闪锌矿矿物结构对Ge超常富集的制约:以贵州竹林沟Ge-Zn矿床为例  

Constraints of Sphalerite Texture on Supernormal Ge Enrichment:A Case Study of the Zhulingou Ge-Zn Deposit,Guizhou Province,China

作　　者：杨德智[1] 周家喜 孔志岗[4] 吴越[5] 黄智龙[6] 金中国 YANG Dezhi;ZHOU Jiaxi;KONG Zhigang;WU Yue;HUANG Zhilong;JIN Zhongguo(Institute of Geophysical and Geochemical Prospecting,Bureau of Geology and Mineral Exploration and Development of Guizhou Province,Guiyang 550018,Guizhou,China;School of Earth Sciences,Yunnan University,Kunming 650500,Yunnan,China;Key Laboratory of Critical Minerals Metallogeny in Universities of Yunnan Province,Kunming 650500,Yunnan,China;Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;College of Resources and Environment,Yangtze University,Wuhan 430100,Hubei,China;State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,Guizhou,China;Guizhou Nonferrous Metal and Nuclear Industry Geological Exploration Bureau,Guiyang 550005,Guizhou,China)

机构地区：[1]贵州省地质矿产勘查开发局地球物理地球化学勘查院,贵州贵阳550018 [2]云南大学地球科学学院,云南昆明650500 [3]云南省高校关键矿产成矿学重点实验室,云南昆明650500 [4]昆明理工大学国土资源工程学院,云南昆明650093 [5]长江大学环境与资源学院,湖北武汉430100 [6]中国科学院地球化学研究所,矿床地球化学国家重点实验室,贵州贵阳550081 [7]贵州省有色金属和核工业地质勘查局,贵州贵阳550005

出　　处：《大地构造与成矿学》2022年第6期1120-1136,共17页Geotectonica et Metallogenia

基　　金：国家自然科学基金项目(42172082、92162218、U1812402);云南大学科研启动项目(YJRC4201804);关键金属成矿与找矿预测创新团队项目(2021-3);贵州省地质矿产勘查开发局地球物理地球化学勘查院与云南大学科研合作项目(2021-2022)联合资助。

摘　　要：锗(Ge)是我国优势战略性关键金属之一,主要赋存在铅锌矿和煤矿中。在铅锌矿中,闪锌矿是Ge的主要载体。已有研究显示,闪锌矿中Ge以类质同象为主,尽管对Ge的替代方式认识有分歧,但是普遍认为闪锌矿中Cu、Ag、Mn、Fe等微量元素对Ge的替代方式和超常富集有明显的影响,果真如此吗?竹林沟Ge-Zn矿床是近年来新发现的中型Zn矿床(Zn金属资源储量>20万吨,Zn平均品位6.5%)、大型Ge矿床(Ge金属资源储量>200吨,Ge平均品位98×10^(−6))。通过对竹林沟Ge-Zn矿床主要硫化物(闪锌矿和黄铁矿)中Ge等微量元素进行原位分析,结果显示Ge主要赋存于闪锌矿(Ge含量为272×10^(−6)~1915×10^(−6),均值776×10^(−6))中,黄铁矿中Ge含量<10×10^(−6)。但是不同矿物结构的闪锌矿中Ge含量差别较大,表现为放射束状闪锌矿中Ge含量(383×10^(−6)~1475×10^(−6),均值919×10^(−6))高于胶状环带闪锌矿中Ge含量(272×10^(−6)~1915×10^(−6),均值632×10^(−6))。而且不同矿物结构闪锌矿中Fe含量也有明显差别,表现为放射束状闪锌矿中Fe含量(858×10^(−6)~15935×10^(−6),均值5220×10^(−6))低于胶状环带闪锌矿中Fe含量(1201×10^(−6)~30817×10^(−6),均值9563×10^(−6)),与Ge的富集规律恰好相反。此外,闪锌矿中Cu(多数<3×10^(−6),最高52.1×10^(−6))、Ag(<1×10^(−6))、Mn(9.51×10^(−6)~171×10^(−6),均值86×10^(−6))等微量元素含量均比Ge含量显著低2~3个数量级;而黄铁矿中除Mn含量(396×10^(−6)~3973×10^(−6),均值1173×10^(−6))较高外,Cu含量(<1×10^(−6))、Ag含量多数低于检测限。相关分析显示,不同矿物结构闪锌矿中Ge与Mn、Fe的相关关系差异明显,表现为放射束状闪锌矿中Ge与Fe、Mn的相系数明显大于胶状环带闪锌矿中Ge与Fe、Mn的相关系数。此外,不同矿物结构闪锌矿中Ge与Cu、Ag等微量元素之间没有明显的相关性。结合Cu、Ag、Mn、Fe等微量元素的Mapping分�Germanium is one of the dominant and strategic critical metals in China,which is mainly found in Pb-Zn ores and coal deposits.In Pb-Zn ores,sphalerite is the main Ge carrier.Previous studies have shown that Ge in sphalerite is dominated by isomorphism.Although there are differences in the understanding of Ge substitution,it is generally accepted that Cu,Ag,Mn,Fe and other trace elements in sphalerite have obvious effects on Ge substitution and supernormal enrichment.The Zhulingou Ge-Zn deposit is a newly discovered medium-scale Zn(with a Zn metal reserve of more than 200,000 tons and an average Zn grade of 6.5%)which hosts Ge metal reserve of more than 200 tons with an average Ge grade of 98×10^(−6)).In this work,in-situ analysis of trace elements such as Ge in the main sulfides(sphalerite and pyrite)of the Zhulingou deposit was carried out.The results show that Ge mainly occurs in sphalerite(272×10^(−6)-1915×10^(−6),mean 776×10^(−6)),and the contents of Ge in pyrite are less than 10×10^(−6).However,the Ge contents in sphalerite with different mineral textures are quite different:the Ge contents of radial sphalerite(383×10^(−6)-1475×10^(−6),average 919×10^(−6))are higher than that of colloform zoning sphalerite(272×10^(−6)-1915×10^(−6),mean 632×10^(−6)).Furthermore,Fe concentrations in sphalerite with different textures are significantly different,showing that Fe contents of the radial sphalerite(858×10^(−6)-15935×10^(−6),average 5220×10^(−6))are lower than those of the colloform zoning sphalerite(1201×10^(−6)-30817×10^(−6),mean 9563×10^(−6)),which was in contrast to the enrichment of Ge.In addition,the contents of Cu(mostly<3×10^(−6),maximum 52.1×10^(−6)),Ag(<1×10^(−6)),Mn(9.51×10^(−6)-171×10^(−6),mean 86×10^(−6))are 2-3 orders of magnitude lower than that of Ge;except for the high Mn contents(396×10^(−6)-3973×10^(−6),average 1173×10^(−6))in pyrite,the contents of Cu are less than 1×10^(−6),and the contents of Ag are mostly lower th

关 键 词：闪锌矿 矿物结构 Ge超常富集 竹林沟Ge-Zn矿床 

分 类 号：P612[天文地球—矿床学] P575[天文地球—地质学]