Low viscosity aluminum hydroxy carbonate gel process
AssigneeBarcroft Company
InventorsWilbur G. Heath, Robert B. Casey
Life of this patent
Estimating the term…
Abstract
Process and system for the preparation of a low viscosity Aluminum Hydroxy Carbonate Gel having viscosity-resistant properties and a predetermined alkali ion content, comprising reacting under constant pH conditions an aqueous carbonate solution and an aqueous aluminum salt solution to form a reaction product, equilibrating the reaction product at naturally occurring pH and washing the equilibrated reaction product to provide the predetermined alkali ion content and the gel product by same processes.
Claims21
A continuous process for the production of aluminum hydroxide carbonate gel having predetermined values of viscosity and alkali ion content and including particles having a predetermined net surface charge comprising:
- (A) forming an acidic aqueous reaction mixture by combining continuously fed charges of an aqueous solution of alkali carbonate and an aqueous solution of aluminum salt;
- (B) forming in said mixture a reaction product which includes aluminum hydroxide wherein the pH of said mixture containing said aluminum hydroxide tends to vary;
- (C) maintaining the pH of said reaction mixture at a predetermined value (.+-.0.1) thereby producing a gel wherein said alkali ion content is correlated to said net surface charge;
- (D) continuously withdrawing from said mixture said product in an unequilibrated form;
- (E) forming an equilibrated product by equilibrating said withdrawn product under naturally occurring pH conditions;
- and
- (F) recovering from said equilibrated product said aluminum hydroxide gel.
In a continuous process for the preparation of an aluminum hydroxide carbonate gel comprising combining in a reaction mixture an aqueous solution of alkali carbonate with an aqueous solution of an aluminum salt to form a reaction product including particles comprising aluminum hydroxide, and wherein the pH of said mixture containing said products tends to very, the improvement comprising providing a gel which includes particles having a predetermined net surface charge and which has a predetermined alkali content by maintaining said reaction mixture at a predetermined pH .+-.0.05 pH unit and equilibrating said reaction product under naturally occurring pH conditions.
A process for the continuous production of an aluminum hydroxide carbonate flowable gel having viscosity change-resistant properties, a viscosity of about 200 to about 800 cps and a sodium content of about 0.19 to about 0.25 mg/g comprising:
- continuously feeding into an agitated reaction mixture an input charge of an aqueous containing sodium carbonate and sodium aluminate solution and an input charge of an aqueous aluminum salt solution;
- forming in said mixture an unequilibrated reaction product including particles of aluminum hydroxide, said product-containing mixture tending to vary in pH;
- withdrawing an output stream of said reaction product from said reaction mixture;
- allowing said withdrawn reaction product to equilibrate to a stable pH to form an equilibrated reaction product including sodium ions and an aluminum hydroxide gel precipitate;
- washing said precipitate to achieve the abovesaid sodium content;
- inducing sufficient shear into said washed precipitate to form said flowable gel;
- wherein said viscosity change-resistant properties of said flowable gel are provided by maintaining said output stream of unequilibrated reaction product at a pH of about 6.+-.0.1.
A continuous process for the production of aluminum hydroxide carbonate gel comprising:
- (A) forming an acidic aqueous reaction mixture by combining continuously fed charges of an aqueous solution of alkali carbonate and an aqueous solution of aluminum salt;
- (B) forming in said mixture a reaction product which includes aluminum hydroxide;
- (C) maintaining the pH of said reaction mixture at a predetermined value (.+-.0.1) by adjusting the relative amounts of the charges fed to said reaction mixture;
- (D) continuously withdrawing from said mixture said product in an unequilibrated form;
- (E) subjecting said withdrawn product in unequilibrated form to equilibrating conditions under which the pH thereof is allowed to vary naturally and in which recoverable aluminum hydroxide carbonate gel particles are formed;
- and
- (F) recovering from said withdrawn and equilibrated product said aluminum hydroxide carbonate gel particles.
Dependencies are inferred from the claim text.