华南铀矿山排水渗流区铀酰矿物发育特征与稳定性研究

In U rich system, such as U deposits, U waste rock and U tailing, the dissolution process typically involves oxidation and destabilition of U（Ⅳ）minerals resulting in acid mine drainage of high concentration of U（Ⅵ）aqueous species. The transport of U with this oxidizing water is an important process of U environmental pollution. In site remediation and control technique that stabilize the U by sorption or incorporation into low solubility solid phases are attractive. The formation of low solubility secondary uranyl-minerals is a key process, and therefore to study these minerals will help in understanding and predicting the environmental behaviors of uranium in drainage of uranium mine, which also is an effective way to evaluate the feasibility of in site remediation U contamination by immobilization of phosphate. In this project, it will be studied that the characteristics of the type, crystal form, tectonics and mineral associations and forming geochemistry conditions of uranyl-minerals. The rates of primary U（Ⅳ）minerals oxidation to U（Ⅵ）aqueous species and subsequent precipition of secondary uranyl-minerals will be discussed. For understanding the long-term stability of uranyl-minerals, the dissolution features of these minerals will be examined by experiments。To build the a diagram of equilibrium and conversion of species, which illustrate the stability field and the conversion relationship of different species. This study result will provide a scientific benchmark for analyzing the theory of controlling the radionuclide pollution around the uranium mine in south China and assessing long-term stability of uranyl phosphate minerals.

铀矿山的矿床、废矿石和尾矿中的铀矿物U（Ⅳ）氧化和分解将产生的水溶相的U（Ⅵ），形成高浓度U的矿山排水，铀随水的渗透而迁移是其污染环境的重要途径。将铀吸附并结合到溶解度低的固体相中的原地固定技术是铀环境污染控制与修复最有潜力的研究方向。该技术的关键是溶解度低铀酰矿物的形成，因此铀酰铀矿物的研究有助于分析和预测铀矿山废水的铀的环境行为，同时也是评价磷酸盐原地固定修复铀污染的可行性的有效途径。本项目将对华南铀矿山排水渗流污染区铀酰矿物发育种类、晶型、结构构造、矿物组合等矿物学特征以及形成地球化学条件进行研究，探讨原生铀矿物的氧化溶解和次生铀矿物沉淀形成的速率，开展次生铀酰矿物溶解实验室研究。建立矿物（次生矿物）/溶液的相平衡与转换图，分析其稳定性，指出稳定区域与相转换关系。研究结果可为华南铀矿山放射性核素环境污染控制机理分析以及磷酸铀酰长期稳定性评价提供科学依据。

铀矿山的矿床、废矿石和尾矿中的铀矿物U（Ⅳ）氧化和分解将产生的水溶相的U（Ⅵ），形成高浓度U的矿山排水，铀随水的渗透而迁移是其污染环境的重要途径。将铀形成稳定矿物或吸附并结合到溶解度低的固体相中的原地固定技术是铀环境污染控制与修复最有潜力的研究方向。该研究的关键是溶解度低铀酰矿物的形成，因此铀酰铀矿物的研究有助于分析和预测铀矿山废水的铀的环境行为。本研究基于铀酰磷酸盐矿物在广泛的地球化学条件下的难溶特征，研究和评估磷酸盐原地固定修复铀污染的可行性以及途径。本项目重点研究了华南铀矿山排水渗流污染区铀酰矿物发育种类、晶型、结构构造、矿物组合等矿物学特征以及形成地球化学条件进行研究，探讨原生铀矿物的氧化溶解和次生铀矿物沉淀形成的速率，开展次生铀酰矿物溶解实验室研究；探讨了铀酰离子在磷酸盐中的吸附与固定行为与机理，分析了矿物的稳定性。通过本项目研究发表了论文15篇，其中SCI和EI收录的论文9篇。获得专利2项。研究结果可为华南铀矿山放射性核素环境污染控制机理分析以及磷酸铀酰固定修复铀污染供科学依据。