广西花山铀矿床氧化带中铀酰矿物特征、成因及其勘查指示意义

本文分析了广西花山铀矿床氧化带中铀酰矿物的类型、组合及赋存特征,探讨铀酰矿物的成因机制及其对深部铀矿体勘查的指示意义。研究发现,花山铀矿床氧化带中铀酰矿物的类型非常复杂,长冲、白石脚和糙米坪等三个矿点出现不同的铀酰矿物组合。长冲矿点发育准钙铀云母、钙铀云母和硅钙铀矿等铀酰磷酸盐和铀酰硅酸盐组合,铀酰矿物的阳离子组分以富Ca为特点;白石脚矿点出现硅铅铀矿和斜磷铅铀矿等铀酰硅酸盐组合,铀酰矿物的阳离子组分以富Pb为特点;糙米坪矿点出现翠砷铜铀矿、铜铀云母和脂状铅铀矿等铀酰磷酸盐、铀酰砷酸盐和铀酰氢氧化物组合,铀酰矿物的阳离子组分以富Cu和As等为特点。花山铀矿床中的铀酰矿物是原生铀矿物(推断为沥青铀矿)在氧化环境下发生次生沉淀作用而形成的,三个矿点铀酰矿物组合的差异归因于原生铀矿体元素地球化场、地下水中络阴离子类型和地下水介质pH环境等多种因素的耦合。研究认为,铀矿床氧化带中的铀酰矿物对于指导深部盲矿勘查具有一定的指示意义。在花山地区,铀酰矿物沿断裂带出现大规模的垂向分布,它的发育位置大致记录了原生铀矿体的产状特征,而铀酰矿物的含量和类型则有助于提供原生铀矿石品位和硫化物含量等重要的成矿信息。本研究预测,在花山矿区内的糙米坪和白石脚矿点仍然存在发现氧化型铀矿体的良好潜力。

Mineralogical Characteristics and Genesis of the Uranyl Minerals in the Oxidized Zone of the Huashan Deposit, Guangxi, and Their Implications for Deep Ore Exploration

This study aims at revealing the mineralogical characteristics of the uranyl minerals from the oxidized zone of the Huashan deposit in Guangxi and investigating their genetic mechanism in relation to deep ore exploration. The authors have found that there are different mineral assemblages in the three ore spots of the study area, with the assemblage of meta-autunite, autunite and uranophane in the Changchong ore spot, that of kasolite and parsonsite in the Baishijiao ore spot, and that of zeunerite, torbernite and gummite in the Zhaomiping ore spot. These uranyl minerals were derived from the primary U-bearing mineral (uraninite) and formed by the secondary precipitation process in an oxidation environment. Different uranyl mineral assemblages in the three ore spots are attributed to element geochemical backgrounds of the primary ore bodies, types of the complex anions in the groundwater solutions, and Ph values of the U-bearing groundwater. This study indicates that the uranyl minerals can provide important clues for deep exploration; for example, the uranyl minerals are extensively developed along the faults, and their characteristics have recorded the location of the primary ore body and the information of the primary ore grade and sulfide content. It is held that there are good potentials for further prospecting in the Baishijiao and Zhaomiping ore spots.