Patent ID: 9725785
Date: 2017-08-08
CPC Classifications: C22B,Y02P

Claim:
1. A process for cold hydrochemical decomposition of sodium hydrogen aluminosilicate, comprising: decomposing the sodium hydrogen aluminosilicate at a low temperature of less than about 100° C. with a circulating solution of chelate in the presence of a weak acid to form a solution comprising soluble compounds comprising an aluminum chelate, a silicic acid and a sodium salt of the weak acid, and insoluble contaminants, separating the insoluble contaminants from the solution by adding a coagulator to the solution and heating the solution to a temperature of about 100 to about 120° C. to coagulate the silicic add and form a silicic acid gel, separating the resulting silicic acid gel from the solution to form a silicic acid-free solution; decomposing the silicic acid-free solution by treating with an excess of sodium hydrogen carbonate to form a precipitate of sodium hydrogen carboaluminate and a mother liquor; separating the precipitate of sodium hydrogen carboaluminate from the mother liquor; concentrating the mother liquor by evaporation; cooling the concentrated mother liquor and regenerating the cooled solution by carbonization with gaseous carbon dioxide under a pressure of at least about 16 bar to form a precipitate of sodium hydrogen carbonate; separating the precipitate of sodium hydrogen carbonate from the regenerated solution; and calcining the sodium hydrogen carboaluminate at temperature of about 700 to about 900° C. and forming sodium aluminate.