贵州铜仁磷块岩型铀矿中有机质与P-U成矿关系探讨  

Investigation of the relationship between organic matter content and P-U mineralization in the uranium-bearing phosphorite in Tongren,Guizhou

作　　者：王孟斋 谢宏[1,2] 白洋 卢正浩 WANG Mengzhai;XIE Hong;BAI Yang;LU Zhenghao(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,Guizhou,China;Key Laboratory of Karst Geologi-cal Resources and Environment of Ministry of Education,Guizhou University,Guiyang 550025,Guizhou,China)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]贵州大学喀斯特地质资源与环境教育部重点实验室,贵州贵阳550025

出　　处：《河南理工大学学报（自然科学版）》2023年第4期64-75,共12页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家自然科学基金资助项目(42062009,41662008);贵州省自然科学基金资助项目(黔科合基础[2020]1Y158);贵州大学引进人才科研项目(贵大人基合字[2015]第37号)。

摘　　要：贵州铜仁磷块岩型铀矿富含有机质,为探究有机质与P-U成矿关系,开展岩/矿石显微特征与地球化学测试研究。结果表明:有机质呈浸染状分布于胶磷矿中,与胶磷矿关系密切;矿石有机质质量分数较高,TOC均值为0.84%,与w(P_(2)O_(5)),w(U)均成一定的正相关关系;TOC/w(N)较低,w(Cr)/w(Zr)较高,指示矿石有机质与P,U来源相同,均以内源为主;高w(U)/w(Th)指示P-U成矿方式为热水沉积;低w(Th)/w(U)、高δw(U)和高w(V)/w(V+Ni)均指示磷块岩型铀矿形成于缺氧-硫化的还原环境。P-U成矿过程中,与P,U同源的有机质主要以吸附、生命组成和生成铀酰络合物等方式参与成矿物质的迁移活化,并通过释放还原性气体、形成腐殖酸和酸性铀酰络合物改变P-U成矿环境,促使P-U富集成矿。The uranium-bearing phosphorite in Tongren,Guizhou is rich in organic matter.In order to ex-plore the mineralization relationship between organic matter and P-U,microscopic characteristics of rock/ore and geochemical studies were carried out.The results showed that the organic matter was distributed in a leached form within the collophanite;The total organic matter content(TOC)in the ore was high,with an av-erage value of 0.84%.TOC exhibited a positive correlation with P_(2)O_(5) and U contents.Moreover,low TOC/w(N)and high w(Cr)/w(Zr)ratios indicated that the organic matter in the ore and P-U were both of endog-enous origin and high w(U)/w(Th)ratios implied that P-U might have enriched in hot waters,while low w(Th)/w(U)ratios,highδU values,and high w(V)/w(V+Ni)ratios indicated that the uranium-bearing phos-phorite might have been formed in a strong reduction environment.During P-U mineralization,organic mat-ter actively participated in the migration and activation of mineralized material mainly by adsorption,life metabolism,and generation of uranyl complexes.These processes changed the P-U mineralized environment by releasing reductive gas,forming humic acid and acidic uranyl complexes,which in turn contributed to P-U enrichment and mineralization.

关 键 词：有机质 成矿关系 磷块岩型铀矿 贵州铜仁 

分 类 号：P611.22[天文地球—矿床学]