黔西北麻乍地区沉积型稀土矿稀土元素赋存状态研究  

The occurrence state of rare earth elements in sedimentary rare earth deposits in Mazha area,northwest Guizhou

作　　者：王彪 黄庆 何良伦 吕绍玉[1] 徐莺[2] 熊兴宇 赵婷 WANG Biao;HUANG Qing;HE Liang-lun;LYU Shao-yu;XU Ying;XIONG Xing-yu;ZHAO Ting(The 113 Geological Team,Bureau of Geology and Mineral Resources Exploration and Development of Guizhou Province,Liupanshui 553000,China;Institute of Multipurpose Utilization of Mineral Resources,Chinese Academy of Geological Sciences,Chengdu 610041,China;Technical Innovation Center of Mineral Resources Exploration Engineering in Bedrock Zones,Ministry of Natural Resources,Guiyang 550081,China)

机构地区：[1]贵州省地矿局113地质大队,贵州六盘水553001 [2]中国地质科学院矿产综合利用研究所,四川成都610041 [3]自然资源部基岩区矿产资源勘查工程技术创新中心,贵州贵阳550081

出　　处：《矿物学报》2023年第6期786-798,共13页Acta Mineralogica Sinica

基　　金：贵州省找矿突破战略行动重大协同创新项目(编号:黔科合战略找矿[2022]ZD004);贵州省财政资金专项资助项目(编号:黔自然资[2021]1360号)。

摘　　要：黔西北地区宣威组底部普遍发育沉积型稀土矿,其品位高,厚度大,呈层状分布,发育稳定,且伴生铌、钪、钛等金属矿产,具有巨大的找矿潜力。前人对该沉积型稀土的研究,多聚焦在其成矿规律和成矿机制,极少涉及研究其稀土元素的赋存状态。本文以黔西北威宁县麻乍地区沉积型稀土矿为研究对象,采用XRF分析、ICP-MS分析、X射线衍射分析,扫描电镜和能谱分析、电子探针分析、物相分析等手段,研究了元素组成、矿物组成及稀土元素的赋存状态。研究表明,稀土矿石主要由Al、Si、Fe、K、Ti组成,其稀土总量(REO)为1064×10^(-6)~14106×10^(-6),呈轻稀土富集、重稀土亏损的特征;矿石中矿物可分为硅酸盐矿物(主要为高岭石、伊利石)、金属氧化矿物(主要为褐铁矿、锐钛矿、金红石等)、碳酸盐矿物以及稀土矿物。稀土元素以纳米级独立矿物形态存在,根据其成分推测为磷铝铈矿、方铈矿,同时稀土元素也可以类质同象赋存于黏土矿物中,离子吸附态很少。Sedimentary type REE deposits are generally developed at the bottom of the Xuanwei Formation in the northwestern Guizhou.Their orebodies are characterized with high REO grade,large thickness,layered distribution,and stable bed,with associated metal minerals including niobium,scandium,and titanium.There is great prospecting potential of REE resources in the bottom part of the Xuanwei Formation in the northwestern Guizhou.Previous researches of this sedimentary type REE deposit are mostly focused on studying its metallogenic regularity and metallogenic mechanism,but rarely involved in studying the occurrence state of the REE in this type of REE deposit.In this paper,we have chosen the sedimentary type REE deposits in the Mazha area,Weining County,Guizhou Province as the research object,and have studied the elemental composition,mineral composition and the REE occurrence state of ores by using the XRF analysis,ICP-MS analysis,X-ray diffraction analysis,scanning electron microscopy and energy spectrum analysis,electron probe analysis,phase analysis and other means.The results show that the REE ore is mainly composed of Al,Si,Fe,K and Ti.It contains total amount of the REE(REO)varying from 1064×10^(-6) to 14106×10^(-6).Its REE distribution patterns are characterized with the LREE enrichment and the HREE depletion.Minerals of the ore can be classified into silicate minerals(mainly kaolinite,illite),metal oxide minerals(mainly limonite,anatase,rutile,etc.),carbonate minerals,and the REE minerals.The REE in the ore occurred in the form of nano-scale independent minerals which are speculated to be florncite and cerianite based on their compositions.At the same time,the REE also occurred in the form of isomorphism in clay minerals,or occurred occasionally in the form of ion adsorption.

关 键 词：沉积型稀土 赋存状态 纳米级独立矿物 麻乍稀土矿 黔西北 

分 类 号：P595[天文地球—地球化学]