从钒精矿中湿法提取五氧化二钒新工艺研究

Research on New Hydrometallurgical Process for Vanadium Extraction From Vanadium Concentrate

针对河南淅川页岩钒矿分级擦洗得到的钒精矿,研究了两段逆流硫酸浸出—中和—还原—萃取—铵盐沉钒新工艺。在矿石w(V2O5)=2.50%、粒度-500目、硫酸用量为矿石质量的50%、浸出液固体积质量比1.3∶1、浸出温度95℃条件下,五氧化二钒浸出率大于75%;浸出液中的钒用15%P204+10%TBP+75%磺化煤油溶液为有机相,在常温下5级逆流萃取,有机相与水相的流量比为1∶1,钒萃取率在98%以上;负载有机相中的钒用1.5 mol/L硫酸溶液在常温下5级逆流反萃取,有机相与水相流量比为5∶1,钒反萃取率在99%以上;反萃取液中的钒氧化后用铵盐沉淀多钒酸铵,然后在氧化气氛中热解2 h,获得五氧化二钒产品。五氧化二钒总回收率大于70%,产品纯度大于99%。此工艺钒回收率高,符合环保要求,有一定的推广应用前景。

Aiming at vanadium concentrates produced by scrubbing-classification,a new vanadium extraction process that two stage counter-current leaching—neutralization—reduction—solvent extraction—vanadium precipitate by ammonium salt was researched.The leaching rate was higher than 75% when the particle size of raw material was-500 mesh,dosage of sulfuric was 50% to ore mass,ratio of liquid to solid was of 1.3∶1 and leaching temperature was of 95℃.Vanadium in leaching solution was extracted using a mixed organic phase made up of 15%P204＋10%TBP＋75%sulfonated kerosene.At the conditions of nomal temperature,five stage counter-current extraction,flow rate of organic phase to liquid phase of 1∶1.The extraction rate of vanadium was more than 98%.Vanadium in loaded organic phase was five stage counter-current stripping using 1.5 mol/L sulfuric acid at the conditions of nomal temperature,flow ratio of organic phase to water phase of 5∶1.The stripping rate of vanadium was more than 99%.Vanadium in stripping solution was oxidized then deposited using ammonium salt.The ammonium polyvanadate was pyrolyzed in oxadition ambience to V2O5 product.The total recovery rate of V2O5 was more than 70% and the purity of V2O5 product was more than 99%.The hydrometallurgical process had high vanadium recovery,accorded with environment protection quirement,and had a good application prospect.