酸性铵盐沉钒产品中杂质分离技术研究

Removal Techniques for Impurities in Acidic Ammonium Salt Precipitation of Vanadate

为解决钠化钒液采用酸性铵盐工艺沉淀多钒酸铵产品中杂质含量较高的问题,进行了多聚钒酸铵中杂质分离技术研究与杂质溶解动力学分析。试验结果表明:采用热水浸泡洗涤工艺,控制洗涤剂pH为5~7、洗涤温度为50~70℃、液固比为(1.5~2.0)∶1、铵盐加入量为1%~2%,钒收率达到99.60%以上,多钒酸铵中TV含量为50.25%,Na2O+K2O为0.15%,S为0.13%。经杂质溶解动力学分析,表观活化能为16.19 kJ/mol,杂质分离过程为固膜扩散动力学过程控制。

The impurities separation technology and the dissolution kinetics analysis of impurities in ammonium polyvanadate were studied, in order to solve the problem of high impurities content in ammonium polyvanadate prepared by acid ammonium salt precipitation from vanadium and sodium solution. The results show that ammonium polyvanadate having 50.25% of total vanadium content, 0.15% of Na2O+K2O and 0.13% of S can be gained by hot water immersion and washing at 5~7 of washing solution pH, 50~70 ℃ of wash temperature,(1.5~2.0)∶1 of liquid-solid ratio and 1%~2% of ammonium salt addition, with the vanadium recovery more than 99.60%. Moreover, the impurities separation process is kinetically controlled by solid film diffusion with 16.19 kJ/mol of apparent activation energy, based on the dissolution kinetics analysis of the impurities.