METHOD AND LINE FOR RECOVERING VANADIUM FROM VANADIUM-CONTAINING SLAG Russian patent published in 1997 - IPC

FIELD: nonferrous metallurgy. SUBSTANCE: invention relates to two-step process including low-acid (pH 2.5-5.0) leaching of slag under predetermined process condition followed by acid (3.5% acid) one. The both steps are carried out in reactors continuously and in countercurrent, vanadium slag slurry before each reactor being separated into solid and liquid phases to separated fine-disperse gypsum from slurry. Solid phase is conveyed from the first reactor to the latter one, and liquid phase in inverse direction. Production line comprises four low-acid and three acid leaching reactors interconnected consecutively and tightly through overflow pipes, pipelines, and slurry and solvent-transferring pumps. According to invention, line is provided with reactor-mounted appliances for continuously separating slurry into solid and liquid phases, for example, hydrocyclone for withdrawing fine gypsum from vanadium slag slurry. To the sand discharge pipeline of reactor-mounted separation appliance of the second (third) reactor, liquid phase discharge pipeline(s) of the separation appliance(s) of the fourth (sixth and seventh) reactor(s) is (are) rigidly connected. To the sand discharge pipelines of the separation appliances of the fifth and seventh reactors, water supply pipelines are rigidly connected. To the sand discharge pipeline of the separation appliance of the sixth reactor, acid supply pipeline and liquid phase supply of the last separation appliance are rigidly connected. All pipelines are made to permit countercurrent advance of solid and liquid phases. EFFECT: enhanced efficiency of process. 3 cl, 1 dwg