摘要
砂岩型铀矿是重要的战略性矿产资源,分析铀钍元素含量对砂岩型铀矿的矿床评价和综合利用有重要意义。砂岩型铀矿中铀钍元素的分析目前主要采用酸溶和碱熔方式处理样品,电感耦合等离子体发射光谱法(ICP-OES)进行检测。敞口酸溶法处理样品时往往分解不完全导致结果偏低,碱熔法过程冗长,不利于快速检测,且砂岩型铀矿中铁元素含量很高会对铀钍测量产生干扰。采用微波消解对样品进行处理,在盐酸提取液中加入EDTA和三乙醇胺混合溶液作为掩蔽剂,与溶液中的铁离子形成配合物有效地消除了共存元素铁对铀钍测定的干扰。实验优化了各元素的分析谱线,对掩蔽剂用量进行对比试验以获得最佳条件,采用干扰校正系数法基本消除了共存元素的谱线干扰。标准曲线线性相关系数大于0.9995,方法检出限铀为0.70μg/g,钍为0.58μg/g,标准物质测定结果的相对误差为1.47%~1.82%,相对标准偏差(RSD,n=12)为1.32%~1.78%。该方法操作简单,能够准确地同时测定砂岩型铀矿中的铀和钍元素。
BACKGROUND:Sandstone-type uranium deposits are important strategic mineral resource.Rapid and accurate analysis of uranium and thorium content is of great significance to the evaluation and comprehensive utilization of this type of deposit.At present,the analysis of uranium and thorium is mainly determined by acid dissolution and alkali fusion methods to decompose samples.For the open acid dissolution method,the decomposition is often incomplete,resulting in lower results.The alkali fusion process is lengthy,which is not conducive to rapid detection.In addition,the high content of iron elements in sandstone type uranium deposits interfere with the measurement of uranium and thorium.OBJECTIVES:To develop a method which can determine uranium and thorium in sandstone uranium deposits by inductively coupled plasma-optical emission spectrometry(ICP-OES)with microwave digestion.METHODS:The samples were treated by microwave digestion technology,EDTA and triethanolamine mixed solution were added to the hydrochloric acid extract as masking agents to form a complex with iron ions in the solution,which effectively eliminated the interference of coexisting elemental iron on the determination of uranium and thorium.The experiment optimized the analytical spectral lines of each element,compared the amount of masking agent to obtain the best conditions,and basically eliminated the spectral line interference of coexisting elements by using the interference correction coefficient method.RESULTS:The linear correlation coefficients of standard curves were greater than 0.9995,and the detection limit of uranium and thorium were 0.70μg/g,and 0.58μg/g,respectively.The relative error of the determination results of reference materials was 1.47%-1.82% and the relative standard deviation(RSD,n=12)was 1.32%-1.78%.CONCLUSIONS:The method is simple to operate,effectively masking the interference of iron on uranium and thorium,and can be used to accurately complete the simultaneous determination of uranium and thorium in sandstone-type uranium deposits.
作者
张莉娟
方蓬达
王力强
王家松
ZHANG Lijuan;FANG Pengda;WANG Liqiang;WANG Jiasong(Tianjin Center,China Geological Survey,Tianjin 300170,China;North China Center for Geoscience Innovation,Tianjin 300170,China)
出处
《岩矿测试》
CAS
CSCD
北大核心
2022年第5期798-805,共8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(2019-2021)”(DD20190472)。
关键词
砂岩型铀矿
微波消解
EDTA
三乙醇胺
电感耦合等离子体发射光谱法
sandstone uranium ore
microwave digestion
EDTA
triethanolamine
inductively coupled plasma-optical emission spectrometry
