从石煤提钒酸浸液中萃取分离硫酸.doc

从石煤提钒酸浸液中萃取分离硫酸 杨晓1，张一敏1,2 （1.武汉理工大学 资源与环境工程学院，武汉 430070；2.武汉科技大学 资源与环境工程学院，武汉 430081） 摘要：采用萃取法从石煤高酸浸出液中优先萃取分离硫酸，考查还原剂用量、萃取剂浓度、萃取温度、萃取时间对硫酸萃取率的影响。结果表明，在还原剂亚硫酸钠用量2 g/L、萃取剂三异辛胺浓度40%、萃取温度25 ℃、萃取时间2 min、相比O/A=1/1的条件下，经4级萃取，浸出液中硫酸浓度由110 g/L降低至5.25 g/L，浸出液pH升高至2.3，可直接用于萃取钒。以60 ℃热水为反萃剂、O/A=1/3条件下，经5级反萃，99%以上的硫酸可被反萃出来。萃取过程无其它药剂消耗，有机相可循环使用，且回收的硫酸可再利用。 关键词：石煤；酸浸液；硫酸；萃取；分离 中图分类号：TF804.2 文献标志码：A 文章编号：1007-7545（2016）11-0000-00 Solvent Extraction of Sulfuric Acid from Acid Leaching Solution of Stone Coal YANG Xiao1, ZHANG Yi-min1,2 (1. School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China; 2. School of Resources and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China) Abstract：Separation of residue sulfuric acid prior to vanadium extraction from acid leaching solution of stone coal was performed by solvent extraction. Effects of reductant sodium sulfite dosage, extractant tri-octyl amine concentration, temperature, and reaction duration on extraction rate of sulfuric acid were investigated. The results show that sulfuric acid concentration in leaching solution drops from 110 g/L to 5.25 g/L after four-stage extraction under the optimum conditions including sodium sulfite dosage of 2 g/L, tri-octyl amine concentration of 40%, temperature of 25 ℃, reaction duration of 2 min, and O/A=1/1. PH value of leaching solution reaching to 2.3 can be directly used in vanadium extraction. Stripping efficiency of sulfuric acid is 99% above after five-stage stripping with 60 ℃water as strip extractant at O/A=1/3. No additional agents are consumed in extraction process, the organic phase can be recycled and recovered sulfuric acid can be reused. Key words：stone coal; acid leaching solution; sulfuric acid; solvent extraction; separation 石煤是我国特有的一种含钒资源，其中五氧化二钒储量巨大，从石煤中提取钒具有重要的意义[1]。酸浸法由于其钒浸出率高、环境污染小等优点广泛用于石煤提钒的研究及工业生产中。为了获得较高的钒浸出率，通常采用高浓度的硫酸浸出，最终浸出液中含有大量残余的硫酸。通常以P204萃取钒时需在pH大于2的条件下进行[2-3]，因此萃钒前需对浸出液中的残余酸加以处理，以