CA1246833A - Hydrous aluminium oxide containing substantially pseudobohmite, a process for producing same and the use thereof - Google Patents
Hydrous aluminium oxide containing substantially pseudobohmite, a process for producing same and the use thereofInfo
- Publication number
- CA1246833A CA1246833A CA000441659A CA441659A CA1246833A CA 1246833 A CA1246833 A CA 1246833A CA 000441659 A CA000441659 A CA 000441659A CA 441659 A CA441659 A CA 441659A CA 1246833 A CA1246833 A CA 1246833A
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/02—Boron or aluminium; Oxides or hydroxides thereof
- B01J21/04—Alumina
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/34—Preparation of aluminium hydroxide by precipitation from solutions containing aluminium salts
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
Abstract
ABSTRACT OF THE DISCLOSURE
The present invention provides hydrous aluminium oxide which contains substantially pseudobohmite has less than 400 p.p.m. of Na2O, less than 2% by weight of sulphate, a peptization degree of less than 60 minutes and a specific surface area of 200 to 400 sq m per gram. It is produced by allowing aluminium-sulphate solution and sodium-aluminate solution to flow simultaneously into a water reciever such that during the precipitation a constant pH value of <5 is maintained. The pH value is then shifted into the alkaline range by further addition of sodium-aluminate liquor. The precipitation product is aged, filtered off, washed and dried. The hydrous aluminium oxide can be used as a catalyst.
The present invention provides hydrous aluminium oxide which contains substantially pseudobohmite has less than 400 p.p.m. of Na2O, less than 2% by weight of sulphate, a peptization degree of less than 60 minutes and a specific surface area of 200 to 400 sq m per gram. It is produced by allowing aluminium-sulphate solution and sodium-aluminate solution to flow simultaneously into a water reciever such that during the precipitation a constant pH value of <5 is maintained. The pH value is then shifted into the alkaline range by further addition of sodium-aluminate liquor. The precipitation product is aged, filtered off, washed and dried. The hydrous aluminium oxide can be used as a catalyst.
Description
~2~6833 The present invention relates to hydrous ~luminium oxide containing substantially pseudobo~mite, a p~ocess for producin~ same and the use thereo~.
Pseudobohmite is an aluminium oxide hydrate modifi-cation which is frequently used as a catalyst, catalyst support, filler and binder because of its large surface area, quality of pores, dispersibility and its binding power.
The production of pseudob`ohmite from aluminium-sul-phate solution is disclosed for example in US Patent ~o.
10 4,297,325, US Patent No. 4,154,812 and German Auslegeschrift No. 2,24~,022. In these processes either long washing and aging times are required or no gellable product is obtained, i.e., the peptization index is >> 60 minutes.
The present invention provides a hydrous aluminium oxide, containing substantially pseudobohmite which contains less than 400 p.p.m. preferably less than 200 p.p.m. of sodium oxide and less than 2% by weight, preferably 1~ by weight of sulphate, computed as SO4, and has a peptization index of less than 60 minutes, preferably less than 10 minutes and a specific surface area of 200 to 400 sq m per gram.
The sodi~lm oxide content is determined by conven-tional analytical methods, as for example, gravimetric deter-mination via BaS~.
The degree of peptization i.e. the peptization index is determined by means ofthe method according to US Patent No 4,297,325.
The specific surface area is determined on the area meter by the conventional method acc~rding to DIN 66132.
The present invention also provides a process for producing the hydrous aluminium oxide containing substantiall~ pseudo-bohmite, which contains less than 40Q p.p,m., preferably less than 200 p.p.m. o~ sodium oxide ~nd less than 2% b~ weight, ~46~33 preferably less tllan 1~ by weight o~ sulphate, computed as SO4, and has a peptization index of less than 60 minutes, prefexably less than 10 minutes, and a specific surface area of200 to 400 sq m per gram in which process an a~ueous aluminium-sulphate solution having a pH value of 3.0 to 2.6, preferably 2.8, and an A12O3 content of 70 to 105 g per litre (5.8 to 8.0% by weight~ is heated to a temperature of 50 to 90C, preferably 60C and aqueous sodium aluminate solution having a content of 120 to 265 g of Na2O per litre (10 to 18.8~ by weight) and 70 to 225 g of A12O3 per litre (5.9 to 15.9~ by weight), preferably 220 g of `.~a2O per litre (16.3%
by weight) and 160 g of A12O3 per litre (11.9% by weight), is heated to a temperature of 50 to 90C, preferably 60C, that thereafter the two solutions are allowed to flow simul-taneously into a water receiver having a temperature of 50 to 90C, preferably 60C, such that during the precipitation the reaction mixture has a constant pH value of less than 5, preferably less than 4 and after the precipitation the pH
value of the reaction mixture is shifted into the alkaline range, preferably higher than 8, by further addition of sodium-aluminate liquor having the same concentration, the - reaction mixture is subjected to aging 3.1 to 20 hours, preferably for 5 to 18 hours at a temperature of 50 to 90C, preferably 80C, alld the precipitate is filtered off, washed, dried and, when required subjected to an ion exchange.
The aluminium-sulphate and sodium-aluminate solutions can be produced b~- dissolving the corresponding salts.
The aluminium sulphate solution can also be produced by reacting aluminium oxide with sulphuric acid and the sodium-aluminate solution can be produced b~ reacting it with a solution of caustic soda.
For example, light hydrate ~58 to 65~ b~ weight), ~2~6~
pseudoboh~ite and particularly moist h~drate (57 to 58% by weight) can be used as aluminium oxide.
In a preferred embodiment of the present invention the precipitation product is aged at a pH value of 8.5 to 9.
The aluminium oxide according to the present invention has advantageously a low content of ~a~O. Despite the relatively short aging time the gelling power is very high.
The process according to the present invention will be further illustrated by way of the following Exammples.
Examples In the Examples 1 to 8 listed in Table 1 an aluminium-sulphate solution having a pH value of 2.8 and a content of 75 to 97 g of A12O3 per litr~ is produced with aqueous sul-phuric acid starting from a technical moist hydrate having a content of 57.5% by weight of A12O3. The two solutions are heated to the precipitation temperature and simultaneously passed into a water receiver having the same temperature.
The desired pH value is kept constant during the precipitation.
The precipitation suspension obtained is subjected to aging under constant conditions.
The product obtained is filtered off and washed with water.
In the Examples 1 to 6 the filter cake is redispersed with water to a suspension having a content of 11~ by weight of A12O3 and the suspension is spray-dried.
In the Examples 7 and 8 the filter cake is dried for 4 to 5 hours at 105C and then ground in a pinned disc mill.
The important parameters and the product data obtained are listed in Table 1.
:~Z46~333 u '~ ~;' L~ O
~ ~ ~ ~ ~ r~ o .,, V U~
a U~
O
~r ~ n ~ ~ ~ ~ ~ ~ u~
Oo\ ~cr~ ....... .
U~ O O O O O O' O
0 N~ ~ V V V V V
U
O o~ ~ ) ~ ~ ~
O ~ ~~ ~ ~ I~ CO CO
S-l 11~ O O ~I I~ If) ') ~I t`~ C~ O
Z o o o o o ~ I O O
O O O O O O O O O O
~ ~ ~1 ~ ~ ~ ~ ~ U~ U~
U O O O O O O O O O O
O ~ ~ co oo co co ~ C~
O O O O O S~
.~ Lf~ O O . . O O
~ X O O O O O
rd o~
.,, X
~ o o o o o o o o o o .~ o ~ ~ ~
N
.
~ a~
~ ~ ~ r u) W r~
E~ ~
~6~33 The rheological p~operties of pseudob~h~ite are characterized by the peptiz~tion index (PI~, which is determined according to the ~ollowing test directions:
A 10~ b~ weight suspension (relative to A1203) is mixed with a 90% formic acid in the ratio of 100:1. The pep-tization index is the time in minutes which the acidified sus-pension requires to attain a viscosity of at least 5000 cps.
Because of its rheological properties pseudobo~nmite is an excellent binder. It imparts the desired abrasion resistance to the most varied end products such as FCC catalysts or endless sanding belts. The peptization index (PI), which is determined according to the standard directions described, serves as a criterion of the binding strength. Accordingly a low index means a rapidly peptizable product having good binding power.
When the componentS (sodium-aluminate liquid/aluninium-sulphate) are passed simultaneously into a water receiver, then the flow ratio determines the pH value of the product suspension.
A comparison of the examples shows the effect of this pre-cipitation-pH value on the peptizability of the product: Under otherwise identical conditions the pseudobohmite samples pre-cipitated at pH 4 have the best peptizability (PI = 1 minute).
The higher tne pH value selected for the precipitation the more will the peptizability decrease.
Since, as is well known, high temperatures accelerate the formation of aluminium oxide trihydrates in strongly alkaline media, care is taken during the precipitation that the pH
value of the suspension increasingly adjusts up to the desired final value. Pure pseudobo~mite is thus obtained in all the tests. Depending ~n the test conditions (p~, temperature, aging time the samples diffex merely by the ae~ree of crystal-linity, paxticularly by the crystal size, which can be deter-mined by X-ray photo~raphy.
~L29L~33 Tile specif.ic surface areas are determined in the ~rea meter after dr~ing the samples over ni~ht at 100C and then rinsing them for 20 minutes at 150C with nitrogen (DIN 66 132).
After the precipitation the suspension is aged at various pH ~7alues while adding sodium aluminate. A distinct gradation could be determined:
-p~ = 8: Allthe tests resulted in nonpeptizable products.
-pH = 8.5-90: The peptizablity of the pseudobo~,lite is enforced only by supporting factors (high temperatures, strictly maintaining the precipitation conditions).
-pH = 9.5-lO.O:In this range pseudob'ohmite is obtained with the desired rheological properties.
In pseudobo~mite sodium as an impurity causes unde-sirable effects in many catalytic reactions. Therefore, as support material the pseudobohmite must have a high degree of purity. As is known the isoelectric point for pseudobohmite lies at pH- 9.5. In more strongly alkaline ranges the material adsorbs sodium ions from the solution to an ever increasing extent.
The results of the chemical analysis confirm that upon aging in strongly alkaline media (pH >9.5) the pseudobohmite product always has a relatively high Na2O content.
The discussion of the rheological properties has shown that even in the pH range of 8.5-9.0 peptizable products can be produced under strictly controlled conditions. By selecting the suitable boundary conditions we actually succeeded in produc-ing pseudoboShmites which are low in sodium and at the same time easily dispersible.
Comparision_Example 1 The example according to US Patent No. 4,154,812, columns 2~, 30 and 31 is adjusted. The concentration of the A12lSO4)3 solution is approximatel~ 8% by weight (as A12O3).
t:~3 The concentration of the sodium aluminate li~uor ~d = 1.46 g per cu ~) is 336 g of Na2O per litre and 236 g of A12O3 per litre, in other words 23% by weight of Na2O and 16.2% by weight of A12O3.
1.6 litres of water are put into a round-necked flask at 70C and 2.5 ml of the aluminium sulphate solution are added.
The pH value of this mixture is thus reduced to 3.1.
Fi~e minutes after this seeding the aluminium-sul-phate and sodium-aluminate solutions, which had been preneated to 65C, are simultaneously dosed in such that the pH value of the suspension remains constant at 7.4.
During the entire reaction the temperature of the mix-ture is maintained at 75C. After a consumption of 0.9 litre the flow of aluminium sulphate is interrupted and the final pH value is adjusted to 10 by adding further 50 ml of aluminate liquor within one minute. The total consumption of aluminate liquor is 600 ml.
On reaching the final pH value the suspension is further stirred for 30 minutes at the same temperature (75C), then filtered with suction while hot and washed until it is free from sulphate.
The results are evident from Table 2.
Comparis~n Example 2 The procedure according to the claims of the German Auslegeschrift 2,249,022 is followed. The concentration of the A12(SO4) solution is 97~0 g of A12O3 per litre. The con-centration of the sodium-aluminate liquor is 166.6 g of A12O3 per litre and 241.7 g of Na2O per litre.
81Q litres o~ water (8Q~C~ are put into ~ 2 cu m 3~ precipitating vat and 600 litres of the aluminiu~-sulphate solution~, preheated to 8QQC, are dosed in. The p~ value o the Suspens~on is adjusted to lQ with 5Q0 litres of NaAlO2 ~Zg~6~33 (80C). After an a~ing time of 2 hours at the same temperature (80C~ the suspension IS fil~ered and washed until it is free from sulphate. The product is further processed in the usual manner and teste~. The xesults have been listed in Table 2.
~;~4~3 ~3 ~
H E~ O O 11~
~D ~
A A
o .,, o~ ~ Ln ,. U~ ~ o ~
~ V ~ ~
~ ." o U~
g '~ ~
rl ~ 0~
~0,~ t~ ,~
cJ z o`P o O a~
., ~^ In a ~ S ~
.._ 0 3 a~ ~o h ~
~
r~ _ a~ O o tJl Q,~o~ I_ '~ .
u~ rn
Pseudobohmite is an aluminium oxide hydrate modifi-cation which is frequently used as a catalyst, catalyst support, filler and binder because of its large surface area, quality of pores, dispersibility and its binding power.
The production of pseudob`ohmite from aluminium-sul-phate solution is disclosed for example in US Patent ~o.
10 4,297,325, US Patent No. 4,154,812 and German Auslegeschrift No. 2,24~,022. In these processes either long washing and aging times are required or no gellable product is obtained, i.e., the peptization index is >> 60 minutes.
The present invention provides a hydrous aluminium oxide, containing substantially pseudobohmite which contains less than 400 p.p.m. preferably less than 200 p.p.m. of sodium oxide and less than 2% by weight, preferably 1~ by weight of sulphate, computed as SO4, and has a peptization index of less than 60 minutes, preferably less than 10 minutes and a specific surface area of 200 to 400 sq m per gram.
The sodi~lm oxide content is determined by conven-tional analytical methods, as for example, gravimetric deter-mination via BaS~.
The degree of peptization i.e. the peptization index is determined by means ofthe method according to US Patent No 4,297,325.
The specific surface area is determined on the area meter by the conventional method acc~rding to DIN 66132.
The present invention also provides a process for producing the hydrous aluminium oxide containing substantiall~ pseudo-bohmite, which contains less than 40Q p.p,m., preferably less than 200 p.p.m. o~ sodium oxide ~nd less than 2% b~ weight, ~46~33 preferably less tllan 1~ by weight o~ sulphate, computed as SO4, and has a peptization index of less than 60 minutes, prefexably less than 10 minutes, and a specific surface area of200 to 400 sq m per gram in which process an a~ueous aluminium-sulphate solution having a pH value of 3.0 to 2.6, preferably 2.8, and an A12O3 content of 70 to 105 g per litre (5.8 to 8.0% by weight~ is heated to a temperature of 50 to 90C, preferably 60C and aqueous sodium aluminate solution having a content of 120 to 265 g of Na2O per litre (10 to 18.8~ by weight) and 70 to 225 g of A12O3 per litre (5.9 to 15.9~ by weight), preferably 220 g of `.~a2O per litre (16.3%
by weight) and 160 g of A12O3 per litre (11.9% by weight), is heated to a temperature of 50 to 90C, preferably 60C, that thereafter the two solutions are allowed to flow simul-taneously into a water receiver having a temperature of 50 to 90C, preferably 60C, such that during the precipitation the reaction mixture has a constant pH value of less than 5, preferably less than 4 and after the precipitation the pH
value of the reaction mixture is shifted into the alkaline range, preferably higher than 8, by further addition of sodium-aluminate liquor having the same concentration, the - reaction mixture is subjected to aging 3.1 to 20 hours, preferably for 5 to 18 hours at a temperature of 50 to 90C, preferably 80C, alld the precipitate is filtered off, washed, dried and, when required subjected to an ion exchange.
The aluminium-sulphate and sodium-aluminate solutions can be produced b~- dissolving the corresponding salts.
The aluminium sulphate solution can also be produced by reacting aluminium oxide with sulphuric acid and the sodium-aluminate solution can be produced b~ reacting it with a solution of caustic soda.
For example, light hydrate ~58 to 65~ b~ weight), ~2~6~
pseudoboh~ite and particularly moist h~drate (57 to 58% by weight) can be used as aluminium oxide.
In a preferred embodiment of the present invention the precipitation product is aged at a pH value of 8.5 to 9.
The aluminium oxide according to the present invention has advantageously a low content of ~a~O. Despite the relatively short aging time the gelling power is very high.
The process according to the present invention will be further illustrated by way of the following Exammples.
Examples In the Examples 1 to 8 listed in Table 1 an aluminium-sulphate solution having a pH value of 2.8 and a content of 75 to 97 g of A12O3 per litr~ is produced with aqueous sul-phuric acid starting from a technical moist hydrate having a content of 57.5% by weight of A12O3. The two solutions are heated to the precipitation temperature and simultaneously passed into a water receiver having the same temperature.
The desired pH value is kept constant during the precipitation.
The precipitation suspension obtained is subjected to aging under constant conditions.
The product obtained is filtered off and washed with water.
In the Examples 1 to 6 the filter cake is redispersed with water to a suspension having a content of 11~ by weight of A12O3 and the suspension is spray-dried.
In the Examples 7 and 8 the filter cake is dried for 4 to 5 hours at 105C and then ground in a pinned disc mill.
The important parameters and the product data obtained are listed in Table 1.
:~Z46~333 u '~ ~;' L~ O
~ ~ ~ ~ ~ r~ o .,, V U~
a U~
O
~r ~ n ~ ~ ~ ~ ~ ~ u~
Oo\ ~cr~ ....... .
U~ O O O O O O' O
0 N~ ~ V V V V V
U
O o~ ~ ) ~ ~ ~
O ~ ~~ ~ ~ I~ CO CO
S-l 11~ O O ~I I~ If) ') ~I t`~ C~ O
Z o o o o o ~ I O O
O O O O O O O O O O
~ ~ ~1 ~ ~ ~ ~ ~ U~ U~
U O O O O O O O O O O
O ~ ~ co oo co co ~ C~
O O O O O S~
.~ Lf~ O O . . O O
~ X O O O O O
rd o~
.,, X
~ o o o o o o o o o o .~ o ~ ~ ~
N
.
~ a~
~ ~ ~ r u) W r~
E~ ~
~6~33 The rheological p~operties of pseudob~h~ite are characterized by the peptiz~tion index (PI~, which is determined according to the ~ollowing test directions:
A 10~ b~ weight suspension (relative to A1203) is mixed with a 90% formic acid in the ratio of 100:1. The pep-tization index is the time in minutes which the acidified sus-pension requires to attain a viscosity of at least 5000 cps.
Because of its rheological properties pseudobo~nmite is an excellent binder. It imparts the desired abrasion resistance to the most varied end products such as FCC catalysts or endless sanding belts. The peptization index (PI), which is determined according to the standard directions described, serves as a criterion of the binding strength. Accordingly a low index means a rapidly peptizable product having good binding power.
When the componentS (sodium-aluminate liquid/aluninium-sulphate) are passed simultaneously into a water receiver, then the flow ratio determines the pH value of the product suspension.
A comparison of the examples shows the effect of this pre-cipitation-pH value on the peptizability of the product: Under otherwise identical conditions the pseudobohmite samples pre-cipitated at pH 4 have the best peptizability (PI = 1 minute).
The higher tne pH value selected for the precipitation the more will the peptizability decrease.
Since, as is well known, high temperatures accelerate the formation of aluminium oxide trihydrates in strongly alkaline media, care is taken during the precipitation that the pH
value of the suspension increasingly adjusts up to the desired final value. Pure pseudobo~mite is thus obtained in all the tests. Depending ~n the test conditions (p~, temperature, aging time the samples diffex merely by the ae~ree of crystal-linity, paxticularly by the crystal size, which can be deter-mined by X-ray photo~raphy.
~L29L~33 Tile specif.ic surface areas are determined in the ~rea meter after dr~ing the samples over ni~ht at 100C and then rinsing them for 20 minutes at 150C with nitrogen (DIN 66 132).
After the precipitation the suspension is aged at various pH ~7alues while adding sodium aluminate. A distinct gradation could be determined:
-p~ = 8: Allthe tests resulted in nonpeptizable products.
-pH = 8.5-90: The peptizablity of the pseudobo~,lite is enforced only by supporting factors (high temperatures, strictly maintaining the precipitation conditions).
-pH = 9.5-lO.O:In this range pseudob'ohmite is obtained with the desired rheological properties.
In pseudobo~mite sodium as an impurity causes unde-sirable effects in many catalytic reactions. Therefore, as support material the pseudobohmite must have a high degree of purity. As is known the isoelectric point for pseudobohmite lies at pH- 9.5. In more strongly alkaline ranges the material adsorbs sodium ions from the solution to an ever increasing extent.
The results of the chemical analysis confirm that upon aging in strongly alkaline media (pH >9.5) the pseudobohmite product always has a relatively high Na2O content.
The discussion of the rheological properties has shown that even in the pH range of 8.5-9.0 peptizable products can be produced under strictly controlled conditions. By selecting the suitable boundary conditions we actually succeeded in produc-ing pseudoboShmites which are low in sodium and at the same time easily dispersible.
Comparision_Example 1 The example according to US Patent No. 4,154,812, columns 2~, 30 and 31 is adjusted. The concentration of the A12lSO4)3 solution is approximatel~ 8% by weight (as A12O3).
t:~3 The concentration of the sodium aluminate li~uor ~d = 1.46 g per cu ~) is 336 g of Na2O per litre and 236 g of A12O3 per litre, in other words 23% by weight of Na2O and 16.2% by weight of A12O3.
1.6 litres of water are put into a round-necked flask at 70C and 2.5 ml of the aluminium sulphate solution are added.
The pH value of this mixture is thus reduced to 3.1.
Fi~e minutes after this seeding the aluminium-sul-phate and sodium-aluminate solutions, which had been preneated to 65C, are simultaneously dosed in such that the pH value of the suspension remains constant at 7.4.
During the entire reaction the temperature of the mix-ture is maintained at 75C. After a consumption of 0.9 litre the flow of aluminium sulphate is interrupted and the final pH value is adjusted to 10 by adding further 50 ml of aluminate liquor within one minute. The total consumption of aluminate liquor is 600 ml.
On reaching the final pH value the suspension is further stirred for 30 minutes at the same temperature (75C), then filtered with suction while hot and washed until it is free from sulphate.
The results are evident from Table 2.
Comparis~n Example 2 The procedure according to the claims of the German Auslegeschrift 2,249,022 is followed. The concentration of the A12(SO4) solution is 97~0 g of A12O3 per litre. The con-centration of the sodium-aluminate liquor is 166.6 g of A12O3 per litre and 241.7 g of Na2O per litre.
81Q litres o~ water (8Q~C~ are put into ~ 2 cu m 3~ precipitating vat and 600 litres of the aluminiu~-sulphate solution~, preheated to 8QQC, are dosed in. The p~ value o the Suspens~on is adjusted to lQ with 5Q0 litres of NaAlO2 ~Zg~6~33 (80C). After an a~ing time of 2 hours at the same temperature (80C~ the suspension IS fil~ered and washed until it is free from sulphate. The product is further processed in the usual manner and teste~. The xesults have been listed in Table 2.
~;~4~3 ~3 ~
H E~ O O 11~
~D ~
A A
o .,, o~ ~ Ln ,. U~ ~ o ~
~ V ~ ~
~ ." o U~
g '~ ~
rl ~ 0~
~0,~ t~ ,~
cJ z o`P o O a~
., ~^ In a ~ S ~
.._ 0 3 a~ ~o h ~
~
r~ _ a~ O o tJl Q,~o~ I_ '~ .
u~ rn
2 0 Q' a~
~_ ~o O U~ Q
CO 1`
O ~---ri ~
a) G) tn P~
'U u~ ,Q) Q~ ~ ~
~: ~ n ~ ,1 U . r~
~ ~ r ,~
'~
3o q! E~o ~
~_ ~o O U~ Q
CO 1`
O ~---ri ~
a) G) tn P~
'U u~ ,Q) Q~ ~ ~
~: ~ n ~ ,1 U . r~
~ ~ r ,~
'~
3o q! E~o ~
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for producing the hydrous aluminium oxide containing substantially pseudobohmite, less than 400 p.p.m., and less than 2% by weight, computed as SO4, and having a peptization index of less than 60 minutes and a specific surface area of 200 to 400 sq m per gram, in which process an aqueous aluminium-sulphate solution having a pH value of 3.0 to 2.6 and an Al2O3 content of 70 to 105 g per litre (5.8 to 8.0% by weight) is heated to a temperature of 50 to 90°C and an aqueous sodium-aluminate solution having a content of 120 to 265 g of Na2O per litre (10 to 18% by weight) and 70 to 2.25 g of Al2O3 per litre (5.9 to 15.9% by weight) is heated to a temperature of 50 to 90°C, the two heated solutions being allowed to flow simultaneously into a water receiver having a temperature of 50 to 90°C such that during the precipitation the reaction mixture has a constant pH value of less than 5 and after the precipitation the pH value of the reaction mixture is shifted into the alkaline range by further addition of sodium-aluminate liquor having the same concentration, the reaction mixture is subjected to aging for 3.1 to 20 hours at a temperature of 50 to 90°C and the precipitation is filtered off and dried.
2. A process as claimed in claim 1, in which the aqueous aluminium-sulphate solution has a pH of about 2.8.
3. A process as claimed in claim 1 or 2, in which the acqueous solutions of aluminium-sulphate is heated to a temperature of about 60°C.
4. A process as claimed in claim 2, in which the sodium-aluminate solution contains about 220 litre of Na2O and about 160 g/litre of Al2O3 and is heated to a temperature of about 60°C.
5. A process as claimed in claim 2 or 4, in which the solutions are allowed to flow into a water receiver at a temperature of about 60°C.
6. A process as claimed in claim 1,2 or 4, in which the pH of the reaction mixture is less than 4 and after precipi-tation the pH value of the mixture is shifted to be above 8,
7. A process as claimed in claim 1,2 or 4, in which the reaction mixture is aged for 5 to 18 hours at about 80°C.
8. A process as claimed in claim 1,2 or 4, in which the filtered precipitation is subjected to one exchange.
9. A process as claimed in claim 1, in which the precipitation product is aged at a pH value of 8.5 to 9.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19823243193 DE3243193A1 (en) | 1982-11-23 | 1982-11-23 | WATER-BASED ALUMINUM OXIDE, CONTAINING IN ESSENTIAL PSEUDOBOEHMIT, METHOD FOR THE PRODUCTION AND USE THEREOF |
| DEP3243193.7 | 1982-11-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1246833A true CA1246833A (en) | 1988-12-20 |
Family
ID=6178752
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000441659A Expired CA1246833A (en) | 1982-11-23 | 1983-11-22 | Hydrous aluminium oxide containing substantially pseudobohmite, a process for producing same and the use thereof |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0113796B1 (en) |
| CA (1) | CA1246833A (en) |
| DE (2) | DE3243193A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5250476A (en) * | 1991-04-30 | 1993-10-05 | Haldor Topsoe A/S | Ceramic binder and use thereof |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| MX170194B (en) * | 1986-05-05 | 1993-08-11 | Petrolfex Ind E Comercio S A | PROCEDURE FOR THE PRODUCTION OF HYDRATED ALUMINUMS |
| DE3801270A1 (en) * | 1988-01-19 | 1989-07-27 | Degussa | ZIRC-Doped PSEUDOBOEHMIT, METHOD FOR THE PRODUCTION THEREOF AND APPLICATION |
| US6713428B1 (en) | 1998-07-06 | 2004-03-30 | Instuit Francais Du Petrole | Dispersible aluminium hydrate, method for preparing same and use for preparing catalysts |
| FR2780716B1 (en) * | 1998-07-06 | 2000-12-22 | Rhodia Chimie Sa | NOVEL DISPERSIBLE ALUMINUM HYDRATE, ITS PREPARATION METHOD AND ITS USE FOR THE PREPARATION OF CATALYSTS |
| FR2793237B1 (en) * | 1999-04-16 | 2002-05-24 | Inst Francais Du Petrole | PROCESS FOR THE PREPARATION OF AN ALUMINUM HYDRATE FOR USE AS A CATALYST SUPPORT |
| CN1088397C (en) * | 1998-09-17 | 2002-07-31 | 中国石油化工集团公司 | Preparation of alumina suitable for being used as catalyst carrier for hydrgenating heavy oil |
| CN1089275C (en) * | 1998-09-17 | 2002-08-21 | 中国石油化工集团公司 | Preparation of pseudo-thin diasphore and gamma-alumina |
| WO2001012554A1 (en) * | 1999-08-11 | 2001-02-22 | Akzo Nobel N.V. | Process for the preparation of quasi-crystalline boehmites |
| FR2874837B1 (en) | 2004-09-08 | 2007-02-23 | Inst Francais Du Petrole | DOPE CATALYST AND IMPROVED PROCESS FOR TREATING HYDROCARBON LOADS |
| FR2926812B1 (en) | 2008-01-28 | 2010-04-30 | Inst Francais Du Petrole | OLEFIN OLIGOMERIZATION METHOD USING A SILICA-ALUMINATED CATALYST |
| FR2932101B1 (en) * | 2008-06-06 | 2011-05-13 | Inst Francais Du Petrole | USE OF SULFUR SUPPORTS FOR CATALYTIC REFORMING. |
| CN101920978B (en) * | 2010-06-25 | 2012-12-12 | 山西铝厂科技化工公司 | Method for producing boehmite by using washing liquor |
| FR3075777A1 (en) * | 2017-12-22 | 2019-06-28 | Rhodia Operations | POROUS ALUMINUM HYDRATE |
| CN111634932B (en) * | 2020-05-28 | 2022-08-05 | 中国铝业股份有限公司 | System for continuously producing pseudo-boehmite and use method thereof |
| CN112520768B (en) * | 2020-12-13 | 2023-04-18 | 中海油天津化工研究设计院有限公司 | Preparation method of rod-shaped high-purity pseudoboehmite |
| CN115724448A (en) * | 2022-11-21 | 2023-03-03 | 岳阳慧璟新材料科技有限公司 | Process method for preparing pseudo-boehmite by continuous carbonization |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2988520A (en) * | 1955-11-09 | 1961-06-13 | Nalco Chemical Co | Alumina compositions and process for the preparation thereof |
| GB1076450A (en) * | 1963-12-06 | 1967-07-19 | Grace W R & Co | Improvements relating to the production of alumina gels |
| DE2249022C3 (en) * | 1972-10-06 | 1982-04-15 | Laporte Industries Ltd., London | Process for the production of hydrous alumina and its use |
| US4371513A (en) * | 1977-03-25 | 1983-02-01 | W. R. Grace & Co. | Alumina compositions |
| US4332782A (en) * | 1980-07-28 | 1982-06-01 | Filtrol Corporation | Method of producing pseudoboehmite |
| US4297325A (en) * | 1980-12-08 | 1981-10-27 | Filtrol Corporation | Method of producing pseudoboehmite from aluminum salt solutions |
| FR2520722A1 (en) * | 1982-01-29 | 1983-08-05 | Rhone Poulenc Spec Chim | BOEHMITES AND PSEUDO- |
-
1982
- 1982-11-23 DE DE19823243193 patent/DE3243193A1/en not_active Withdrawn
-
1983
- 1983-07-16 EP EP83106997A patent/EP0113796B1/en not_active Expired
- 1983-07-16 DE DE8383106997T patent/DE3369114D1/en not_active Expired
- 1983-11-22 CA CA000441659A patent/CA1246833A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5250476A (en) * | 1991-04-30 | 1993-10-05 | Haldor Topsoe A/S | Ceramic binder and use thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3369114D1 (en) | 1987-02-19 |
| EP0113796B1 (en) | 1987-01-14 |
| EP0113796A1 (en) | 1984-07-25 |
| DE3243193A1 (en) | 1984-05-30 |
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