酸溶-电感耦合等离子体质谱法测定煤系样品中稀土元素的方法研究  

Determination of Rare Earth Elements in Coal-related Samplesby Inductively Coupled Plasma-Mass Spectrometry with Acid Dissolution

作　　者：张欣[1] 孙红宾[1] 安子怡[1] 秦婧[1] 赵九江 于汀汀 王蕾[1] ZHANG Xin;SUN Hongbin;AN Ziyi;QIN Jing;ZHAO Jiujiang;YU Tingting;WANG Lei(National Research Center for Geoanalysis,Beijing 100037,China)

机构地区：[1]国家地质实验测试中心,北京100037

出　　处：《岩矿测试》2023年第5期903-914,共12页Rock and Mineral Analysis

基　　金：国家重点研发计划项目(2021YFC2903000)课题“战略性矿产多元素同时分析技术和标准化”;中国地质科学院基本科研业务费项目(CSJ-2022-04)。

摘　　要：煤和含煤岩系在特定地质条件下可以富集稀土等金属元素。煤及矸石燃烧后产生的飞灰,其金属元素富集度更高,有望成为稀土等关键矿产的替代来源之一。针对煤系样品有机物含量高、基体组成复杂等问题,本文通过溶样方式、消解酸体系、浸提液、质谱干扰及扣除等条件实验研究,利用高压密闭酸溶法和半密闭酸溶法建立了分别适用于煤和煤系样品中稀土元素的电感耦合等离子体质谱(ICP-MS)分析方法。结果表明,硝酸-氢氟酸高压密闭酸溶法能够实现煤中稀土元素的准确测定,但对煤飞灰和煤矸石的稀土元素回收率不稳定,不同样品稀土回收率在37%~123%之间。在原有消解酸体系中,加入硫酸和高氯酸或改用盐酸复溶,均不能有效地提高稀土元素的回收率。五酸半密闭酸溶可以实现煤飞灰、煤矸石等煤系样品中稀土元素的完全分解。利用X射线衍射(XRD)和扫描电子显微镜(SEM)技术对煤系样品中元素的赋存状态进行了初步解析,揭示了高铝矿物是造成煤矸石等煤系样品中稀土元素溶出率低的主要原因,为实验方案的制定和优化提供了理论依据。利用标准物质和实际样品开展了方法验证,所建方法具有良好的精密度(相对标准偏差为0.05%~9.98%)和正确度(相对误差为-10.2%~7.62%),检出限低,可以实现煤系样品中稀土元素的多元素准确测定,适用于大批量样品中稀土元素的分析测试。BACKGROUND:Coal and coal-bearing rock series can enrich beneficial elements such as rare earth under specific geological conditions,forming coal-related key metal deposits.In recent years,highly enriched rare metal elements such as gallium,germanium,uranium,gold,silver and rare earth elements have been successively discovered in coal.The fly ash produced by the combustion of coal and gangue has a higher enrichment degree of rare earth and other elements.These highly enriched metal elements will become one of the alternative sources of rare earth and other strategic key metals.In order to realize the comprehensive utilization of rare earth elements in coal-related samples,it is necessary to objectively evaluate the content level of rare earth elements in coal-related samples.Therefore,it is of great practical significance to establish a set of multielement quantitative analysis methods suitable for rare earth elements in coal-related samples.OBJECTIVES:To establish a set of analytical methods for the determination of rare earth elements in coal-related samples,and provide theoretical basis for the formulation and optimization of experimental schemes by analyzing the occurrence state of elements.METHODS:The method research of rare earth elements in coal-related samples was carried out by using a highpressure closed acid dissolution method and semi-closed acid dissolution method respectively.The sample mass,dissolution mode,acid decomposition system and extracting solution were analyzed experimentally.The recovery rates of rare earth elements by different methods were compared and analyzed,and the optimal dissolution method was determined.The interferences and interference elimination methods in the mass spectrometry determination of rare earth elements were discussed in detail.The occurrence state of elements in coal-related samples was analyzed by using XRD and SEM techniques,and the reason why the high-pressure closed acid dissolution method could not completely decompose coal gangue,coal fly ash and other sample

关 键 词：煤 煤矸石 煤飞灰 稀土元素 高压密闭酸溶 半密闭酸溶 电感耦合等离子体质谱法 

分 类 号：O657.63[理学—分析化学]