Application of SEM and EDS for Phase Characteristics Analysis of Platinoid Mineral in the Danba Area
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摘要: 丹巴地区铜镍硫化物铂族矿床品位低、铂族矿物颗粒细、铂族元素间的类质同象普遍,此类铂族资源的赋存状态研究及矿石的选冶长期以来都是较为棘手的问题。本文采用扫描电镜-X射线能谱仪器组合,对丹巴铜镍硫化物铂族矿床中含量达到1‰的元素进行快速的定性/定量分析,研究了铂族矿物原位的赋存状态和形貌特征。通过扫描电镜观察到该矿床的铂族矿物主要为砷铂矿、锑钯矿、碲锑钯矿,其次以自然铂、硫砷铑矿、硫砷铱矿,呈椭圆状、纺锤状等形式赋存于黄铁矿、磁黄铁矿及蛇纹石中,部分以类质同象的形式存在,极少量的铂与钯元素呈固溶体形式存在。X射线能谱分析表明该矿床中主要的铂族元素为Pt、Pd,其次为Ru、Rh、Ir、Os;点分析表明砷铂矿中Pt的含量为52.84%,锑钯矿中Pd的含量为45.15%;线扫描和面扫描分析表明铂族元素主要分布在含铁的硫化物中,Pt、Pd等铂族元素的含量与铁、镍的含量成正相关关系,反映了丹巴地区铂族元素亲铁、亲镍、亲硫的地球化学特征。Abstract: The study on of occurrence states of PGE resources and the smelting of ore mineral has long been a difficult problem to solve due to low grade copper and nickel sulfide, fine grain and the isomorphism of PGE elements in the Danba area. The phase characteristics and morphological properties of platinum group minerals of copper and nickel sulfide ores in the Danba area by using a combination of Scanning Electron Microscope (SEM) and X-ray Energy Dispersive Spectrometer (EDS) are presented in this paper. Observations demonstrate that platinoid mineral mainly contains sperrylite, stibiopalladinite and antimony tellurium palladium, secondly native platinum, rhodium arsenic sulfur ore and irarsite, which occurs in pyrite, pyrrhotite and serpentine with shapes of oval and cambiform. Platinum and palladium are the main elements of PGE in copper and nickel sulfide deposits in the Danba area, existing mainly in the form of a single mineral, secondly akin to isomorphism, rarely being a solid solution. The contents of platinoid minerals were qualitatively/quantitatively measured by using EDS rapidly. Tthe test quality percentage of platinum element in sperrylite is 52.84%, and the test quality percentage of palladium in stibiopalladinite is 45.15%, with an error of theoretical value is within 5%. PGE are mainly distributed in the iron sulfide by line and area scanning of EDS, and the contents of PGE such as platinum and palladium, are positively correlated with the contents of iron and nickel, which reflects the siderophile, thiophile and chalcophile geochemical characteristics for Danba PGE deposits.
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表 1 铂族矿物能谱点分析结果
Table 1. Analytical results of platinum group elements by EDS point analysis
序号 含量 w/% Pd Pt Rh Os Ir Sb Te As Co Ni Fe S Bi 1 33.29 - - - - 44.87 14.69 - - 5.10 1.17 0.25 - 2 13.51 - - - - - 61.21 - - 9.04 2.06 - 14.18 3 - 52.84 - - - 2.78 - 40.62 - 1.35 2.41 - - 4 - - 10.64 3.26 - - 0.67 35.34 8.34 5.41 5.47 20.26 - 5 45.15 - - - - 50.87 2.76 - - - 1.22 - - 6 - 9.64 7.14 - 35.26 - - 27.67 1.21 1.62 4.46 13.00 - 7 - 54.72 1.59 - - - - 40.43 - - 1.06 2.19 - 8 - 34.29 - - - 5.12 - 38.87 - - 1.72 - - -
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