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