METHOD OF PROCESSING OF BAUXITES INTO ALUMINA Russian patent published in 2002 - IPC

FIELD: nonferrous metallurgy, particularly, technology of alumina production from bauxites. SUBSTANCE: method includes wet grinding of low-silicon bauxite; leaching of bauxite on circulating solution; thinning of red mud. Aluminated solution is combined with aluminate solution of sintering branch and supplied for decomposition. Washed red mud is directed to dump. From decomposition, washed producing aluminum hydroxide is subjected to calcination to produce alumina. Mother liquor is evaporated with subsequent separation of circulating soda directed for sintering. Circulating solution is supplied for bauxite grinding. High-silicon bauxite is ground on circulating solution and leached. Aluminate solution separated from red mud is combined with aluminate solution of Bayer branch processing low-silicon bauxite. Washed red mud is fed for preparation of mud charge for sintering. In preparation of charge, introduced into it are limestone and circulating and calcined sodas. Dosing of the latter takes into account compensation losses of alkali in sintering branch and Bayer branches processing low- and high-silicon bauxites. Obtained sintered material is leached. Mud after washing is discarded. Aluminated solution after desilication and separation of white mud is combined with aluminated solutions of Bayer branches. White mud is directed for preparation of charge. EFFECT: reduced consumption of fuel, alkalis, higher recovery of aluminum oxide. 2 dwg, 1 tbl