熔融制样X射线荧光光谱法测定铜矿石中16种主次量元素

Determination of 16 Elements in Copper Ores by X-ray Fluorescence Spectrometry with Fused Sample Preparation

铜矿石类型繁多,矿石赋存状态各异,成分复杂.在现有的铜矿石熔融制样X射线荧光光谱（XRF）分析方法中,选取标准物质个数和矿石类型少、分析范围宽,与实际样品类型相差太大,且制备的熔融片质量不高.本文选用铜含量既有良好浓度变化范围,又符合铜矿石常见含量的包括铜金银铅锌钼铜镍等各类矿石的24个标准物质,以四硼酸锂-偏硼酸锂-氟化锂为混合熔剂,熔剂与样品质量比为30：1,以溴化锂为脱模剂,改进样品预处理方式,将通常采用样品预氧化后或熔融中加入脱模剂的方式,改进为加入脱模剂后再用混合熔剂完全覆盖的方法制备了高质量的熔融片,建立了XRF测定铜矿石中铜锌铅硅铝铁钛锰钙钾镁钼铋锑钴镍16种元素的分析方法.分析铜矿石国家标准物质GBW 07164、GBW07169,各元素的精密度（RSD）为0.1％ ～5.4％.分析国家标准物质GBW07163（多金属矿石）、GBW07170（铜矿石）的测定值与标准值相符;分析实际铜矿石样品,铜锌铅钼铋锑钴镍的测试结果与电感耦合等离子体发射光谱法和其他方法的测定值相符.本文方法扩大了基体的适应性,提高了实际应用价值.

Accuracy and precision of the analytical results for major and minor components in copper ores by the X-ray Fluorescence Spectrometry （XRF） with fused sample preparation can be seriously affected by the type of copper ore being analysed and the complex components it contains.The existing XRF analysis method is limited by the following factors：only having a small number of reference materials and ore types,single and wide scope of analysis not matching the actual samples,and low quality of pellet.In this study,we choose 24 ores of reference materials including copper,gold,silver,lead,zinc,molybdenum,copper and nickel which has a good range of copper content with common Cu levels.Lithium tetraborate-lithium metaborate-lithium fluoride was used as flux,the ratio of flux and sample being 30 ∶ 1.Using LiBr as the release agent,the high quality melt sheet was prepared by adding later mixed flux which completely covered the release agent,but not by adding release agent after the pre-oxidation or during molten,as is the most common method used.The quantitative analytical method for determination of 16 elements including Cu,Zn,Pb,SiO2,Al2O3,TFe2O3,TiO2,MnO,CaO,K2O,MgO,Mo,Bi,Sb,Co and Ni in copper ore by X-ray Fluorescence Spectrometry with fused pellet was established.The method was verified by the analysis of the copper ore certified reference materials of GBW 07164 and GBW 07169,and the relative standard deviations （RSD） were from 0.1% to 5.4%.Analytical results of certified reference materials （GBW 07163,GBW 07170） which did not participate in regression were basically in good agreement with certifiedvalues.The results of Cu,Zn,Pb,Mo,Bi,Sb,Co and Ni for practical samples by the proposed method were consistent with those obtained by Inductively Coupled Plasma-Atomic Emission Spectrometryand other analysis methods.The method expanded the adaptability of ore matrix and improved value in the practical application.