Process for cold hydrochemical decomposition of sodium hydrogen aluminosilicate

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.