Abstract:An experiment was designed to intensify the grinding and mixing of vanadium slag and limestone powder using a kind of wheel mill. The obtained material was compared with the ordinary mixture using agitation mixing method. The size distribution, powder morphology and mixing degree of two kinds of mixtures were investigated. The effects of calcination temperature and calcium vanadium ratio(m(CaO)/m(V₂O₅)) of the mixture on the roasting conversion were analyzed. The initial pH value, acid consumption and leaching time difference owing to agitation mixing during the leaching course were also studied. The results show that the mixed grinding pretreatment can significantly improve the roasting conversion of the mixture under the same calcium vanadium ratio. When the value of m(CaO)/m(V₂O₅) is 0.6, the calcination conversion of the mixture after mixed grinding at 870 ℃ is about 2% higher than that of the ordinary mixture. At the same conversion level, the amount of limestone can be reduced by using mixed grinding pretreatment. The calcination conversion of the mixed grinding mixture with m(CaO)/m(V₂O₅) of 0.4 at 870 ℃ is 90.18%, which is equivalent to 90.76% of the conventional mixture with m(CaO)/m(V₂O₅) of 0.6. During the acid leaching process, the initial pH value of the clinker obtained by roasting the mixed grinding mixture is lower than that of the conventional clinker, the acid consumption is reduced by about 13%, as well as the leaching time can be significantly shortened. The mixed grinding pretreatment can reduce the production cost and improve the production efficiency, which has a certain application prospect.

Key words: mixed grinding; vanadium extraction by calcination; immersion rate