重庆芦塘矿晚二叠世煤中微量元素和稀土元素的地球化学特征  

Geochemical characteristics of trace and rare earth elements in the late Permian coals from the Lutang Mine,Chongqing

作　　者：邹建华 王冰峰[1] 王慧 田和明 李甜[2] ZOU Jianhua;WANG Bingfeng;WANG Hui;TIAN Heming;LI Tian(School of Civil Engineering,Chongqing Three Gorges University,Chongqing 404020,China;Chongqing Key Laboratory of Exogenic Mineralization and Mine Environment(Chongqing Institute of Geology and Mineral Resources),Chongqing 400042,China)

机构地区：[1]重庆三峡学院土木工程学院,重庆404020 [2]外生成矿与矿山环境重庆市重点实验室(重庆地质矿产研究院),重庆400042

出　　处：《煤炭学报》2022年第8期3117-3127,共11页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(41502162);重庆市自然科学基金资助项目(cstc2020jcyj-msxmX0042);重庆市教委科技资助项目(KJQN202001206)。

摘　　要：近年来,由于稀有金属需求的日益增长以及传统矿床的逐渐耗竭,煤和含煤岩系被认为是提取稀有金属的潜在来源。为了解重庆芦塘矿晚二叠世煤中Li,Ga,Nb,Ta,Zr,Hf和稀土元素(REY)的成矿潜力,采用电感耦合等离子体质谱仪(ICP-MS)、X射线荧光光谱仪(XRF)和X射线衍射仪(XRD)等方法测试了煤的微量元素、稀土元素和矿物组成。研究发现,芦塘矿晚二叠世煤为高硫中低灰无烟煤,煤中高含量的硫(5.06%)与海相沉积环境有关。煤中矿物主要为伊利石、伊蒙混层、高岭石和黄铁矿,其次为钾长石、方解石、铁白云石、石英、黄钾铁矾和熟石膏。与世界硬煤相比,芦塘煤中富集Li,Be,B,F,V,Cr,Zn,Ga,Ge,Se,Zr,Nb,Mo,Ag,Cd,Hf,Ta,Hg,Th,U和REY,其中Li,Ga,Nb,Ta,Zr,Hf和REY的富集系数分别为7.81,2.19~7.99,6.58,8.39,5.82和2.85。从顶至底沿着煤层剖面,Li,Ga,Nb(Ta),Zr(Hf)和REY含量逐渐升高。由于与灰分呈明显的正相关,煤中Li,Ga,Nb(Ta),Zr(Hf)和REY主要赋存于矿物中。芦塘煤中稀土元素以中稀土富集型为主,稀土元素地球化学参数δCe和δEu表明,煤中矿物质不来源于康滇古陆的基性玄武岩。煤中Li,Ga,Nb(Ta),Zr(Hf)和REY富集的主控因素是地下水对煤层下伏凝灰岩的淋滤作用。芦塘矿晚二叠世煤的煤灰中REY可作为提取稀土元素的潜在原料,其伴生的Li,Ga,Nb(Ta),Zr(Hf)等有益金属可共同提取,其工业利用价值值得关注。In recent years,owing to the increasing demand for rare metals and the depletion of traditional deposits,coal and coal-bearing strata are considered as the potential sources for extracting rare metals,which has attracted much attention.To understand the metallogenic potential of Li,Ga,Nb,Ta,Zr,Hf,and rare earth elements plus yttrium(REY)in the late Permian coals from the Lutang Mine of Chongqing,the concentrations of trace and rare earth elements and mineralogical compositions in coals were determined using inductively coupled plasma spectrometry(ICP-MS),X-ray fluorescence(XRF),and X-ray diffraction(XRD).The results indicate that the Lutang coals are classified as high sulfur,low-medium ash anthracite.The high sulfur(5.06%)in the Lutang coals is associated with the marine sedimentary environment.The minerals of the Lutang coals are mainly composed of illite,mixed-layer illite/smectite,kaolinite,and pyrite,followed by K-feldspar,calcite,ankerite,quartz,jarosite,and anhydrite.Compared with world hard coals,Li,Be,B,F,V,Cr,Zn,Ga,Ge,Se,Zr,Nb,Mo,Ag,Cd,Hf,Ta,Hg,Th,U,and REY are enriched in the Lutang coals,where the concentration coefficients of Li,Ga,Nb,Ta,Zr,Hf,and REY are 7.81,2.19~7.99,6.58,8.39,5.82,and 2.85,respectively.From top to bottom,the concentrations of Li,Ga,Nb,Ta,Zr,Hf,Ga,and REY increase gradually along the coal seam profile.Li,Ga,Nb,Ta,Zr,Hf,and REY mainly occur in minerals due to their significant positive correlations with ash yield.Medium rare earth elements are enriched.TheδCe andδEu indicates that the sediment source region is not mafic basalt of the Kangdian upland.Enrichment of Li,Ga,Nb,Ta,Zr,Hf,and REY is mainly attributed to the leaching of the tuff layer,immediately underlying the K1 coal.The Lutang coal ash is a possible material for extracting REY,Li,Ga,Nb(Ta),and Zr(Hf).

关 键 词：芦塘矿 晚二叠世煤 微量元素 稀土元素 地球化学 

分 类 号：P595[天文地球—地球化学]