内蒙古石匠山矿区矿石特征及银赋存状态

Analysis on Ore Composition and the Occurring States of Ag of Shijiangshan Mining Area, Inner Mongolia

摘要: 石匠山多金属矿床为热液脉状裂隙充填矿床，其伴生银品位较高，由于基础地质工作缺乏，银赋存形式未知，导致银的综合回收利用存在一定困难。因此，矿床基础地质及银赋存形态研究对于下一阶段勘探和银的回收具有十分重要的指示意义。本文在野外调研的基础上，采集了8个矿石样品，通过偏反光显微镜观察和电子探针分析，研究了矿石中金属硫化物矿物特征以及银的赋存形式。石匠山矿区深部矿石以方铅矿、闪锌矿、毒砂、黄铜矿、黄铁矿等为主要硫化物而矿石中的银大部分以不可见银形式存在。含银矿物为铁锑银黝铜矿，主要呈半自形包裹体存在于黄铁矿等硫化物内部，粒径小于1 μm。大多数方铅矿中含银超过0.08%，含量从晶粒边部向内部逐渐降低，表现为晶格银形式。

Abstract: Although the average grade of silver is high in Shijiangshan mining area, lacking basic geological works and states of Ag in the ore, it is really difficult to recover Ag in the ore. In order to get rid of this situation, necessary basic geological researches are of great importance for the next stage exploration to recover Ag. This paper is based on field investigation, data of eight deep ore samples analyzed by partial reflective microscope and EPMA, aiming to discuss features of sulfide minerals, states of Ag and the genetic type of this mineral deposit. The experiment result shows that deep ore samples are composed of galena, sphalerite, arsenopyrite, chalcopyrite and pyrite as its main occurring states. More importantly, further study shows that there are two forms of silver in the samples belonged to invisible silver, which are the silver of microscopic inclusions and in the form of isomorphism. Specifically, microscopic inclusion is tetrahedritedyscrasite with hypidiomorphic granular texture in pyrite and the other form silver exists mainly in the form of isomorphism in the galena with a tendency that silver content reduces from the edge to the interior. The size of the inclusion is less than 1μm, and the content of silver in galena is over 0.08 percent.