熔融制样-X射线荧光光谱法同时测定稀土矿石中萤石、重晶石及天青石  

Simultaneous Determination of Fluorite,Barite and Celestite in Rare Earth Ores by X-Ray Fluorescence Spectrometry after Fusion Sample Preparation

作　　者：李可及[1] 张丽军[1,2] 熊文良[1,2] LI Keji;ZHANG Lijun;XIONG Wenliang(Institute of Multipurpose Utilization of Mineral Resources,Chinese Academy of Geological Sciences,Chengdu 610041,China;Technology Innovation Center of Rare Earth Resources Development and Utilization,CGS,Chengdu 610041,China)

机构地区：[1]中国地质科学院矿产综合利用研究所,成都610041 [2]中国地质调查局稀土资源应用技术创新中心,成都610041

出　　处：《理化检验（化学分册）》2021年第9期855-859,共5页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：自然资源部科技创新人才培养工程(12110600000018003914)。

摘　　要：建立了熔融制样-X射线荧光光谱法(XRFS)同时测定稀土矿石中萤石、重晶石及天青石含量的方法。参考DZ/T 0130.2-2006制备样品粉末,以150 mL水磁力搅拌溶解样品中的硫酸钙,静置后弃去部分上清液,剩余溶液体积约30 mL。随后加入与剩余溶液等体积的含钙和锶的乙酸溶液,于电热板上微沸5 min,再补加与剩余溶液等体积的乙醇,混匀静置后过滤,排除样品中的碳酸钙、碳酸钡和碳酸锶等干扰。将滤纸及沉淀转移至铂-金坩埚内,烘干后置于马弗炉内,于800℃灰化,补加二氧化硅至灰分质量达到0.800 0 g,加入8.000 0 g混合熔剂(由质量比为12∶22的四硼酸锂和偏硼酸锂混合而成)及0.1 g脱模剂碘化铵,于1 100℃熔融620 s,所得样片按照XRFS工作条件测定。以纯物质和标准物质混合熔融配制的标准样品系列制作校准曲线,以基本参数法校正基体效应,将氧化钙、氧化钡和氧化锶的含量转换成氟化钙、硫酸钡和硫酸锶的,以表征萤石、重晶石和天青石的含量。结果显示:校准曲线的相关系数均大于0.999 5;方法用于自制样品及实际样品的分析,自制样品的测定值与已知值基本一致,实际样品测定值的相对标准偏差(n=6)均不大于2.0%。A method for simultaneous determination of contents of fluorite, barite and celestite in rare earth ores was established by X-ray fluorescence spectrometry(XRFS) after fusion sample preparation. The sample powder was prepared through DZ/T 0130.2-2006, and calcium sulfate in the sample was dissolved by 150 mL water with magnetic stirring. After standing still, part of the supernatant was discarded, the remaining solution volume was about 30 mL. The same volume of acetic acid solution containing calcium and strontium as the remaining solution was added and kept boiling slightly for 5 min on the electric hot plate, the same volume of ethanol as the remaining solution was added, and the mixed solution was kept steady condition and filtered, thus to remove the interference from calcium carbonate, barium carbonate and strontium carbonate. The filter paper together with precipitate was transferred into a Pt-Au crucible and dried. The crucible was placed into a muffle furnace for ashing at 800 ℃, and silica was added until the ash mass reached 0.800 0 g. Mixed flux(8.000 0 g) composed of lithium tetraborate and lithium metaborate with mass ratio of 12∶22 and 0.1 g release agent of ammonium iodide were added for melting at 1 100 ℃ for 620 s, and the glassy slice of sample was analyzed under the optimal XRFS instrument working conditions. The series of standard samples by mixing pure substances and standard substances were prepared to make calibration curves, matrix effect was calibrated with the basic parameter method, and the contents of calcium oxide, barium oxide and strontium oxide were calculated and converted to those of calcium fluoride, barium sulfate and strontium sulfate to characterize the content of fluorite, barite and celestile. The results showed that correlation coefficients of standard curves were above 0.999 5;the proposed method was used for the analysis of self-made samples and actual samples, with the determined values basically consistent with the known values of the self-made samples and RSDs(

关 键 词：熔融制样 X射线荧光光谱法 萤石 重晶石 天青石 稀土矿石 

分 类 号：O657.34[理学—分析化学]