在压力场下从石煤中浸取钒和浸出渣综合利用

VANADIUM EXTRACTION FROM BLACK SHALE UNDER PRESSURE FIELD AND COMPREHENSIVE UTILIZATION OF LEACHING RESIDUE

本文对贵州某地石煤进行了加压酸浸提钒实验研究。在压力场条件下,考察了反应时间、硫酸浓度、反应温度、液固比、添加剂(FeSO4)浓度对钒浸出率的影响,同时进行了两段逆流浸出实验。结果表明钒浸出率可达90%以上。浸出液经过废酸回收、还原、调整pH值等预处理后,采用溶剂萃取的方法能够有效地分离和富集钒,钒萃取率可达98.1%,反萃率为99.14%;用氨水沉淀反萃液中的钒,得到的NH4VO3在550℃下煅烧3h即可产出合格的粉状V2O5。浸出渣可制成建筑材料,全流程钒回收率为85%左右,资源综合利用率大于85%。

Extracting vanadium from black shale in Guizhou is investigated by pressure acid leaching.The effects of reaction time,H2SO4 concentration,reaction temperature,ratio of liquor to solid and additive（FeSO4） concentration on leaching rate of vanadium are investigated under pressure field,and the experiment of two-step countercurrent leaching is developed.The results show that leaching rate of vanadium can reach above 90%.The vanadium in leaching solution is efficiently separated and enriched by solvent extraction after preprocess of recovering residual H2SO4,reducing,adjusting pH value.The rates of extracting and stripping of vanadium are 98.1% and 99.41%,respectively.Ammonia is employed to precipitate vanadium in stripping liquor,subsequently;the solid NH4VO3 is calcined at temperature of 550℃ for 3 hour to produce qualified V2O5 powder.Residue can be processed into building material,and the recovery yield of vanadium in whole process and utilization percent of resource are 85% and 85%,respectively.