含钒石煤硫酸化焙烧—超声浸出试验

Sulphating Roasting-Ultrasonic Leaching Test of Vanadium-containing Stone Coal

为了解决传统石煤提钒工艺存在的污染大、酸耗高、钒浸出率低等问题,以湖南某地石煤为研究对象,对硫酸化焙烧—超声浸出提钒工艺条件进行了研究。结果表明:在硫酸用量(与石煤的质量比)为18%、液固比为1.2∶1 mL/g、焙烧温度为240℃、焙烧时间为2.5 h,焙砂超声浸出时的磷酸用量(与石煤的质量比)为8%、液固比为2∶1mL/g、超声功率为100 W、浸出温度为80℃、浸出时间为60 min情况下,钒浸出率可达88.21%;该工艺浸钒效果优于硫酸化焙烧—机械搅拌浸出工艺和钙化焙烧—超声浸出工艺,其原因在于超声波的搅拌作用、空化作用、热效应和化学效应有助于改变钒的聚集状态,加快钒的浸出,使钒浸出过程较为充分。

In order to solve the problems caused by traditional process of vanadium extraction, such as high pollution, high acid consumption,low vanadium leaching rate, regarding the stone coal from Hunan province as the research target, the conditioning tests of vanadium extraction were investigated by sulphating roasting-ultrasonic extraction. The results showed that when the stone coal was firstly treated with 18% sulfuric acid （mass ratio with stone coal） ,liquid-to-solid ratio at 1.2：1 mL/g at 240 ~C for 2.5 h, and then the roasted ore is treated by ultrasonic leaching with 8% phosphoric acid （mass ratio with stone coal） ,liquid-to-solid ratio at 2：1 mL/g, and ultrasonic power of 100 W at 80 ~C for 60 min, the leaching rate of vanadium reached 88.21%. Compared with the process of sulphating roasting-mechanical stirring leaching and the process of calcified roasting-ultrasonic leaching,the process had a better performance. The main reason was that agitation,cavitation,thermal and chemical effects of ultrasonic wave contributed to change the aggregation state of vanadium and accelerate the leaching of vana- dium, so that the vanadium leaching was more sufficient.