FIB-TEM解析微生物铀矿化:以松辽盆地海力锦砂岩型铀矿为例  

Deciphering Microbial-Mediated Uranium Mineralization via FIB-TEM Nanotomography:A Case Study from the Hailijin Deposit,Songliao Basin

作　　者：金伟国 尹烁 王庆飞 潘家永[1] JIN Weiguo;YIN Shuo;WANG Qingfei;PAN Jiayong(National Key Laboratory of Prospecting,Mining and Remote Sense Detecting on Uranium Resources,East China University of Technology,Nanchang,Jiangxi 330013,China;School of Earth Sciences,East China University of Technology,Nanchang,Jiangxi 330013,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]东华理工大学铀资源探采与核遥感全国重点实验室,江西南昌330013 [2]东华理工大学地球科学学院,江西南昌330013 [3]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《现代地质》2025年第2期248-262,共15页Geoscience

基　　金：东华理工大学核资源与环境国家重点实验室开放基金项目(2022NRE13)。

摘　　要：针对砂岩型铀矿中微生物与矿物互作机制证据链薄弱的关键科学问题,本研究以松辽盆地海力锦矿床姚家组下段含铀独居石为研究对象,通过微区矿物学分析揭示其溶蚀过程与铀活化机理。基于钻孔岩心系统取样,采用FIB-TEM联用技术首次在独居石溶蚀界面识别出氢铀云母与沥青铀矿纳米矿物组合,结合电子探针原位分析发现溶蚀相独居石平均损失75%初始铀。研究揭示:(1)石英包裹效应导致独居石选择性溶蚀特征,开放体系下溶蚀强度提升3~4个数量级;(2)溶蚀界面纳米矿物相的定向分布指示微生物代谢产生的有机酸主导磷铀耦合释放过程;(3)建立的生物膜催化动力学模型显示,微生物介导的界面反应使铀活化至沉淀。该研究不仅为微生物与纳米矿物间协同成矿机制提供了关键的显微尺度证据,而且对于促进铀矿地质学研究向更精细的微观领域深入拓展具有重要的意义。Resolving the evidentiary gap in microbe-mineral interactions within sandstone-hosted uranium systems,this study presents nanoscale evidence elucidating the biogeochemical controls on uranium mobilization.Focusing on uranium-bearing monazite in the Lower Yaojia Formation of the Hailijin deposit,we integrate FIB-TEM nanotomography with EPMA geochemical mapping to decode dissolution-uranium release coupling mechanisms.Three pivotal findings emerge:(1) Quartz-encapsulated monazite preserves pristine surfaces,whereas exposed grains exhibit 75% uranium depletion with intense dissolution features;(2) FIB-TEM nanotomography reveals epitaxial overgrowths of chernikovite and uraninite nanoparticles along dissolution fronts,forming characteristic U-P biogeochemical halos;(3) The established biofilm catalytic kinetics model shows that the microbe-mediated interfacial reaction activates uranium to precipitation.This study not only provides critical microscopic-scale evidence elucidating synergistic mineralization mechanisms between microorganisms and nano-minerals,but also holds significant implications for advancing uranium deposit geology research into refined microscopic domains.

关 键 词：海力锦铀矿床 独居石溶解动力学 微生物铀矿化 FIB-TEM联用技术 纳米矿物 

分 类 号：P619.14[天文地球—矿床学]