ICP-MS测定川滇黔相邻区高岭石黏土岩矿物中伴生关键三稀元素的前处理方法研究  

Research on Pretreatment Methods for ICP-MS Determination of the Associated Critical Three Rare Elements in Kaolinite Clay Rock Minerals in the Adjacent Areas of Sichuan,Yunnan,and Guizhou

作　　者：周万峰 王永鑫[2] 张安丰 ZHOU Wan-feng;WANG Yong-xin;ZHANG An-feng(Key Laboratory of Strategic Minerals Intelligent Exploration of Guizhou Province,Guiyang 550081,Guizhou,China;Guizhou Central Laboratory of Geology and Mineral Resources,Guiyang 550018,Guizhou,China;Engineering Technology Innovation Center of Mineral Resources Explorations in Bedrock Zones,Ministry of Natural Resources,Guiyang 550081,Guizhou,China)

机构地区：[1]贵州省战略矿产智慧勘查重点实验室,贵州贵阳550081 [2]贵州省地质矿产中心实验室,贵州贵阳550018 [3]自然资源部基岩区矿产资源勘查工程技术创新中心,贵州贵阳550081

出　　处：《贵州地质》2024年第1期101-108,17,共9页Guizhou Geology

基　　金：毕节试验区威宁县麻乍“三稀”矿产普查(黔自然资源函〔2021〕1360号)。

摘　　要：在川滇黔相邻区峨眉山玄武岩顶部与宣威组底部之间发育一套厚度较为稳定的风化壳,主要为高岭石黏土岩,富集有三稀元素。为弄清其品位及含量,本文采用XRD衍射分析、XRF分析主次量元素,选用几种熔矿前处理进行对比,试液用电感耦合等离子质谱(ICP-MS)测定。实验结果表明:①试样矿物组成主要为高岭石、锐钛矿、伊利石、钛铁矿、板钛矿等,其中高岭石占比62.3%~89.85%,锐钛矿占比2.50%~11.8%,伊利石占比1.8%~18.0%,钛铁矿占比0.10%~1.00%,板钛矿占比0.70%~7.00%,其主量元素主要为Si、Al、Fe、Ti。②微波消解法较适用于Sc的消解处理,但对于Nb和Zr元素,数据偏低,其余差异性不显著。③碱熔-沉淀分离法较适用于难溶矿物分解,不仅打开矿物晶格,且在沉淀剂或络合剂的作用下,实现纯化试液目的,有效降低基体干扰,提高数据准确性,较适用于Pr、Nd、Tb、Dy、Nb、Zr元素的方法前处理;④碱熔-熔融物酸化法适用于Ga的熔矿前处理,在KED模式下,有效降低背景干扰,提高了准确性。体系方法检出限介于0.011~1.66μg/g之间,测定下限介于0.044~6.65μg/g之间,RSD介于2.06%~11.1%之间,RE介于0.99%~9.90%之间。经实际样品验证,方法较适用于该地区试样中关键三稀元素的测定。There is a set of weathering crusts with relatively stable thickness between the top of Mount Emei basalt and the bottom of the Xuanwei Formation in the adjacent areas of Sichuan,Yunnan,and Guizhou,it is enriched with three rare elements and mainly composed of Kaolinite clay rock.In order to find out its ore grade and content,this study used X-ray diffraction(XRD)to analyze the mineral composition,and X-ray fluorescence(XRF)to analyze the major and trace elements.Several different pre-melting treatment methods were used for comparison,and the test solution was determined by inductively coupled plasma-mass spectrometry(ICP-MS).The test results show that:①The mineral composition sample mainly consists of kaolinite,anatase,illite,ilmenite,brookite,etc.,of which kaolinite accounts for 62.3% to 89.85%,anatase accounts for 2.50% to 11.8%,illite accounts for 1.8% to 18.0%,ilmenite accounts for 0.10% to 1.00%,and brookite accounts for 0.70% to 7.00%.Its major elements are Si,Al,Fe,and Ti.②High-pressure closed microwave dissolution method is suitable for the dissolution of the concomitant rare earth element Sc,but for Nb and Zr,the data show a lower trend,while differences in other elements are not significant.③Alkali fusion-precipitation separation method is suitable for the decomposition of the insoluble metal minerals,which not only opens the mineral lattice but also effectively purifies the test solution through the use of precipitant or test complexing agents.It effectively reduces matrix interference and improves data accuracy.The method is suitable for the pre-treatment of elements Pr,Nd,Tb,Dy,Nb,and Zr.④Alkali fusion-acidification of fused material is suitable for the pre-fusion treatment of the spersed element Ga.By using kinetic energy discrimination(KED)mode,it effectively reduces spectral interference and improves the accuracy of Ga determination.The detection limit of the system method ranged from 0.011μg/g to 1.66μg/g,the lower limit of determination ranged from 0.044μg/g to 6.65μg/g.The relative

关 键 词：三稀元素 碱熔法 微波消解法 电感耦合等离子体质谱法(ICP-MS) 

分 类 号：P588.22[天文地球—岩石学] O657.63[天文地球—地质学] O652.4[理学—分析化学] O614.33[理学—化学] O614.37