高硅高钙低品位钒渣提取五氧化二钒的研究

以碳酸钠为添加剂,采用氧化焙烧-水浸工艺从高硅高钙低品位钒渣中提取五氧化二钒.考察了碳酸钠加入量、焙烧温度、焙烧时间、浸出温度、浸出时间、浸出液固比等对钒浸出率的影响.结果表明:氧化焙烧过程对钒的提取影响显著,而水浸过程影响较小.通过氧化焙烧使钒转化为可溶性的钒酸钠与不溶性的钒酸钙.在水浸过程中,钒酸钠溶于水；而钒酸钙与磷酸钠或硅酸钠反应转化为可溶性的钒酸钠,可同时除去浸出液中的杂质硅和磷.通过实验获得了优化工艺参数:碳酸钠加入量为18％,焙烧温度为700℃,焙烧时间为2.5h；浸出温度为90℃,浸出时间为30 min和液固比为5∶1 ml·g-1.在此优化条件下,钒浸出率可达到89.5％以上,浸出液中主要杂质为Si,P和Cr.产物五氧化二钒的纯度大于99％.

Extraction of Vanadium Pentoxide from Low Grade Vanadium Slag with High Silicon and High Calcium

The extraction of vanadium from low grade vanadium slag of high silicon,high titanium and high calcium using Na2CO3 as additive was studied by oxidation roasting,followed by water leaching process.The influencing factors such as addition of Na2CO3,temperature and time of roasting,leaching parameters such as liquid to solid ratio,temperature and time of leaching were investigated.According to experimental results,the oxidation roasting process had more significant effect on extraction of vanadium than the wa...