钒渣钙化焙烧参数对钒浸出率的影响

在分析钒渣(V2O3 8.07%)钙化焙烧过程反应机理的基础上，采用钙化焙烧-酸浸法研究了钙化焙烧过程中CaO/V2O3(质量比)、焙烧温度、焙烧时间对钒浸出率的影响. 结果表明，焙烧温度在600~900℃之间时，V2O5等钒氧化物可与CaO发生反应，形成以CaV2O6, Ca3V2O8, CaV3O7为主的钒酸钙. 当CaO/V2O3由0.48提高到约1.125时，钒浸出率由55.3%提高到69.2%，当CaO/V2O3>1.125时，钒浸出率开始下降. 焙烧温度由750℃提高到825℃时，钒浸出率由56.3%提高到69.7%，温度进一步升高，物料开始烧结，浸出率逐渐下降. 随焙烧时间延长，钒浸出率逐渐提高，2 h后达最大；时间继续增加，钒浸出率会因物料间发生二次反应而下降.

Effects of Vanadium-containing Slag Calcium Roasting Conditions on Leaching Rate of Vanadium

Based on the analysis of reaction mechanism of vanadium-containing slag(V2O3 8.07%) calcium roasting process,the effects of various factors on vanadium leaching rate were investigated by means of calcium roasting coupled with acid leaching.The results showed that various calcium vanadates namely CaV2O6,Ca3V2O8,CaV3O7 would form between V2O5 and CaO at 600-900℃.The acid leaching of roasted slag indicated that the mass ratio of CaO to V2O3 in the roasted slag played an important role in the roasting process.Vanadium leaching rate increased from 55.3% to 69.2% when the ratio was from 0.48 to 1.125,while the rate decreased when the ratio exceeded 1.125.When the roasting temperature increased from 750 to 825℃,the leaching rate from 56.3% to 69.7%.However,the slag roasted the temperature higher than 825℃ lead to the decrease of leaching rate.Vanadium leaching rate increased with the roasting time.The maximum rate was achieved when the roasting time was 2 h.With longer roasting time,the slag reacted further,leading to the decrease of vanadium leaching rate.