乳状液膜法分离富集废旧镍镉电池中的镉

该文介绍了乳状液膜法分离富集废旧镍镉电池中的镉离子。乳状液膜主要由溶剂(煤油)、表面活性剂(Span80)、载体〔二(2-乙基己基)膦酸,P204〕和内水相氨水组成。对影响镉离子渗透和分离过程的重要变量进行了考察,分析了乳状液膜的载体体积分数、外水相pH、搅拌时间、乳水比(乳液与外水相体积比)及Span80体积分数对镍镉分离效果的影响,从而选择出最佳的分离条件为:φ(P204)=4.4%,φ(Span80)=8.8%,pH=5.5,乳水比0.5,搅拌时间10min。用此乳状液膜进行100L反应釜的工业放大实验,镉的迁移率可达93.3%,而镍的迁移率仅为14.6%。

Separation and Concentration of Cadmium from Spent Nickel-Cadmium Batteries by Emulsion Liquid Membranes

For separation and concentration of cadmium from spent nickel-cadmium batteries,the liquid membrane includes mainly a diluent(kerosene),a surfactant(Span 80),a carrier〔bis(2-ethylhexyl)phosphonic acid,P204〕 and ammonia solution used as the internal aqueous phase.The important variables governing the permeation of cadmium and the separation process were the volume fraction of P204,pH of external aqueous phase,stirring time and volume ratio of emulsion to external aqueous phase.The optimal separation conditions were:φ(P204)=4.4%,φ(Span 80)=8.8%,pH=5.5,volume ratio of emulsion to external aqueous phase 0.5 and stirring time 10 min.In the 100 L reactor commercial test with the emulsion liquid membrane,the migration rate of cadmium can reach as high as 93.3% from spent nickel-cadmium battery compared to 14.6%of nickel.