稀土稀有稀散元素现代仪器测试全新方法的建立

本文系统总结了自2011年以来在三稀矿产实验测试方面取得的新进展。重点介绍了离子相稀土单元素浸泡提取实验研究、稀土原产地Nd同位素与微量元素示踪技术研究、离子吸附型稀土样品野外现场快速定性定量手持X射线荧光(XRF)分析研究成果。结果表明，采用25%硫酸铵浸泡提取，电感耦合等离子体光、质谱(ICP- AES、ICP- MS)测定，可以清晰反映出各稀土元素的浸泡提取率；采用高精度多接收电感耦合等离子体质谱仪(MC- ICP- MS)进行稀土矿石中Nd143/Nd144同位素比值测定，其比值差异可以示踪不同稀土矿石产地；通过精确测试分析不同产地稀土精矿样品中的稀土和其他微量元素含量，并进行数据相关性分析和数据分类分析，通过Y、Be和Bi三种元素含量的比较，可以判断稀土精矿来源；野外现场快速分析，20分钟可完成1件样品测试，不仅可定性判断是否为离子吸附型稀土，同时可定量各离子相稀土单元素含量，与室内精确分析结果符合性良好，可为我国离子吸附型稀土矿床的找矿快速筛查提供技术支撑。 同时介绍了混合酸微波分解样品- 电感耦合等离子体光、质谱(ICP- AES、ICP- MS)同时测定钨矿石、钼矿石、铌钽矿石中的多种稀有稀散稀土元素含量的方案。该方案的特点在于采用了耐氢氟酸体系，尤其对高含量W、Nb、Ta样品更具优势，否则易产生水解，导致测定结果系统偏低。同时梳理总结了我国常见三稀矿石地质样品的特点，针对不同矿种、不同矿床样品类型与基体特点，以及所测试元素种类的不同，研究建立了专门针对“稀有、稀散、稀土元素”现代仪器分析的10个全新的配套方法及其相应的技术指标(准确度、精密度、检出限)，可满足地质矿产实验室测试质量管理的规范要求，而且为我国三稀金属矿产资源的战略调查、国家重点研发计划“深地锂资源探测”和四川甲基卡等地找矿突破做出了贡献。

Establishment of new method for critical elements determination using modern analytical in struments

This paper systematically summarizes the new progress made incritical elements mineral experimental testing since 2011. The experimental research results of extracting ionic rare earth elements from ion- adsorption type rare earth samples by soaking with ammonium sulfate and tracing rare earth origin by Nd isotopes and trace elements, and, quick qualitative and quantitative analysis in field using XRF for ion- adsorption type rare earth sample are mainly introduced. The results showed that the difference of extraction rate of each rare earth elements could be clearly reflected by using 2.5% ammonium sulfate solution immersion extraction and ICP- AES and ICP- MS determination. Nd143/Nd144 isotope ratios in rare earth samples were determined by high precision MC- ICP- MS. The difference can be used to trace different rare earth samples origins. Through accurate analysis of rare earth and other trace elements in rare earth concentrate samples from different producing areas, data correlation analysis and data classification analysis were carried out. By comparing the contents of Y, Be and Bi, the source of rare earth concentrate can be judged. Rapid qualitative and quantitative analysis in the field can complete the determination of one sample in 20 minutes. This method can not only qualitatively judge whether it is ion adsorbed type rare earth, but also quantify the content of rare earth elements in each ion phase, and the result is in good agreement with the accurate analysis results in the laboratory. It can provide technical support for rapid screening of ion adsorbed type rare earth deposits in China. Determination scheme of critical elements in tungsten molybdenum and niobium tantalum ores using ICP- AES & ICP- MS with mixed acids microwave decomposition of samples are also mainly introduced. The characteristic of this scheme is that the hydrofluoric acid- resistant system is adopted. Especially for high content W, Nb and Ta samples. Otherwise, hydrolysis is easy to occur, which results in systematic low determination results. The characteristics of common geological samples of critical element ores in China are summarized. According to sample types, matrix characteristics and elements of interest, 10 new methods for critical elements determination using modern analytical instruments have been established. These methods meet the specification of testing quality management for geological laboratories.