CA1047225A - Hydroxychlorides of aluminium and method - Google Patents
Hydroxychlorides of aluminium and methodInfo
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- CA1047225A CA1047225A CA211,359A CA211359A CA1047225A CA 1047225 A CA1047225 A CA 1047225A CA 211359 A CA211359 A CA 211359A CA 1047225 A CA1047225 A CA 1047225A
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- Prior art keywords
- alumina
- aluminium
- solution
- active
- hydroxychlorides
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- 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
- C01F7/48—Halides, with or without other cations besides aluminium
- C01F7/56—Chlorides
- C01F7/57—Basic aluminium chlorides, e.g. polyaluminium chlorides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- 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
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
- Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Separation Of Suspended Particles By Flocculating Agents (AREA)
Abstract
HYDROXYCHLORIDES OF ALUMINIUM AND METHOD
Abstract of the Disclosure The preparation of a material consisting essentially or largely of aluminium hydroxychlorides having the general formula Al2 (OH)xCl6-X' in which X is a value up to 5 or more and obtained by reacting active alumina, secured by partial dehydration of hydrates of alumina, with hydrochloric acid or aluminium chloride in which the active alumina has a specific surface area of at least 200 m2/g.
Abstract of the Disclosure The preparation of a material consisting essentially or largely of aluminium hydroxychlorides having the general formula Al2 (OH)xCl6-X' in which X is a value up to 5 or more and obtained by reacting active alumina, secured by partial dehydration of hydrates of alumina, with hydrochloric acid or aluminium chloride in which the active alumina has a specific surface area of at least 200 m2/g.
Description
~04l7~25 ~
This invention relates to products which are entirely or largely made up of hydroxychlorides of aluminium obtained from active alumina.
. Basic inorganic salts of trivalent metals, and more particularly hydroxychlorides of aluminium of the general formula A12 ~OH)xCl6 X~ are known to have various applications, especially in the fields of cosmetics, the treatment of water and mud, and the manufacture of catalyst carriers.
The various previously described methods of preparing aluminium hydroxychlorides comprise either making hydrochloric acid or aluminium chloride react with aluminium, or hydrolysing aluminium chloride, or dissolving hydrates or gels of alumina in aluminium chloride or hydrochloric acid.
Some of these methods have obvious economic drawbacks where metal-v~ lic aluminium is used, while most of the other methods have technical draw-, backs. These are due to the variation in the reactivity of the compounds used as the source of aluminium, which may lead to difficulties in reacting on the substance and to inconsistency in the properties of the products obtained.
, . . i According to the invention, there is provided a method for pre-,, paring products consisting essentially of aluminium hydroxychlorides in homo-r geneous solution in which the aluminium hydroxychlorides have the general for-mula A12 (OH)xCl6 X~ in which X is a value of 3 to more than 5 but less than 6, comprising reacting activated alumina with an aqueous solution of a com-pound selected from the group consisting of aluminium chloride, hydrochloric ','~r acid and mixtures thereof at a temperature of 60F to reflux temperature with vigorous agitation to provide said aluminium hydroxychloride in homogeneous ..~.
~' solution, the activated alumina consisting of the product of the partial de-hydration of hydrates of alumina in a stream of hot gases to less than 2 . moles combined water and a specific surface area of at least 200 m2/g.
:; ~
.
;.
.",' qF
., ' -- 1 --'' ' -. .
10472~5 complex products consisting chiefly of aluminium hydrochlorides may be obtained by adding, to the partially dehydrated alumina, compounds which will provide other anionic, e.g. polyvalent radicals and various other metals, such as alkali and/or alka-line earth metals. Moreover, these more complex products can also be obtained by adding the desired compounds to previously ~-prepared aluminium hydroxychlorides.
Products obtained by partially dehydrating hydrates of alumina, and commonly réferred to as active aluminas, are known to be used very widelyO particularly in adsorption and in catalysis. It has now been found that this activity, due to the specific sur~ace area which may be several hundreds of m2/g, enables the aluminas to be dissolved gradually and evenly in solutions of hydrochloric acid and/or aluminium chloride without the same disadvantages as are encountered with hydrates of alum-ina, even if freshly prepared; these drawbacks often consist of the fact that gelled products are obtained, and clear solutions of hydroxychlorides can be separated from them only with diffi-culty.
The previously used term "aluminium chloride" naturally covers various soluble compositions containing chlorine and aluminium, where the ratio of aluminium to chlorine can thus be varied by reaction on the active alumina; the term "aluminium chloride" particularly includes hydroxychlorides of aluminium already obtained from active aluminas.
Active aluminas, according to the invention, may have a specific surface area which varies within broad limits but which must preferably be fairly high if fairly large X values are desired. ~oreover, the aluminas may be used as appropriate, 3 either in powder form or in the form of agglomerated granulaF
., .
~2-.. ' ~ - .
~047~25 ?
substancesO The use of the latter may e.g. make the aluminas easier to react on by improving the circulation o~ liquids be-tween the granules; this is particularly important for large scale manufacture by continuous processes.
Active aluminas, which are particularly suitable, can be ob~ained by partially dehydrating hydrargillite, particularly :,, by dehydrating the hydrargillite obtained in large quantities by the Bayer process, and by dehydrating various alumina gels The æpecific surface areas of the active aluminas thus obtained may vary widely, ~ut for the method of the invention should prefer-ably be over 200 to 250 m2/g and even over 350 m2/g when the active aluminas are made from gels. Such aluminas are in powder form and can be used in the method of the invention either with-out further treatment or after being crushed to adjust the dis-tribution of grain sizes, or in the form of agglomerated sub-stances, particularly pellets obtained from a rotary granulator.
~, The reactivity of the active aluminas is such that the ;~ temperature of the reaction medium may rise spontaneously and -i' will then encourage the aluminas to dissolve in the solutions of hydrochloric acid and/or aluminium chloride. However, it is sometimes advisable to heat the solutions somewhat, e.g. to ` temperatures of about 60 to 90C, and under these conditions, the temperature may rise to over 100C when the alumina has been added.
The temperature rise is also particularly helpful in dissolving preliminary compounds which provide other anionic radicals and other metals, when the intention is to obtain more complex products than hydroxychlorides of aluminium. In such cases it may be more advantageous to carry out the reactions in 3 an autoclave, which will further facilitate the dissolving of ., ~3-. . .
.,~, 10~7225 the various substances. The dissolving process is not completed in one operation, and the non-dissolved pOTtiOn of the active alumina may be brought back into contact with a reacting solution with fresh active alumina added to it, and so on until all the alumina involved has been dissolved.
,~ According to the various operating conditions, it is possible to obtain aluminium hydroxychlorides in which X has variable values, which may more particularly be from 3 to 4, when the aim is to obtain products particularly designed for treating water and mud. Higher X values, which . 10 may be over 5, are suitable for products designed for the manufacture of catalyst carriers. -Finally, the products obtained according to the invention, which owing to the method of manufacture usually consist initially of solu-tions of various concentrations containing from 100 to 250 grams of alumina ~ , " A1203 per litre, may equally be put into the form of solid, powdered or granular products, obtained by known methods such as spraying.
Non-restrictive examples will now be given of the preparation of aluminium hydroxychlorides of various compositions, using active alu-; minas obtained from hydrargillite and from gel treated in streams of hot gases, the aluminas having various specific surface areas and being in powder form. An example is also given in which S04 ions are added to the ` reacting solution and finally, by way of comparison, an experiment is de-- scribed in which aluminium hydroxychloride is prepared by hydrochloric re-action on non-activated alumina gel.
Hydrargillite obtain by the BAYER process is partially de-hydrated in a stream of hot gases, to give an active . ~ - 4 -:
.
1047%25 alumina with a specific surface area of 312 m2/g. The alumina is in the form of a powder with the following distribution of .
graln slzes:
grains < 90~ 84% by weight grains < 58~ 50% by weight grains < 29,u 16% by weight 430 g of the alumina is stirred into a solution, heated to 85C, of 420 ml of 36% hydrochloric acid in 800 ml of water, the addition of the alumina taking thirty minutes. The temperature rises spontaneously to 103C. Agitation of the sus-pension ana reflux are maintained at this temperature for 16 hours. Then heating and agitation are terminated, the excess alumina is decanted and the liquid above it drawn off and cen-trifugedO This gives 0.80 litre of a 10186 dense solution of aluminium hydroxychloride with an X value of 3.93.
The excess alumina is put back into suspension in 800 ml of water and heated to 85C. 420 ml of 36% hydrochloric acid is added and the temperature rises to 103C. Reflux is main-tained for 2 hours at this temperature. 225 g of the same ac-~ 20 tive alumina is stirred in, in the course of 5 minutes, and - agitation and reflux are continued at this temperature for 22 hours. In the same way as before~ the excess alumina is s9par-ated from the liquid, which has a volume of 1.05 litre and a density of 1.18. The value of X is 3.53.
EX~MPLE 2 A powdered active alumina is again prepared from hydrar-gillite emanating from the BAyER process, by partial dehydration in a stream of hot gases but under less severe thermal conditions than those used to obtain the active alumina in the previous 3 example. m is alumina has a specific surface area of 285 m2/g ,', , _5_ ~0472Z5 and the following distribution of grain sizes:
grains ~ 90~ 84% by weight grains < 60~ 50% by weight grains < 25,u 16% by weight 248 kg of the alumina is stirred at 60 kg/h into a -reactor which is heated to 80C and which contains a solution made up of 300 litres of water and 300 kg of 36% hydrochloric acid. m e temperature rises spontaneously to 105C. Reflux `
and agitation are maintained for 10 hours at that temperature.
400 litres of a solution of aluminium hydroxychloride is separ-ated from the remaining alumina in the same way as in the pre-vious examples. m e solution has a density of 1.303 and an X
value of 3,5~.
e undissolved alumina, thus recovered, is put back into suspension in 300 litres of water and heated to 85C, and 250 litres of 36% hydrochloric acid is added. The temperature rises to 104C. After the reflux action has been maintained for 2 hours, 120 kg of the same active alumina is added in the course of 2 hours. Agitation and reflux are maintained at that temperature for 15 hours, after which the undissolved alumina ,. ...
is separated from 530 litres of a solution of aluminium hydroxy-- chloride with a density of 1.270 and an X value of 3.54.
Active alumina with a specific surface area of about -25 300 m2/g, obtained as indicated in example 1, is calcined to ;.:i ' reduce that area to 101 m2/g.
430 g of the alumina is introduced with agitation in the course of 10 minutes into a solution comprising 700 ml of water and 420 ml of 36% hydrochloric acid, heated to 90C.
3 The temperature rises spontaneously to 103C. Reflux and . .
, . .
.
agitation are maintained at that temperature for 22 hours. In the same way as in the previous examples, the undissolved alumina is then separated from 0.7 litre of a solution of aluminium hydroxychloride with a density of 1.150 and an X
; 5 value of 1.58.
If the results of these first three examples are com-pared one can see the effect of the specific surface area of the active aluminas used on the X values of the solutions of aluminium hydroxychloride obtained. In addition, examples 1 and 2 show that the aluminas can be totally dissolved by re-using the insoluble portions in a fresh orieration, and that this does not appreciably affect the value of X.
This example concerns the dissolving of active alumina ; 15 in aluminium chloride. 126 g of the same active alumina as was used in example 2 is stirred, in the course of 60 minutes, into a reactor heated to 80C and containing a solution of 216 g of anhydrous aluminium chloride AlC13 in 800 ml of water. The temperature rises to 103C. Heating under reflux is maintaine~
for 15 hours. By the same method as before, 0~8 litre of a solution of aluminium hydroxychloride is separated from the undissolved alumina. The solution has a density of 1.235 with an X value of 3.15. This example shows the great reactivity of ; active aluminas, even in relation to aluminium chloride in solu-tion, and the possibility of thus obtaining aluminium hydroxy-chlorides with large X values.
.
is example concerns a method of obtaining complex products by reaction with a mixture of HCl and H2SO4.
The reacting ll~uor is made up of 1526 ml of water, :
`:
~ -7-.
.
1047~25 14 ml of concentrated sulphuric acid and 374 ml of 36% hydro- -chloric acid. This solution is heated to 75C and 414 g of the alumina of example 1 is introduced with stirring over 40 minutes.
m e temperature rises to 102C. ~gitation, heating and reflux '~ 5 are maintained for 20 hours, then the undissolved alumina is separated, as indicated above, from 0.58 litre of a solution of aluminium hydroxychloride. The solution has a density of 1.270, contains 10.1 g/litre of SO4 and has an X value of 3.51.
EX~MPLE 6 i A substantially amorphous alumina gel is obtained by neutralising sodium aluminate with nitric acid at pH 8.5, while keeping the temperature below 35C. The freshly precipitated gel is agitated for 2 hoursO It is then filtered, washed and sprayed to reduce it to finely divided form and dried while keep-ing it in an amorphous state. It is activated by treatment in a stream of hot gases. The resulting alumina is in the form of a white powder with a specific surface area of 374 m2/g; it loses 10% by weight when heated to 1200C. Its x-ray diffraction diagram indicates an amorphous appearance with some traces of pseudoboehmite.
m e following are placed in an agitated 2 litre glass reactor:
, , .
-0.333 litre of a 36% solution of HCl -0.500 litre of purified water (eau permutée).
~
m is is all brought to reflux and 430 g of the alumina $; obtained as indicated abo~e is added in the course of 30 minutes.
After reacting for 7 hours at boiling point (100-101C) the reac-tion medium is cooled and a solution of the following formula is decanted:
~;
A1203 : 376g/1 , .
. . . .. . . .. . . .
'. . ' . :' ~ - :
: 104722S
Cl 2 : 131 . 3 g/l d : 1.40 ~, , pH : 2.7 m e empirical formula of the aluminium hydroxychlor-icle obtained is A12 (OH)5 Cl.
EX~MPLE 7 900 litres of a solution of basic aluminium chloride of the formula A12 (OH)2 88Cl30l2~ previously obtained by dissolving active alumina in hydrochloric acid, diluted with 1000 litres of purified water is placed in an agitated reactor ~ and brought to boiling point. m e reactor is made of glazed i steel with a capacity of 3 m3 and is equipped with a total reflux condensor. 700 kg of active alumina, having a specific surface area of 290 m2/g, obtained by partial dehydration of hydrargillite in a stream of hot gases, is added to the reflux.
All the ingredients are left to react for 18 hours at boiling temperature. After cooling and decanting, 1500 litres of a solution of density 1.22 and pH 4.0 is recovered. Each litre of the solution contains 205 g of alumina A1203 and 74.5 of chlorine; this substantially corresponds to the formula A12 (OH) 5 ~ 05 Clo 0 95 -; EX~MPLE 8 ' This is a comparative example and concerns the dis-solving of an alumina gel in aluminium chloride. An alumina gel is prepared by precipitating a solution of sodium aluminate, containing 230 g/litre of alumina A12`03, with 58% nitric acid at pH 8~5 and a temperature of 57Co m e gel obtained is `` washed, drained and filtered, then left to developO This gives a product which contains 12~55% by weight of alumina A1203.
1000 ml of a solution containing 167 g of aluminium chloride . .!
" _ 9_ '' ' : ' . ' ` " .
. , . : ' ' . . , ~ ' ' ` ' ' is heated to boiling point in a reactor and 1 ~g of the pre-viously prepared gel is gradually stirred in, The heating and reflux action are maintained for 15 hours, after which the liquid obtained is separated as before. It has a density of 1.25 and an X value of 2.74. However, if one tries to continue the reaction instead of separating the liquid, the alumina swells and absorbs the liquid and it becomes impossible to separate the liquid by filtration or centrifuging.
This is an example of the specificity of the behaviour -of active aluminas, which enable a seriPs of reactions to be carried out until they are completely dissolved, while at the same time reaching high X values.
. .
' ;
; 25 , .
.
.
.
This invention relates to products which are entirely or largely made up of hydroxychlorides of aluminium obtained from active alumina.
. Basic inorganic salts of trivalent metals, and more particularly hydroxychlorides of aluminium of the general formula A12 ~OH)xCl6 X~ are known to have various applications, especially in the fields of cosmetics, the treatment of water and mud, and the manufacture of catalyst carriers.
The various previously described methods of preparing aluminium hydroxychlorides comprise either making hydrochloric acid or aluminium chloride react with aluminium, or hydrolysing aluminium chloride, or dissolving hydrates or gels of alumina in aluminium chloride or hydrochloric acid.
Some of these methods have obvious economic drawbacks where metal-v~ lic aluminium is used, while most of the other methods have technical draw-, backs. These are due to the variation in the reactivity of the compounds used as the source of aluminium, which may lead to difficulties in reacting on the substance and to inconsistency in the properties of the products obtained.
, . . i According to the invention, there is provided a method for pre-,, paring products consisting essentially of aluminium hydroxychlorides in homo-r geneous solution in which the aluminium hydroxychlorides have the general for-mula A12 (OH)xCl6 X~ in which X is a value of 3 to more than 5 but less than 6, comprising reacting activated alumina with an aqueous solution of a com-pound selected from the group consisting of aluminium chloride, hydrochloric ','~r acid and mixtures thereof at a temperature of 60F to reflux temperature with vigorous agitation to provide said aluminium hydroxychloride in homogeneous ..~.
~' solution, the activated alumina consisting of the product of the partial de-hydration of hydrates of alumina in a stream of hot gases to less than 2 . moles combined water and a specific surface area of at least 200 m2/g.
:; ~
.
;.
.",' qF
., ' -- 1 --'' ' -. .
10472~5 complex products consisting chiefly of aluminium hydrochlorides may be obtained by adding, to the partially dehydrated alumina, compounds which will provide other anionic, e.g. polyvalent radicals and various other metals, such as alkali and/or alka-line earth metals. Moreover, these more complex products can also be obtained by adding the desired compounds to previously ~-prepared aluminium hydroxychlorides.
Products obtained by partially dehydrating hydrates of alumina, and commonly réferred to as active aluminas, are known to be used very widelyO particularly in adsorption and in catalysis. It has now been found that this activity, due to the specific sur~ace area which may be several hundreds of m2/g, enables the aluminas to be dissolved gradually and evenly in solutions of hydrochloric acid and/or aluminium chloride without the same disadvantages as are encountered with hydrates of alum-ina, even if freshly prepared; these drawbacks often consist of the fact that gelled products are obtained, and clear solutions of hydroxychlorides can be separated from them only with diffi-culty.
The previously used term "aluminium chloride" naturally covers various soluble compositions containing chlorine and aluminium, where the ratio of aluminium to chlorine can thus be varied by reaction on the active alumina; the term "aluminium chloride" particularly includes hydroxychlorides of aluminium already obtained from active aluminas.
Active aluminas, according to the invention, may have a specific surface area which varies within broad limits but which must preferably be fairly high if fairly large X values are desired. ~oreover, the aluminas may be used as appropriate, 3 either in powder form or in the form of agglomerated granulaF
., .
~2-.. ' ~ - .
~047~25 ?
substancesO The use of the latter may e.g. make the aluminas easier to react on by improving the circulation o~ liquids be-tween the granules; this is particularly important for large scale manufacture by continuous processes.
Active aluminas, which are particularly suitable, can be ob~ained by partially dehydrating hydrargillite, particularly :,, by dehydrating the hydrargillite obtained in large quantities by the Bayer process, and by dehydrating various alumina gels The æpecific surface areas of the active aluminas thus obtained may vary widely, ~ut for the method of the invention should prefer-ably be over 200 to 250 m2/g and even over 350 m2/g when the active aluminas are made from gels. Such aluminas are in powder form and can be used in the method of the invention either with-out further treatment or after being crushed to adjust the dis-tribution of grain sizes, or in the form of agglomerated sub-stances, particularly pellets obtained from a rotary granulator.
~, The reactivity of the active aluminas is such that the ;~ temperature of the reaction medium may rise spontaneously and -i' will then encourage the aluminas to dissolve in the solutions of hydrochloric acid and/or aluminium chloride. However, it is sometimes advisable to heat the solutions somewhat, e.g. to ` temperatures of about 60 to 90C, and under these conditions, the temperature may rise to over 100C when the alumina has been added.
The temperature rise is also particularly helpful in dissolving preliminary compounds which provide other anionic radicals and other metals, when the intention is to obtain more complex products than hydroxychlorides of aluminium. In such cases it may be more advantageous to carry out the reactions in 3 an autoclave, which will further facilitate the dissolving of ., ~3-. . .
.,~, 10~7225 the various substances. The dissolving process is not completed in one operation, and the non-dissolved pOTtiOn of the active alumina may be brought back into contact with a reacting solution with fresh active alumina added to it, and so on until all the alumina involved has been dissolved.
,~ According to the various operating conditions, it is possible to obtain aluminium hydroxychlorides in which X has variable values, which may more particularly be from 3 to 4, when the aim is to obtain products particularly designed for treating water and mud. Higher X values, which . 10 may be over 5, are suitable for products designed for the manufacture of catalyst carriers. -Finally, the products obtained according to the invention, which owing to the method of manufacture usually consist initially of solu-tions of various concentrations containing from 100 to 250 grams of alumina ~ , " A1203 per litre, may equally be put into the form of solid, powdered or granular products, obtained by known methods such as spraying.
Non-restrictive examples will now be given of the preparation of aluminium hydroxychlorides of various compositions, using active alu-; minas obtained from hydrargillite and from gel treated in streams of hot gases, the aluminas having various specific surface areas and being in powder form. An example is also given in which S04 ions are added to the ` reacting solution and finally, by way of comparison, an experiment is de-- scribed in which aluminium hydroxychloride is prepared by hydrochloric re-action on non-activated alumina gel.
Hydrargillite obtain by the BAYER process is partially de-hydrated in a stream of hot gases, to give an active . ~ - 4 -:
.
1047%25 alumina with a specific surface area of 312 m2/g. The alumina is in the form of a powder with the following distribution of .
graln slzes:
grains < 90~ 84% by weight grains < 58~ 50% by weight grains < 29,u 16% by weight 430 g of the alumina is stirred into a solution, heated to 85C, of 420 ml of 36% hydrochloric acid in 800 ml of water, the addition of the alumina taking thirty minutes. The temperature rises spontaneously to 103C. Agitation of the sus-pension ana reflux are maintained at this temperature for 16 hours. Then heating and agitation are terminated, the excess alumina is decanted and the liquid above it drawn off and cen-trifugedO This gives 0.80 litre of a 10186 dense solution of aluminium hydroxychloride with an X value of 3.93.
The excess alumina is put back into suspension in 800 ml of water and heated to 85C. 420 ml of 36% hydrochloric acid is added and the temperature rises to 103C. Reflux is main-tained for 2 hours at this temperature. 225 g of the same ac-~ 20 tive alumina is stirred in, in the course of 5 minutes, and - agitation and reflux are continued at this temperature for 22 hours. In the same way as before~ the excess alumina is s9par-ated from the liquid, which has a volume of 1.05 litre and a density of 1.18. The value of X is 3.53.
EX~MPLE 2 A powdered active alumina is again prepared from hydrar-gillite emanating from the BAyER process, by partial dehydration in a stream of hot gases but under less severe thermal conditions than those used to obtain the active alumina in the previous 3 example. m is alumina has a specific surface area of 285 m2/g ,', , _5_ ~0472Z5 and the following distribution of grain sizes:
grains ~ 90~ 84% by weight grains < 60~ 50% by weight grains < 25,u 16% by weight 248 kg of the alumina is stirred at 60 kg/h into a -reactor which is heated to 80C and which contains a solution made up of 300 litres of water and 300 kg of 36% hydrochloric acid. m e temperature rises spontaneously to 105C. Reflux `
and agitation are maintained for 10 hours at that temperature.
400 litres of a solution of aluminium hydroxychloride is separ-ated from the remaining alumina in the same way as in the pre-vious examples. m e solution has a density of 1.303 and an X
value of 3,5~.
e undissolved alumina, thus recovered, is put back into suspension in 300 litres of water and heated to 85C, and 250 litres of 36% hydrochloric acid is added. The temperature rises to 104C. After the reflux action has been maintained for 2 hours, 120 kg of the same active alumina is added in the course of 2 hours. Agitation and reflux are maintained at that temperature for 15 hours, after which the undissolved alumina ,. ...
is separated from 530 litres of a solution of aluminium hydroxy-- chloride with a density of 1.270 and an X value of 3.54.
Active alumina with a specific surface area of about -25 300 m2/g, obtained as indicated in example 1, is calcined to ;.:i ' reduce that area to 101 m2/g.
430 g of the alumina is introduced with agitation in the course of 10 minutes into a solution comprising 700 ml of water and 420 ml of 36% hydrochloric acid, heated to 90C.
3 The temperature rises spontaneously to 103C. Reflux and . .
, . .
.
agitation are maintained at that temperature for 22 hours. In the same way as in the previous examples, the undissolved alumina is then separated from 0.7 litre of a solution of aluminium hydroxychloride with a density of 1.150 and an X
; 5 value of 1.58.
If the results of these first three examples are com-pared one can see the effect of the specific surface area of the active aluminas used on the X values of the solutions of aluminium hydroxychloride obtained. In addition, examples 1 and 2 show that the aluminas can be totally dissolved by re-using the insoluble portions in a fresh orieration, and that this does not appreciably affect the value of X.
This example concerns the dissolving of active alumina ; 15 in aluminium chloride. 126 g of the same active alumina as was used in example 2 is stirred, in the course of 60 minutes, into a reactor heated to 80C and containing a solution of 216 g of anhydrous aluminium chloride AlC13 in 800 ml of water. The temperature rises to 103C. Heating under reflux is maintaine~
for 15 hours. By the same method as before, 0~8 litre of a solution of aluminium hydroxychloride is separated from the undissolved alumina. The solution has a density of 1.235 with an X value of 3.15. This example shows the great reactivity of ; active aluminas, even in relation to aluminium chloride in solu-tion, and the possibility of thus obtaining aluminium hydroxy-chlorides with large X values.
.
is example concerns a method of obtaining complex products by reaction with a mixture of HCl and H2SO4.
The reacting ll~uor is made up of 1526 ml of water, :
`:
~ -7-.
.
1047~25 14 ml of concentrated sulphuric acid and 374 ml of 36% hydro- -chloric acid. This solution is heated to 75C and 414 g of the alumina of example 1 is introduced with stirring over 40 minutes.
m e temperature rises to 102C. ~gitation, heating and reflux '~ 5 are maintained for 20 hours, then the undissolved alumina is separated, as indicated above, from 0.58 litre of a solution of aluminium hydroxychloride. The solution has a density of 1.270, contains 10.1 g/litre of SO4 and has an X value of 3.51.
EX~MPLE 6 i A substantially amorphous alumina gel is obtained by neutralising sodium aluminate with nitric acid at pH 8.5, while keeping the temperature below 35C. The freshly precipitated gel is agitated for 2 hoursO It is then filtered, washed and sprayed to reduce it to finely divided form and dried while keep-ing it in an amorphous state. It is activated by treatment in a stream of hot gases. The resulting alumina is in the form of a white powder with a specific surface area of 374 m2/g; it loses 10% by weight when heated to 1200C. Its x-ray diffraction diagram indicates an amorphous appearance with some traces of pseudoboehmite.
m e following are placed in an agitated 2 litre glass reactor:
, , .
-0.333 litre of a 36% solution of HCl -0.500 litre of purified water (eau permutée).
~
m is is all brought to reflux and 430 g of the alumina $; obtained as indicated abo~e is added in the course of 30 minutes.
After reacting for 7 hours at boiling point (100-101C) the reac-tion medium is cooled and a solution of the following formula is decanted:
~;
A1203 : 376g/1 , .
. . . .. . . .. . . .
'. . ' . :' ~ - :
: 104722S
Cl 2 : 131 . 3 g/l d : 1.40 ~, , pH : 2.7 m e empirical formula of the aluminium hydroxychlor-icle obtained is A12 (OH)5 Cl.
EX~MPLE 7 900 litres of a solution of basic aluminium chloride of the formula A12 (OH)2 88Cl30l2~ previously obtained by dissolving active alumina in hydrochloric acid, diluted with 1000 litres of purified water is placed in an agitated reactor ~ and brought to boiling point. m e reactor is made of glazed i steel with a capacity of 3 m3 and is equipped with a total reflux condensor. 700 kg of active alumina, having a specific surface area of 290 m2/g, obtained by partial dehydration of hydrargillite in a stream of hot gases, is added to the reflux.
All the ingredients are left to react for 18 hours at boiling temperature. After cooling and decanting, 1500 litres of a solution of density 1.22 and pH 4.0 is recovered. Each litre of the solution contains 205 g of alumina A1203 and 74.5 of chlorine; this substantially corresponds to the formula A12 (OH) 5 ~ 05 Clo 0 95 -; EX~MPLE 8 ' This is a comparative example and concerns the dis-solving of an alumina gel in aluminium chloride. An alumina gel is prepared by precipitating a solution of sodium aluminate, containing 230 g/litre of alumina A12`03, with 58% nitric acid at pH 8~5 and a temperature of 57Co m e gel obtained is `` washed, drained and filtered, then left to developO This gives a product which contains 12~55% by weight of alumina A1203.
1000 ml of a solution containing 167 g of aluminium chloride . .!
" _ 9_ '' ' : ' . ' ` " .
. , . : ' ' . . , ~ ' ' ` ' ' is heated to boiling point in a reactor and 1 ~g of the pre-viously prepared gel is gradually stirred in, The heating and reflux action are maintained for 15 hours, after which the liquid obtained is separated as before. It has a density of 1.25 and an X value of 2.74. However, if one tries to continue the reaction instead of separating the liquid, the alumina swells and absorbs the liquid and it becomes impossible to separate the liquid by filtration or centrifuging.
This is an example of the specificity of the behaviour -of active aluminas, which enable a seriPs of reactions to be carried out until they are completely dissolved, while at the same time reaching high X values.
. .
' ;
; 25 , .
.
.
.
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for preparing products consisting essentially of aluminium hydroxychlorides in homogeneous solution in which the aluminium hydroxy-chlorides have the general formula Al2 (OH)XCl6 - X' in which X is a value of 3 to more than 5 but less than 6, comprising reacting activated alumina with an aqueous solution of a compound selected from the group consisting of aluminium chloride, hydrochloric acid and mixtures thereof at a temperature of 60°F to reflux temperature with vigorous agitation to provide said aluminium hydroxychloride in homogeneous solution, the activated alumina consisting of the product of the partial dehydration of hydrates of alumina in a stream of hot gases to less than 2 moles combined water and a specific surface area of at least 200 m2/g.
2. The method of claim 1 in which the active alumina is obtained from hydrargillite or alumina gels.
3. The method of claim 1 in which the active alumina is in powder form.
4. The method of claim 1 in which the active alumina is in grain form.
5. The method as claimed in claim 1 in which compounds containing polyvalent anionic radicals are added to the partially dehydrated alumina re-acted with the aluminium chloride or hydrochloric acid in solution.
6. The method as claimed in claim 5 in which the anionic polyvalent radicals are added in the form of compounds of a metal selected from the group consisting of polyvalent metals, alkali and alkaline earth metals.
7. The method as claimed in claim 1 in which SO? ions are added to the reaction medium.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7336846A FR2247425A1 (en) | 1973-10-16 | 1973-10-16 | Aluminium oxy-chlorides from activated alumina - having uniform properties, for sewage and sludge treatment and catalyst carrier prodn |
| FR7422201A FR2276266A2 (en) | 1974-06-26 | 1974-06-26 | Aluminium oxy-chlorides from activated alumina - having uniform properties, for sewage and sludge treatment and catalyst carrier prodn |
| FR7422968A FR2277039A2 (en) | 1974-07-02 | 1974-07-02 | Aluminium oxy-chlorides from activated alumina - having uniform properties, for sewage and sludge treatment and catalyst carrier prodn |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1047225A true CA1047225A (en) | 1979-01-30 |
Family
ID=27250190
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA211,359A Expired CA1047225A (en) | 1973-10-16 | 1974-10-15 | Hydroxychlorides of aluminium and method |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS537157B2 (en) |
| AU (1) | AU7434474A (en) |
| BR (1) | BR7408563D0 (en) |
| CA (1) | CA1047225A (en) |
| DE (1) | DE2449100C3 (en) |
| DK (1) | DK539074A (en) |
| GB (1) | GB1460328A (en) |
| IE (1) | IE40245B1 (en) |
| IT (1) | IT1021811B (en) |
| LU (1) | LU71103A1 (en) |
| NL (1) | NL7413520A (en) |
| NO (1) | NO134583C (en) |
| SE (1) | SE397821B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1602858A (en) * | 1977-11-12 | 1981-11-18 | Kuy B | Medical and other compositions |
| SE425847B (en) * | 1979-11-16 | 1982-11-15 | Boliden Ab | PROCEDURE FOR PREPARING WATER-SOLUBLE BASIC ALUMINUM CHLORIDE AND / OR BASIC ALUMINUM SULPHATE CHLORIDE |
| DE3515341A1 (en) * | 1985-04-27 | 1986-10-30 | Kali-Chemie Ag, 3000 Hannover | METHOD FOR PRODUCING SOLID ALUMINUM CHLORIDE COMPOSITIONS |
| JP5228389B2 (en) * | 2007-07-18 | 2013-07-03 | 栗田工業株式会社 | Method for reducing odor of aluminum chloride solution |
-
1974
- 1974-10-15 BR BR8563/74A patent/BR7408563D0/en unknown
- 1974-10-15 JP JP11859574A patent/JPS537157B2/ja not_active Expired
- 1974-10-15 DE DE2449100A patent/DE2449100C3/en not_active Expired
- 1974-10-15 CA CA211,359A patent/CA1047225A/en not_active Expired
- 1974-10-15 IT IT53545/74A patent/IT1021811B/en active
- 1974-10-15 IE IE2118/74A patent/IE40245B1/en unknown
- 1974-10-15 NO NO743699A patent/NO134583C/no unknown
- 1974-10-15 NL NL7413520A patent/NL7413520A/en not_active Application Discontinuation
- 1974-10-15 DK DK539074A patent/DK539074A/da unknown
- 1974-10-15 AU AU74344/74A patent/AU7434474A/en not_active Expired
- 1974-10-15 SE SE7412965A patent/SE397821B/en not_active IP Right Cessation
- 1974-10-15 LU LU71103A patent/LU71103A1/xx unknown
- 1974-10-15 GB GB4461774A patent/GB1460328A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2449100A1 (en) | 1975-04-17 |
| DK539074A (en) | 1975-06-16 |
| IE40245B1 (en) | 1979-04-11 |
| NO134583C (en) | 1976-11-10 |
| BR7408563D0 (en) | 1975-08-05 |
| JPS537157B2 (en) | 1978-03-15 |
| IT1021811B (en) | 1978-02-20 |
| AU7434474A (en) | 1976-04-29 |
| NL7413520A (en) | 1975-04-18 |
| SE397821B (en) | 1977-11-21 |
| NO743699L (en) | 1975-05-12 |
| JPS5078594A (en) | 1975-06-26 |
| LU71103A1 (en) | 1975-06-24 |
| IE40245L (en) | 1975-04-16 |
| NO134583B (en) | 1976-08-02 |
| GB1460328A (en) | 1977-01-06 |
| SE7412965L (en) | 1975-04-17 |
| DE2449100C3 (en) | 1978-04-06 |
| DE2449100B2 (en) | 1977-01-27 |
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