便携式Li-K分析仪的研制及其在锂辉石中锂的分析应用  

Development of a Portable Li-K Analyzer and Its Application in the Determination of Lithium in Spodumene

作　　者：焦距 杨啸涛[1] 袁继海[1] 樊兴涛[1] 刘晓[1] 詹秀春[1] 

机构地区：[1]国家地质实验测试中心,北京100037

出　　处：《岩矿测试》2016年第4期366-372,共7页Rock and Mineral Analysis

基　　金：国土资源公益性行业科研专项(201311013)

摘　　要：我国锂钾主要矿产资源大多分布在西部偏远地区,其勘查找矿或综合利用迫切需要现场快速分析技术的支持。本文介绍了自行开发的便携式Li-K分析仪的主要性能及其在锂辉石中锂的分析应用。Li-K分析仪是一种基于大气压的液体阴极辉光放电光谱仪,以待测液体为放电阴极,实现了样品中Li、K等元素的原子化和激发。该仪器以光纤传导CCD光谱仪作为检测器,其波长范围为345-1015 nm,分辨率3 nm;以Li 670.78 nm和K 769.90 nm分析谱线,在仪器最佳工作条件下测定Li、K的精密度（RSD,n=14）均低于2%,检出限为0.03μg/m L,检测范围0.1-10μg/m L。研究表明,不同酸度和酸的类型对谱线强度影响较大,且存在显著的样品基体效应,标准曲线法分析锂辉石中Li的结果偏差高达267%;而标准加入法可克服基体效应的影响,获得与ICP-OES一致性较好的分析结果,为现场开展固体样品中Li的测定奠定了基础。Most of the mineral resources of lithium and potassium are distributed in remote western China. Fast,on-site analytical techniques are urgently needed for their exploration and comprehensive utilization. In this work,a newly developed portable Li-K analyzer was introduced for its analytical performance and the application of this equipment in determining lithium in spodumene is also discussed. The analyser is a type of atomic emission spectrometer based on solution cathode atmospheric glow discharge. Sample solution was used as a graphite cathode,which atomized and excited the elements Li and K. A charge coupled device（ CCD） was used to detect the characteristic lines of Li and K,which had wavelengths ranging from 345 to 1015 nm with a 3 nm resolution.Using a Li analytical line of 670. 78 nm and a K analytical line of 769. 90 nm under the optimized working conditions,the measurement precisions for Li and K were greater than 2% RSD with the limit of detection of 0. 03μg / m L. Results show that different types and concentrations of acids strongly affect the intensities of Li and K,and co-existent elements produce serious matrix effect. Quantification of Li in spodumene ores by use of a calibration curve without matched matrix could not produce accurate results with relative standard deviation up to 267%.Standard addition methods can eliminate the influence of the matrix effect and obtain analytical results consistent with those by Inductively Coupled Plasma-Optical Emission Spectrometry,which thus provides a basis for on-site determination of Li in solid samples.

关 键 词：便携式Li-K分析仪 液体阴极辉光放电 CCD光谱仪 锂辉石 标准加入法 

分 类 号：TH744.1[机械工程—光学工程] P578.954[机械工程—仪器科学与技术]