化学学报 ›› 1962, Vol. 28 ›› Issue (3): 139-147. 上一篇    下一篇

论文

鈧与釷之分离及测定 Ⅲ.以四氯邻苯二甲酸作试剂

梁樹权, 洪水皆   

  1. 中国科学院化学研究所
  • 修回日期:1961-09-12 发布日期:2013-06-03

ON THE SEPARATION AND DETERMINATION OF SCANDIUM AND THORIUM Ⅲ. TETRACHLOROPHTHALIC ACID AS A REAGENT

LIANG SHU-CHUAN, HUNG SHUI-CHIEH   

  1. Institute of Chemistry, Academia Sinica
  • Revised:1961-09-12 Published:2013-06-03

本文报告以四氯邻苯二甲酸作钪的沉淀剂。适宜于沉淀的溶液酸度为pH2.4—4.4。每一克原子钪需2.5—3克分子沉淀剂,而多至8克分子沉淀剂亦无影响。测定范围在1—102毫克氧化钪之间。本文尚列有四氯邻苯二甲酸的钪盐和钍盐之热分解曲线,钪盐之曲线在80—150℃之间有一平台,经分析证明其钪盐之粗成为C6Cl4(COO)-2Sc(OH)·H2O。另在670—960℃(高于960℃未测)有一平台(形成氧化钪)。钍盐之热分解曲线形式与钪盐相仿,亦有二平台,(a)在80—150℃之间和(b)在720—960℃之间,分别相当于[C6Cl4(COO)2]2Th·3H2O及氧化钍之形式。两盐经在120℃干燥后均适于作称衡形式。文中尚报告数种阴离子和碱金属盐之影响,以及与希土元素之分离情形,经两次沉淀轻希土虽多至一百倍而钇多至十倍亦不干扰。在pH2.5—3.4之间希土与本斌剂的沉淀极少(0.3—2毫克希土氧化物)。同时尚设计测定钪和钍的方法,系先在pH1.0—1.1之间两次沉淀钍,再将滤液调节至pH3.0沉淀钪,曾试验Sc2O3:ThO2重量比在1:2.5至1:9.8时结果良好,绝对误差在±0.0至+0.7毫克二氧化钍和+0.1至+0.3毫克氧化钪范围内。

Tetrachlorophthalic acid has been used as a precipitant for the determinations of thorium[1] and zirconium[2].These two metals precipitate at rather high acidifies.Recently, the solubility products of thorium, lanthanum, praseodymium, and neodymium tetra-chlorophthalates have been reported[3].It is interesting to note that Crookes[4] already prepared scandium tetrachlorophthalate in 1910.These facts lead us to study the said acid as a reagent for scandium and its separation from thorium.It is found that scandium precipitates quantitatively with tetrachlorophthalic acid in the pH range of 2.4-4.4 (cf.Table 1*), whilst thorium in pH 1.0-1.1[1].Hence, there exists the possibility of separating these two elements simply by adjusting the acidity of the solution, which has been substantiated experimentally in this communication.