Abstract: A process for the simultaneous recovery of substantially pure alumina and silica from an aluminosilicate. The process comprises the following steps: (i) heating the aluminosilicate with hydrated CaCl.sub.2 to obtain calcium-alumino-silicate and calcium-aluminate products, wherein the CaCl.sub.2 is substantially free of MgCl.sub.2 ; (ii) leaching the products with HCl to form a solution comprising AlCl.sub.3 and CaCl.sub.2, and insoluble silica; (iii) separating the insoluble silica from the solution; and (iv) crystallizing AlCl.sub.3 from the solution and recovering the alumina from the crystallized AlCl.sub.3. The process may further comprise the following steps: (v) substantially removing MgCl.sub.2 from the CaCl.sub.2 solution of step (iv); and (vi) recycling the CaCl.sub.2 solution for use in step (i).
Type:
Grant
Filed:
December 15, 1998
Date of Patent:
November 30, 1999
Assignee:
Mashal Alumina Industries Ltd.
Inventors:
Shlomo Nehari, Chanoch Gorin, Israel J. Lin, deceased, Amos Berkovich