二苯硫腙萃取分离磷酸钠溶液中微量锌离子  

Extraction and separation of trace zinc ion in sodium phosphate solution by dithizone

作　　者：欧小菊 何倩 李正科 王威燕[1] 刘文英[1] 杨运泉[1] OU Xiao-ju;HE Qian;LI Zheng-ke;WANG Wei-yan;LIU Wen-ying;YANG Yun-quan(School of Chemical Engineering,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]湘潭大学化工学院,湘潭411105

出　　处：《中国有色金属学报》2020年第10期2435-2443,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51974274);湖南省自然科学基金资助项目(14JJ5027)。

摘　　要：采用理论分析与实验验证相结合的方法,研究了二苯硫腙萃取分离磷酸钠溶液中锌离子的萃取行为,考察了二苯硫腙在甲苯、苯、三氯甲烷及四氯化碳中的溶解度。在此基础上,研究以苯及三氯甲烷为溶剂的二苯硫腙萃取体系对磷酸钠溶液中微量锌的萃取平衡关系,探讨体系pH值、搅拌速度、萃取剂用量、温度及相比等因素对萃取效果的影响。结果表明:二苯硫腙在三氯甲烷中的溶解度最大,25℃时达17.55 g/L;在萃取体系pH为7.25、搅拌转速为550 r/min、温度为25℃、相比(A/O)为1:1时,浓度为1.2 g/L的二苯硫腙−三氯甲烷有机相对磷酸钠溶液中微量锌的单级萃取率可达92.57%;萃取时,二苯硫腙与溶液中的锌离子以近似2:1的摩尔比进行螯合;该螯合反应为吸热反应,反应焓变值为26.02 kJ/mol。The extraction behavior of trace zinc(II)in sodium phosphate solution was studied by dithizone extraction.The solubility of dithizone in toluene,benzene,chloroform and carbon tetrachloride was investigated experimentally.On this basis,the extraction equilibrium relationship of trace zinc in sodium phosphate solution was studied by using dithizone as extractant and benzene or chloroform as its solvent,respectively.The effects of the extraction system pH,the stirring speed,the amount of extractant,the temperature and the phase ratio on the extraction efficiency were investigated.The results show that,among the four solvents,the solubility of dithizone in chloroform is the highest,reaching 17.55 g/L at 25℃.When the pH of the extraction system is 7.25,the stirring speed is 550 r/min,the temperature is 25℃and the phase ratio is 1:1,the single-stage extraction efficiency of trace zinc can reach 92.57%with a concentration of 1.2 g/L of dithizone in trichloromethane.During the extraction,the molar ratio of dithizone and zinc in the chelate was estimated at approximately 2:1;the chelating reaction was an endothermic reaction with a reaction enthalpy change of 26.02 kJ/mol.

关 键 词：二苯硫腙 萃取 锌离子 磷酸钠溶液 反应焓变 

分 类 号：TQ115[化学工程—无机化工]