US2839191A - Phosphate rock beneficiation process - Google Patents

Description

United States atent O PHOSPHATE RGCK BENEFICIATION PROCESS Louis T. Morison, Puentc, and Roy W. Wagoner, Alhambra, Calif., assignors to Petrolite Corporation, Los Angeles, Calif., a corporation of Delaware No Drawing. Application September 11, 1956 Serial No. 609,054

13 Claims. (Cl. 299-166) This application is a continuation-in-part of our pending application, Serial No. 598,233, filed July 17, 1956, now abandoned.

This invention relates to a process for the beneflciation of phosphate rock, for the purpose of removing siliceous impurities therefrom. The problem is an important one.

Some million tons of phosphate rock are produced annually from the Florida pebble phosphate deposits. Located principally in Poll: and Hillsborough Counties, these marine deposits produce three-fourths of the U. S. supply of phosphate and about three-eighths of the World supply. roduction is approximately 5 times as great as in 1940; and productive capacity is now being greatly expanded by the companies in the industry.

Such pebble phosphate, as mined by the conventional strip-mining methods, includes undesirably large proportions of non-phosphate minerals, principally siliceous and principally silica, which reduce the quality and the price of this large-tonnage, small-unit-value product. Extensive and costly ore'dressing plants have consequently been required to be used, todeliver a finished product of acceptable grade.

Among the procedures required to be employed, and one which is almost universally used by the industry, is a two-stage or double flotation process. In the first stage (or rougher flotation circuit), Washed phosphate rock having particle sizes usually between about 28- and about ISO-mesh is subjected to the action of a reagent conventionally comprising tall oil, fuel oil, and caustic soda. The concentrate delivered by such rougher circuit is a phosphate rock of grade higher than the original rock; but which still contains too much silica and similar impurities to be of acceptable market grade.

The rougher concentrate is therefore dc-oiled with dilute sulfuric acid, to remove the tall-oil-soap-and-fueloil reagent; and is thereafter subjected to flotation in a secondary or cleaner circuit. The froth product delivered from this secondary circuit is high in silica and similar impurities; and is desirably low in phosphate values, because it is thereafter discarded.

The process of this invention relates to such secondany or cleaner flotation circuit of such conventional flotation scheme, not to such rougher circuit. (Our process may of course be applied to beneficiate a phosphate rock that has not been subjected to such preliminary roughercircuit flotation process.)

The conventional cleaner-circuit flotation reagent or collector of the industry has been a long-chain aliphatic amine acetate. The reagent is a paste, as supplied. The paste is required to be dissolved in hot water, to prepare a dilute solution which can be fed to the cells. Such handling procedure is obviously burdensome, and desirably to be avoided, as by use of a liquid reagent dispersible in cold water.

The search for such a liquid, easily-handled reagent has been pursued for years; but the standardsilica collector of the phosphate rock industry is still aliphatic amine acetate. In recent years it has been found possible 2,839,191 Patented June 17, 1958 to extend such standard reagent by including a proportion of rosin amine acetate; and, sometimes, also some free or unneutralized rosin amine. Such extender reagents are not sufliciently effective to be used alone, instead of aliphatic amine acetate; but since their cost is lower and since they are compatible with the aliphatic amine acetate reagent, they have found some use.

The unneutralized aliphatic amines are in some instances liquids; but they been have found to possess highly undesirable characteristics as regards skin irritation. Use of such free amines has therefore not offered a solution of the problem of handling or avoiding the use of solid reagents.

One characteristic that a silica collector should desirably possess if it is to be valuable in the present instance is a tolerance for slimes. Phosphate rock as mined includes particles of all sizes. Hydraulic sizing and other preparatory operations are employed in order to deliver to the flotation plant a feed having a particle size rang ing from about 2- to about -mesh. Particles smaller than about ISO-mesh are classed as slimes in the industry. However, even though all slimes originally present, both clay and very small phosphate rock particles, are washed from the flotation cell feed, the phosphate rock is sufficiently soft to produce more slimes by the attrition incident to handling and flotation. It is therefore impossible to have a flotation cell feed entirely free from slimes.

Slimes consume an inordinate amount of flotation reagent because of their relatively vast surface area per unit of weight, and possibly also because of surface forces present on them. The conventional aliphatic amine acetate reagents .are not as slime-resistant or slimetolerant as desired.

The conventional aliphatic amine acetate reagents, customarily used in a dilute aqueous dispersion as just noted, are used at pH level of about 7 and higher. To maintain such pH levels, it is conventional practice to feed caustic soda solution into the cell, along with the amino reagent. Consumption of caustic soda conventionally amounts to as much as 1 lb./ton of feed rock; and its use is a significant cost item.

The conventionally-operated secondary or cleaner flotation circuit includes the use of kerosine. This liquid is fed at rates sufiicient to produce froths of optimum characteristics. If too much or too little kerosine is fed, the froth changes appearance in a manner and to a degree which, although diflicult to describe, is nonetheless readily appreciated by a skilled operator, who knows that, under such conditions of poor froth appearance, the volume and quality of froth product will be respectively low and poor. Naturally, from an economic standpoint,

size variations within the about 28-150 range of particle size.

A collector should desirably operate with equal effectiveness on feeds of diflerent grade. While it is naturally desirable to operate a mill on feed rock of constant composition, this is nearly impossible. Feed must be accepted as mined; and variations in the deposit make for larger or smaller proportions of impurities, different particle sizes, and other variations in the composition of the feed.

A collector should be selective in its action. Since the fthem in an important degree, r

. 3 froth product, as delivered from the secondary flotation circuit, isidischarged from the plant, any phosphatevalues it contains are permanently .lost.' The less selective the f collector used in that circuit, the higher the phosphate content of the froth product, and the higher the phosphate recovery losses' from the plant. Under such conditions, is said to be low or poor.

An .eflicient collector, used su'iiicient proportions,

is capableof removing substantially all the tree, grains of siliceous impurities from the phosphate rock. 'The purified rock is conventionally sold on a basis of BPL (bone phosphate of lime) content; and 72% BPL is, a

standard minimum acceptable figure. If the processed rock contains much silica or other impurities its 'BPL.

content drops below 72%, with consequent penalties. (Even'wh en' a flotation process is conducted in such fashion as to show substantially no free silica grains .in the recovered phosphate rock, under the microscope, such recovered rock may'still analyze l.O1.5% insolubles. This is due to the fact that some of the insoluble matter 7 simply filling a tank part-full of solution water, starting is occluded within grains of phosphate rock; not being 7 free, it cannot be floated by the silica collector.) Some collectors will remove the bulk of the insoluble matter economically; butare unable to clean the rock of the last several percent of insolubles without consumption of large proportions of reagent.

.This last' statement leads to consideration of another important factor. Some "collectors are of such character that their performance does not change markedly and quickly with the amount of reagent fed. For example,

in some instances,a considerable proportion of reagent must be fed before there is evidence of substantial collection or insolubles. Then, one can feed the reagent at a considerably increased rate without improving this first levelof performance. Finally, as-stated just above, one

maybe unable to remove the last traces of insolubles, regardless of the proportion of reagent that is fed. Prompt responseof the operation to changes in reagent feed rate-or, to express itanother ,way sensitivity of the reagent to changes in the amounts usedis animportant characteristic of a desirable collector. V

Dispersibility of the collecting reagent in the system is an extremely important characteristic, and an equally difficult 'one tocatalogf If the reagent is not sufficiently; dispersible inthepulp in the flotation cell, it is present-in relatively large aggregates, or globules orparticles. One

such particle of, reagent can float only one particle of silica or other impurity, even though the lifting of that particle could have been achieved using'only a fraction of the particle of reagent.

to'concentrate at the rock -air-liquid interface;

Dispersibility may be controlled in a number of ways.

First, the inherent dispersibility characteristics of the 'indi-f vidual reagents will vary. Second, the degree of neutrali-.

Zation of the reagents with'ani acid, such as acetic acid, will usually affect their dispersibility. Finally, the conventional silica flotation plant, in the phosphate industry includes acaustic soda supply system; and caustic soda is conventionally fed at required proportions, to maintain the most desirable level of reagent dispersion in the secondary circuit. Conventional aliphatic amine acetate soda feed. ,7 V V V The foregoing dozen desirable characteristics of a silica reagents conventionally require the use of such'caustic collector .in the beneficiatioh of phosphate rock have'be'e'n recited for the reason that theclass of reagents we have such use possesses.

discovered to be highly effective 'fo'r first, our reagents are liquid} They may'be trans-i ported in conventional steel drums and removed therefrom by simply removing one of the bungs; They flow readily at all temperatures to. which they may be'subjected ihi transportation and use, inithephosp'hate rock application.

On the contrary, if a reagent is too dispersible in the pulp, it mayhave relatively "weak' collecting power, because it has relatively less tendency They maybe made into diluteaqueous'disp'ersions by Whereas the conventional aliphatic amine acetates rapidly lose the abilityto float'silica in the presence of slimes, our present class of reagents appears to have a high slime tolerance, in that they continue to float silica under such conditions.

rises to several hundred parts per million, in the. case of the conventional reagents; but the curve remains quite flat, with our reagents, at even greater slime concentra tions. V e

Fourth, our reagents are highly effective at the natural pH of the flotation circuit, and without addition ofcaustic soda to produce pH levels higher than about 7. 'We have found that the cell without additional caustic soda usually has a pH of just under 7. At any rate, irrespective of .the exact pH value, our" reagents appear to' be not critically sensitive to somevan'ations in pH in the region of ordinary operation.

Fifth, while our reagents are advantageously used in conjunction with kerosinc, it appears *that the volume of such liquid required to be used with our reagents is somewhat lower than it is when the conventional aliphatic amine reagents are used. We do not beiieve that use of kerosine can be entirely dispensed with, however. ,The' reason for the smaller consumption of kerosinewhen our reagents are used is considered later herein. a

content; V v

E1ghth, our reagents appear to have improved seleclarge and small particles of siliceous impurities. .random feed'particle sizes'coming into the plant, our reagents have consistently produced concentrateshaving Sixth, our reagents appear to be equally. effective on With low percentages of insoluble matter. This adaptability to different particle sizes is' an obviously important characteristic of a collector. Seventh; our reagents appear to be tio-ns in cell feed.

adaptable to variacentrate, shift after shift, with only the usual minor adjustments of reagent feed and kerosine feedthat must he made in'the case of any reagent. In no case in whichour reagents have been used on' full-scale operations has there been any difiiculty in keeping the plant on-stream.

Feed rock having higher percentages-of insolubleshas' been processed along with other fee-d having appreciably lower insolubles, without affecting the continuity of the; run or the acceptability of the concentrates recovered."

During one such run, ourreagentproduced high-grade concentrate for days, althoug-hiat times the feed "rock was belngatakenfiorn' a highagradepit 'and at other times camefrom a newly-opened lf'o'wgrade :pit and included 7 bits of overburden. Evenwhen thefeed rock contained much occluded silica, freely visible under the microscope l (as clear spots on the'milky'phosphate grains), thejrecovered concentrate had an acceptably low insolu bles tivity, as comparcd with conventional reagents,- in that they fioat relatively much of the siliceous impurities and relatively little phosphate. The betterreagents of'our class produce concentrates havingvery low insolubles;

yet therecovery of phosphate (which is a measure of selectivity, when coupled with low insolubles content in the concentrate) is good. i

v In other words, the figure for percentage of insolubles in the cencentrate rises steeplyas slime content Full-scale plant runs .haveshown that thefreagent will continueto'recover high-grade con-.

Ninth, our class of reagents is capable of producing concentrates with very low insolubles contents. During an extended plant run of one such reagent it was difficult to locate more than one grain of silica per field, when the concentrate was examined under a low-power microscope; and reagent consumption at the time was below normal for that plant.

Tenth, the insolubles content of the recovered concentrate quickly reflected changes in reagent feed rate, during the plant run above mentioned. Whenever a grab sample of concentrate showed a slight increase in siiica content, the reagent feed rate was increased slightly; and a grab sample taken minutes later showed that a satisfactorily low level of insolubles had been restored.

Eleventh, our reagents have good dispersibility in water, even cold water. They have appreciable inherent dispersibility in water in the un-neutralized state; and as explained below, their performance is sometimes improved by using them in partial salt form.

The reagents we employ in practising our process cornprise a mixture of a petroleum distillate, particularly a high-boiling aromatic petroleum solvent, and a co-generic mixture of organic compounds, which may be best described in terms of its method of manufacture because of the number and complexity of its components.

The manufacturing procedure used to produce the cogeneric mixture involves several separate and distinct steps. We have found that such steps must be performed separately and in the sequence recited below, if reagents of high effectiveness are to be produced.

To prepare our reagents, we first react a polyethylenepolyamine with tall oil, under closely controlled conditions of reactant proportions and reaction conditions. in a second and separate step, We then subject the product, so prepared, to reaction with dichloroethylether. Such second reaction product is mixed with an appreciable proportion of a petroleum distillate, preferably a high-boiling aromatic petroleum solvent, to produce a homogeneous liquid. This liquid, as such or in partially neutralized form, is our finished reagent. As will be shown later, it is extremely important from a performance standpoint that the. finished product include such petroleum material.

The polyethylenepolyamines are Well-known articles of commerce. They include diethylenetriamine, triethylene- .tetramine, tetraethylenepentamine, and binary and ternary mixtures of these in various proportions. For example, :an 80/20 mixture of the first two of these is offered as :a commercial product. So is a 40/60 mixture of the last two; an 80/ 12/ 8 mixture of the three; and also a ternary mixture of the three in approximately equal weight proportions.

These are synthetic products, made by a reaction that produces varying proportions of these homologs, which are separated from the reaction mass by fractional distillation. Such distillation leaves a still residue comprising a mixture of polyethylenepolyarnines. Such still residue, which includes minor proportions of the above-recited three polyamines, also is believed to include the higher polyamines such as pentaethylenehexamine, hexaethyleneheptamine, and the like. Such still residue is likewise a useful reactant for preparing our reagents, and may be so used either alone or admixed with one or more of the individual polyethylene polyamines mentioned.

We have prepared our reagents from various of the polyamines and mixtures thereof. We prefer to use the tower members of the series or mixtures rich in such lower members. Our preferred reactant of this class is a mixture comprising about 80% by weight diethylenetriarnine and 20% triethylenetetramine, although we have also prepared a very desirable reagent of the present kind using triethylenetetramine and tetraethylenepentamine.

We use tall oil as the second reactant in the production of our first intermediate reaction product. A mixture of fatty and rosin acids, this product arises in the pulp and paper industry. It is of unique composition, is available in large quantities on the open market, and is inexpensive. Either crude or refined grades of tall oil may be used to produce our reagents. We prefer to use crude tall oil for economic reasons.

The polyamine and the tall oil must be reacted in carefully controlled proportions if a flotation reagent of desirably high eifectiveness is to be produced. Others have in the past reacted these two classes of reactants in either equimolar proportions or using an excess of polyamine; but we have found the reagents prepared using such proportions are definitely inferior to those produced using our proportions.

We have determined that a clearly superior finished rea ent is obtained if there is present in this reaction mixture appreciably less than an equimolar proportion of the polyamine reactant. As one reduces the molar proportion, polyamine-to-tall oil, from 1:1 down to 0.9:1 and then to 0.8: 1, the effectiveness of the finished reagent obtained from such intermediate reaction product increases materially. As the proportion is reduced further, the improvement in finished-product quality continues.

While there is no sharp break-point in the effectiveness curve, we prefer to employ a ratio, polyamine-to-tall oil, of from about 0.621 to about 08:1. The intermediates made using reactant proportions within this last-recited range produce finished reagents whose effectiveness is clearly better than others made with ratios much outside this range. We therefore limit ourselves herein to reagents made from intermediates whose reactant ratio lies within this narrow range. Our preferred molal ratio, polyamine-to-tall oil, is about 0.63: l.

The polyamine and the tall oil are reacted by heating together, with stirring, at a temperature range of quite narrow limits, as we shall next explain.

When one reacts tall oil and a polyamine, by heating and stirring, water is evolved as the temperature of "the reaction mass rises. Evolution of water first occurs in the neighborhood of C.; and from one-half to two-thirds. of all the water that will eventually be evolved has come over by the time the temperature has reached 200 C- Finished reagents made from intermediates prepared by heating these two reactants at temperatures not exceeding. 200 C. have poor effectiveness in our process.

As the temperature of the reaction mass is increased to about 250 C., more water and a small portion of nonaqueous distillate are evolved. (The 250 C. point is mentioned here because it has been the reaction temperature specified in numerous descriptions of procedures for preparing amides from polyamines of the present kind.) Products prepared from intermediates made at 250 C. do not have acceptable effectiveness in our process, however.

in fact, to prepare our desired intermediate the reaction temperature must be held at between 270 and 300 C. for at least part of the reaction period. Usual practice is to mix the reactants and start heating and stirring the reaction mass at atmospheric temperature, or slightly above. produces a salt, in a slightly exothermic reaction.) The reaction vessel and contents are then brought to the desired reaction temperature prudently, and the reaction is continued as long as required, at that temperature. Prudence in heating is required because appreciable foaming accompanies the reaction and the liberation of water from such reaction mass.

In commercial steel processing vessels, our desired intermediate can be so produced in about 12 hours, of which about 9-10 hours are consumed in reaching a temperature of 285 -290 C.; and about 23 hours are consumed in completing the reaction at this temperature. Below about 270 (2., the final and critical portion of the reaction does not occur. It is not necessary to raise the temperature much above our preferred range of (Mixing the tall oil and the polyamine limiting, however.

asacgiai 7 about 285 -290 C. to complete the desired reaction in a relatively few'hours, as stated; I t a It is also practicable to prepare this first intermediate reactionproduct byheating the-=tall oilto a temperature somewhat above that at which foaming usually occursin such reaction. For example, ifthe tall oil-isheated to 200-260 C. and the polyamine is then introduced in small increments, foaming is substantially-eliminated and an acceptableintermediate is produced.

'I'na second and separate step of preparing ourfinished flotation reagents, the intermediate reaction product prepared as just described is subjected to reaction with dichloroethylether; While this second reaction may be conducted inthe same reaction vesselas was; employed to prepare the above intermediate, and without-removing thati first reaction mass from the vessel, it must be emphasized that the second reaction, using dichloroethylreaction temperatures appreciably: higher than these.

For example, we have started the dichloroethylether 7 reaction at 100 C. as above; butthereafter have raised the reaction mass to 150 C. Again, we have added the dichloroethylether at 150 C. and have thereafter raised the temperature of the reaction mass to,20(i' C; t In each case, the reagent so prepared is effectiveffor the present purpose.

This reaction converts a portion of the organically boundchlorineatoms to. chloride ions. The degree of convers'ion'of chlorine to chloride ion will importantly influence the characteristics of the finished reagent. We prefer to achieve conversion of atleast 35% of the total chlorine, 'as a minimum; and we ordinarily convert from about 40% to about 70%.of such' organically-bound f chlorine atoms to chloride ions.

The amount of "chlorine converted can of course be measured by conventional titration "of the chloride ion produced.

As un-ionized, organically-bound chlorine atoms are i converted into chloride ions, the inherent dispersibility of the product in water'increases. Water-dispersibility of a basic material can usually be increased by neutralizing it with a low-molal acid, such as acetic, as is Wellknown in this and other arts. We have coined the term inherent dispersibility to distinguish from the conventional neutralization-derived dispersibility; it'means the tendency of our basic material itself to disperse in water.

Such tendency may be concealed in some instances because of the presence in the molecule of large hydrophobic elements; and two such materials may appear to be equally not dispersible in water. However, one may be much more readily converted into water-dispersible' form, as by neutralization, because of its relatively greater inherent dispersibility. Conversely, two materials may appear to be equally dispersible in water in, say, con- ..centration. Both may produce dispersions which, appear alike; yet one dispersion may be considerably more stable and comprise smaller, more completely hydrated particles. 7 Such inherent dispersibility in water may usually beaugrnented by neutralization of the material with an acid, like acetic acid; but it is notdestroyed by the addi-" tion' of. dilute alkali to a. dispersion, of, such neutralized product.

Such inhereintdispersibility in water, although diflicult to explain, is. believedbv us toberesponsible in part'for We have prepared our reagents using.

the improved effectiveness of our reagents, as compared with conventional aliphatic amine acetate reagents:

To achieve, it we have found it necessary to employ an appreciable proportion of dichloroethylether in preparing our reagents. We prefer to employ at least 0.5 equivalent (0.25 mol) of dichloroethylether for every 1 equivalent (1 mol) of tall oil used in preparing the first'intermediate reaction product above, and not more than about 2 equivalents (1 mol) of dichloroethylether per equivalent (mol) of tall oil.

The range of proportionsof dichloroethylether which may be used to prepare reagents of acceptable effectiveness in our process cannot be stated with decimal exactness. There is no abrupt change in effectiveness of the products as the proportion of dichloroethylether used in their preparation is varied. As a practical matter, We

can state that unless we employ about 0.5 equivalent of' dichloroethylether' for each equivalent of tall oil, and unless we so conductthe reaction that at least about of the total chlorine present is converted to ch10 ride ion, the resulting product is of inferior quality when used'in our process.

After conducting the foregoing two reactions, separately and in the sequence stated, the final' reaction'ma'ss is mixed with a substantial proportion of a petroleum dish'la. late, preferably a high-boilingv aromatic petroleum'solvent; The reaction mass maybe partially neutralized either before or after it is mixed with such petroleum distillate, The petroleum constituent of our finished reagents is not optionally added to theiother ingredients, when it is desired to reduce their viscosity 'or lower the products" cost. On the contrary, its presence is essential. Its

presence is in part responsible for the high effectiveness.

of our reagents. a r

We believe there is an explanation of this important discovery. When our reagents are dispersed in water, either in a solution tank prior to introduction into the flotation cell or else in the cell, the reagent particle that so disperses includes an appreciable proportion of petroleum distillate; and the behavior of the particle isdiflfe'rant, and more favorable to the flotation of siliceous im-' purities; thanit would have been in absence of the petroleum' distillateconstituent,

At any rate, we requirethat our finished flotation reagent include from about 25% to about 75% of petroleum distillate. T here-is no option in this matter; the fin ished reagent must include such constituent, No figure can be given for the optimum proportion of such constituent to beusedp However, it chooses less than about 25% petroleum, distillate and more than about. 75% of,

' final reaction product, prepared as' above described, .the

favorable effect of the combination becomes so small as to be negligible. If one usesmore than about 75% petroleum distillate and less than about-25% of reaction product, dispersibility in water becomes poor; and the effectiveness of the reagent is further reduced because in part the petroleum distiilatejis acting simply as a diluent.

We prefer thatourfinished flotation reagentsinclude.

about reaction product and about 50% petroleum distillate, Such proportions of reactionproduct and petroleum distillate should preferably lie 'atleast between 40% and .We greatly prefer that the petroleum distillate con stituent of our finished reagents be 'a so-called'high-boiiingarornatic petroleum solvent. Such liquids areavailable from refineries, as well-known articles of commerce;

They have boiling ranges of the order of 400 F. initial to over 600 F. endpoint. specification reciting; their content of sulfonatable constituents, a value determined by reacting the distillate with 98% sulfuric acid and noting the percentage of the sample that dissolves in such sulfonating agent- Both. the aromatic and'theunsaturated constituents of the pe- 1 'troleum distillate dissolve under such conditions.

not distinguish between these two classes of constituents We do They are usually sold 'on f in our preferred petroleum distillate, because we do not know their respective proportions in the liquids we have used. We do prefer that the petroleum distillate employed as a constituent of our finished flotation reagent contain a major proportion of sulfonatables, i. e., of aromatics and unsaturates, and preferably at least about 75% thereof.

Specifications of two representative high-boiling aromatic petroleum solvents which we have used in preparing So far we are aware, such high-boiling aromatic petroleum solvents have not been used in the phosphate industry, and particularly not in connection with the flotation of siliceous impurities from phosphate rock. So far as we know, such liquids have never been proposed for use as diluents with the conventional aliphatic amine acetate reagents. (For that matter, we do not believe even kerosine has been suggested to date as a solvent for such conventional reagents; because they are not soluble in kerosine at atmospheric temperatures. Where it has been proposed to prepare solutions of such conventional reagents, alcohols have been suggested.)

It should be clearly understood that our mixture of reaction product and high-boiling aromatic petroleum solvent is a homogeneous, single-phase system, not a dispersion or emulsion or suspension of one constituent in the other.

The homogeneous mixture of reaction product and pertoleum distillate, prepared as just described, may be partially neutralized with a suitable acidic neutralizing agent. We have employed acetic acid, although it is equally practicable to use hydroxyacetic acid or other organic acid of low molecular weight. It is equally practicable to use mineral acids like sulfuric and hydrochloric acids. Acetic acid appears to produce reagents having very desirable physical properties; it is our preferred neutralizing agent. We prefer to use it in 94% concentration, although We have used other concentrations. For example, during one field run, we added common vinegar acetic acid) to our finished reagent, when it became desirable to examine the influence of slight additional neutralization.

Only sufficient neutralizing agent is used to produce a reagent capable of making a smooth, creamy, stable dilute aqueous dispersion; but not so much as to neutralize the basic constituents completely or even nearly completely. If no neutralizing agent is used, the aqueous dispersions of the product may in some cases contain particles sufficiently coarse or large so that the collector does not do as good a job, even though the dispersion may appear stable to the eye. If too much neutralizing agent is used, the tendency of the reagent particles to concentrate at the rock-air-liquid inetrface is reduced.

The foregoing statement does not imply that the proportion of neutralizing agent usable is so critical that manufacture and use of the reagent are impracticable. We have found that desirably about 1%2% of acetic acid (100% basis) may be included in some examples of our finished flotation reagent if it is to have greatest effectiveness.

A slight deficiency in degree of neutralization, in such instances where any neutralization at all is used, is not tion of acetic acid to a factory-finished reagent, during the course of a field run, and as the reagent was being dispersed in water preparatory to feeding it to the cell. As our reagents come into settled use in the industry, installation of acid-feeding systems may be made, by means of which neutralization of the reagents can be effected as desired, for optimum performance.

Similarly, slightly excessive neutralization of our reagents is not critical. As stated above, conventional flotation plants presently feed caustic soda solutions to the cleaner-circuit cells, along with the conventional flotation reagents. It is a simple matter to use a slightly over neutralized reagent; and then use a small feed of caustic soda solution to reduce slightly such degree of neutralization of the reagent.

Some operators, accustomed to using caustic soda to control froth characteristics, like to have such additional means available to bring unsatisfactory-looking froths back to the desired state. This is another reason why slight over-neutralization of our reagents is not critical, and may in fact sometimes be desirable.

There is another important reason for not reciting a more specific degree of neutralization. The rock fed to the cleaner circuit is the concentrate from the rougher flotation circuit, after de-oiling and washing. De-oiling is accomplished by mixing the rougher concentrate with dilute sulfuric acid. Washing is used to remove any excess sulfuric acid from the de-oiled concentrate. In some cases, however, washing is incomplete; and the feed to the cleaner circuit is more acidic than usual. In such instances, a sli htly under-neutralized reagent gives better performance than a slightly over-neutralized one.

It is a virtue of our reagents that they have good adaptability to such variations in pH. They do not lose effectiveness sharply on reduction of cell pH, as do conventional aliphatic amine reagents.

Where neutralization is used, we prefer to neutralize our reagents after admixing the reaction productwith the petroleum distillate. However, it is entirely feasible to effect such neutralization of the reaction product and then mix the neutralized reaction product with the petroleum distillate. Neutralizing the mixture of reaction producvt and petroleum distillate is usually more practicable, because such mixture has a viscosity lower than that of the reaction product alone; and distribution of the neutralizing agent is more readily eflfected in such procedure.

Although we have emphasized the use of aromatic petroleum solvents in preparing our reagents, we have also referred to this general class of constituent as petroleum distillates. We do not intend, by emphasizing the one example of the class, to imply that it is the only petroleum distillate that may be used. For example, we have used kerosine in preparing our reagents; and have found that a mixture of reaction product and kerosine, within the proportion limits previously set out, is a flotation reagent of high efiectiveness, in our process.

One observation made during a full-scale run of our preferred reagent will illustrate how different from conventional reagents our reagents are. Prior to our run, the plant had operated using the conventional aliphatic amine acetate reagents, extended with rosin amine acetate and free rosin amine. The rakes of the flotation cells were heavily slimed with a deposit of residues from such fatal. As stated above, we have added a minor proporreagents. The solution tank in which an aqueous dispersion of such reagents was prepared, and the steel gauge pole used to measure the level of the liquid in such solution tank, were similarly slimed. After our reagent had been in use two days, such accumulations began to slough off the cell rakes; and the solution tank wall and the gauge pole were free of deposits.

We have above described in detail our preferred re ac'tants and the proportions thereof employed to produce our finished flotation reagents. The following examples describe the preparation of a number of our reagents from that they should limit 'the 'preceding description:

' 30 minutes. The resulting homogeneous liquid is allowedmols of alkylene oxide are used, per mol of polyamine,

such reactants and by such procedures. 'It is not intended.

Example lt.

We first react 2070 pounds of commercial crude tall oil) with 450. pounds of a mixed polyamine, 80% by weight diethylenetriamine and triethylenetetramine, in.a steelprocessing.vessel equipped withstirrer', and gas-fired. Themass is brought to a temperature of 285 290 C., in tl1e course of about 9.5 hours, care'being taken ,to avoid=foamovers and reaction-is'continued at temperature for 2 .25 hours.

Thistfirst intermediate reaction product isallowed-to coolzto 100C. in the'vessel,;at which .temperature- 300 15 tocool to atmospherictemperature; after which 98 poundsaof 94% commercial acetic acid are added. The. I whole is stirred for another minutes until the acid. is well distributed and neutralization has been accomplished. 30

The finished reagent,'so prepared, is a very effectivev flotation reagent for removing siliceous impurities fromphosphate rock.

The performance of our collector reagent,$of which the. product: of Exampleil is representative, may: fre- '35 quentlybeimproved byusing it in conjunction with a 'minor proportion of a somewhat relatedcomposition which we. have found to act as a depressor for phosphate rock. The effect of incorporating such-depressorin -ourfinishedfiotation reagent is to make the reagent'more 40 selective for'siliceous and particularly silica impurities in phosphate'rock. The ability of the collector component to float siliceous impurities is seemingly not ad=- versely affected .by the presence of minorproportions of j such depressor. a V

The depressor components composition is closelyallied to thecomposition of the collector component of those of our' reagents which include both components. Boththe-collector and the depressor are made'fronr tall oil. Both are made from any. of the polyamines recited above: Both are made using' dichloroethylether'in the second intermediate reaction procedure. Both are eventually mixed with a petroleum.'distillate;'and bothmay be' used in unneutralized or partially neutralized state.

The essential difference between the depressor component class and the collector component class is that the former is made from an oxyalkylated derivative of i one or more of the foregoing polyamines, rather than 1 from the polyamine itself.

We prefer to.employ ethylene oxide alone, .of the alkyleneioxides, for this purpose, although propylene oxide'sometimes is valuable. At times, a mixture of propylene oxide and ethylene oxide will give the best depressor action;'but whereboth are used we prefer that M the propylene oxide be reacted first, followed by the ethylene oxide. Butylene oxide is not 'useful'alone; but

is useful in conjunction with ethylene oxide.

We prefer that approximately 1 mol of alkylene oxide be used per molof polyamine. If more than about 2 the desirable characteristics of this depressor component are greatly reduced.. Where-more than one alkylene oxide is used the molal ratio is for total alkylene oxide.-

to-polyamine and we prefer to use a ratio lessth'an abouf r V V 12 about 1 mol total alkylene oxide to 1 mol of polyamine, 'Thefollowing' is anex'a'mple of the preparation'of such depressor component. 1

Examp 'Wefirst react 750 Example. 1: with 295 pounds of ethylene'oxide in the conventional manner, employing .a' reaction temperature of 1309-135? C.-' No'catalyst is required, inlight of the natural basicity of thestarting material; Theoxyethylanon reaction is eompleteiin-2j5 hours. 1 Byathis reaction l mol of. ethylene oxideis introduced into each mol of;

polyamine. l I V Thereafter,- the procedure is essentially that-of Example 1 above; We react 2070 pounds of tall oil. with:

I 627. pounds of the oxyethylated polyamine-justprepared},

raising the temperature to 285290 C. iuabout 10- 7 hours; and 'maintaining it'at thatlevel' for 2.5 hours; 7

Such first intermediate reaction product is cooledin V the' reaction vessel to' C., as before; thenJBOO' pounds of dichloroethyletherlare reacted as before; The reaction rises spontaneously to about C., where it is maintained for '1 hour. Conversion of chlorine atoms to chloride -ions:is about 45%. i V i l The reaction mass is thereafter mixed with BOO-gallons of high-boiling aromatic-petroleum solvent (solvent B5 0 above), andstirred-until'the mixture is homogeneou Thereafter; 100 poundsof acetic acid (94%)are added;-" and the mass is stirred an additional 30 minutes; 7

The finished reagent-so prepared, when mixed in minor 'proportion'with a collector component like that-of' Ex ample 1, improves -theselectivity of thatreag ent in re moving siliceous impurities'from phosphate rock. We have-found it advantageous to 'preparea' mixture of such collector and depressor components, e1; our preferred finished flotatio n reagerit, simultaneously ina single" manufacturing procedure: illustrates such "procedure."

Example 3 V V i We prepare afiotation reagent'having both collector and depressor constituents, as follows: We first oxyethylate 35 pounds" of a mixed polyamine, having by" v weight diethylenetria'mine' and 20% triethylenetetramine, with l3 pounds of ethylene oxide. v I *gether 2229*pounds of crude commercial talfoil; pounds of'the above-polyamine, and 48 pounds "of" the" above oxyethylated' polyamine, using a maximum're:

action temperature of 285290 C. for 2.25 'hours,afterf taking some 10 hoursto raise the reaction mass'tothis" We cool- 'theireactio'n C., andadd 323 pounds'of commercial. 7

temperature from atmospheric. mass'to 100 dichloroethylether. The exothermic reaction which en-i sues raises the'temperature of the mass to about 123 '0 Conversion of chlorine atoms to Ichloride 'ionslisfabout" 40%? Thereafter; we mix such final reaction' product with. 268 gallons of high-boiling aromatic petroleumsol vent (solvent A, above), producing'a homogeneous liquid;

Example 4 V we repeat :Example l above,but substituting-for;someI of the reactants and proportions, as followszj'we-react '1850'pounds of talLoil with 587 pounds of trietliyl'ene tetram'ine, proceeding as before. We ,thereaftfer rea'c with such first intermediate reaction -product 800ippund" of dichioro etliyleth'er, as before: ,We'tlien' mix'this'secorid 1 2:1'in.any case. Most desirably, we use not morethan intermediate reactioniproductwith'Zdilifpotiirdeofjhigfir pounds of the mixed polyamine of The following example' We then react to 13 boiling aromatic petroleum solvent (solvent A, above), as before. Finally, we partially neutralize the mass with 110 pounds of 94% acetic acid, before. The finished prodnot is an efiective flotation reagent for the present purpose.

Example We first react 2070 pounds of tall oil with 965 pounds of commercial tetraethylenepentamine, using the procedure and conditions of Example 1, above. Thereafter, We cool the reaction mass to 105 C. and introduce, with stirring, 230 pounds of dichloroethylether. The temperature rises to about 130 C., where it is maintained 1 hour. The final reaction mass is dropped into 2000 pounds of high-boiling aromatic petroleum solvent (solvent A, above); and after cooling to room temperature is mixed with 98 pounds of 94% commercial acetic acid. The finished product is an ef ective flotation reagent for removing siliceous impurities from phosphate rock.

Example 6 We prepare a depressor component of the kind described in Example 2 above; but with the following reactants and proportions: We use 2070 pounds of tall oil, as before. We use 965 pounds of an oxyethylated triethylenetetramine (prepared as in Example 2, but from 978 pounds of triethylenetetramine and 295 pounds of ethylene oxide). These two reactants are reacted as in Example 2, to produce a first intermediate reaction product. This is next reacted with 230 pounds of dichloroethylether, as before, maximum temperature produced by the exothermic reaction being about 120 C. Thereafter, we mix the final reaction product with 3000 pounds of kerosine; and neutralize the mass partially with 110 pounds of 94% acetic acid.

. Example 7 We prepare another example of our depressor component as follows: We react 447 pounds of tetraethylenepentamine and 105 pounds of ethylene oxide, following the procedure set out in Example 2, above. We then react 552 pounds of this oxyalkylated polyarnine with 1290 pounds of tail oil; and thereafter react this last reaction product With 290 pounds or" dichloroethylether, using the procedures and conditions of Example 2, above. (In the reaction with dichloroethylether, about 70% of the chlorine is converted to chloride ion.) The final reaction product is mixed With 2800 pounds of high-boiling aromatic petroleum solvent; after which the homogeneous liquid is partially neutralized, using 63 pounds of 94% acetic acid.

Example 8 We prepare a flotation reagent having both collector and depressor constituents, by adding, to 900 pounds of the product of Example 1, 100 pounds of the product of Example 2, above, and stirring until thoroughly mixed. The mixture is homogeneous and is an effective collector for removing siliceous impurities from phosphate rock. It has a high degree of selectivity for such impurities.

Example 9 We prepare a flotation reagent having both collector and depressor components, by adding, to 870 pounds of the product of Example 4, above, 130 pounds of the product of Example 6 above, and stirring thoroughly. The homogeneous mixture is an effective collector for removing siliceous impurities from phosphate rock; and has a high degree of selectivity for such impurities.

Example 10 We prepare a flotation reagent having both collector and depressor components as follows: We react 8321 pounds of commercial crude tall oil with 2536 pounds of commercial triethylenetetramine for 2.25 hours at a temperature of 285290 C., after taking about 10 hours to raise the temperature to this level. The product is cooled to C.; and 1216 pounds of dichloroethylether are added, with stirring. The reaction mass temperature rises to about C. (About 60% 0f the chlorine present is converted to chlorine ions.) Then, 7425 pounds of this second intermediate reaction product are dumped into 8112 pounds of a high-boiling aromatic petroleum solvent (solvent A, above); and the mixture is stirred for 45 minutes. Thereafter, pounds of 94% commercial acetic acid are added at atmospheric temperature; and the mass is stirred for another hour. Then, 15,697 pounds of this finished product are mixed with 1429 pounds of the product of Example 7, above. The homogeneous liquid so prepared is a very etfective collector for removing siliceous impurities from phosphate rock; and it exhibits a high degree of selectivity for such impurities.

Example 11 Example 1 is repeated exactly, except that, instead of neutralizing with 98 pounds of 94% commercial acetic acid, we neutralize with pounds of commercial muriatic acid. The product is an effective collector for removing siliceous impurities from phosphate rock.

Example 12 We prepare a depressor component of the kind described in Example 2. Example 2 is repeated; but instead of introducing 1 mol of ethylene oxide into the polyamine as a first step, we react 750 pounds of the polyamine first with pounds of propylene oxide and then with 148 pounds of ethylene oxide, conditions being substantially the same as in Example 2. Thereafter, we follow the procedure of Example 2 to the end thereof, but using 656 pounds of the present oxyalkylated polyamine instead of 627 pounds of the derivative of Ex ample 2. 1

Example 13 Example 14 We prepare another example of a depressor component as follows: Example 2 is repeated except that, instead of first reacting 750 pounds of the 80/20 mixture of diethylenetriamine/triethylenetetramine with 295 pounds of ethylene oxide, We use 590 pounds of this alkylene oxide. The oxyalkylation reaction time is approximately 5 hours. The oxyalkylated polyamine is thereafter used in the procedure of Example 2, employing 804 pounds of the present oxyalkylated derivative instead of 627 pounds of the derivative used in Example 2.

Example 15 We repeat Example 1 exactly; but instead of using 2000 pounds of high-boiling aromatic petroleum solvent we use only 840 pounds of such solvent. The product is an effective collector for removing siliceous impurities from phosphate rock.

Example 1 6 We repeat Example 1 exactly; but instead of using 2000 pounds of high-boiling aromatic petroleum solvent we use 7500 pounds of such solvent. The product is an eifective collector for removing siliceous impurities from phosphate rock.

Example 17 We repeat Example 1 above, except that we use, instead of 450 pounds of an 80/20 mixture of diethylenetriamine/triethylenetetramine, 930 pounds of a still residue from the manufacture of polyethylenepolyamines.

l A typical Florida pebbl This is available from at le'as't one manufacturer, under thedesignation' Residue H. Thefirstreaction described under Example 1' isthen' conducted as there described, except that heat-up time is extended to some 12 hours. 'The other conditionsand reactantproportions are substantially as stated in Exarnple' l. The product is an effective flotation'reagent for removing siliceous impurities from phosphaterock.

' 7 Example 18 We react 2455. pounds of crude tall oil', 492 pounds of mixed polyamine (80% by weight diethylenetriamine, 20% triethylenetetramine), and 53 pounds of the monooxyethylated polyamine of' Example 2, using the procedureof Example 3, above. The first intermediate reaction. product, 2705 pounds, is next reacted with 367 pounds of commercial dichloroethylether, using-a startingreaction temperature of 100 C. and-prudently raisingthe temperature to 150 C. The latter temperature is maintained for 1 hour. Thereafter, 72 poundsofsuch second. reaction product are mixed with 2365 pounds of ties from phosphate rock; and has good selectivitylrwhen so used.

' Example '19 r We react 2291 pounds ofc'rude tallroil, 459 -pounds ofthe 'rnixedpolyamine of Example 18, and 50 poundsof the oxyallrylated polyamine of Example Reaction conditionsare as recited in Example 3, above To 2 5 24 pounds of this first intermediate reaction product, we=add 253 pounds of dichloroethylether: at 150 C.,-iaddingthe latter reactant slowly.- Thereafter, w'e' raise the' re action mass to 200 C., and maintain that temperature for 0.5 hour. After cooling, .theifsecondreactionproduct is mixed with 2153 pounds of aromatic petroleum solvent "(solvent 'A, abbve); and 101 pounds' of 94 .acetic acid are then added, with stirring. 'The finished reagent, so prepared, is an eflectiveflotaitionreagent-for removing siliceous impurities frorr rpl iosphaterock;v an

exhibits good selectivity whensoused. 1 1 3 Example 'j V V We repeat each of the foregoing; exampleg'Examples 1-19 inclusive; but we omit the neutralizationstep and employ the reagent in unneutralized form. The finished reagent, so; prepared, are effective flotation reagents for removing siliceous impurities from phosphate rock; and they exhibit good selectiw'ty when "so used, especially 7 in-those casesfwhe're a depressorcomponent is included 7 infthe reagent.

Of all the foregoing examples,'we consider the product about /t; below conventional reagent cost.

of Example 3ftorepresent our preferred reagent. .As-a

second choice, we'p'refer. the product of Example 10. .As'. a'third preferred example of our reagents, we name the reagent. of Example-3; but in'unneutr'alized. form.

Because our'finished'reagents are mosti advantageously usedin conventional flotation plants in the phosphate continued in normal fashion, the only change being .11 9

otherwise used.

Forisake completeness; the' following .brief jexample I of their use isrpresented, without limiting-the'invention:

in any degree; i p r 1 V V e phosphate rock was subjected to'conventionalpraflotationueatment and sizing; That portion ha vin a'particle-size range'of from about 28 to; about l-rnesh was processed through a conventional r rougher flotation circuit employing the conventional tall oil, fuel oil, and caustic soda reagents to float a phosphate rock concentrate. The concentrate delivered from'such rougher circuit contained 12l4% insoluble matter, after" de-oiling with dilute sulfuric acidandwashing with'water;

In the consequent secondary flotation circuit, our preferred reagent, as produced in Example 3 above, was used at a rate of about 0.85 pound per ton of rougher concentrate.

Our preferred reagent was dispersed in well Water atrequired for optimum performance was found to be less than normal. Caustic soda, although conventionally fed to the circuit, was'discontinued for optimum performance of our reagent. After running the plant on feed stocks from several pits over a period of 3 days,

the performance of the plant'while using our preferred" reagent was compared with the performance during the preceding period when conventional aliphaticamine' acetate reagent, extended with rosin amine acetate androsin amine, was in use.

Our preferred reagent delivered a concentrate analyzing about.l.5% higher in BPL (bone phosphate of lime), and about 2% lower in-in'solubles;

The froth product obtained with our reagent analyzed 9% lower in BPL than did the froth product produced by theconventional reagents. BPL recovery wasabout 3% higher using our reagent, on an overall'basis. The plant was operated at higher tonnage rates .duringour run; but-reagent costs per ton, were nevertheless reduced Elimination of the caustic soda feed produced another saving of some 3 cents per ton. A smaller (uncalculated) saving was effected by the reduction in kero sin'e feed rate'.' In another application of ourreagents, the product was made in the plant of a different producer, the conditions, proportions, and results were'essentially the same as those. described above, except that a 'smallfeed ofQ 'pine oilwas included in the operating procedure. 7, As in such other application, no diificulty whatever was" experienced in ch'anging over from the conventional liquid-j;

reagent to our reagentyand the performance of-"our reagent was technologically satisfactory.

As a third example of the application of ourprocess; the reagent of Example '1 is used and is eflective in a system of the kinddescribed just above. In such third example, the reagent ofExarnple l'is used in the'same proportions, and underthe same conditions, as in;.the,. .first of the above-described fplant procedures. V w r V In, a'fourth operatingexample, the reagen'tlofEx l ample 3 above is used effectively in unneutralized form,"

instead of in partially neutralized form. The first-'de-j scribed operating procedure above is'emplo'y'ed; The foregoing portion of this application has been devoted to the use of our reagents in conventional silica r substitution of our reagents-for the 'conventionalreagents flotation circuits of phosphate rock beneficiation plants.

'We wish now to state' that ourreagents are likewise" adapted touse' in any of the other conventional con centration processes in'tlie phosphate rock jindustry,'such as in film flotation and tabling, wherein .thefconventionalT aliphatic amine reagents" find 'u tility, In some of the appended claims we have therefore claimed 'the'use of' our reagents in such related'pro ce'sses. The principal applicationof our reagents is believed to lie in the froth'flotationprocedure for removingsili ceousiim urities l from phosphate rock, as,conv'ent'iona'lly' operated the phosphate fields 'of Florida.

The proportions of. our reagents required w'b'chuseki? Weused gallonsof our reagent to'800 It was pumped to the clean'efv Kerosine was fed to the cleaner Q circuit in the conventional fashion; but the feedrate will in each case depend upon the composition of the phosphate rock with which they are used. However, we believe that our reagents will not be used in proportions greater than those in which the conventional aliphatic amine reagents are used in this industry. Because our reagents are generally more effective, pound for pound, such superiority may be expressed in either of two ways: a smaller feed rate will produce a concentrate of equal quality; or an equal feed rate will produce a rock of higher quality.

With phosphate rock of sufficiently high grade, our process is applicable to the washed and sized rock without subjecting such rock to the action of a rougher flotation operation with tall oil, fuel oil, and caustic soda, or similar reagents. We therefore do not wish to be limited here to a process in which our reagents are used only on the de-oiled and washed concentrate delivered by such rougher flotation operation.

In some of the foregoing examples, we have shown the use of an acid and the partial neutralization of the reagent. It should also be pointed out that where it is desired to use our reagents in partially neutralized form, they might equally well be manufactured in the factory without using any neutralizing agent whatever; and any neutralizing acid be added to the reagent later, e. g., as the latter is introduced into the solution tank at the flotation plant or to the cells. It is essential only, in such cases, that the reagent, as it reaches the flotation cell, be partially neutralized, as described.

We have specified that our depressor component, if present at all, be present in only minor amounts. To be more specific, we believe it should comprise not more than about 20% of the total finished reagent. The exact maximum tolerable proportion will of course depend on the individual characteristics of the collector and depressor components of that particular composition.

In the foregoing specification and in the appended claims we refer to mols of tall oil. It is obvious that, since tall oil is a mixture of fatty and rosin acids, it cannot strictly be said to have a molecular weight. However, since the acids of tall oil are monocarboxylic, 1 equivalent of tall oil will be the same as 1 mol, total, of the various acidic constituents of tall oil. Stated another way, if tall oil has an acid number of 173.2, it has an equivalent weight of 324. One equivalent Weight of tall oil is composed of fractional mols of its respective constituent acids, such fractional mols totaling 1.

We claim:

1. A concentration process using differential surface wettability principles for separating siliceous impurities from phosphate rock, characterized by subjecting the rock to the action of a material selected from the class consisting of (I) a liquid reagent which includes: (A) a reaction product obtained by (1) first reacting tall oil and a polyethylenepolyamine to provide an intermediate, said reaction including a reaction temperature between 270 and 300 C., the molal proportion of polyamine to tall oil being between about 0.6:1 and 08:1, then (2) reacting such intermediate with dichloroethylether, the molal proportion of dichloroethylether to tall oil being between about 0.25:1 and 1:1; (B) a high-boiling petroleum distillate, the proportion of such petroleum distillate in the finished reagent being between about 25% and 75%; and a minor proportion of a depressor for phosphate rock, (C) which depressor is a reaction product obtained by (1) first reacting tall oil and an oxyalkylated polyethylenepolyamine, said reaction including a reaction temperature between 270 and 300 C., the molal proportion of oxyalkylated polyamine to tall oil being between about 06:1 and 0.8:1, the oxyalkylated polyamine being derived by reacting the polyamine with a material selected from the class consisting of ethylene oxide and propylene and ethylene oxides, using not more than about 2 mols of total alkylene oxide for each mol of polyamine; and then reacting such tall oil-oxyalkylated polyethylenepolyamine reaction product with dichloroethylether, the molal proportion of dichloroethylether to tail oil being between about 0.25:1 and 1:1; and (II) partial neutralization products thereof.

2. The process of claim 12, in which the concentration process for separating siliceous impurities from phosphate rock is a froth flotation process in which such impurities are floated from such rock.

3. The process of claim 2, in which the petroleum distillate is a high-boiling aromatic petroleum solvent, and of which the finished reagent includes about 40% to 60%.

4. The process of claim 3, in which the high-boiling aromatic petroleum solvent contains, as a minimum, about of sulfonatable constituents.

5. The process of claim 4 in which the reaction with dichloroethylether produces a conversion of chlorine atoms to chloride ions of at least about 35%.

6. The process of claim 5 in which the reaction with dichloroethylether produces a conversion of chlorine atoms to chloride ions between about 40% and 70%.

7. The process of claim 13, in which the oxyalkylated polyamine used to produce the depressor component is an oxyethylated polyamine in which the molal ratio of ethylene oxide residues to polyamine is not greater than about 1:1.

8. The process of claim 7, in which the collector and depressor components of the reagent are prepared simultaneously by using a mixture of polyamines and monooxyethylated polyamines in the reaction.

9. The process of claim 6, in which the polyamine reactant employed to produce the reagent includes a major proportion of diethylenetriamine.

10. The process of claim 9, in which the reagent is at least partially neutralized as manufactured, and before being used.

11. The process of claim 10, in which the neutralizing agent employed is acetic acid.

12. A concentration process using differential surface wettability principles for separating siliceous impurities from phosphate rock, characterized by subjecting the rock to the action of a material selected from the class consisting of (I) a liquid reagent which includes: (A) a reaction product obtained by (1) first reacting tall oil and a polyethylenepolyamine to provide an intermediate; said reaction including a reaction temperature between 270 and 300 C., the molal proportion of polyamine to tall oil being between about 0.621 and 0.8:1, then (2) re acting such intermediate with dichloroethylether, the molal proportion of dichloroethylether to tail oil being between about 0.25:1 and 1:1; (B) a high-boiling petroleum distillate, the proportion of such petroleum distillate in the finished reagent being between about 25% and 75 and (II) partial neutralization products thereof.

13. The process of claim 1 in which the depressor component (C) included in the finished flotation reagent is not more than about 20% of the finished reagent.

References Cited in the file of thls patent UNITED STATES PATENTS 2,368,968 Christmann Feb. 6, 1945 2,494,132 Jayne Jan. 10, 1950 2,569,417 Jayne Sept. 25, 1951

Claims (1)

1. A CONCENTRATION PROCESS USING DIFFERENTIAL SURFACE WETTABILITY PRINCIPLES FOR SEPARATING SILICEOUS IMPURITIES FROM PHOSPHATE ROCK, CHARACTERIZED BY SUBJECTING THE ROCK TO THE ACTION OF A MATERIAL SELECTED FROM THE CLASS CONSISTING OF (1) A LIQUID REAGENT WHICH INCLUDES: (A) A REACTION PRODUCT OBTAINED BY (1) FIRST REACTING TALL OIL AND A POLYETHYLENEPOLYAMINE TO PROVIDE AN INTERMEDIATE, SAID REACTION INCLUDING A REACTION TEMPERATURE BETWEEN 270* AND 300*C., THE MOLAL PROPORTION OF POLYAMINE TO TALL OIL BEING BETWEEN ABOUT 0.6:1 AND 0.8:1, THEN (2) REACTING SUCH INTERMEDIATE WITH DICHLOROETHYLETHER, THE MOLAL PROPORTION OF DICHLOROETHYLETHER TO TALL OIL BEING BETWEEN ABOUT 0.25:1 AND 1:1, (B) A HIGH-BOILING PETROLEUM DISTILLATE, THE PROPORTION OF SUCH PETROLEUM DISTILLATE IN THE FINISHED REAGENT BEING BETWEEN ABOUT 25% AND 75%, AND A MINOR PROPORTION OF A DEPRESSOR FOR PHOSPHATE ROCK, (C) WHICH DEPRESSOR IS A REACTION PRODUCT OBTAINED BY (1) FIRST REACTING TALL OIL AND AN OXYALKYLATED POLYETHYLENEPOLYAMINE, SAID REACTING INCLUDING A REACTION TEMPERATURE BETWEEN 270* AND 300*C., THE MOLAL PROPORTION OF OXYALKYLATED POLYAMINE TO TALL OIL BEING BETWEEN ABOUT 0.6:1 AND 0.8:1, THE OXYALKYLATED POLYAMINE BEING DERIVED BY REACTING THE POLYAMINE WITH A MATERIAL SELECTED FROM THE CLASS CONSISTING OF ETHYLENE OXIDE AND PROPYLENE AND ETHYLENE OXIDES, USING NOT MORE THAN ABOUT 2 MOLS OF TOTAL ALKYLENE OXIDE FOR EACH MOL OF POLYAMINE; AND THEN REACTING SUCH TALL OIL-OXYALKYLATED POLYETHYLENEPOLYAMINE REACTION PRODUCT WITH DICHLOROETHYLETHER, THE MOLAL PROPORTION OF DICHLOROETHYLETHER TO TALL OIL BEING BETWEEN ABOUT 0.25:1 AND 1:1; AND (II) PARTIAL NEUTRALIZATION PRODUCTS THEREOF.