敞开酸溶-电感耦合等离子体质谱法测定铀矿石中15种稀土元素  

Determination of 15 Rare Earth Elements in Uranium Ore by Open Acid Dissolution-Inductively Coupled Plasma-Mass Spectrometry

作　　者：曾江萍 王家松 朱悦 张楠[1,3] 王娜[1,2] 吴良英 魏双 ZENG Jiangping;WANG Jiasong;ZHU Yue;ZHANG Nan;WANG Na;WU Liangying;WEI Shuang(Tianjin Center,China Geological Survey,Tianjin 300170,China;North China Center for Geoscience Innovation,Tianjin 300170,China;Key Laboratory of Coast Geo-Environment,China Geological Survey,Tianjin 300170,China;Tianjin Geological and Mineral Testing Center,Tianjin 300191,China)

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]华北地质科技创新中心,天津300170 [3]中国地质调查局海岸带地质环境重点实验室,天津300170 [4]天津市地质矿产测试中心,天津300191

出　　处：《岩矿测试》2022年第5期789-797,共9页Rock and Mineral Analysis

基　　金：中国地质调查局地质调查项目“地质调查标准化与标准制修订(中国地质调查局天津地质调查中心)”(DD20190472);中国地质调查局地质调查项目“国家地质大数据汇聚与管理(中国地质调查局天津地质调查中心)”(DD20190382)。

摘　　要：研究铀矿石中的稀土元素特征可以判断其成矿流体物质来源、成岩构造环境和物化条件等,因此准确测定铀矿石中稀土元素的含量显得尤为重要。目前测定稀土元素主要采用电感耦合等离子体质谱法(ICP-MS),样品处理多采用封闭酸溶法,而敞开酸溶法应用不多,主要原因是敞开酸溶时常常加入高氯酸,溶样温度难以将稀土氟化物完全分解而造成测定结果偏低,但在溶样过程中引入硫酸,利用硫酸的高沸点则能完全分解稀土氟化物。基于此原理,本文采用硝酸-氢氟酸-高氯酸-硫酸四酸体系对铀矿石样品进行敞开酸溶,采用在线加入铑内标的方式,建立了ICP-MS法测定铀矿石中15种稀土元素的方法。结果表明:溶样时加入硫酸能完全溶解铀矿石样品,溶液澄清,15种稀土元素的相对标准偏差(RSD)在0.54%~5.98%之间,回收率在96.0%~106.0%之间。将本方法应用于分析岩石国家标准物质(GBW07103、GBW07104、GBW07122),其测定值与标准值一致,相对误差在-8.33%~7.24%之间,表明本方法测定稀土元素是可行的。BACKGROUND:Studying the characteristics of rare earth elements in uranium ore can determine the source of the ore-forming fluids,the mineralization environment,and the physical and chemical conditions.It is particularly important to accurately determine the content of rare earth elements in uranium ore.At present,rare earth elements are mainly determined by inductively coupled plasma-mass spectrometry(ICP-MS).High-pressure closed acid-dissolution is commonly used.The open acid dissolution method is rarely used because perchloric acid is routinely used to dissolve samples,and the temperature is relatively low,which may cause incomplete decomposition of some samples.OBJECTIVES:In order to solve the problem that the rare earth elements have contents lower than real values in open acid dissolution.METHODS:The tetracid system of nitric acid-hydrofluoric acid-perchloric acid-sulfuric acid was used in the open acid dissolution method.ICP-MS with Rh as internal standard was used to determine 15 rare earth elements in uranium ore.RESULTS:The relative standard deviation(RSD)of the 15 rare earth elements was between 0.54% and 5.98%,and the recovery was between 96.0% and 106.0%.Applying to national rock standard materials(GBW07103,GBW07104,GBW07122),the measured values were consistent with the standard values,and the relative error(RE)was between-8.33% and 7.24%,indicating that this method was effective for the determination of rare earth elements.CONCLUSIONS:The method has simple operation,accurate and reliable results,and is suitable for the determination of rare earth elements in large quantities of uranium ore.

关 键 词：铀矿石 稀土元素 硝酸-氢氟酸-高氯酸-硫酸敞开酸溶 电感耦合等离子体质谱法 

分 类 号：O657.31[理学—分析化学]