A CLEANER AND EFFICIENT PROCESS TO PREPARE VANADIUM PENTOXIDE FROM THE CONVERTER VANADIUM SLAG

摘要

Converter vanadium slag is a byproduct of the iron making process when using the vanadium titanomagnetite as iron raw material. A cleaner process including calcified roasting, dilute acid leaching, precipitation purification, vanadium precipitation with ammonium salt followed by pyrogenic decomposition was proposed to extract vanadium resource from this slag. And then vanadium pentoxide with purity over 98% was prepared, which can be used as additives for high strength low alloy steel production. A total vanadium recovery beyond 80% was achieved in this whole process. Since no sodium and potassium salt was introduced, waste water generated was closed-circulating after removing the enriched impurities of P, Si, Ti and Cr with adding powder CaO. The content of V_2O_5 in residues after vanadium extraction was lower than 1.2wt.%, while other valuable metals like Fe, Mn, Cr and Ti were concentrated. With no alkaline metal salts added in this process, the metals of Fe, Mn, Cr and Ti in the residues were more likely to be recovered with pyrometallurgy processes.