锆英砂样品中锆铪谱线饱和厚度的计算及应用  

Line Saturation Thickness Calculation for Zirconium and Hafnium in Zircon Sand Samples and Its Application

作　　者：李小莉[1] 安树清[1] 于兆水[2] 张勤[2] 

机构地区：[1]天津地质调查中心,天津300171 [2]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

出　　处：《岩矿测试》2014年第2期224-229,共6页Rock and Mineral Analysis

摘　　要：应用熔融制样X射线荧光光谱法测定锆英砂中的锆,通常采用Zr Kα线,而采用Zr Ko线作为分析线对熔融片来说并未达到饱和厚度,因此Zr的线性差,测定结果误差大.本文采用波长色散X射线荧光光谱法测定锆英砂样品中锆铪硅铝钙钛铁镁钠铪磷锰等12种组分.重点研究了锆分析谱线的选择,通过理论计算熔融片中Zr Kα线的饱和厚度为6638μm,而Zr Lα线的饱和厚度为20μm.由于熔融制备样片厚度为2500 μm,在熔融片中Zr Kα线远未达到饱和厚度,因此测定锆时应用Zr Lα谱线取代文献中应用的Zr Kα谱线.采用Zr Lα线,校准曲线的标准偏差（RMS）为0.39,而Zr Kα线的RMS为1.03,ZrO2分析结果的准确度和精密度有了显著的提高.对于锆,Hf Lα和Hf Lβ线饱和厚度分别为971 μm、1444μm,由于Hf Lα1谱线与Zr Kα二次谱线重叠,因此测定铪时应用Hf Lβ线作为分析线.实验还对四硼酸锂-偏硼酸锂混合熔剂、熔样比例和熔样温度等实验条件进行了优化,使用理论α系数和经验系数法校正基体效应,各元素计算的检出限与实际能报出的结果基本一致,方法精密度（RSD）为0.1％ ～10.9％,各元素的测定值与化学法测定值相符,表明通过饱和厚度的计算确定的锆和铪测定谱线具有可行性.For the determination of Zr in Zircon sand,the spectral line of Zr Kα is mainly used.However,the spectral line of Zr Kα does not reach the saturation thickness for the fused bead,which leads to poor linearity and large errors in the results.The determination of ZrO2,HfO2,SiO2,Al2 O3,CaO,TiO2,Fe2O3,MgO,Na2O,Cr2O3,P2O5,and MnO in Zircon sand samples has been developed with fused bead by Wavelength Dispersive X-ray Fluorescence Spectrometer.In this article,a detailed description of the study for the selection of the Zr spectrum line is given.Through theoretical arithmetic,the saturation thickness of the Zr Kα is 6638 μm,which is far beyond the thickness of the fused bead of 2500 μm while the saturation thickness of the Zr Lα is only 20 μm,which is within the range of the bead.Therefore,the Zr Lα is much more suitable than Zr Kα,as mentioned in published articles.The RMS of Zr Kα is 1.03 while the RMS of Zr Lo is 0.39.The accuracy and the precision of the ZrO2 are greatly improved.The respective saturation thickness for Hf Lα and Hf Lβ is 971 μm and 1444 μm.The Hf Lα1 line is overlapped by the second line of Zr Kα,hence,the Hf Lβ line is selected as the analysing line.The mixed flux of Li2 B4 O7 and LiBO2,the proportion of the flux and sample and the temperature of the fused sample are all optimized.The matrix effect was corrected by the theoretical α coefficient and empirical coefficient.The calculated detection limits of the respective elements coincide with the measured results.The precisions of the method （RSD） are 0.1%-10.9%.The results are in agreement with the certified values obtained by chemical methods,which showing that the measured spectral line determined through calculation of saturated thickness of Zr and Hf has certain feasibility.

关 键 词：锆英砂 锆 铪 X射线荧光光谱法 熔融片制样 谱线饱和厚度 

分 类 号：O614.412[理学—无机化学] O614.413[理学—化学]