MF/Mi (where MF is the mass of solids in the final product and Mi is the mass of particles or nuclei initially) and the cube of the ratio between the particle di~meter of the product DF and the nuclei diameter Di:

BR = F =( DF ) When the layers of new material formed on the nuclei are not porous to liquid nitrogen, the relationship between build-up ratio and specific surface area of the product (SF) and the nuclei (Si) as measured by nitrogen adsorption, will be MF ~Si~3 Mi ~ SF J
However, it is pointed out that these formulac apply only when thc dcnsity of the dcpositcd aluMinosilicatc is the samc as that of the nuclci particles. Where thc dcllsities are different, suitable corrcctions must be made.

- 2'~ -~ Z3~

Thus having selectcd the particle size or speci~ic ~urface area of the final aluminosilicate sol, the formulae relating build-up ratio to particle sizes or surface areas and total masses or concentrations can be used to select the particle size and concentration of the required heel.
The nuclei or particles in the heel are caused to grow into a uniform particle size by the simultaneous but separate addition of a silica sol or a sodium or potassium . -silicate and sodium or potassium aluminate into a heel in the presence of a cationic exchange resin in the hydrogen - or ammonium form for pH contro~. The nuclei or particles in the heel grow by an accretion process. The cationic exchange resin in the hydrogen or ammonium form may be added to the heel prior to the simultaneous but separate addition of the silica sol or the silicate and aluminate solutions, or it may be added at the time the addition starts or shortly thereafter. Thereafter said resin is added to maintain a constant pH + 0.2.
It is required that the rate o~ addition of silica or silicate and aluminate is not permitted to reach that point where the silicate and aluminate will react in solu-tion and form new particles or a precipitate. The aluminate and silicate must bc hydrolyzed and deposited as completely as possible on the nuclei. The build-up or growth of the nuclei in the hee,l is thus limited by the rate that will permit the moleculcs of silicate and aluminate to deposit on said nuclei. Generally, the silicate and aluminate must not be add~d at a ratc greater than that by W]liCIl 10 g of SiO2 per 1000 square meters of surfacc area is ac~ded to thc system pcr hour. Gcnerally, thc addition of rc3ct~nts ~1~.238~4 will be such that 5 to 10 g of SiO2 arc added per 1000 square meters of surface area available in the system per hour. Rates of addition above the maximum specified above are undesirable because they will permit new nuclei to form which will result in nonuniform particle slze in the final sol.
The procedure of the present invention involves adding the solutions supplyin~ the silica and alumina simul-taneously, but separately to the heel sol in which the particles are growing. Premixing the reactants results in the formation of a precipitate and therefore must be avoided. The heel is vigorously stirred during the deposi-tion process to permit almost constant dispersion of the reactant solutions. The use o~ very thin feed tubes or jets for ihe introduction of reactants assists in the dispersion of the reactants. Generally, the discharge of the feed tubes is inside the liquid of the heel immediately above the agitation blades. The heel sol may be circulated from a reaction vessel through a centrifugal pump, through a mass of weak base ion exchange resin in ammonium form, and then bac~ to the vessel while the feed solution is fed in at à point close to the pump impeller.
The pH' of the heel must be controlled to remove the sodium or potassium of the reactants and control the solubility of the particles. The pll is held constant within + 0.2 units, preferably + 0.1 at a value betwc~n 9 and 12, preferably 10 to 10.5. The addition of the reactants at a lowcr pll such as 8 would rcsult in the formation of additional nuclci, and lcss complet~ dcposition of thc aluminosilicate on thc nuclci. This is bccause thc maximum ratc at which dcposition call occur is lowcr at lower pll.

~ Z3~314 Generally, the temperature during particle ~rowth is from 50 to 100~C. Particle growth below 50C may be achieved but relatively slowly. The higher the temperature, the faster the rate of growth, but in any case, the speci-fied rate of addition of reactants should not be exceedcd.
Temperatures above 100C may also be used provided care is taken to avoid evaporation by using greater than atmos-pheric pressure. However, at sufficiently high temperature - under pressure certain compositions of aluminosilicate, particularly sodium aluminosilicate with a Si:Al ratio of around 1:1, tends to crystallize and the desired amorphous layer on the nuclei is not deposited. Instead crystalline nuclei tend to form in suspension. The formation of such crystalline æeolite compositions should be avoided. On the other hand, aluminosilicate compositions with Si:Al ratios of 10:1 or 19:1 are less likely to crystallize and temperatures of up to 150C might be used if an economic advantage resulted.
The feed solution of sodium or potassium silicate may contain from 1 to 36R by t~ei~ht of silica, preferably 15 to 25~ silica. The most prefer-ed concentration is 20~
silica. Generally a feed solution of sodium silicate with a ratio of SiO2:~a2O of from 2.6 to 3.8 is preferred, while about 3.3 is most prefcrred.
The soclium or potassium aluminate solutions used in this invention may be purchased commercially, or thcy may be preparcd from commcrcially available solid sodium or potassium aluminate. In prcparin~ a solution o the aluminatc, it is sometimcs dcsirablc to add cxecss al~ali, e.~., NaOII or ~OII or LiOII, in.ordcr to dccrcasc thc cxtellt 3~ 4 of hydrolysis of the aluminate, but the amount should be minimized so as to reduce the amount of ion exchange resin that is needed.
Freshly prepared or commercially stabîlized solu-tions free from precipitate should be used in any case.
The aluminosilicate surface that results from the accretion of the sodium or potassium silicate and sodium or potassium aluminate onto the nuclei must have a Si:~l mole ratio of from 1:1 to 19:1. The concentrations and volumes of the added silicate and aluminate solutions must be such that they are ~Jithin the above final ratio. This often places a restriction on the concentrations that can be used.
The aluminate solution may be as concentrated as 15~ by weight aluminate, but at that concentration the addition would have to be very slow to pre~ent local precipitation of aluminosilicate. Generally, a solution containing 5%
aluminate is very convenient.
In the process of this invention the desixed con-centrations of silicate and of aluminate being added must be held constant, unless compensating changes in the flow rate are made. Once the ratio of Si:Al desired is deter-mined, and the rate of silicate addition is selected, the correspondin~ aluminate solution feed is set. The maximum addition rate of 10 g of SiO2 per 1000 square meters of surface area of the solids in the mixture per hour will thus limit the feed rate of both reactants.
Solllble electrolytes, such as sodium chloride, lithium carbonate or potassiUnl nitrate, tend to coa~ulate the aluminosilicatc particles. For this reason the hecl and fecd solutions sl-ould be essentially ~ree OI extrancous ;3~J.~
electrolytes such as those indicated. Salts liberatlng polyvalent catlons should specifically be avoided during the build-up operation.
The build-up or growth is continued until the desired particle size is reached. At this point, the aluminosilicate particles contain sodium or potassium cations.
The uniform particle size a~uasols of this in-vention have ion-exehange properties. Although the parti-cles have ion-exehange properties they are nonporous to organie moleeules. This indleates that the Al in this eomposition is in the 4-fold eoordination state as M A102 rather than in the 6-fold eoordination state as A12O3. Eaeh aluminum in the 4-fold eoordination is aeeompanied by a Na or X ion. For this reason, the maximum total exchange eapaeity ean be ealeulated on the basis of the Si/Al mole ratio.
The aetual exchange capacity for the various metal ions that ean replaee Na or K in the aluminosilicate a~uasol ean be measured by saturating the partieles in the sol or powder with the speeifie ion, and either analyz-ing the amount of metal in the sGlution after separating the aluminosilicate solids or by removing the excess of added salts and analyzing the solid phase for the specific metal ion.
The aluminosilicate sol may be treated with various ion exchange resins to remove the sodium or potas-sium ions. In some cases with aluminosilicate of high Si:Al ratio the resin in hydrogen ion form may be used, but the ammonium form is preferred. Dowex* 50W-X8, an ion exchange * denotes trade mark ,~,l 238~

resin, is a strong acid cation exchan~e resin o sulfon~tc~
polystyrene-divinyl bcnzene type and is commercially avail-able from Dow Chemical Co. The sodium or potassium alumino-silicate solution is converted to the ammonium form by passing the solution through an ion exchan~e column packed with wet Dowex 50W-X8 previously converted to the ammonium form.
The aluminosilicate solution may be adjusted in concentration by dilution with water or concentration to the range of 5 to 40% by weight solids content before ion exchanging.
When the aquasols are converted from the sodium or potassium form to the ammonium form the sols are less stable. For example, an aquasol of 3.7 nanometers particle size with a concentration of 8 weight percent at pH 7 is stable in the Na form for at least 9 months at room temperature (R.T.) but the NH4 form of the same sol forms a gel after about one month.
It is important to notice that since the aquasols are only precursors to the powder compositions, it is not required that they are stable for lon~er than the period of elapsed time between sol preparation and drying.
In ~eneral, the sols of the present invention before drying are at least temporarily stable at a pll in the range from 4 to 12. The lower pl~ limit depends on the Si/~l ratio: the higher the Si/~l ratio, the lower the pI~
limit of chcmical stability or tlle sol. For example, a sol of Si/~l ratio of 1/1, when freshly made, is in equili-brium w~th 200 mg/l o~ ~1 expressed as A].O2 in thc solution at pll 4 and R.T., but a~tcr 18 l~ours the ~12 in the solu-~ion increascs to morc thall 300 m~/l. On the othcr hand, ~.Z38~

a sol of Si/Al ratio of 6/1 when freshly made is in equili-brium with 15 mg/l of Al in the solution expressed as ~12 at pH 4 and R.T. and the equilibrium is maintained ~or at least 18 hours.
The aluminosilicate sols of this invention are made up of uniform particles of aluminosilicate having a uniformity such that the maximum standard deviation is 0.37d where d is the weight average particle diameter.
The aforesaid sols are especially useful when the maximum standard deviation is 0.30d. The uniformity of the particles in the sols of this invention can also be expressed in a form based on the number average of particles rather than weight average. The uniformity based on particle number average is a maximum standard deviation of 0.43d where d is the number average particle diameter.
The aluminosilicate sols of this invention may be modified with various metals defined herein by replacing some of the a~monium ions with metallic ions. The metal desired in the final powder may be introduced by replacing the ammonium ion in the aluminosilicate sol by addition of a soluble salt of the metal. In this case a salt is selected with an anion such as nitrate or formate that can be elimin-ated by heating the powder at relatively low temperature, or one that does not interfere with the use of the powder as ~ catalyst.
The metal desired in the final powder can also be introduced in the aluminosilicate sol in some cases by re-placing the replaceable ammonium in the aluminosilicate sol using an ion exchange resin containing the desired metal ion prior to the drying step. The ion e~change step can be made by either the batch method or the column method.

~L f Z~

~ Iydrogen can also be substituted for the replace-able ions by heating the ammonium aluminosilicate in the powder form to eliminate ammonia.
Some dilute sols with Si:Al ratios of 10:1 or more having sodium or potassium ions may be exchanged directly with hydrogen ions, providing the particles are not allowed to aggrec3ate before drying.
- Metal cations that may replace the sodium, potassium or ammonium in the aluminosilicate solution be-fore drying may be Cs, Li, Rb,. Mg, Ca, Sr, Ba, rare earth metals, transition metals, electron donor metals and Bi, Sn, Cd, and Sb.
What is meant by transition metals is Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, Tc, Rn, Rh, Pd, Hf, Ta, W, Re, ~s, Ir and Pt.
What is meant by rare earth metals is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.
What is meant by electron donor metals is Cu, Ag and Au.
The preferred cations to replace the sodium or potassium of the aluminosilicate are NH4, H, Ca, Mg, Mn, Ru, Rh, Pd, La, W, Re, Ir, Pt, Ce and mixed rare earth metals.
In all cases where metals are exchanged in the sol, conditions must be such as to avoid any aggregation or gelling of the sol particles.
~eplaceable ions can al:,o be replaced in the po~7der after drying by adding a metal soluble salt to a suspension of the powder in water and drying or separating the powder by filtration or centrifugation, washing and drying.
The final concentration of the aluminosilicate .~^3.Z3~3~4 sol is limited by the finAl particle size of the sol.
This is because the maximum concentration at which a sol is still stable with respect to gelation is a function of its particle size. Larger particle size sols can be concentrated to stable sols of higher concentrations than smaller particle size sols.
Table 1 illustrates the maximum stable concen-tration limits of aluminosilicate sol where the particles consist entirely of aluminosilicate:
- 10 Table 1 Particle Dia.Max. Conc. Alumino-(d) nanometersilicate, % by weight The maximum stable concentration, cm of inter-mediate particle sizes appears to follow the equation Cm = 5.1d'56 whcre d is the diameter of the particles.
The heel concentration likewise is limited by the particle size of th~ sol but may vary generally from 0.2 to 55~ by weight of the aluminosilicate or silica. The uppper concentration level depends on the composition and particle diameter of the heel particles. Discrete silica particles are in general less solvated than aluminosilicate particles Silica sols are stable toward gelation or flocculation at higher concentration than corresponding ~lumillosilicAte sols of the same particle size. Thus, the 3Q uppcr limit of heel concentration is higher for silica than .Z~

for aluminosilicate. However, as soon as deposition o~
aluminosilicate has started the sol of silica or other re-fractory oxide takes on the colloid characteristics o~ an aluminosilicate sol.
Low concentrations of heel sol are generally em-ployed when the heel particles are very small or the build-up ratio is to be high. Concentrated heel sols are used only when the heel particles are large and only a low or moderate build-up ratio is anticipated. In any case, it is advan-tageous to start with as conccntrated a heel sol as ispractical so as to provide as much surface as possihlc ~or deposition of aluminosilicate and thus permit the coating process to operate at ma~imum allowable speed.
The particle size and particle size distribution of the colloidal particles of the aquasol can be determined by photomicroscopic counting techniques involving micro-graphs obtained with the electron microscope by transmission or scanning electron micrography. The electron micrographs show that the ultimate particles of the sol are essentially discrete or unag~regated. The micrograph is used to 3~

determine the particle size and particle size distribution of the colloidal pa~ticles of the aquasol by employing a photomicroscopic counting technique utilizing a Zeiss Particle Size Analyzer TGZ3 to assist in the counting. The technique is described in the literature as, for example, "Semiautomatic Particle Size Analysis", Ceramic Age, December, 1967, and "Applications of Pho~omicroscopic Technique to the Particle Analysis of a Sample from a Nuclear Cratering Cloud", by G. F. Rynders, IMS Proceedings, 313 (1969).
The following table illustrates results of particle size distribution determinations of homogeneous aluminosili-cate aquasols of this invention obtained by electron micro-graph counting techniques.~

1~ ~3l3~

Z

OOOOOO

~.Z3~1~

~ he sols prcpared by the proc~ss of this invcntion m~y contain 3 to 70~ solids depending on th~ir composition and particle size~ The sols are stable, that is th~ir vis-cosity does not increase substantially when stor~d at room temperature (20 to 35C) over a ten-month period.
The amorphous aluminosilicate sols having uniform particle sizes, prepared by the process of this invention, are dried to achieve a powdered amorphous aluminosilicate with uniform pore si2e dis~ribution. In order to attain 10 the uniform pore si~e, the particles must pack themselves uniformly into a porous a~regate sa that the final mass or aggregate is not bridged by particles leaving lar~er voids internally.
The ~ols o ~his invention consisting of uni~orm-sized particles have the cha~acteri~tic tha~ as water is removed and the percent solid in~xeases, the viscosity does ~ot change drastically until a certain rather na~row concen-tratian ran~e is reached, a~t~r ~hich ~urther increase in ~oncentratian causes a sharp increasc in the viscosity o the soi~ ~his paL-ticular concentra~ion ~ange depends to a la~ge ~xt~nt an ~he ~l~imate pa~icle si2e of the sol~ I~
the so~ is concentrated up to this more o~ less critical cohcehtr~tion, ~, so ~h-at it becomes viscous, it becomes unstable i~ ~hc sénse ~hat the ~iscosity of tlle sol will then spontaneously incr~ase with time ~ven thouqh no more - water is remo~ed. I~ this spontaneous increase in vis~osity is pcrmitted to occurr the sol is convert~d to a solid mass of hydrated ~el containin~ all the ~ater ~hat was present in the so]. ~hcn a gel of ~his typc is th~ ro~cn up and furthcr dried to a powder, it is folllld that t11e pore dia-mctcr in ~hc dricd ~cl is not uniorm.

~L~.Z3~314 On the other hand, if the sol is rapidly and con-tinuously concentrated beyond W by further rapid removal of water, the viscosity increases until the mass becomes rigid.
When this is further dried it is found the pores are uniform.
Thus, if the sol has been concentrated to some point less than 1~, and then it is dried very rapidly as by spray drying, the water is removed and the ultimate particles move closely together to form a closely packed nnass, In such ~ powder the pores between the particles are relatively uniform. In order for this to occur the water must be re-moved relatively quick1y so that the particles do not have time to form the chain networks that occur during the gelling process.
Accordingly, drying must be sufficiently rapid that once the critical total solids concentration W is reached, water is removed fast enough to prevent bridging of the sol particles and consequently gelling. An example of too slow water removal is where the sol was allowecl to stand at elevated temperature in a humid atmosphere. How-ever, it is usually most economical to dry usincJ processes where the sol is fed in drops or thin streams of liquid or ~atomized" in a fine mist so that water is removed from the sol particles in a matter of seconds. If, howevcr, freeze drying techniques are used, the sublimation or water re-moval can bc extremely slow but still no c3elling wil] occur.
However, other forms of drying will r~sult in gclling if sufficiently slow.
Once tl-e sol has bcen prcparecl, it may bc neccs-sary to further conccntratc it in order to minimizc the amount of water that must bc rcmoved W11c1l it is dricd ro ~ 38~

the sol to a 9~1 powder. In some instances, this concen-tratic)n may be so high that the sol is only tcmporarily stable, as evidenced by the fact that the viscosity in-creases with age due to the incipient formation of gel.
It is important that if the sol has to be conccn-trated to the pc)int where experience shows that it is only temporarily stable, the sol should be dried at once before the viscosity has increased appreciably.
Examples of suitable drying processes include tray dryers, sheeting dryers, rotary dryers, spray dryers, through-circulation dryers, cylinder dryers, drum dryers, screw conveyor dryers, agitated pan dryers, freeze dryers, vacuum dryers, etc.
Adding alcohol or electrolytes to precipitate the aluminosilic~te to separate by filtration or centrifugation the solid particles from the bulk of the water and drying the wet residue, will cause bridging of the particles, forming a precipitate, a coagulum or a gel with nonuniform pore size.
~he preferrcd drying method is spray drying. Spray drying involves the "atomization" of the sol into a mist made of ~inedrops which dry almost instantaneously in con- -tact with hot air. Spray drying produces a regular hollow, sph~roidal, porous aggrecJate with a uniform pore size dis-tribution where the average pore diameter as measured by nitrogcn adsorption-desorption techniques is roughly half the diameter of the particles forminc3 the closely pac~cd, porous agCJrcgate. The ~veragc diameter of the aggregates ~nd the agcJL-egate size distribution c~n be controllcd ~y controlling the conditions of sprtly dL-ying. For examl~le, :~L3.23~ 4 the type of atomizer used in spr~y dryin~ influences the microspheroidal aggregate size distribution of the p~oduct.
Rotating discs produce more uniform aggregat~ size distri-bution than pressure nozzles. In the case of two-fluid pressure nozzles or pneumatic atomization, the lower the concentration oE the aquasol fed into the spray dryer, the higher the atomizing force (feed pressure in the spraying nozzle), and feed rate, and the lower the inlet drying t~ perature, the smaller the aggregate size.

When the sol is drum dried the aggregates tend to be irregularly shaped and the product shows a very broad aggregate size distribution. However, within the aggre-gates, the original aluminosilicate particles are very closely packed, and since they are spheroidal, the pores that they create within the assembly have a very uniform -size distribution and the average size is approximately half the diameter of the uniformly sized particles con-stituting the assembly.
The powders having pore diameters between 45 A
and 250 A with a uniformity such that at least 80% of the pore volume is made up of pores of from 0.6D to 1.4D, where D is the median pore diameter are also especially useful even though they are not as uniform as the powder with 20A to 150 A pores.
To obtain such a close packing of particles and therefore such a uniform pore size distribution, the aquasol has to be dried without substantial gelling or coagulation.
When the particles are allowed to remain ~.Z3~314 unaggr~gatcd until most of the water between the partic~es evaporates, the surface tension of the water film around the particles, and especially in crevices around points o contact between particles, creates a force equivalent to compressing the assembly particles at high pressure. As a consequence, each sol droplet forms an aggregate or more of closely packed spherical particles. In this case, the pores are fairly regular in shape throughout the aggregate, and the size of the pores is very uniform.
The composition of this invention can be charac-terized by their chemical analysis, X-ray analysis, speci-fic surface area measurement, pore size and pore size dis-tribution determination, appearance under the electron microscope by transmission electron microscopy (TE~) and scanning electron microscopy (SEM), aggregate size measure-ment with Coulter counter, surface acidity measurement by titration with adsorbed indicator in nonaqueous liquid phase, ion exchange capacity, infrared analysis, differential thermal analysis (DTA), thermogravimetric analysis (TGA) and measurement of bulk density.
The chemical composition of the powders of this invention can be determincd by analytical techniques con-ventional in the art. Broadly, the powders comprise chemi-cally combined silicon, aluminum, hydrogcn, oxygen and a metal ion, and physically or chemically combined water.
Water associatcd with the aluminosilicate can be analyzed by infrared, DTA and TG~ techniques conventional in the art.
Watcr can be in thc form o~ ~hysically adsorbcd 1~2O,ci~cmisorbcd 1~2O and Oll structural groups. Chcmisorbcd ~.23~14 H2O includes water of hydration of Na iOIls and }I-bound water on the surface of the particles. Physically adsorbcd H2Q is released at atmospheric pressure at 100C and chemisorbed ~12 between about 100 and 200C. Thcre is more than one kind of 0~ structural group. Most Ol-~ groups stay on the surlace of the aluminosilicate particles only up to temperatures in the order of 600 to 700C.
Thermogravimetric analysis of said compositions - in the Na form shows a gradual weight loss up to about 800C
and very little weight loss at higher temperatures. The total weight loss of the spray dried powders is about 20%.
The structure of said compositions is shown to be amorphous by X-ray diffraction analysis.
Specific surface area o. the powders of this in-vention can be measured by the well known BET method in-volving nitrogen adsorption ~Brunauer, S.; Etnmett, P. H.;
and Teller, E. J.; J. ~n. Chem. Soc. 60, 309 (1938)~ or by a nitrogen adsorption method involving continuous-flow equipment based on principles of gas phase chromatography [Nelson, F. M., and Eggertsen, F. T., Anal. Chem., 30, 1387 (1958)]. Results of surface area measurements and electron micrograph observation of the precursor sol and the resultant powder can be combined and show that the powders of this invention are constituted by closely packed dense spherical or sph~roidal part~cles nonporous to nitrogen with a uniform particle diameter in tl~e range of 3 to 90 nanometcrs forming porous aggregates with an aggregate size lar~er than 1 micron.
. Spccific surfacc area of the powdcrs of this in-velltion ran~3e bctwccll 30 an~ 750 m2jg~ Diamctcr of thc - ~7 -nonPorous spherical particles making up the aggregates can be calculated by the formula:
Particle Diameter [nanometerJ =

Specific Surface Area [m /g] x Density of the Particles [g/cc]
The density of the particles can be measured by techniques well known in the art. The density varies wi-th the chemical composi-tion (Si/Al ratio) of the particles.
The shape and si~e of the aggregates are estimated from electron micrographs taken by TEM or SEM. For aggregates smaller than 100 ~m, it is convenient to use micrographs made by transmission electron microscopy or by scanning electron microscopy.
Micrographs of powders of this invention made by spray drying show hollow spheres ranging in diameter between l and 200 microns. The aggregate size and aggregate size distribution of these spheres is a function of the conditions used for spray drying and whether a rotary disk or a spraying nozzle is utilized. Aggregates obtained by drum drying are irregular in shape and have an irregular size in the micron range.
Aggregate size and aggregate size distribution can also be obtained by a well known technique using the Coulter counter ("Particle Size Measurement", T. Allen, 2nd Edition, Chapter 13, Chapman and Hall, London, 1975). The Coulter technique is a method of determining the number and size of particles or aggregates by suspending the powder in an electrolyte and causing the particles or aggregates to pass through a small orifice on either side of which is immersed an electrode. The changes in resistance as particles pass ~.Z38 3L~

through the orifice gcnerate volta~e pulses whose amplitudes are proportional to the volumes of the particles. The pulses are amplified, sizcd and countecl and from the derived data the size distribution of the suspended phase may be determined.
Pore volume, average and median pore diameter and pore size distribution can be calculated using data on nitro-gen adsorption and desorp.ion obtained on a Model 2100 D
Orr Surface-~rea Pore-Volume Analyzer. This instrument is available from Micromeritics Instrument Corporation of Norcross, Georgia.
; Pore volume distribution analysis can be made based on the method proposed by B. F. Roberts, J. Colloid and Interface Science 23, 266 ~1967). This method provides a consistent method of pore volume distribution analysis allowing to estimate the distribution of the pore volùme and area of a porous material as a function of pore size. The limitations are very few. The range of pore diameters is O O
20 A < pore diameter < 600 A. Other limitations are common to all procedures which use the capillary condensation approach including the fact that the pore model may not be representative of the pore structure.
Results are computed using a PORDIS-PORPTL com-puter program which generates BET surface area calculation, nitrogen dcsorption isotherm, plots of pore volume distri-bution, surfacc area distribution usin~ the assumcd pore model (cylindcrs) and plot of cumulativc perccnt of both the po~e volume distributioll and surface arca distrib~ltion.
Spccific surface area is dctermincd by thc B~T mcthod.
~vcraqc cxpcrimental porc diam~ter is ca]culatcd by thc ~ 23~

ratio pore volume at saturation to the BET surface area.
A plot of the cumulative percent o the pore volume dis-tribution permits median pore and maximum and minimum dia-meter of pores constituting 90~ of the pore volume to be determined.
The especially use-ful powders within the scope of this invention as measured by the method mentioned above O O
showed median pore diameters between 20 A and 150 A with at least 90~ of the pores in the approximate range -~ 40%
of the median pore size. Thus said pores are of such uniformity that at least 90% of the pore volume is made up of pores that are from 0.6D to 1.4D in diameter, where D
is the median pore diameter.
The powders of this invention have a "tapped"
bulk density of at least 0.5 gram per cubic centimeter.
"Tapped" density is measured by placing a weighed quantity of sample in a graduated cylinder, and tapping the cylinder until the volume is essentially constant. If the bulk density is less than about 0.2 g/cc, it will be found that the powders are e~tremely difficult to compact uniformly, and will give catalyst pellets or compacts having internal strains and in which stratification of the solids will be present.
When the bulk density of the powder as dried is ~oo low as it may be in the case of some dryin~ techniques, the bul~ density can be increascd by pressiny the powdcr at low prcssures into a compact and brea~ing up the compact to scrccn it or to use it in thc form of small granulcs or particles.
Thc amorphous aluminosilicatc powdcrs of t]liS
invcntion arc ef~ectivc catalysts. Thcir uniform porc - 5~ ~

~.Z3~i4 opcnin(~s permit them to discriminate on the basis of size and configuration o~ molecules in a system. For example, the narrow pore size distribution of the powdcrs of this invention enable them to be more effective catalysts in petroleum rcfining and catalyst cracking processes by thelr improved selectivity. The narrow pore size distribution of the powder permits the selection of a pore size for the catalytic operations ~ithout the accompanying of widely varying selectivity based on wide pore size ranges. Thus, the powders of this invention give an optimum catalyst selectivity in cat cracking operations wherehy the desired isomers are obtained through narrow control of the pore slze .
The compositions of this invention are amorphous aluminosilicates. Crystalline aluminosilicate zeolites are known to possess among other properties catalytic activity.
However, crystalline aluminosilicate zeolites are so highly active âS catalysts that, when used in the pure state, com-mercial catalytic crac~ing units cannot easily control the reaction involved to ~ive desirable rcsults. The present trend in the petroleum industry with re~ard to such zeolites favors the use of Y-type synthetic aujasite crystalline zeolites of silica/alumina ratios of 4.5 to 5.5/1 because they are thermally and hydrothermally more stable than X-type synthetic faujasite crystalline zeolites of silica/alumina râtios o~ 2.5/1.
The powders of this invention can be used together with crystalline aluminosi]icate zeolites. The uniform distribution of crystalline zcolitcs within said powders as a matrix substalltially improvcs thc pcrformancc of the ~ 23~

zeolites in catalytic crackin~ by dilutin~ the active zco-lite and modcrating its activity while taking advantagc of the bcnefits of the powders of this invention The amor-phous aluminosilicates of this invention are specially suited for this purpose because (1) they provide a matrix cataly-tically active itself (instead of inactive), (2) they pro-vide access of reactants to the zeolite crystals through pores of controlled size and controlled size distribution . and therefore controlled selectivity, (3) they are stable to the high temperature hydrothermal treatment received in commercial re~enerators, and (4) the~ form zggre~ates or grains hard enough to survive interparticle and reactox wall collisions without excessive breakage or attrition. However, the use of the amorphous aluminosilicates as a matrix and co-catalyst is not limited to one type of crystalline zeolite. The choice of crystalline zeolite to be incorpor-ated in the amorphous aluminosilicate of this invention is based on the type of reaction involved and the type of reactor unit available.
Another advantagc of the amorphous aluminosilicates as matrices or co-catalysts with crystalline zeolites is that preferred ions, as for example the mixed rare earth ions in the case of catalytic crackin~ catalysts, can be uniformly and intimately distributed in the matrix by ion exchange techniques described herein for the parent amorphous alum-inosilicate aquasol or the powder o~tained by drying the aguasol.
The crystalline aluminosilicate zeolitcs are well known in the art and dcscril~cd in dctail, for exampl~, in Donald t~. ~reck's book on "Zco.litc Molecular Sievcs", Wilcy-Intcrscicllcc, ~cw York, 197~.

~: z38~

Compositions involvin~ known crystalline alumino-silicate zeoli~s and the amorphous aluminosilicates of this invention can be made by using the mixing, compoundin~, etc., techniques disclosed in the art to make zeolite-amorphous aluminosilicate catalysts (see for example, "Preparation and Performance of Zeolite Cracking Catalysts", by J. J.
Magee and J. J. Blazek, Chapter 11 of ACS Monograph 171, "Zeolite Chemistry and Catalysis", edited by J. ~. Rabo, ACS, W~sh. D.C. 1976) or by othèr techniques specially suited to the characteristic properties of our compositions. For example, one way of intimately and uniformly distributing crystalline aluminosilicate zeolite crystals in the amorphous aluminosilicate matrix is to disperse the zeolite crystals of microscopic size in the amorphous aluminosilicate aqua-sols of the present invention, followed by drying of the aqueous dispersion in the manner described herein.
The amount of crystalline aluminosilicate zeolite that is advanta~eously incorporated in the amorphous silicate powders of this invention ~enerally is from 5 to 50~ by wei~ht. Thus, catalyst crac~ing compositions can consist of 5 to 50~ by weight (preferably 10 to 25~) of crystalline aluminosilicate 7.eolites and 95 to 50% by weight (preferably 90 to 75~) of the amorphous aluminosilicates of this invention.
The following examples further illustrate the compositions of this invention and the metho~s for their preparation. In the examples that followf all parts are by wei~ht unless otherwise notcd.

EX~MrLE 1 This is an example of thc preparation of ~ hydrous ~.Z38~L~

amorphous aluminosilicate powder of the invention where a heel of silica 501 is used to form the core of the particles making up the powders.
A heel solution was prepared in a reactor vessel fitted with stirrer paddles in the following manner: 2000 ml of water were heated to 50C and 20 ml of sodium sili-cate JM* diluted to a concentration of 20 g SiO2/100 ml were added. Sodium silicate JM is an aqueous solution of sodium silicate with SiO2/Na2O weight ratio of 3.25 and a con-centration of 29.6 weight percent silica (41.9 g SiO2/100 ml).Ten grams of cationic ion exchange resin, Amberlite* IRC-84-S, in the H+ form were then added and the pH of the solution dropped from 10.2 to 9. At this point a dilute sol (0.2 g SiO2/100 ml) of extremely small silica particles is formed. Amberlite IRC-84-S is a weak-acid carboxylic methacrylate cation exchange resin available from Rohm & Haas Company of Philadelphia, Pa. This resin has a total exchange capacity of 3.5 meq/ml wet, an approximate pK value of 5.3 with respect to sodium in a 1 molar solu-tion, an apparent wet density of 0.75 g/cc, an effectiveparticle size of 0.38 to 0.46 mm and a pH range 4 to 14, maximum operating temperature for this resin is about 120C.
To this heel two feed solutions were added simul-taneously and separately with vigorous agitation of the heel. One solution was an aqueous solution of sodium sili-cate with aSiO2/Na2O weight ratio 3.25, with a silica concentration of 20 g/100 ml and the other was an aqueous solution of sodium aluminate, with a concentration of NaA102 of 5 g/100 ml. The sodium aluminate solution was prepared by dissolving 67.61 g of Nalco* 680 grade sodium aluminate in enough 0.lN NaOH to make 1 liter of solution.

* denotes trade mark ,. ~

81'~

Nalco 680 is the Nalco Chemical Company, Chicago, Illinois, trademark for a white granular sodium aluminate trihydrate.
Maximum solubility of Nalco 680 a-t 22C is 80 parts in 100 parts of water Nalco 680 has a Na2O/A12O3 molecular ratio of 1.12 to 1, A1203 content is 46~, and Na2O cont~nt 31.0~.
This analysis corresponds to 73.95~ NaAlO2. The sodium silicate solution was prepared by mixing 1351 g of JM grade sodium silicate with enough tap water ~o make 2 liters of solution. The two feed solutions were fed through capillary tubes into the heel solution just above the stirrer paddles at a rate of 4.3 ml/min for the silicate and 5.9 ml/min for the aluminate. Throughout the run the pH of the heel was kept constant at pH 9.1 + 0.2 units by periodically ~dding - measured amounts of the IRC~84-S ion exchange resin and temperature was kept constant at 50C ~ l~C. Measurement of pH was done continuously at room temperature with ~
glass electrode by circulating part of the heel ~hrough a cooler.
A total of 1265 ml of sodium silicate salu~ion, 1650 ml of sodium aluminate solution and 610 g of resin were used. At the end of the addition, the product was filtered first through cloth and then through fil~er paper to separate the resin from tlle aquasol. The pH of the product was 9Ø
The resultin~ product was 3.9 liters of a sta~le sodium aluminosilicate sol having a pll of 8.9. Solids concentration was det~rmined by evaporating a wei~hed s~m~le to dryness and calcinin~ to ~linlinate 1l2O. The solids concentration was 8.1 ~ p~r lnO ml. Ch~mical ~l~a]ysis of the res~lltill~ sol illdicatcd that it ~ontained ~.Z3~14 ~.50 g SiO~/100 ml, 1.45 g ~1O2/100 ml, and 0.~7 g Na/100 ml.
Thus the resulting product was an aluminosilicate sol hav-inq the approximate cmpirical formula of NaAlO2 3.75 SiO2 n H2O. An electron micrograph of the sol sho~ed very small particles in the order of 5 nanometers diameter or less.
To determine the d~gree of aggregation which is an indication of the closeness to gelling, the percent hydrated colioid solids or percent S value was calculated from a . measurement of viscosity in an Ostwald pipette and found to be 40. Calculation of percent S was made using the ~looney equation as described in J. Colloid Sci. 6, 162 (1951).
The value of 40 indicates there is no extensive aggregation.
The sodium aluminosilicate sol was converted to the ammonium form by passing it through an ion exchange column pac~ed with wet ~owex 50~ 8 ion exchange resin in the NH4 form. Dowex 50W-X8 is the trademark of the Dow Chemical Co. for a strong-acid cation e~change resin of the sulfonated polystyrene-divinylbenzene polymer type.
Dowcx 50W-X8 has a total exchange capacity of 1.7 meq/ml wet resin. Mesh size of the wet resin is 20 to 50, density is 50 to 53 lb/ft3 and moisture content as shipped by the manufacturer in the H form is 53%. Effective pH range of Dowex 50W-X8 is 0 to 14~ and the resin is stable up to 150C. When the sol was thus treated, NH4+ ions replaced most of the Na+ i,ons attached to ~12 sites and chemical analysis showed that only 0.017 g Na/100 ml (3Qo of the original Na content) remained in the aquasol.
The ammonium aluminosilicate thus formed had a pll of 9 and it was spray dricd in a Bowen Engineering f Inc.
No. l Ccramic Dryer usin~ a two-~luid nozzle typc 59-BS.

~Z3~1~

Operating conditions for spray drying were the following:
Feed Weight % solids: 8 Total feed: 2000 ml Feed rate: 120-125 ml/min Inlet temp.: 300-310C
Outlet temp.: 140-148C
Atomizing pressure: 20 psig Powder samples were collected in the cyclone and chamber collectors. Total product collected was 128 g for 80~ recovery on a wet basis.
Electron micrographs of the spray dried powder showed that it was constituted by spheroidal aggregates with an average diameter o about 15 microns.
Chemical analysis of the powder gave the follow-ing Si/Al ratio and A12O3 content:
Si/Al ratio 3.75:1 A123 17~ by weight.
Surface area and pore volume, pore diameter and pore size distribution analysis of the spray dried powder were made hy a nitrogen absorption-desorption method using a Micromeritics 2100-D apparatus. Micromeritics 2100-D
is the trademark o Micromeritics Instrument Corporation of Norcross, Georgia, for an Orr Surface-Area Pore-Volume Analyzer.
Results were obtained as follows:
Specific Surface Area 590 m2/g Experiment~l average pore 22 A
diametcr Pore volumc 0.330 ml/g Pore volumc distribution analysis was maclc bascd on the B. F. ~o~erts met:]lod [J. Colloid and Intcr~ace ~L~.Z3~

Science 23, 2G6 (1967)] and thc rcsults computed a~d plottcd using the PO~DIS-PORTI computer program.
The arithmetic probability plot of the pore dia~
mete~ versus pore volume data computed by the PORDIS program ~howed a median pore diameter of 28 ~. Ninety percent of the volume of the pores w~s constituted of pores ranging in diameter from the smallest measurable by the method (20 A) - up to 39.5 A (416 above the median pore diameter). Seventy percent of the volume of the pores was constituted of pores ranging in diameter from 20 A, the smallest measurable by the method, up to 32.5 A (16% above the median pore diameter).

The usefulness of the product of this invention in catalyst cracking of petroleum is illustrated by this example.
Using the procedures well kno~m in the art, 200 parts of the dried product obtained above is intimately mixed with 800 parts of an acid-activated halloysite clay, blending in sufficient water to produce a thin paste. The paste is prcpared to the consistency required for extrusion and is converted by extrusion to 1/8' x 1/8'l cylinders.
It should he noted that if a more abrasion resistant mater-ial is requircd, the product can be pilled on a typical phaL~maceutical pil]in~ machine to obtain harder and much stronger material than th~t obtained by ~xtrusion.
After formin~ into the cylinders, the catalyst is impre~nated with 0.5~ Pd ~y ion cxchange from an aqueous solution o~ palladium tetraaminc chloride. Thc dri~d cata-lyst is then rcduccd and char~ed to a typical small scale hydrocracXill~ test unit whcre thc followin~ conditions per taincd an~ ~csults o~taillcd.

~.Z3~

Chargc: Catalyt.ically crackcd gas oll Tem~erature ,650~F
Pressure, psi~ 1,600 Liquid space velocity 2.50 H2/oil ratio scf/barrel 8000 -,~ Product; Jet Fuel Wei~ht percent based on - feed .65.2 Specific gravity 0.802 Sulfur contcnt ppm 950.0 Freezing point _-76F
H2 consumption scf/bbl 2?50,0 ThiSwas an example of the preparation of a hydrous amorphous aluminosilicate powder of the invention where a heel of silica sol prepared in situ was used in the apparatus described in Example 1 to form the core of ~he par.ticles of this invention.
A 1% silica sol heel was prepared in situ at 70C
and pH of 9 by diluting 160 ml o 20R SiO2 sodlum silicate JM (SiO2/Na2O weight ratio 3.25) t~ a total ~olume of 3000 ml with hot tap water to ma~e 3 litcrs of 1. 06o SiO2 heel (32 g SiO2 in 3000 ml of solution), The he.el was heated to 70~C and then deionized to pH 9 ~ 0,1 ,with 80 g of ion exchange resin ~mberlite IRC-84-S. ,A .sample of .the solution was extracted at this point to measure speciflc surface arca of the silica thus formed. Spccific surface area of the silica as measured by the titration method o G. W. Sears ih ~nal. Chcm. 2~, 19~1 (1961) w~s 675 m2/g. ~ssumin~ that the silica is ;.n the orm of spherical particles o~ amor-phous SiO2 of dcnsity 2.2 ~/cc t~lC avcra~c partic}.e di.amc~cr of the silica calculated on the basis of the specific surface area value obtained is 4 nanometers. Feed solutions were added in the manner explained in Example 1 to build-up with sodium silicate and sodium aluminate, each at a rate of 12 ml/min while simultaneously heating the heel to 100C.
Heating from 70C to 100C took about 30 minutes. The two feed solutions of Example 1, aqueous sodium silicate solu-tion 20 g SiO2/lO0 ml and aqueous sodium aluminate solution 5 g NaA102/100 ml were used. In 10 minutes the pH of the heel rose to 10.3 due to the alkalinity of the feed solu-tions being added. From this point on the heel was kept at 10.4 + 0.1 by periodic additions of IRC-84-S resin.
A total of 3958 ml of sodium silicate solution, 3950 ml of sodium aluminate solution and 1440 g of resin were used. At the end of the addition the hot colloidal solution obtained was filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The resulting product was 9050 ml of a stable 20 sodium aluminosilicate sol of pH 10.7 containing 10.72 g/lO0 ml solution. Solids concentration was determined as disclosed in Example l. Chemical analysis of the resulting sol indi-cated that it contained 10.4 g SiO2/100 ml, 1.44 g A102/100 ml and 0.854 g ~a/100 ml. Thus the resulting product was an aluminosilicate sol having the empirical formula NaA102.7SiO2.n~2O. The specific surface area of the sol was determined after the sol was drled by measuring the sur-face area by nitrogen adsorption using the flow method.
5pecific surface area thus measured was 135 m2/g.

~ ~, .

3~

An e]ectrOn micrograph of the sol showed discrete spheres of uniform diameter. Weight average diameter was 18 nanometers and number average diameter was 16 nanometers.
The standard deviation in both cases was 3 nanometers.
The sol was converted to the ammonium form by ion exchange in the manner described in Example 1.
The ammonium aluminosilicate thus formed was dried in vacuum in a Hoffman* drum dryer at 100C. A Buflovak*
laboratory size vacuum double drum dryer manufactured by the Buffalo Foundry & Machine Co. was used. It had two - 18x18 Type 304 stainless steel drums, 6" diameter x 8" face, designed for 150C steam or 100C water. The casing was designed for full vacuum and provided with doors for access into the drums. Drum spacing was adjustable from the out-side shell. The sol was allowed to drip into the cavity formed by the two hot rotating metal cylinders. The cylin-ders were under vacuum and heated internally with steam at 100C, therefore a very fast rate of evaporation was achieved. The dried material was scraped with a Type 410 hardened chrome steel cutting knife. Drying conditions were as follows:
Steam Temperature 100-103C
Vacuum 8-15 mm Drum Speed 7 rpm The drum dried powder was analyzed for specific surface area, pore volume, pore diameter and pore size distribution as in Example 1. The resul~s obtained were as follows:
Specific surface area 250 m2/g Experimental average O
pore diameter 40 A
Pore volume 0.256 ml/g * denotes trade mark .238~

Th~ data showed a median pore diameter of ~3 The upper (52.1 ~) and lower (27.9 A) limits for 90~ of th~ pore volume were within the medi.an pore diameter.
Chemical analysis of the powder.-showed that Si/Al ratio was 3~75 and A1203 content 18~ by weight.
E~lPLE ~
The usefulness of the product of.the:.~'nvention for Fluid Catalytic Cracking Operations (FCC)-coùld be . .illustrated by the example~
Using the procedures well known:.in-.the~~.rt, 200 parts of the dried product obtained above is:intimatèly mixed with 800 parts of an acid-activated halloysite:'clay, blending in sufficient water to produce a:thin pSste. ~'The paste i5 prepared to the consistency required'for'spray drying and then the spray drying operation ~s per~o-rmed, and a microspheroidal product is ~btained.
The catalyst thus obtained is-evàluated:i'n a typical bench scale fluid catalytic cracking~con~erter equipped so that the catalyst can be .tr.eate`d be'fore`:t'e-s`t with steam at 1100F and 20 psig for 10.hours. ~Ther'eafter, the fluidized catalyst is treated with:H2~ 'or-2:h'ours-also at 1100F but at only 10 psig.
A feed of Lybian gas oil of '6'50 to 1120F boil'ing range is processed at temperatures of 880 ~o :1020F-to produce the following products at the low, mi~-point 'and top of the reactor tempexature ranges.

23~3~4 ~r ~J ~O O ~ ~- ~ O O
o a~
a~ u) o ~3 . ~ o ~r ~r o u~ ~D CO
'' a ~r .

~I o o rl U~ ~ ~ ~ ~ ~ ~1 0. 0 ta-,~
~ ~ ~ ~ CO CD ~ ~I r~
.C o .

~ ~ C -C
~ U V
~ U ~ .

~ ~ ~ Z O O
0,~ u) o o o m ~
h ,, ~ h h u~ I ~ m c~ ~) o Pl ~ p, P, H æ m a ~ ;c o ~ 63 --238~4 The eatalyst can be shown to be equally directive with other feed types and other operating conditions. The eatalyst ean be used without the clay matrix or it can be mixed with other clays or binders as economically pref~r-able. The proportion of clay to catalyst can be varied also to achieve the optimum.
The liquid space velocity can be varied from th~
2.0 employed above to as low as 0.5 or as high as 6.5 with . appropriate modifications in the operating temperature cind eonditions.
The used eatalyst becomes deaetivated by coke (earbon) deposition, but it is readily regenerable by eontrolled oxidation of the deposit with a controlled at-mosphere of low percentages of oxygen in steam or in nitrogen. Beeause of the uniform pores of the produet of the invention, regeneration is more uniformly and completely possible. Consequently the catalyst is regenerated essen-tially to its original selectivity and activity.
Further modifications of the eatalyst may be aeeomplished by utilizing the ion exehange properties of the product of the invention. Manganese, magnesium, rare earths, especially lanthanum, and mixed rare earths are introdueed into the strueture in place of alkali by ion exehange.
The eatalyst of the invention ean be modified (promoted) with one or more metals to derive a catalyst useful for catalytie reformillcJ. The spray dried product derived in the first paragrap}l of the deseription of the prepar~tion of the FCC (fluid craekincJ catalyst) is further treated by methods ~nown in the art so as to imprec~nate or - 6~ -ion exchange the catalyst with platinum, for example, as platinum a~line chloride. The treatment is effected in such a way as to attain a 0.56 platinum content. l~he platinum-containing catalyst is dried and reduced in a hydrogen atmosphere at 200C (392~F). The reduced catalyst is then coated with sufficient perrhenic acid solution to attain a level of 0.3% Re in and on the catalyst. To reduce the salts to the metallic form, the salt-impre~nated catalyst is heated to 250 to 300C in a hydrogen flow. The metals in and on th~ catalyst now comprise 0.5% Pt and 0.3% Re in reduced form. The catalyst at this point is suitable for use in the reforming operation and is evaluated in equipment well known in the art as follows:

~.Z;383~

U~
O ~ O --1 N ~ 7 CC) .,1 Q, ~r o ~ co ~ ~r o o O ~ ~1 ~ r~ ~ ~ ~ 1`

o , ,~
o O ''l Ul o -`~O o ~ ~ ~ ~ ~t7 ~ 1~- ~

o ~ ~ ~ ~ a) aJ h U
u u a ul ~ u u ~) u U ~ ~ ~ ~ ~ 0 - O "
0 0 ~U 3 3 ~; 3 .Y rl O (d ~ N ~ ~ `7C.) U ~7 ~7 o .~ t) U U rl ~ C~ U
O O ~ h u) m u ~ ~
,~ Ul QJ Q~
a~ . h 38~L~

The used catalyst can bc r~generated by rcmoval of coke and the activity is restored to that of fresh cata-lyst. The use and rc~cneration can bc repeated with the same results of high activity and selectivity because of the high thermal stability of the catalyst of the invention.
Space velocities that the catalyst will effectively permit are in the range 0.5 to 4.6 liquid/vol cat/hour.
EX~MPLE 5 Thiswas an example of the preparation of a hydrous -10 amorphous aluminosilicate powder of the invention where a heel of sodium aluminosilicatewas used as the core for the particles making up the powder.
A heel was made by diluting 1166 ml of the aquasol product of Example 3 (specific surface area 135 m2/g) in the Na form (pH 10.4) containing 10.7~% solids, with hot water to complete a total volume of 3 l~ters. Thus the heel was 4.16~ solids and contained 125 g of sodium aluminosillcate.
The heel was heated t~ 100C and the pH was measured (pH 10).
When the heel reache~ 100C, the feed solutions of E~ample 1 were added each at a rate of 12 ml/min in the manner des-cribed in Example 1 while keeping the temperature of the heel at 100C + 1C and the pE~ at 10.4 + 0.1. The pH was kept constant by periodically adding IRC-84-S ion exchange resin. A total of 3980 ml of each of the feed solutions and 1360 g of resin were used. The build-up ratio (BR) for this first build-up step was there~ore 8.96. Bui]d-up ratio is calculated by dividin~ the total amount of soli~s in thc feed solutions added during the process by the amount o solids prcsent in thc heel beforc startin~ thc additionO
Thc build Up ratio c~lculatcd above and the S

~.Z~38~L~

~speeiic surface area initially) determined indepcndently by measurement were used to calculate the final specifie surfaee ar~a (SF) with the followin~ formula:

3 r 3 r 2 SF = Si ~ 1 = 135 ~ 1 = 65 m /g Using the formula d = 600 DxS
where d is the diameter of the particles in nanometers where D is the density of the particles g/cc where S is the speeifie surfaee area in m /g of the partieles.
The diameter of the final partieles was ealeulated as follows:

d = 2626~ = 4~ nanometers.
At the end of the addition the slurry was filtered first through eloth and then through filter paper to separate the ion exehange resin from the aquasol.
The volume of the produet reeovered was ~700 ml.

The concentration was 11.76 g solids per 100 ml. This coneen tration was determined by evaporating a weighed sample to dryness, caleining the residue and reweighing.
Chemieal analysis of the sol ~ave the following results: 10.5 g SiO2/100 ml, 1.64 g AlO2~100 ml and 0.854 g Na/100 ml. A sample was dried on steam and the speeifie surfaee area as measured by the Flow Method of nitro~en adsorption ~as 70 m /~. An eleetron micro~raph of the sol showed discrete, dcnse spherieal partieles with a uni~orm particle size distribution, a weicJht avera~e diamcter of 38 nanometers and a numbcr avc?.ra~e diamet~r of 36 nallometcrs.

Standard cleviatlon in both CaSc!s was 5 nanomcters.

38~

Because of limitations in the size of the vessel and the feed concentration, the above particle build up was continued in a second step. sased on an initial surface - area of 70 m /g, it was calculated that a build-up ratio (BR) of about 5 would be needed to attain a specific surface area of about 40 m2/g. The particle size calculated from SF = 40 was 65 nanometers.
A heel for the second step of the build up was prepared by diluting 850 ml of the sol of concentration - 10 11.76 g solids/100 ml just described with hot tap water to a total volume of 5 liters. The heel was therefore 2~
solids and contained a total of 100 g of sodium aluminosilicate.
The heel was heated to 100C and feed solutions were added each at a rate of 6 ml/min while keeping the pH
constant at 10.3 ~ 0.2 with the periodic addition of ion exchange resin IRC-84-S. The two feed solutions were the same used in the first build-up step, aqueous silicate solu-tion 20 g SiO2/100 ml and aqueous aluminate solution 5 g NaAlO2/100 ml.
A total of 1640 ml of each of the feed solutions and 560 g of ion exchange resin were used. At the end of the addition, the slurry was filtered first throu~h cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The volume of the product recovered was 7600 ml.
Analysis of the product gave the followinc3 results:
Concentration = 6.96 g solicls/100 ml sio2 = 5.31 ~100 ml ~lO~ = 0.87 ~J/100 ml Na = 0.~6G (J/100 ml Speci~ic Sur~ace ~re.l = 4G m2/c3.

_ ~9 _ An el~ctron microgr~ph of the sol showed discrete, dense sphcrical particles with a uniform particle size dis-tribution, a weight average diameter of 65 nanometers (standard deviation = 5 nanometers) and a number average diameter of 64 nanometers (standard deviation = 6 nanometers).
The sodium aluminosilicate aquasol was converted to the ammonium form by passing it through an ion exchange column packed with wet Dowex SOW-X8 ion exchange resin in the NH~ form. pH of the NH4 sol thus formed was 9.5 The sol was vacuum drum dried under the same con-ditions given in Example 2 and the dry power obtained was analyzed for pore size distribution and pore volume by nitrogen adsorption-desorption as described in Example 1.
The results obtained are as follot~s:
Experimental average pore diameter = 150 A
~ore Volume = 0.306 ml/g.
The powder had a narrow pore size distribution:
both the upper t229 A) and the lower limit (110 A) o pore size for ~0% of the pore volume were within 40~ of the median pore diameter (180 Al.
Ex~rlpL-E 6 The powder of Example 5 was tested for its ability to catalyze the synthesis of methylamines. A continuous flow reactor was used in which NH3 and methanol were pumped continuously throu~h a 1" tube containing 50 ~ of powder.
Feed rate used for liquid methanol was 1.50 cc/min, feed rate for ammonia gas, 1100 cc/min. The tube was kept at a constant tcmpcrature o~ 450~C and at a constant pressure of 1 atm. The cxit and inle~t strcams of thc tube wcr~
analyzecl with a ~as chromato~rapll and thc yiclds of mcthyl-amines and tllc conversion o~ mcthallol dctermincldO

~3.~:3~

The operation was repeated using commercial Davison silica-alumina gel Clrade 970, a trademark of the Davison Ch~mical Division of W. R. Grace & Co., with about the same alumina content of our sample. The results ob-tained with both catalysts are as follows:

3~

U~ o ,~
Oa~
~ a~ o ~
~a a~
~1 h a .~
o t-- N ~ O Q~
U~ H a~ --1 ~I N ~J
Q, t 0~ ~
C~ ~ O
~0 O

O

~ O
o ~1 ~1 a) s~
~ ~ >1 a) o ,t ~ ~ a Id o o ~ ~ ~

3~

Thus, the r~sul~s show that a composition of this invention gave hicJher methanol conversion, higher desirable monomethylamine production and more favorable product dis-txibution than standard commercial silica-alumina gel.

This was an example of the preparation of an amorphous aluminosilicate powd~r of the invention using a freshly pr~pared sol of silicic acid and a solution of . sodium aluminate as reactants and a heel of water.
A heel of 1.5 liters of water was heated to re-flux at 100C. To this heel, simultaneously and separately, was added (a) 1200 ml of 2~ silicic acid solution prepared from "F" grade sodium silicate, which contained 28.6~
SiC2 content, then passed through a column of Dowex 50~X8 cation exchange resin in the hydrogen form, the resulting silicic acid effluent contained 2~. SiO2 and had a pH of about 3.2 and (b) 1200 ml of a sodium aluminate solution (2.7 g NaAlO2 per 100 ml) prepared by dissolving 42 g of NaAlO2 (74% reagent) in water and diluting to volume. The rate of addition of each was 200 ml per hour. During the addition of th~ two feed solutions, the temperature was maintained at 100C and the p~ at 11.3 ~ 0.2 by adding IRC-84-S ion exchange resin. The resulting sol was cooled, deionized with ~mberlite IRC-84-S in the hydrogen form by stirring this resin with the sol until the pH reached 7.6.
The resulting 3800 ml of product was a stable sodium aluminosilicate sol containing 1.08 g so].ids per 100 ml. Chemical analysis of the resulting sol indicated that it containecl 0.~7 C3 SiO2~100 ml, 0.39 g ~1O2/].00 ml and 0.24 g Na/100 ml~ Thus, the rcsu].ting procluct was t~n ~.238~

aluminosilicate sol having the empirical formula NaAlO2-SiO2, An electron micrograph of the sol showed discrete spheres of uniform diameter. The weight average diameter is 13 nano~
meters (standard deviation 4 nanometers) and the number average diameter is ll nanometers (standard deviation 3 nanometers), The sol was converted to the ammonium form and spray dried in the manner described in Example 1. The powder obtained was analyzed as in Example l.
The results obtained were as follows:

Specific surface area: 280 m2/g Experimental average pore diameter: 57 A
Pore volume: 0.3995 ml/g.
Median pore diameter was 51 A. Ninety percent of the volume of the pores was constituted of pores ranging in diameter from 32 A to 68 A (within ~ 40% of the median pore diameter).

The usefulness of the product of Example 7 for the isomerization operation is shown by this example.

The procedure of Example 4 is followed with the product of EXample 7, except that a paste is made to a consistency for extrusion. The paste is extruded into l/8"
x l/8" cylinders. The cylinders are impregnated with pro-moters, 0.5~ Pt and 0.2% Re and the impregnated catalyst is reduced to form the respective metals. The catalyst is then given a typical isomerization test in small scale equipment as follows:

Charge: Pentanes and Hexanes - HDS treated.
Conditions:
Tempera-ture 300 to 400 F
Pressure 300 psig Space velocity 3.0 LVH
H2 to oil, mole ratio 0.1 to 0.5:1 Components, wt percentFeed Product C4 and lighter 0.2 1.0 Isopentane 24.8 39.9 n-Pentane 21.4 10.8 2,2-dimethylbutane1.0 16.3 2,3-dimethylbutane2.9 4.5 Cyclopentane 1.5 1.1 2-methylpentane 14.0 12.5 3-methylpentane 12.3 6.9 n-Hexane 13.1 4.2 Benzene 1~6 Methyl cyclopentane 1.8 1.3 Cyclohexane 0.0 1.0 Research Octane No. 72.0 85.0 The catalyst shows excellent stability and con-tinued selectivity.
EX~MPLE 9 This is an example of the preparation of an amor-phous aluminosilicate powd~r of this invention with silica as the particle nucleus or core.
Three thousand grams of a 50% by weight, 60 nano-meters particle size silica sol heel is heated to 100C and the pH is adjusted to 10.3 with sodium hydroxide. The silica sol used is com~ercially available under the trade mark of ~ - 75 -23c~3~L4 NalcoacJ 1060 Erom the Nalco Chemical Company o~ O~k Brook, ~llinois. ~eed solutions`and ion exchange resin are added in the manner described in Example 1 and sodium silicate ~nd sodium aluminate, each added at a rate of 6 ml/min while ~eeping the heel at 100C. The two feed solutions of EXample 1, aqueous sodium silicate solution 20 g SiO2/100 ~1 ahd aqueous sodium aluminate solution 5 g Na~102/100 ml, a~e used. The heel is kept at pH 10.3 ~ 0.1 by periodic adclitions of IRC-84-S resin.
A total of 340 ml of sodium silicate solution, 340 ml of sodium aluminate solution and 117 g of resin are usec~. At the ehd of the addition, the hot colloidal solution ôbtained is filtered first through cloth and then through f;lte~ paper to separate the ion exchange resin from the aquasol.
The resulting product is 3010 ml of a stable sol made o~ siiica particles coated with sodium aluminosilicate, of pH 10.7 containing 43 g of solids per 100 ml solution.
Soiids concèhtration is determined as explained in Example 1.
Dry powder is obtained by drying the sol. The sur~ace area o~ the powder is measured by nitrogen adsorption using the flow method. The specific surface area thus measured is O -m2/
Ah eiectron micrograph of the sol shows discrete sphe~es of ùniform diameter. Average diameter is about 65 nanometers.
~ he sol obtained is converted to the ammonium form by passillcJ it throucJh an ion exchancJe column packed with w~t Dowex 501~-X~ ion exchanc~e rcsin in the N1l4 ~orm as ex-plail-ecl in ~xamplc? 1.

~! Z3~3~1L4 The aquasol in t~le ammonium form thus formcd is spray dried as described in ~xample 1 using the samc spray drying conditions, Powder samples ~re collected in the cyclone and chamber collectors. Total product collected is 1035 g.
Electron micrographs of th~ spray dried powder showed spheroidal aggregates with an average diameter of about 21 microns.
- Surface area and pore volume, pore diamater and pore size distribution analysis of the spray dried powder are made by th~ nitrogen absorption-desorption method used in Example 1.
Results obtained were as follows:
Specific Surface Area 40 m2/g Experimental Average Pore Diameter 155 A.
The arithmetic proba~ilit:y plot of the pore dia-meter versus pore volume data computed by the PORDIS program shows a median pore diameter of 150 A. Ninety percent of the volume of the pores is constituted of pores ranging in diameter from 108 A to 20~ A. Only 5~ of the pores are larger than 202 A. This pore fraction is smaller than 280 A.
EX~IPLE 10 This is an example of the preparation of an amor-phous aluminosilicate catalyst of the invention with a zirconia heel as t,he particle nucleus.
One thousan~ grams of 10~ weight, 25 nanometers particle size zirconia aquasol is used as a heel. The sol is made of spherica]. particles with a uniform particle size distribution. ~rhe pll of ~he sol is 3.5. Onc hundred milli-liters of a sodium citratc solution containing 2.8 g of ~lZ~

sodium citratc are addcd to thc sol at a r~tc of about 12 ml/min with stron~ a~it~tion. The resulting sol is 2.8 g of sodium citrate/100 g ZrO2. The p~l of the sol is raised to 10.3 with NaOEI.
The two feed solutions of Example l, aqueous sodium silicate solution 20 g SiO2/100 ml and aqueous sod-ium aluminate solution 5 g NaAlO2/100 ml and ion exchange resins are added as described in Example l at a rate of . 4.3 ml/min for the silicate and 5.9 ml/min for the aluminate while keeping the heel at 100C. The heel is kept at pH
10.3 + 0.1 by periodic additions of IRC-84-S resin.
A total of 205 ml of sodium silicate solution, 286 ml of sodium aluminate solution and 70 g of resin are used. At the end of the addition the hot colloidal solu-tion obtained is filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The resulting product is 1010 ml of stable sol made of zirconia particles coated with sodium aluminosilicate, of pH 10.7 containing 11.5 g solids/100 ml solution. Solids concentration is determined as ex21ained in Example l.
A sample of this sol is dried and the dry powder obtained is used for measurement of surface area by nitrogen adsorption using the flow method. Specific surface area thus mcasured is 37 m2/g. An electron micrograph of the sol s]lOws discre~c splleres of uni~orm diameter. Average diameter is about 30 nanometers.
The sol obtaincd is convertcd to the amrnonium form by passing it through an ion c.Ychange column packed with wet 3~ DOW~X 50W-x~ iOIl exchan~c resi~ in the Nll~ rorm as dcs-c~ibcd in ~xamll~ l. Thc aqllasol in thc ammoni~lm fo~m thus ~.231~4 ormcd is spray dried as d~scrib~d in Example 1 using the same spray drying conditions. Powder samples are collected in the cyclone and chamber collectors. Total product col-lected is 81 g.
Electron micro~raphs of the spray dried powder showed spheroidal aggregates with an average diameter of about 10 micrometers.
Surface area and pore volume, pore diameter and . pore size distribution analysis of the spray dried powder are made by the nitrogen absorption-desorption method of Example 1.
The specific surface area is 35 m2/g and the~ex-perimental average pore diameter is 120 A.
The arithmetic probability plot of the pore dia-meter versus pore volume data com?uted by the PORDIS pro-gram shows a median pore diameter of 110 A. Ninety percènt of the volume of the pores is constituted of pores ranging o O
in diameter from 77 A to 143 A. Only 5~ o the pores are lar~er than 1~3 ~. This pore fraction is smaller than 210 Ao This is an example of the preparation of an amor-phous aluminosilicate catalyst of this invention with an eta alumina heel as the particle nucleus.
One thousand grams of 10~ weight, 50 nanometer particle size eta alumina aquasol is used as a heel. The sol is made o~ spherical particles with a uniform particle size distribution. The L~l of the sol is 3.5. One hundrcd millilitcrs o~ a sodium citrate solution containing 5 ~ of sQdi~m citratc are ~dded to th~ sol at a rat~ oE about 3a 12 ml/min with stro~ gitat:ion to yield a sol with 0.55 g ~.23~

sodium citrate/100 g ~12O3. The pH of the sol is raised to 10.3 with N~OH.
The two feed solutions of Example 1, aqueous sodium silicate solution 20 g SiO2/100 ml and aqueous sodium aluminate solution 5 g NaAlO2/100 ml and ion ex-change resins are added as described in Example 1 at a xate of 4.3 ml/min for the silicate and 5~9 ml/min for the aluminate while keeping the heel at 100C. The heel is kept at pH 10.3 + 0.1 by periodic additions of IRC-84-S
resin.
A total of 97 ml of sodium silicate solution, 133 ml of sodium aluminate solution and 50 g of resin are used. At the end of the addition, the hot colloidal solu-tion obtained is filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The resulting product is 950 ml of stable sol made of alumina particles coated with sodium aluminosilicate, of pH 10.7 containing 9.9 g solids/100 ml solution. Solids concentration is determined as in Example 1.
A sample of this sol is dried and the dry powder obtained is used for measurement of surface area by nitrogen adsorption using the flow method. Specific surface area thus measured is 34 m2/g. An electron micrograph of the sol shows discrete spheres of uniform diameter. Average diameter is about 55 nanometers.
The sol obtained is converted to the ammonium form by passing it through an ion exchc~nge column packed with wet Dowex 50W-X8 ion e~change resin in the Nli4 form as in Ex~mple 1.

38~4 The aquasol in the ammonium form thus formed-is spray dricd as described in Example 1 using the samc spray drying conditions. Powder samples are collected:in-the cyclone and chamber collectors. Total product coll~cted is 76 g. Electron micrographs of the spray dried po~der showed spheroidal aggregates with an average diameter:of about 11 micrometers.
Surface area and pore volume, pore diameter-and . pore size distribution analysis of the spray dried powder are made by the nitrogen absorption-desorption method used in Example 1.
The specific surface area was 30 m2/g and-the experimental average pore diameter was 130 A.
The arithmetic probability plot of the pore dia-meter versus pore volume data computed by the POR~IS pro-gram shows a median pore diameter of 145 ~. Ninety -percent of the volume of the pores is constituted of pores ranging c~ O
in diameter from 102 A to 189 A. Only 540 of the pores are larqer than 189 A. This pore fraction is smaller than This is an example of the preparation of an amor~
phous aluminosilicate catalyst of the invention with a ti-tania heel as the particle nucleus.
One tl~Qusand grams of 10~ weight, 10 nanometers particle size titania aquasol is used as a heel. The sol is made of spherical particles with a uniform particle size distribution. The pll of the sol is 3.5. One hundred milli-liters o~ a sodium citratc solution containing 135 g of sodium citrate are addcd to tl~e sol at ~ rate o~ abou~

1~238~L~

12 ml/min with stron~ agitation to yield a sol with 13 7 5 g s~dium citrate/100 g Tio2; The pll of the sol is rais~d to 10.3 with N~OH.
The two feed solutions of Example 1, aqueous sodium silicate solution 20 g SiO2/100 ml and aqueous sodium aluminate solution 5 9 NaAlO2/100 ml and ion exchange resins are added as described in Example 1 at a rate of 4.3 ml/min for the silicate and 5.9 ml/min for the aluminate while keeping the heel at 100C. The heel is kept at pH
10.3 + 0.1 by periodic additions of IRC-84-S.
A total of 641 ml of sodium silicate solution, 894 ml of sodium aluminate solution and 220 g of resin are used. At the end of the addition, the hot colloidal solu-tion obtained is filtered first tllrough cloth and then through filter paper to separate _he ion exchange resin from the aquasol.
The resuling product is 1980 ml of stable sol made of titania particles coated with sodium aluminosilicate, of pH 10.7 containing 10.5 ~ solids/100 ml solution. Solids concentration is detcrmined as in E~ample 1.
A sample of this sol is dried and the dry powder obtained is used for measurement of surface area by nitrogen adsorption using the Flow Method. Specific surface area thus measured is 94 m /g. An electron micrograph of the sol shows discrete spheres of uniform diam~ter. Avera~e dia-meter is about 15 nanometers.
The sol obtained is converted to the ammonium form by passing it through an ion exchange column packed with wet Dowex 50W-X8 ion cxchange rcsin in the N~14+ form as dcs-cribcd in Example 1. ~hc ~quasol in thc ammonium form thus ~ormcd is spray drie~ as d~scribed in ~xamplc 1 using the 3~1~

same spray dryin~ conditions. Powder samples are collected in the cyclone and chamb~r cOllcctors. Total product col-lected is 165 g.
Electron microyraphs of the spray dried powder showed spheroidal ag~regates with an average diameter of about 8 micrometers.
Surface area and pore volume, pore diameter and pore size distribution analysis of the spray dried powder are made by the nitrogen absorption-desorption method used lQ in Example 1.
The specific surface area was 95 m /g and the ex-perimental average pore diameter was 75 A.
The arithmetic probability plot of the pore dia-meter versus pore volume data computed by the POR~IS pro-gram shows a median pore diameter of 70 A. Ninety percent of the vclume of the pores is constituted of pores ranging in diameter from 49 A to 91 A. Only 5~ of the pores are larger than 91 A. This pore fraction is smaller than 170 A.
Thus, the porous powder compositions of this in-vention may be used for the hydrocracking of petroleum dis-tillates by contacting said compositions with said distillates, under conditions well known in the art.

~L~31~

This was an example of the preparation oE a hydrous amorphous aluminosilicate powder of the invention where a heel of silica sol prepared in situ was used in the apparatus described in Example 1 to form the core of the particles of this invention.
A 1% silica sol heel was prepared in situ at 70C and pH of 9 by diluting 127 ml of 20% SiO2 sodium silicate JM (SiO2/Na2O weight ratio 3.25) to a total volume of 3000 ml with hot tap water to make 1.270 liters of 1~ SiO2 heel (12.7 g SiO2 in 1270 ml of solution). The heel was heated to 70C and then deionized to pH 9 + 0.1 with 80 g of ion exchange resin Amberlite~ IRC-84-S.
Feed solutions were added in the manner explained in Example 1 to buildup with sodium silicate and sodium al~lminate, the sodium silicate solution at a rate of 12 ml/min and the sodium aluminate solution at a rate of 27 ml/min while simultaneously heating the heel to 100C.
Heating from 70 to 100C took about 48 minutes. The two feed solutions of Example 1, aqueous sodium silicate solu-tion 20 g SiO2/100 ml and aqueous sodium aluminate solution 5 g NaAlO2/100 ml were used. In 4 minutes the pH of the heel rose to 11.3 due to the alkalinity of the feed solu-tions being added. From this point on the heel was kept at 11.3 + 0.1 by periodic additions of IRC-84-S resin.
A total of 3770 ml of sodium silicate solution, 8420 m~ of sodium aluminate solution and 1450 g of resin were used. At the end of the addition the hot colloidal solution obtained was filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.

~ 84 -1~231~
The resulting product was 11.8 litersof a stable sodium aluminosilicate sol containing 10 g/100 ml solution.
Solids concentration was determined as disclosed in Example 1. ~hemical analysis of the resulting sol indi-cated that it contained 4.98 g SiO2/100 ml, 2.47 g AlO2/100 ml and 1.01 g Na/100 ml. Thus the resulting product was an aluminosilicate sol having the empirical formula NaAlO2-1.98SiO2 nH2O. The specific surface area of the sol was determined after the sol was dried by measuring the surface area by nitrogen adsorption using the flow method. Specific surface area thus measured was 122 m2/
An electron micrograph of the sol showed discrete spheres of uniform diameter. Weight average diameter was 26.6 nanometers. The standard deviation was 4.7 nanometers.
The sol was converted to the ammonium form by ion exchange in the manner described in Example 1.
The ammonium aluminosilicate thus formed had a pH of 9 and it was spray dried in a Bowen Engineering, Inc.
No. 1 Ceramic Dryer using a two-fluid nozzle type 59-BS.
Operating conditions for spray drying were the fol,owing:
Feed Weight % solids10 Total feed 3000 ml Feed rate 100 ml/min Inlet temp. 350C
Outlet temp. 190C
Atomizing pressure5 psig Powder samples were collected in the cyclone and cham~er collectors. Total product collected was 117 g for 39% recovery on a wet basis.

~3~

Ninety-four g of the cyclone product were sus-pended in 1 liter of saturated ammonium carbonate solution at room temperature and stirred gently for 5 hours. The slurry was centrifuged and the cake obtained was reslurried in a 50:50 mixture of concentrated ammonium and H2O. The washing operation was repeated four times and the cake obtained was dried in vacuum oven at 80C overnight. The dry powder was analyzed for sodium and it contained 0.27%
Na by weight. The extraction operation was then repeated and the dry powder obtained was analyzed again for Na and gave 0.12% Na by weight.
Surface area and pore volume, pore diameter and pore size distribution analysis of the spray dried powder were made by a nitrogen absorption-desorption method using a Micromeritic~ 2100-D apparatus. Micromeritics~ 2100-D
is the trademark of Micromeritics Instrument Corporation of Norcross, Georgia, for an Orr Surface-Area Poxe-Volume Analyzer.
Results were obtained as follows:
Specific surface area 122 m2/g Median pore diameter 61 A
Pore volume 0.325 ml/g ~ ore volume distribution analysis was made based on the B. F. Roberts method [J. Colloid and Inter~ace Science 23, 266 (1967)] and the results computed and plotted using the PORDIS~PORTL computer program.
Eighty-four percent of the volume of the pores was constituted of pores ranging in diameter from 0.6 to 1.4 of the median pore diameter.
The powder was mixed with a rare earth zeolite and pro~-ed in testing to be an excellent catalyst for the cat-cracking of petroleum.

~.23~314 It is to be understood that any oE the components and conditions men-tioned as suitable herein can be sub-stituted for its counterpart in the foregoing examples and that although the invention has been described in consider-able detail in the foregoing, such detail is solely for the purpose of illustration. Variations can be made in the invention by those skilled in the art without departing from the spirit and scope of the invention except as set forth in the claims.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method for the preparation of a porous powder composition comprising porous aggregates of spheroidal particles of from 3 to 90 nanometers which particles are nonporous to nitrogen, said process com-prising:
(a) preparing a heel sol of discrete colloi-dal particles selected from sodium, potassium or ammonium aluminosilicate, silica, and one or more re-fractory oxides selected from alumina, zirconia, lan-thana, thoria, titania and rare earth oxides, said particles having a substantially uniform diameter with-in the range of 2 to about 85 nanometers, said alumino-silicate having a molar ratio of Si:Al of from 1:1 to 19:1, the initial concentration in the heel sol of sodium, potassium, ammonium aluminosilicate or re-fractory metal oxide being at least 0.2% by weight, with the particles stabilized against aggregation in the pH range 9 to 12;
(b) adding to said heel, separately but sim-ultaneously, two feed solutions, one being a solution of sodium or potassium silicate having from one to 36 grams of silica per 100 cc, or a sol of silicic acid contain-ing from 1 to 12% silica, the other being a solution of sodium or potassium aluminate containing from 1 to 15%
alumina, said feed solutions being added in relative rates and proportions to maintain a constant molar ratio of Si:Al in the feed streams of from 1:1 to 19:1 with the rate of addition of silica not to exceed 10 grams of SiO2 per 1000 square meters of total surface area of particles in the heel sol per hour;
(c) maintaining the pH of the heel sol at a constant value between 9 and 12 by adding cation exchange resin in the ammonium form, maintaining the temperature of the heel sol at from 50° to 100°C until the particles in the heel sol have attained an increase in diameter of at least 1 nanometer and a maximum size of 90 nano-meters;
(d) filtering the sol from (c) to remove the cation exchange resin and optionally adjusting the con-centration of the resulting aluminosilicate sol to a solids content of up to 60% by weight; and (e) drying the resulting substantially gel-free sol of particles having an aluminosilicate surface to a powder by removing water at a rate at which no gelling will occur.

2. The method of Claim 1 wherein the pH of the heel sol during the addition of the feed solutions is maintained between 10 to 10.5.

3. The method of Claim 1 wherein the discrete colloidal particles of the heel sol are silica.

4. The method of Claim 1 wherein the discrete colloidal particles of the heel sol are a sodium, pot-assium or ammonium aluminosilicate sol.

5. The method of Claim 1 wherein the discrete colloidal particles of the heel sol are one or more refractory oxides.

6. The method of Claim 1 wherein the re-fractory oxides in the heel sol are selected from the group consisting of alumina, zirconia, lanthana and titania.

7. The method of Claim 1 wherein the sodium or potassium silicate solution is 15 to 25% by weight of silica.

8. The method of Claim 1 wherein the sol from (d) is ion-exchanged to partly or completely re-place the sodium or potassium ions by hydrogen or ammonium ions before the drying step.

9. The method of Claim 8 wherein the hydrogen or ammonium ions are replaced, completely or in part, with one or more metal ions selected from the group Cs, Rb, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Bi, Cd, Sn, Sb and mixtures thereof.

10. The method of Claim 8 wherein the dried composition after (e) is impregnated with a solution comprising one or more metal cations selected from Os, Rb, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Bi, Cd, Sn and Sb and drying.

11. The method of Claim 8 wherein metal cations are introduced by adding a solution of a metal salt to the sol from (d) with intensive agitation at the point of mixing.

12. The method of Claim 8 wherein the ammonium ions are replaced, completely or in part, by exchanging the ammonium ions of the sol with metal ions on a sulfonic acid type ion exchange resin.