METHOD FOR COMPLEX PROCESSING OF SERPENTINITE MINERAL Russian patent published in 1997 - IPC

FIELD: electrical engineering; metallurgy; production of rubber and refractories. SUBSTANCE: serpentinite mineral is decomposed with sulfuric acid taken in concentration 20-50 wt. %. As result, in first process step, amorphous silica deposit, undecomposed magnetic minerals, viz. chromite and magnetite, and filtrate are produced. Deposit is subjected to electromagnetic separation to isolate silicon dioxide and magnetite-chromite concentrate. Filtrate is neutralized to pH = 7-8.5 and to precipitate from it chromium, nickel and iron hydroxides. Remaining filtrate is subjected to carbonization to obtain magnesium carbonate. Latter is subjected to calcination to convert it to magnesia. Residual solution is evaporated to produce sodium sulfate (thenardite). EFFECT: method offers all-sided economic use of all serpentinite components which were hitherto regarded as wastes. 2 tbl, 3 dwg