METHOD OF ISOLATION OF ALUMINA AND SILICA

摘要

chemical industry, more particularly isolation of essentially pure alumina and silica from stock comprising alumosilicates. SUBSTANCE: method comprises (i)heating alumosilicate with hydrated CaCl2 to prepare calcium alumosilicate and calcium aluminate products wherein CaCl2 is predominantly free from MgCl2; (ii) leaching HCl products to form solution containing AlCl3; and CaCl2 and insoluble silica; (iii) isolating insoluble silica from solution and (iv) crystallizing AlCl2 from solution and isolating alumina from crystallized AlCl3. Method further comprises removing predominantly MgCl2 from CaCl2 solution in stage (iv) and recycling CaCl2 solution for use in stage (i). Invention makes it possible to isolate essentially pure alumina and silica. EFFECT: more efficient isolation method. 13 cl, 1 dwg, 3 ex