METHOD OF PROCESSING HIGH-CALCIUM VANADIUM-CONTAINING MATERIALS Russian patent published in 2000 - IPC

FIELD: nonferrous metallurgy. SUBSTANCE: invention relates to steelmaking vanadium-containing slags and aims at increasing vanadium recovery, improving quality of vanadium pentoxide by way of reducing level of impurities contained therein, including silicon dioxide, increasing solution filtration velocity when processing starting material, and also reducing cost price of vanadium produce and improving environmental condition. To that end, in a process wherein vanadium-containing slag is ground and treated with mineral acid, after which slurry is filtered, solution and precipitate washed, and solution subjected to isolation of vanadium pentoxide, slag is first treated with sulfuric acid in amounts 0.5 to 0.9 its stoichiometric amount required to form calcium salts, whereupon carbonate-containing reagent is added in amounts 0.01 to 0.3 the weight of original slag. Washed precipitate is then fired under air- oxidation conditions, treated with sulfuric acid, and vanadium pentoxide is isolated from sulfuric acid solution. EFFECT: enhanced process efficiency. 1 tbl