硫氰酸盐介质中P_(538)萃取镧(Ⅲ)的机理  

Study on the Mechanism of the Extraction of Lanthanum(Ⅲ) with P538 in Thiocyanate

作　　者：玉占君[1] 张文伟[1] 董金庆[2] 迟理建[2] 

机构地区：[1]辽宁师范大学化学系,辽宁大连116029 [2]大连经济技术开发区 东泰废弃物处理有限公司,辽宁大连116600

出　　处：《辽宁师范大学学报（自然科学版）》2001年第1期57-59,共3页Journal of Liaoning Normal University:Natural Science Edition

摘　　要：借助直接光度法确定硫氰酸盐介质中Ｐ５３８萃取镧（Ⅲ）的机理为离子交换机理．萃合物的组成为Ｌａ（ＨＡ）３·２Ｈ２Ａ，萃取平衡常数Ｋｅｘ＝１．３７ ±０．０４，具有硫氰酸根与分配比呈减函数关系和硫氰酸根未进入有机相的特点．提出萃取法测定硫氰酸镧（Ⅲ）的配合物稳定常数，得到β１＝２．６３，β２＝２．１７（２５℃，Ｉ＝１．６）．可应用ＮＨ４ＳＣＮ水相浓度调节萃取镧（Ⅲ）的分配比从而提高萃取分离镧（Ⅲ）的选择性，得到不含ＳＣＮ－１的萃取有机相．In this paper, we study the mechanism of the extraction of Lanthanum(Ⅲ) with P538 with the help of direct spectroscopy. The mechanism of this extraction was found the ionic exchange. The extract component are La(HA)3.2H2A.No thiocyanate comes in extracts. The stability constants of the extraction were determined as β1=2.63,β2+2.17 (25℃,I=1.6). The extraction equilibrium constant Kex=1.37±0.04.An experimental rule which no aqueous second liqand(SCN-) can insert to extracte was suggest.

关 键 词：萃取平衡 硫氰酸镧 P538 硫氰酸盐 直接光度法 萃取机理 离子交换机理 

分 类 号：O614.331[理学—无机化学] O658.2[理学—化学]