伊犁洪海沟矿区富铀煤的元素地球化学以及铀的价态特征  

Element geochemistry and uranium speciation characteristics of uranium-rich coal in Honghaigou mine,Yili basin

作　　者：李家新 王文峰[1,2] 白洪阳 陆青锋 何鑫 王文龙 师志龙 LI Jiaxin;WANG Wenfeng;BAI Hongyang;LU Qingfeng;HE Xin;WANG Wenlong;SHI Zhilong(School of Resources and Geosciences,China University of Mining&Technology,Xuzhou,Jiangsu 221116,China;School of Geology and Mining Engineering,Xinjiang University,Urumqi,Xinjiang 830047,China;School of Civil Engineering,Luoyang Institute of Science and Technology,Luoyang,Henan 471023,China;Nuclear Industry 216 Brigade,Urumqi,Xinjiang 830011,China)

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]新疆大学地质与矿业工程学院,新疆乌鲁木齐830047 [3]洛阳理工学院土木工程学院,河南洛阳471023 [4]核工业二一六大队,新疆乌鲁木齐830011

出　　处：《地质学报》2024年第8期2439-2451,共13页Acta Geologica Sinica

基　　金：国家重点研发计划项目(编号2021YFC2902003);新疆维吾尔自治区重大科技专项(编号2022A03014);国家自然科学基金项目(编号41972176);新疆第三次综合科学考察(编号2022xjkk1003)联合资助的成果。

摘　　要：铀是重要能源矿产和国家战略资源,煤岩型铀矿对我国核能产业可持续发展和“双碳”目标实现具有重要意义。本文采用X射线荧光光谱(XRF)、电感耦合等离子体质谱(ICP-MS)和X射线光电子能谱(XPS)等手段,研究了伊犁盆地洪海沟矿区煤的元素地球化学、富铀因素以及铀活化迁移过程的价态变化特征。结果表明:①洪海沟煤中U超常富集,平均含量为258.91μg/g。石炭纪—二叠纪中—酸性火成岩和海西期花岗岩是煤中铀的物质来源,稳定的单斜构造,头屯河组砂砾岩和粗砂岩的岩性组合,晚侏罗世以来干旱气候及后生富铀溶液的入渗共同控制煤层中U、Re、Se、Mo等元素共同富集。②煤岩型铀矿的形成与氧化环境中U6+以络合物或酸根形式迁移,氧化—还原过渡环境中富铀含氧流体中U6+被还原成U4+沉淀富集有关。洪海沟矿区弱氧化—还原过渡环境高价态的变价元素被还原,以Se-U-Re-Mo模式共同富集于煤层顶部。③洪海沟矿区“上铀下煤”矿产资源分布和铀矿下部多煤层的发育,需要合理划分煤-铀矿产资源之间保护区距离,上部砂岩型铀矿优先进行地浸开采,下部煤岩型铀矿采用井工开拓方式进行“煤炭地下气化+煤灰原位地浸开采”,将煤灰中铀提取至地表利用,实现煤-铀资源协调开采利用。Coal-type uranium deposits are critical for the sustainable development of Chinas nuclear energy industry and the achievement of its‘double carbon’goals.This study,using X-ray fluorescence spectroscopy(XRF),inductively coupled plasma-mass spectrometry(ICP-MS),and X-ray photoelectron spectroscopy(XPS),investigates the elemental geochemistry,U-enrichment controlling factors,and valence state characteristics of uranium during activation and migration processes in coals from the Honghaigou mine in the Yili basin.Our results indicated that:①The Honghaigou coal displays abnormally high uranium enrichment,with an average of 258.91μg/g.This enrichment can be attributed to several contributing factors:the presence of U-rich Permian-Carboniferous Hercynian granites with a stable monoclinic structure;the association of sandy conglomerate and coarse sandstone of the Toutunhe Formation;arid climatic conditions following the Late Jurassic;and the infiltration of epigenetic U-rich solutions.These factors collectively controlled the co-enrichment of U,Re,Se,Mo,and other elements in this coal.②In the oxidation zone of the coal-rock-type uranium ore,U6+migrates in the form of complexes or acid radicals.As this migration continues to the oxidation-reduction transition zone,U6+is reduced to U4+and precipitates,leading to enrichment in uranium-rich oxygenated fluids.The uranium content of the original,reduced zone decreases and tends towards a solid state.In contrast,in the weak oxidation-reduction transition zone of the Honghaigou mine,uranium content exhibits a sharp increase,and the high-valence variable elements become co-enriched at the top of the coal seam in the Se-U-Re-Mo combination.③The spatial distribution of mineral resources in Honghaigou mine,characterized by‘upper uranium and lower coal’,alongside the development of multiple coal seams in the lower part of the uranium mine,allows for a strategic and balanced mining approach.The upper sandstone-type uranium mine is preferentially mined by in-situ leaching

关 键 词：富铀煤 元素 地球化学 价态 协调开采 

分 类 号：P618.11[天文地球—矿床学] P619.14[天文地球—地质学]