METHOD OF PROCESSING DEPLETED VANADIUM CATALYST OF SULFURIC ACID PRODUCTION Russian patent published in 1995 - IPC

FIELD: chemical technology. SUBSTANCE: process is carried out by treatment of parental vanadium-containing catalyst with alkali hydroxide solution (concentration is 30-100 g/l as Na₂O_к), at 30-100 C, separation of solution from slime and washing. Then prepared solution is neutralized in the presence of phosphorus-containing reagent following by filtration, evaporation of vanadium-containing solution up to concentration 40-80 g/l as V₂O₅,, crystallization of alkaline metal sulfates from its at 20-80 C and separation of precipitate from solution. Then solution is fed to stage of ammonium-vanadate salt isolation by ammonium salt addition. After separation from mother liquid salt is processed to V₂O₅.. Under these conditions high quality of V₂O₅ is provided, process is simplified due elimination of extractive conversions, energy consumption is decreased by 35%, and specific vanadium-containing flow intensity is decreased by 41%. EFFECT: elimination of vanadium loss, simplified process. 2 tbl