METHOD OF PROCESSING OF VANADIUM-CONTAINING CONVERTER SLAGS Russian patent published in 2000 - IPC

FIELD: vanadium and ferrovanadium technology in various industries. SUBSTANCE: method includes oxidizing-nitriding roasting of slag with sodium nitrate or nitrite, aqueous leaching of cinder, hydrolytic separation of vanadium, absorption of nitrogen oxides from roasting gases, cleaning of effluent gases, evaporation of solution and crystallization of salt of mixture of sodium nitrate and nitrite, separation of solid salt, and supply of salt to stage of change preparation. Nitrogen oxides from roasting gases are absorbed with solution after hydrolytic separation of vanadium pentoxide. The solution is evaporated to obtain condensate and then, salt is crystallized from this solution by evaporation with obtaining acid condensate. Evaporation condensate is supplied for aqueous leaching of cinder, and acid condensate of crystallization is supplied to stage of hydrolytic separation of vanadium pentoxide. EFFECT: higher ecological safety due to exclusion of formation of effluent water.