稀土產品中釷的測定
朱智超
摘 要：為解決高含量稀土和釷的分離問題對稀土產品中釷進行測定。該方法對比酒石酸、三乙醇胺的用量，設計分離富集工藝，采用743型大孔樹脂分離稀土和釷，使用偶氮胂III比色法測定。試樣經過堿熔，水浸取加入三乙醇胺，過濾。沉淀用鹽酸（4 mol/L）溶解，在酒石酸存在下，用鹽酸（4 mol/L）淋洗雜質，用氯化銨溶液（20%）將樹脂轉化為銨型后，再用草酸銨溶液（4%）洗脫釷。在鹽酸（4 mol/L）介質中，用偶氮胂III顯色于波長660 nm處測定。實驗表明該方法操作簡便，設備簡單，結果穩定，精密度和準確度高。
關鍵詞：稀土產品；釷；743型大孔樹脂；偶氮胂III；分離富集
中圖分類號：TG146.4；TF125.2+4；O615.2；O633 文獻標志碼：A 文章編號：1674-5124（2013）05-0053-03
Determination of thorium in rare earth products
ZHU Zhi-chao
（Sichuan Radiation Detection and Protection Institute of Nuclear Industry，Chengdu 610503，China）
Abstract: In order to separate thorium from the high-content rare earth and determine thorium in rare earth products， the authors studied the impact of tartaric acid， triethanolamine at different dosage， designed the routing of extraction and enrichment with macroporous resin 743 as separation materials， and thorium contents was determined by arsenazo III colorimetric method. In this method， the sample was digested with alkaline solution， extracted with aqueous triethanolamine. After it was filtered， the precipitate was dissolved with 4 mol/L hydrochloric acid. In the presence of tartaric acid， the impurities of resin was eluted with 4 mol/L hydrochloric acid， and the resin was converted to ammonium resin with 20% ammonium chloride solution， then thorium was eluted with 4% ammonium oxalate solution. In 4 mol/L hydrochloric acid， the extract was reacted with arsenazo III， and measured at the wavelength of 660 nm. This method is easy in operation， simple in the requirement of equipments， and the measurement results is stable， precise and accurate.
Key words: rare earth product； thorium； 743 macroporous resin； arsenazo III； separation and enrichment
