扫描电镜能谱法测定独居石中铈、镧、钍等元素的含量

CONTENT DETERMINATION OF CERIUM, LANTHANUM, THORIUM AND OTHER ELEMENTS IN MONAZITE WITH SEM-EDS ANALYSIS

粒度细小的独居石、锆石等矿物在变质岩中含量少,利用岩石薄片偏反光显微镜鉴定技术一般不易确认,X射线粉晶衍射分析通常也检测不出此类微量矿物.利用电镜能谱分析技术能够检测出矿物主要组成元素,并能给出所测元素的浓度值.运用Casino程序和Quanta程序,据元素的浓度值可以计算出矿物中各元素的质量分数(%).本次研究利用扫描电镜能谱仪检测了6个样品中微量矿物,结果表明:6个样品中主要元素组成为O、Ce、Nd、La、Al、P、Ca、Si、Ag、Th,与独居石矿物化学组成一致,可以判定所检测的6个样品为独居石.

There are tiny content of fine-grained minerals like monazite and zircon in metamorphic rocks and they can behardly tested by polarized reflecting microscope identification technology and X-ray diffraction analysis. With the SEM-EDSanalysis technology, the main mineral components and element concentration can be determined. With the Casino andQuanta programs, the mass fraction （%） of each element can be calculated based on the element concentration. This studytests the trace minerals of 6 samples by SEM-EDS. The result shows that the main elements are composed of O, Ce, Nd, La,A1, P, Ca, Si, Ag and Th, which is consistent with the composition of monazite. Thus it can be concluded that the 6 samplesbelong to monazite.