磷铍钙石中铍元素的电子探针定量分析  

Quantitative Analysis of Be in Herderite by Electron Probe Microanalysis

作　　者：刘泽 陈振宇[1] 陈小丹 徐文坦 刘春花[1] 诸泽颖 牛之建 赵晨辉 赵云彪 LIU Ze;CHEN Zhenyu;CHEN Xiaodan;XU Wentan;LIU Chunhua;ZHU Zeying;NIU Zhijian;ZHAO Chenhui;ZHAO Yunbiao(Key Laboratory of Metallogeny and Mineral Resource Assessment,Ministry of Natural Resources,Institute of Mineral Resource,Chinese Academy of Geological Sciences,Beijing 100037,China;School of Earth Science,Institute of Disaster Prevention,Langfang 065201,China)

机构地区：[1]自然资源部成矿作用与资源评价重点实验室,中国地质科学院矿产资源研究所,北京100037 [2]防灾科技学院地球科学学院,河北廊坊065201

出　　处：《岩矿测试》2024年第5期703-712,共10页Rock and Mineral Analysis

基　　金：国家自然科学基金项目(42330806,41872096,42002109);国家重点研发计划项目(2019YFC0605200)。

摘　　要：前人使用配有LDEB或LDE3H的电子探针,建立了针对铍硅酸盐、铍氧化物以及铍硼酸盐中Be含量的定量分析方法。然而,缺乏对铍磷酸盐矿物中Be含量的定量分析方法。目前,使用配备LSA300分光晶体的电子探针对铍磷酸盐矿物进行分析时,P元素的高级次阶峰会抬高Be Kα峰的上背景值,从而导致Be含量的测量结果不准确。本文使用配备LDE3H分光晶体的电子探针,对江西狮子岭花岗岩中的磷铍钙石,采用不同的加速电压和分析束流,进行最佳定量分析条件的探索。实验结果表明:磷铍钙石的最佳电子探针定量分析条件为:加速电压10kV,分析束流20nA。在此条件下,获得的磷铍钙石P_(2)O_(5)平均含量为43.23%,BeO平均含量为15.39%,CaO平均含量为33.89%,F平均含量为7.94%,BeO标准误差为0.3%。本研究发现配有LDE3H分光晶体的电子探针,可以设置合适的Be背景来消除P的高级次阶峰的干扰。此外,含Be矿物的测量难点与Be特征X射线本身的特征、含Be矿物的晶体结构、化学成分均有关。磷铍钙石定量分析方法的探索,解决了电子探针对铍磷酸盐矿物Be元素进行准确定量时,P元素产生的干扰难题,进一步提升电子探针对铍含量测量的准确度。Previously,researchers employed electron probe microanalysis(EPMA)furnished with LDEB or LDE3H to establish a quantitative analysis approach for the Be content in beryllium silicates,beryllium oxides,and beryllium borates.Nevertheless,a quantitative analysis method for the Be content in beryllophosphate minerals is still lacking.At present,when EPMA equipped with LSA300 crystal is used to analyze beryllophosphate minerals,the higher-order peaks of P will raise the upper background value of the Be Kαpeak,resulting in inaccurate measurement results of Be content.In this study,the EPMA equipped with LDE3H crystal was used to explore the optimal quantitative analysis conditions for herderite in Shiziling granite in Jiangxi Province by using different accelerating voltages and probe currents.The experimental results show that the optimal EPMA quantitative analysis conditions for herderite are:acceleration voltage of 10kV,and probe current of 20nA.Under these conditions,the average content of P_(2)O_(5),BeO,CaO,F is 43.23%,15.39%,33.89%,and 7.94%,respectively,and the standard error of BeO is 0.3%.It is found that the EPMA equipped with LDE3H crystal can set a suitable Be background to eliminate the interference of the higher order peaks of P.In addition,the difficulty of Be measurement is related to Be characteristic X-ray,crystal structures and chemical composition of Be minerals.The exploration of a quantitative analysis method of herderite solves the problem of interference of P element when the EPMA accurately quantifies the Be element of beryllophosphate minerals,and further improves the accuracy of the measurement of beryllium content by EPMA.

关 键 词：电子探针 Be 磷铍钙石 铍磷酸盐矿物 江西狮子岭花岗岩 

分 类 号：O614.21[理学—无机化学] P575.1[理学—化学]