低钙镁石煤钒矿熟化浸出工艺研究

Curing and Leaching Technique for Vanadium Extraction from Low Calcium and Low Magnesium Stone Coal

针对低钙镁钒矿碱度低、二氧化硅含量高的特点,采用硫酸熟化-水浸出工艺处理石煤钒矿,考察了矿物粒级、硫酸用量、熟化温度、熟化时间等参数对钒浸出的影响。结果表明,在矿石粒度-0.15 mm、硫酸用量20%、熟化温度120℃、熟化时间8.5 h的优化条件下,所得熟料在液固比2∶1、室温下用水搅拌浸出2 h,钒浸出率达到了88.6%。熟化过程矿物中包裹钒的云母结构得到高效解离,并释放可溶性钒,浸出液中硅含量低(0.08 g/L),比直接酸浸或焙烧酸浸工艺中硅含量大幅降低,对后续萃取工序非常有利。

As for a kind of low⁃calcium and low⁃magnesium stone coal featuring low alkalinity and high content of silica,a process of sulfuric acid curing followed by water leaching was adopted in an experiment,and the effects of grain size,sulfuric acid dosing,curing temperature and curing time on vanadium leaching were investigated.The results show that the leaching rate of vanadium reaches 88.6%when the raw ore with grain size of-0.15 mm was cured at 120℃for 8.5 h by adding sulfuric acid at 20%,and then water leaching at the room temperature for 2 h with liquid and solid at a ratio of 2∶1.During the curing process,the mica structure with the locked vanadium therein is effectively dissociated and soluble vanadium is released.It is shown that the leaching solution has a lower content of silicon(0.08 g/L),significantly reduced compared to the process of direct acid leaching or the process of roasting plus acid leaching,which is beneficial to the subsequent extraction process.