湖南香花岭锡多金属矿田铟的赋存状态及富集规律研究  

Study on indium occurrence state and enrichment patterns in the Xianghualing Sn-Pb-Zn orefield in southern Hunan

作　　者：马晓花 郭福生[1,2] 冷成彪 李凯旋 高粉粉 陈涛亮 任志 田振东 MA XiaoHua;GUO FuSheng;LENG ChengBiao;LI KaiXuan;GAO FenFen;CHEN TaoLiang;REN Zhi;TIAN ZhenDong(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;School of Earth Sciences,East China University of Technology,Nanchang 330013,China;State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,南昌330013 [2]东华理工大学地球科学学院,南昌330013 [3]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,贵阳550081

出　　处：《岩石学报》2023年第10期3087-3106,共20页Acta Petrologica Sinica

基　　金：国家重点研发计划项目(2016YFC0600305);国家自然科学基金项目(41972080);江西省国家级高层次人才创新创业项目;江西省“双千计划”项目联合资助.

摘　　要：In作为一种分散元素,通常极难形成独立矿床,而主要以伴生组分的形式赋存在锡多金属矿床中。香花岭矿田蕴藏着丰富的Sn、Pb、Zn等矿产资源,是我国潜在的In资源基地,但目前该矿田中In的赋存状态、分布规律及成矿潜力尚不清楚。鉴于此,本文以香花岭矿田3个典型锡多金属矿床(新风、铁砂坪、茶山)为研究对象,在野外地质及矿相学观察的基础上,采用ICP-MS、EPMA和LA-ICP-MS开展了全岩地球化学和闪锌矿元素地球化学研究。结果表明,In主要以类质同象的形式富集在闪锌矿中,可能的替代方式为In^(3+)+Cu^(+)2←→Zn^(2+)。不同矿床中In的富集程度明显不同,其中,新风最富In(平均品位213.7g/t),其次为茶山,而铁砂坪最贫In。发现当闪锌矿中Cd含量介于5000×10^(-6)~7000×10^(-6)区间时,对应的In含量最高(>1000×10^(-6))。3个矿床的闪锌矿均富集Fe、Mn、In等高温元素,显著亏损Ga和Ge等低温元素。通过对比发现,这些闪锌矿与典型中高温岩浆-热液矿床(如远端矽卡岩型矿床)中闪锌矿的元素地球化学特征相似,应用闪锌矿地质温度计估算的结晶温度为345~372℃,且新风闪锌矿温度略高。闪锌矿中In的含量主要受温度控制,越靠近岩体、温度越高的闪锌矿越富In。结合前人资料,估算香花岭矿田伴生In资源量超过15000t,潜在经济价值巨大,应予以回收利用。Indium(In),as a typical dispersed element,is extremely difficult to form an independent deposit,which is usually enriched in Sn-Pb-Zn polymetallic deposits as an associated component.Xianghualing orefield hosts abundant resources of Sn,Pb,Zn,and is a potential area of In resources in China.However,the occurrence state,distribution regularities and mineralization potential of In in the Xianghualing orefield are still unknown.In view of this,this paper takes three large and medium-sized tin polymetallic deposits(i.e.,Xinfeng,Tieshaping and Chashan)in Xianghualing area as the research object.Based on detailed field geological and mineralogical research,ICP-MS,EPMA and LA-ICP-MS are applied to systematically carry out whole-rock geochemistry,sphalerite mineral chemistry and in-situ micro-element geochemistry research.Our results show that,In is mainly enriched in sphalerite in the form of homomorphism,and the possible replacement mechanism is In^(3+)+Cu^(+)2←→Zn^(2+).The enrichment degree of In within different deposits is significantly different,among which,Xinfeng ore is the highest(average grade 213.7g/t),Tieshaping is low,and Chashan is the middle.In addition,when the Cd content of sphalerite ranges from 5000×10^(-6) to 7000×10^(-6),the corresponding In content increases sharply to 1000×10^(-6) and above.All the analyzed sphalerite samples from the Xianghualing orefield is enriched in Fe,Mn,In and other high-temperature elements,but significantly depleted in Ga and Ge and other low-temperature elements.By comparison,it is found that the elemental composition of sphalerite is very similar to that of typical middle-high temperature magmatic-hydrothermal deposits(such as distal skarn type deposits).Combined with the geological thermometer of sphalerite,the formation temperature of sphalerite is estimated to be 345~372℃,and the Xinfeng deposit is slightly higher than the other two deposits.In summary,we believe that the concentration of In is mainly controlled by temperature,that is,the closer to the graniti

关 键 词：铟 闪锌矿 赋存状态 富集规律 香花岭矿田 湘南 

分 类 号：P578.23[天文地球—矿物学] P595[天文地球—地质学] P618.82