熔融制样-X射线荧光光谱法测定钨钼矿石中主量元素及矿化元素钨钼

Determination of Major Elements and Trace Elements(Tungsten and Molybdenum)in Tungsten and Molybdenum Ores by X-ray Fluorescence Spectrometry with Fusion Sample Preparation

建立了熔融玻璃片法制样,波长色散X射线荧光光谱法测定钨矿石和钼矿石中主量元素(SiO2,Al2O3,Fe2O3,CaO,MgO,K2O,Na2O,TiO2,P2O5,MnO)及矿化元素W、Mo含量的方法。通过调整样品与熔剂稀释比,优化预氧化温度和时间、熔融温度和时间、基体效应校正等,确定分析条件为:m(四硼酸锂-偏硼酸锂混合熔剂)∶m(硝酸锂)∶m(样品)为30∶5∶1,预氧化温度650℃,熔融时间3 min,1050℃下熔融10.5 min,可得到表面光滑无气孔的熔片。选用钨矿石和钼矿石国家一级标准物质绘制工作曲线,采用理论α系数和经验系数相结合的方法进行基体效应校正。对样品进行精密度实验,各组分测定结果的相对标准偏差RSD(n=12)在0.11%-7.69%之间。按照本方法对钨钼矿石标准物质进行准确度验证,测定值与认定值基本一致,计算误差满足实验室质量管理规范的要求。

A method was established to determinate the major elements(SiO2,Al2O3,Fe2O3,CaO,MgO,K2O,Na2O,TiO2,P2O5,MnO)and mineralized elements(tungsten and molybdenum)in tungsten and molybdenum ores by X-ray fluorescence spectrometry(XRF)using the glass fusion preparation technique.We discussed some influencing factors such as:the dilution ratio between flux and samples,the pre-oxidation temperature and time,the fusion temperature and time,the correction of matrix effect.The optimum analytical conditions were obtained as follows∶m(Li2B4O7-LiBO2)∶m(LiNO3)∶m(sample)was 30∶5∶1,the pre-oxidation temperature and time was 650℃and 3min,the fusion temperature and time was 1050℃and 10.5 min.In this condition,the prepared sample was got with smooth surface and without air hole.Different certified reference materials of tungsten and molybdenum ores were determined according to the experimental method,and corrected by theoreticalαcoefficient and empirical coefficient methods.The relative standard deviations(RSD,n=12)of determination results of each component were between 0.11%and 7.69%.The accuracy verification of tungsten and molybdenum ores were carried onaccording to the experimental method,the results showed that:the found results were consistent with the certified values,and the relative error could meet the requirements of the specification of testing quality management for geological laboratories of DZ/T 0130-2006.