N235/异辛醇体系从仲钨酸铵结晶母液中萃取钨的研究

Study on Tungsten Extraction from Crystal Mother Liquor of Ammonium Paratungstate in N235/Isooctanol System

提出并研究了N235/异辛醇体系从仲钨酸铵(APT)蒸发结晶母液中萃取回收钨的新方法,考察了有机相组成、料液pH值、温度等因素对钨萃取的影响,绘制了萃取和反萃取等温线,并进行了模拟多级逆流萃取全流程实验。结果表明,N235/异辛醇萃取体系能够从仲钨酸铵蒸发结晶母液中实现钨的高倍富集回收及其与SO_(4)^(2-)、Cl^(-)的高效分离。对于含WO_(3)22.1g/L、pH为3.5的酸化料液,采用组成为10%N235+20%异辛醇+磺化煤油的有机相,经4级逆流萃取-1级洗涤-2级反萃取,萃余液WO3含量低于0.02g/L,WO3回收率高于99.5%,反萃液WO_(3)含量高于230g/L,SO_(4)^(2-)、Cl^(-)的去除率大于98.5%。

A new process for the extraction and recovery of tungsten from APT crystal mother liquor in N235/isooctanol system was proposed and studied.The effects of organic phase composition,feed pH,temperature and other factors on tungsten extraction were studied.The extraction and stripping isotherms were drawn.And the test of simulated multi-stage countercurrent extraction was conducted.The results show that high-fold enrichment and recovery of tungsten and efficient separation of SO_(4)^(2-)and Cl^(-)from the ammonium paratungstate crystal mother liquor can be achieved in the solvent extraction system of N235/isooctanol.When the acidified feed liquid with WO3content of 22.1g/L and pH value of 3.5is subjected to4-stage countercurrent extraction,1-stage washing and 2-stage stripping,and the organic phase consisting of 10%N235,20%isooctanol and sulfonated kerosene is used,the results are obtained as follows:WO_(3)content in the raffinate is less than 0.02g/L,WO3recovery rate is higher than 99.5%,WO_(3)content in the stripping solution is higher than 230g/L,and the removal rate of SO_(4)^(2-)or Cl^(-)is greater than 98.5%.