微波消解-电感耦合等离子体质谱法测定钨钼矿中多种微量稀土元素  

Determination of Trace Rare Earth Elements in Tungsten-Molybdenum Ore by Inductively Coupled Plasma-Mass Spectrometry with Microwave Digestion System

作　　者：曹俊飞 王婷 李剑 李鹰 CAO Junfei;WANG Ting;LI Jian;LI Ying(Hangzhou Expec Technology Development Inc.,Hangzhou 311300,China)

机构地区：[1]杭州谱育科技发展有限公司,浙江杭州311300

出　　处：《岩矿测试》2023年第4期863-875,共13页Rock and Mineral Analysis

基　　金：杭州市重大科技创新项目“基于质谱技术的全自动重金属智能分析系统研制及产业化”(20182011A25)。

摘　　要：钨钼矿和稀土均是重要战略资源,评估钨钼矿中稀土元素含量对矿产中稀土资源开发利用具有重要意义。钨钼矿样品前处理时碱熔熔剂会引入盐分基体,酸溶法钨钼元素易水解和产生稀土氟化物。本文拟建立一种在微波中以混合酸体系实现快速消解,结合电感耦合等离子体质谱法(ICP-MS)准确分析钨钼矿中16种稀土元素的分析方法。样品采用硝酸-氢氟酸-高氯酸-盐酸体系在微波中进行处理,随后赶酸至黏稠状并以柠檬酸-盐酸溶液温热溶解络合钨钼,避免在酸性环境下钨钼易发生水解及产生稀土氟化物等问题;利用ICP-MS在线加内标及动能歧视策略对样品分析稀土元素进行实时校正,降低基体效应、多原子离子等干扰的影响。该方法精密度RSD<2.0%(n=7),检出限为0.0002~0.0087μg/g,加标回收率为80.0%~114.0%,样品测试平均值与标准物质标准值对数误差的绝对值|ΔlgC|≤0.1,符合地质矿产行业要求。应用该方法分析钨钼矿标准物质(GBW07239和GBW07238)和三种实际样品,结果表明标准物质中16种稀土元素含量在标准值范围;应用于分析河南钨钼矿中稀土元素测定值在0.198~41.2μg/g之间,与吉林辉钼矿石中0.013~5.53μg/g和云南钨矿石石英片岩0.68~107.0μg/g、电气石岩0.071~2.11μg/g相较,具有空间分布特征和岩石种类差异研究意义。BACKGROUND:Tungsten-molybdenum ore and rare earth are both important strategic resources.It is of great significance to evaluate the contents of rare earth elements in tungsten-molybdenum ore for the development of rare earth resources in minerals.During the pretreatment of tungsten and molybdenum ore samples,the alkali melting flux will introduce the salt matrix,and the tungsten and molybdenum elements in an acid dissolution condition are easy to hydrolyze into tungstic acid and molybdic acid and produce rare earth fluoride.OBJECTIVES:To establish an analytical method for accurate determination of the 16 rare earth elements including La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y,and Sc,in tungsten-molybdenum ore by inductively coupled plasma-mass spectrometry(ICP-MS).METHODS:Tungsten-molybdenum ore samples were fast digested by microwave with four acid system(HNO3-HF-HClO4-HCl)in a high temperature and high-pressure environment.Then the digestion acid solution was evaporated to the viscous state,and the mixed solution(citric acid-hydrochloric acid)was used to dissolve the complexed tungsten and molybdenum at warm temperature,which effectively avoided the introduction of salt matrix in the pretreatment of tungsten-molybdenum ore samples.The problem of tungsten and molybdenum easily hydrolyzing into tungstic acid and molybdic acid was also solved,and rare earth fluoride in an acid environment was produced.Online internal standard and kinetic energy discrimination(KED)strategy were used in real-time to calibrate the sample analysis by ICP-MS,which solved the interference problems of matrix effect and polyatomic ions in the analysis process.RESULTS:The 16 rare earth element contents of tungsten molybdenum standard material(GBW07239 and GBW07238)and real samples(1#,2#and 3#)was efficiently measured.The results showed that the concentrations of 16 rare earth elements were within the scope of the standard value,the contents of real samples were 0.198-41.2μg/g.Relative standard deviation(RSD)of method precision was lower

关 键 词：钨钼矿 稀土元素 微波消解 电感耦合等离子体质谱法 动能歧视 

分 类 号：O614.33[理学—无机化学] O657.63[理学—化学]