自动矿物识别和表征系统在辽东吉祥峪稀土矿矿物鉴定和赋存状态研究中的应用  

Application of Automated Mineral Identification and Characterization System to Identify Minerals and Occurrences of Elements in Jixiangyu Rare Earth Deposit of Eastern Liaoning

作　　者：孙晓旭 冯坚 李超 高野 王雷 苗彤 徐杨 闫伟 SUN Xiaoxu;FENG Jian;LI Chao;GAO Ye;WANG Lei;MIAO Tong;XU Yang;YAN Wei(Liaoning Geology and Mineral Research Institute Co.,Ltd.,Shenyang 110032,China)

机构地区：[1]辽宁省地质矿产研究院有限责任公司,辽宁沈阳110032

出　　处：《岩矿测试》2023年第6期1120-1131,共12页Rock and Mineral Analysis

基　　金：辽宁省省级地质勘查项目“辽宁省辽阳县吉祥峪稀土矿预查”(JH20-210000-05760)。

摘　　要：辽宁省已知的稀土矿类型较少,以往稀土矿床的勘查评价偏重于独居石砂矿和碱性岩型稀土矿,沉积变质型稀土矿涉及较少,其矿石学、矿物学研究程度偏低。本文以吉祥峪稀土矿床为研究对象,应用自动矿物识别和表征系统(AMICS),结合高分辨率扫描电子显微镜(SEM)和高通量能谱仪(EDS)对矿石进行分析,获得吉祥峪稀土矿石中矿物化学成分、元素赋存状态及矿物共生组合关系。结果表明,矿石中稀土元素以La、Ce、Pr、Nd等轻稀土元素为主;主要稀土矿物为独居石(0.73%)、褐帘石(6.25%)、方铈石(0.25%)和磷灰石(类质同象)等;通过背散射图像结合光学显微镜观察得出矿石中的褐帘石、独居石、方铈石及磷灰石等具有较好的连生关系,这些矿物以单颗粒或聚粒结构与磁铁矿交叉镶嵌,或分布在磁铁矿边缘及间隙中。矿石中稀土矿物与磁铁矿密切共生,含量呈正相关,其原因可能为:①沉积富集。吉祥峪稀土矿位于辽吉裂谷的核部,裂谷为矿床提供了有利的沉积环境。②岩浆改造。岩浆热液可能与里尔峪一段变粒岩产生反应,使其中的稀土和铁元素集聚。③构造控制。吉祥峪稀土矿位于吉祥峪—算盘峪背斜核部穹隆之上,构造发育,断裂带和褶皱可能在地壳的应力作用下形成矿物质富集的通道,使矿质从深部运移至浅部。BACKGROUND:In Liaoning Province,there are limited known types of rare earth deposits,and historically,exploration and evaluation efforts have mainly focused on monazite placer and alkaline rock type rare earth deposits.Less attention has been given to sedimentary metamorphic rare earth primary deposits.Previous studies have shown that the Jixiangyu rare earth deposit is categorized as a sedimentary metamorphic remodeling deposit related to ancient volcanic structures.The analysis of existing data and previous exploration results prove that this type of rare earth deposit has a considerable rare earth content with monazite and allanite.However,unresolved issues remain,such as the occurrence status of rare earth minerals and the feasibility of extracting and utilizing rare earth minerals.OBJECTIVES:To explore the metallogenic mechanism and unveil the formation process of rare earth deposits by identifying the types of rare earth minerals,investigating the occurrence and distribution of rare earth elements within minerals,and analyzing the composition,structure,and distribution characteristics of rare earth minerals and associated minerals.METHODS:The experimental testing was conducted at the Henan Provincial Rock and Mineral Testing Center.The experimental instruments used in this study included an ultra-high resolution field emission scanning electron microscope(Zeiss Sigma500),an electric cooling energy spectrometer(Bruker XFlash6610),and a set of AMICS automatic mineral identification and characterization systems.During the experiments,a high vacuum environment was maintained,with an accelerating voltage of 20kV and a beam current of 5nA.The working distance was set at 11.8mm,and the point analysis acquisition time reached 250kcps before stopping automatically.RESULTS:The primary rare earth minerals in the Jixiangyu rare earth deposit were identified as allanite,monazite,and cerianite,constituting 6.25%,0.73%,and 0.25%of the total mineral content,respectively.Light rare earth elements such as La,Ce,Pr,and Nd wer

关 键 词：自动矿物识别和表征系统(AMICS) 沉积变质型稀土矿 独居石 褐帘石 磁铁矿 稀土矿物赋存状态 

分 类 号：P575[天文地球—矿物学]