离子选择电极法与电感耦合等离子体原子发射光谱法联用测定锡石和铅锌硫化物共/伴生萤石中氟化钙  

Determination of calcium fluoride in cassiterite and lead zinc sulfide co/associated fluorite by ion selective electrode method combined with inductively coupled plasma atomic emission spectroscopy

作　　者：王学伟 陈春永 冯丽琼 金婷婷 陈娜 方文韬 WANG Xuewei;CHEN Chunyong;FENG Liqiong;JIN Tingting;CHEN Na;FANG Wentao(Testing Center of Yunnan Nonferrous Geological Bureau,Kunming 650216,China;Geological,Geophysical and Chemical Exploration Institute of Yunnan Nonferrous Geological Bureau,Kunming 650216,China)

机构地区：[1]云南省有色地质局测试中心,云南昆明650216 [2]云南省有色地质局地质地球物理化学勘查院,云南昆明650216

出　　处：《冶金分析》2024年第11期89-96,共8页Metallurgical Analysis

基　　金：云南省2023年度新一轮找矿暨地勘基金项目(K202312)。

摘　　要：锡石和铅锌硫化物共/伴生萤石中CaF_(2)含量为1%~50%(质量分数,下同),而现行的行业标准方法适用于CaF_(2)含量大于3%的萤石样品。行业标准方法中存在0.30%的经验校正系数,因此含量在10%以下的CaF_(2)测定结果准确性不高。实验使用乙酸(1+9)分离除去CaCO_(3)、CaSO_(4)等易溶于乙酸的含钙杂质,离子选择电极法测定微溶于滤液中的F-;残渣采用AlCl_(3)浸取,选择In作为内标元素,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定浸取液中的Ca;将两种方法的结果换算成CaF_(2)后相加即为萤石中CaF_(2)含量,从而建立了离子选择电极法与ICP-AES联用测定锡石和铅锌硫化物共/伴生萤石中氟化钙的方法。实验考察了AlCl_(3)溶液质量浓度、AlCl_(3)溶液浸取时间、Ca及其内标元素的谱线等对Ca测定的影响。方法中CaF_(2)的检出限为0.010%,定量限为0.040%。按照实验方法测定锡石实际样品、铅锌硫化物实际样品和萤石标准物质中CaF_(2),测定结果的相对标准偏差(RSD,n=6)为0.22%~0.90%,相对误差(RE)为0.08%~0.63%。方法解决了CaF_(2)测定过程中经验校正系数的问题;ICP-AES中采用内标法消除了由于环境温度波动和电子元件性能变化等导致仪器漂移而对分析结果产生的影响;方法的测定范围得到有效改善,可用于测定锡石和铅锌硫化物共/伴生萤石中CaF_(2)。The content of CaF_(2)in cassiterite and lead zinc sulfide co/associated fluorite is in range of 1%-50%(mass fraction,the same below).However,the current industry standard method is applicable for fluorite samples with CaF_(2)content higher than 3%.There is an empirical correction coefficient of 0.30%in industry standard methods,so the accuracy of CaF_(2)determination results below 10%is not high.In this study,acetic acid(1+9)was used to separate and remove calcium containing impurities such as CaCO_(3)and CaSO_(4)that are easily soluble in acetic acid.Then the content of F-which was slightly soluble in the filtrate was determined by ion selective electrode method.The residue was extracted using AlCl_(3),and In was selected as the internal standard element.The content of Ca in the extraction solution was determined by inductively coupled plasma atomic emission spectrometry(ICP-AES).The results of two methods were converted into CaF_(2)and then added together to obtain the CaF_(2)content in fluorite.Therefore,a method for the determination of calcium fluoride in cassiterite and lead zinc sulfide co/associated fluorite by ion selective electrode combined with ICP-AES was established.The effects of AlCl_(3)solution mass concentration,AlCl_(3)solution extraction time,and the selection of Ca and its internal standard element spectral lines on the determination of Ca were investigated.The limit of detection of CaF_(2)in the method was 0.010%,and the limit of quantification was 0.040%.The contents of CaF_(2)in actual samples of cassiterite,lead zinc sulfide,and fluorite certified reference material were determined according to the experimental method.The relative deviations(RSD,n=6)of the measurement results were between 0.22%and 0.90%,and the relative errors(RE)were between 0.08%and 0.63%.The method solved the problem of empirical correction coefficient in the CaF_(2)determination process.The internal standard method was employed in ICP-AES to eliminate the impact of instrument drift caused by environmental temperature

关 键 词：锡石 铅锌硫化物共/伴生萤石 氟化钙 离子选择电极法 电感耦合等离子体原子发射光谱法(ICP-AES) 内标 

分 类 号：O657.31[理学—分析化学] TF031[理学—化学]