溶剂萃取法自铝材抛光废液中分离去除硫酸及其机理的研究  

Study on the separation and removal of sulfuric acid from waste aluminum polishing solution by solvent extraction and its mechanism

作　　者：陈慧 李世鑫 宾丽英[1] 汤兵[1] CHEN Hui;LI Shi-xin;BIN Li-ying;TANG Bing(School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学环境科学与工程学院,广东广州510006

出　　处：《应用化工》2024年第2期332-336,共5页Applied Chemical Industry

基　　金：广东省科技计划(2010B031700026);企业联合攻关项目(20HK0333)。

摘　　要：研究了利用溶剂萃取体系自铝材抛光废液中分离去除硫酸并纯化提取磷酸的工艺。系统考察三烷基胺(N235)浓度、萃取温度、相比、振荡时间等因素对萃取率的影响,并用McCabe-Thiele图解法预测理论阶段数,结果表明在相比为O/A=2的三个理论阶段后,98%以上的H_(2)SO_(4)将被去除。设计了一系列串级实验进行三级逆流萃取模拟,得到H_(2)SO_(4)的萃取率为95.40%,H_(3)PO_(4)的萃取率仅为3.33%。结果表明该体系对硫酸具有较高选择性,可实现H_(3)PO_(4)与H_(2)SO_(4)的高效分离。通过机理研究可知,萃取配合物以H_(2)SO_(4)·2[N235]形式存在,H_(2)SO_(4)通过与N235形成离子对络合物被萃取进入有机相中。The present work investigated a solvent extraction system of removing sulfuric acid and purifying phosphoric acid from waste aluminum polishing solution.The effects of trialkylamine(N235)concentration,extraction temperature,phase ratio and oscillation time on the extraction rate were systematically studied.The McCabe-Thiele diagram method predicts that more than 98%H_(2)SO_(4) could be removed after three theoretical stages at a phase ratio of O/A=2.A three-stage counterflow extraction was carried out through a series of batch countercurrent experiments,indicating that 95.40%H_(2)SO_(4) can be extracted,with co-extraction of only 3.33%H_(3)PO_(4).The results show that the system has high selectivity for H_(2)SO_(4) and achieves efficient separation of H_(3)PO_(4) and H_(2)SO_(4).According to the mechanism study,the compositions of the extraction complex was determined to be H_(2)SO_(4)·2[N235],and the N235 extraction of H_(2)SO_(4) occurred by the ion pair association mechanism.

关 键 词：溶剂萃取法 N235 铝材抛光废液 硫酸 磷酸 

分 类 号：TQ126.35[化学工程—无机化工] TQ028.32