固体进样-发射光谱法测定钼矿石矿粉中的高含量钼  

Determination of High Content of Molybdenum in Molybdenum Ore by Emission Spectrometry with Solid Sampling Technique

作　　者：郭心玮 李昆 郝志红[1,2] 姚建贞 徐进力[1,2] 白金峰 GUO Xinwei;LI Kun;HAO Zhihong;YAO Jianzhen;XU Jinli;BAI Jinfeng(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang 065000,China;UNESCO International Centre for Global-scale Geochemistry,Langfang 065000,China)

机构地区：[1]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000 [2]联合国教科文组织全球尺度地球化学国际研究中心,河北廊坊065000

出　　处：《岩矿测试》2023年第5期1031-1040,共10页Rock and Mineral Analysis

基　　金：国家重点研发计划项目(2021YFC2903000)课题“战略性矿产多元素同时分析技术和标准化”。

摘　　要：全面、系统地建立钼矿石、钼矿粉分析方法,对钼元素研究开发和保障钼矿工业发展具有重要意义。目前多采用酸溶或碱熔样品后进行分析,其不足是测定钼含量的范围窄,消耗样品量大,还需使用大量酸碱,且受仪器限制,分析高含量钼时多需对样品溶液进行数次稀释,使分析步骤更加繁琐。发射光谱法则可避免上述问题,但用之准确分析高含量钼矿石钼矿粉尚有测试方法的瓶颈需要突破。本文研究通过内标元素、分析线对、缓冲剂配比、电流程序等环节的实验分析,建立了固体进样-交流电弧发射光谱法测定钼矿石中高含量钼的分析方法:优化样品与光谱缓冲剂质量比至1∶2,优化分析线对,截取曝光时间35s,采用以国家一级合成硅酸盐光谱分析标准物质和国家一级矿石标准物质组成的自研标准系列制作标准曲线,由全谱交直流电弧发射光谱仪自动扣除分析线和内标线背景后以对数坐标二次曲线拟合计算,使测定范围扩展为500~500800μg/g,检出限为27.38μg/g,相对标准偏差(RSD)为3.28%~8.30%,相对误差为-0.43%~0.73%。结果表明,本文方法在实现绿色分析的同时,在检出限相当、精密度合格的条件下,一次性分析高含量钼的上限从5%提高至50%。BACKGROUND:The majority of current molybdenum ore analysis techniques use absorbance,gravimetric methods,ICP-MS,ICP-OES,XRF,etc.,which are primarily based on liquid injection,with a lengthy analytical procedure,complex steps,and a measurable range of 0.01%-5.17%[16].The joint technologies of EPMA,SEM,and X-ray spectroscopy are more expensive,and the results may not be reproducible[18-21].Compared with the above methods,AC-Arc atomic emission spectrometry(Arc-AES),which does not call for the use of acids and bases,has the potential to be applied to the analysis of molybdenum ore and molybdenum powder with a high content of Mo over 5%.OBJECTIVES:To improve the current analytical techniques for determining high content of molybdenum in molybdenum ore.METHODS:The mixed sample was loaded into the lower electrode after being ground at 2400Hz for 30min with the different sample-to-buffer ratio in a 5mL crucible.Two drops of a 2%mass fraction sucrose-ethanol solution were added and dried at 70℃for 1h.The samples were mounted on an AES-8000 direct-reading atomic emission spectrometer using the vertical electrode method.The internal reference method was used to fit the quadratic curve in logarithmic coordinates by subtracting the background spectral lines of the analyzed elements and the internal reference elements.The experiments were conducted by choosing the internal reference element types and spectral lines,selecting the Mo spectral lines,deciding the sample-to-buffer ratio,optimizing the current loading procedure,setting the spectral uptake time,and other conditions.A set of national-level reference materials and national-level synthetic silicate spectral analysis reference materials were used for calibration.The relative standard deviation and logarithmic deviation were utilized for quality control.RESULTS:(1)The analytical line pair is chosen to be Mo 277.54nm/Ge 326.9494nm.The uniformity of internal reference elements is ensured by the excessive addition of germanium dioxide.Mo 277.54nm and Ge 326.9494nm evapora

关 键 词：钼矿石 高含量钼 交流电弧发射光谱法 固体进样 

分 类 号：O657.31[理学—分析化学] O614.61[理学—化学]