X射线衍射全谱拟合法快速分析长石矿物含量  

Rapid Analysis of Feldspar by X-ray Diffractometry Rietveld Refinement Method

作　　者：冉敬[1] 杜谷[1] 王凤玉[1] 

机构地区：[1]中国地质调查局成都地质调查中心,四川成都610081

出　　处：《岩矿测试》2017年第5期489-494,共6页Rock and Mineral Analysis

基　　金：国土资源部公益性行业科研专项经费项目(201111028-3;201311081-2)

摘　　要：长石中矿物的含量需要根据化学分析结果计算获得,分析流程长、计算复杂,而光学显微镜测定长石含量易受切片位置的影响。本文利用High Score软件对长石样品进行X射线衍射全谱拟合分析,能有效降低衍射峰重叠影响,修正择优取向造成的衍射强度误差,方法的准确度优于参比法(RIR法);样品定量分析结果与绝热法结果接近,相对偏差小于1.69%;与化学分析结果换算的矿物含量比较,绝对误差小于5%,满足了DZ/T 0130—2006所规定的绝对误差允许限。采用钾长石国家一级标准物质进行验证,主要矿物成分的分析误差小于1.34%,与钾长石化学成分标准值相比,绝对误差均小于1%。对长石物相进行定量分析的结果表明:X射线衍射全谱拟合法操作简单,分析质量能够满足相关标准对衍射分析的要求,用于地质实验中岩石矿物物相含量分析是可行的。The content of minerals in feldspar can be calculated by chemical analytical results,but the analytical process is long and the calculation process is complex.Moreover,slice position could affect the result of feldspar content determined by optical microscopy.Feldspar samples were quantitatively analyzed using the Rietveld method in High Score software.This method can effectively reduce the effect of diffraction peak overlap and correct the diffraction intensity error caused by the preferred orientation.The accuracy of the method is superior to the reference method (RIR method).The quantitative analysis results of the samples are close to the results of the adiabatic method,and the relative deviation is less than 1.69%.Compared to the mineral content by conversion from chemical composition,the absolute error is less than 5%,which meets the allowable error provided by DZ/T 0130—2006.As proved by first grade standard materials of potassium feldspar,the absolute error is less than 1%.The results of quantitative analysis of the feldspar show that the X-ray diffraction full-spectrum fitting method is simple and the analytical quality meets the quality requirements of the relevant standard for the diffraction analysis.It is feasible to analyze rock mineral content in geological samples using this method.

关 键 词：X射线衍射 全谱拟合 半定量分析 长石 物相组成 

分 类 号：P575.5[天文地球—矿物学] P619.235[天文地球—地质学]