河北武安地区黏土岩的稀土元素赋存状态  

The REE occurrence state in claystone in the Wu'an area,Hebei Province

作　　者：朱丹 白明[3] 童铄云 杜登峰 李献龙 刘爽 ZHU Dan;BAI Ming;TONG Shuoyun;DU Dengfeng;LI Xianlong;LIU Shuang(Hubei Geological Research Laboratory,Wuhan Hubei 430000,China;Key Laboratory of Rare Earth Rare and Scattered Minerals,Ministry of Natural Resources,Wuhan Hubei 430000,China;Ninth Geological Brigade of Hebei Bureau of Geology and Mineral Exploration and Development,Xingtai Hebei 054000,China)

机构地区：[1]湖北省地质实验测试中心,湖北武汉430000 [2]自然资源部稀土稀有稀散矿产重点实验室,湖北武汉430000 [3]河北省地质矿产勘查开发局第九地质大队,河北邢台054000

出　　处：《矿物学报》2024年第4期598-606,共9页Acta Mineralogica Sinica

基　　金：湖北省自然科学基金项目(编号:2023AFD208)。

摘　　要：黏土岩是稀土元素的主要赋存岩石之一,具有非常大的资源潜力。目前,由于其稀土元素赋存状态不明确,黏土岩稀土矿产开发利用受限。本文选取河北武安市暴庄地区富稀土黏土岩,利用岩矿鉴定、矿物自动定量系统(AMICS)、X射线衍射仪(XRD)等方法对矿石的岩石学特征进行分析,同步利用激光剥蚀-等离子质谱(LA-ICP-MS)微区原位分析、高岭石黏粒提取、化学分步提取、飞行时间二次离子质谱仪(TOF-SIMS)及密度函数理论(DFT)计算等技术手段,从矿物学、地球化学及结构学等多尺度多角度对样品中的稀土元素赋存状态进行科学研究。结果表明,该地区黏土岩的主要组成矿物为高岭石(88.19%),盐类浸出试验结果表明离子型稀土仅占2.67%,而稀土独立矿物仅含0.04%的褐帘石,证明稀土元素以离子态及独立矿物型存在的占比较少,而稀土元素与高岭石之间的强相关性可以推测多数稀土元素或以超微细粒稀土矿物形式夹杂于高岭石颗粒之间,或以类质同象替代存在于高岭石晶格内。Claystone is one of the main host rocks containing rare earth elements(REE).It has a huge potential of the REE resource.Currently,due to the unclear understanding of the REE occurrence state in claystone,the development and utilization of REE in claystone are limited.In this study,the REE-rich claystone samples from the Baozhuang area in Wuan City,Hebei Province were selected for analyzing their petrological characteristics using the rock and mineral identification,automated mineral identification and characterization system(AMICS),and X-ray diffraction(XRD)and for studying the occurrence state of REE in claystone samples in terms of mineralogical,geochemical,and textural perspectives at multiple scales by using techniques including the in-situ laser ablation-inductively coupled plasma mass spectrometry(LA-ICPMS),kaolinite colloid extraction,chemical stepwise extraction,time-of-flight secondary ion mass spectrometry(TOFSIMS),and density functional theory(DFT)calculation.The results show that the main mineral component of claystones in this area is of kaolinite(88.19%).Leaching test results indicate that there is only 2.67%ionic REE,and only 0.04%independent REE mineral of allanite,proving that there is only a small portion of REE in ionic and independent mineral forms in the claystone.The strong correlation between the REE and kaolinite suggests that the REE could be mostly presented in forms of ultrafine REE minerals between kaolinite particles,or as isomorphic substitution ions within the kaolinite lattice.

关 键 词：稀土元素 赋存状态 矿物自动定量系统(AMICS) 原位分析 

分 类 号：P616.4[天文地球—矿床学]