METHOD OF PROCESSING LEAN MANGANESE-CONTAINING ORES Russian patent published in 2001 - IPC

FIELD: manganese metallurgy; applicable in production of metallic manganese, ferromanganese and manganese compounds for production of high-grade ferromanganese, for medicobiological industry and production of catalysts from lean manganese-containing ores. SUBSTANCE: method of processing of lean manganese-containing ores, for instance, sea ferrous-manganese concretions, particularly, with high content of phosphorus and silicon includes thermochemical treatment of ore with ammonium chloride in ammonium chloride-ore manganese ratio of 2.0-2.5 at temperature of 150-400 C with production of manganese chloride which is subsequently leached with water, and gases containing ammonia which are directed for preparation of ammonium chloride. Solutions obtained after water leaching of manganese chloride and free of iron, phosphorus and silicon are directed for preparation of electrolyte and for membrane electrolysis in three-cell electrolyzer. Membrane electrolysis is carried out at cathode current density above 8 A/sq.dm with concentration of manganese chloride in solution of at least 60 g/l with obtaining of metallic manganese on cathode and hydrochloric acid in middle cell. For production of manganese-containing product for obtaining of ferroalloys, initial raw material before thermochemical treatment is subjected to classification with obtaining part of grains sizing -10+0.044 mm containing iron and manganese, and manganese-containing fine fraction. Grainy part is directed for production of manganese concentrate for production of ferroalloys. Fine fraction is subjected to thermochemical treatment. For correction of electrolyte composition with respect to manganese chloride content and improvement of quality of electrolytic manganese, aqueous solution of manganese chloride is treated with ammonium hydroxide with obtaining of precipitate of manganese hydroxide enriched with impurities. Manganese hydroxide is calcined to obtain manganese dioxide which is mixed with manganese concentrate for production of ferromanganese. EFFECT: provision of ecologically safe wasteless technology of processing of lean manganese ores with production of metallic manganese without use of acids and strong oxidizers applied, particularly, in processing of sea ferrous-manganese concretions. 10 cl, 1 dwg, 2 tbl, 1 ex