title: Release behavior of uranium in uranium mill tailings under environmental conditions.
abstract: Uranium contamination is observed in sedimentary geochemical environments, but the geochemical and mineralogical processes that control uranium release from sediment are not fully appreciated. Identification of how sediments and water influence the release and migration of uranium is critical to improve the prevention of uranium contamination in soil and groundwater. To understand the process of uranium release and migration from uranium mill tailings under water chemistry conditions, uranium mill tailing samples from northwest China were investigated with batch leaching experiments. Results showed that water played an important role in uranium release from the tailing minerals. The uranium release was clearly influenced by contact time, liquid-solid ratio, particle size, and pH under water chemistry conditions. Longer contact time, higher liquid content, and extreme pH were all not conducive to the stabilization of uranium and accelerated the uranium release from the tailing mineral to the solution. The values of pH were found to significantly influence the extent and mechanisms of uranium release from minerals to water. Uranium release was monitored by a number of interactive processes, including dissolution of uranium-bearing minerals, uranium desorption from mineral surfaces, and formation of aqueous uranium complexes. Considering the impact of contact time, liquid-solid ratio, particle size, and pH on uranium release from uranium mill tailings, reducing the water content, decreasing the porosity of tailing dumps and controlling the pH of tailings were the key factors for prevention and management of environmental pollution in areas near uranium mines.
authors.affiliation: School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621010, Sichuan, PR China; Institute of Mineral Materials and Application, Southwest University of Science and Technology, Mianyang 621010, Sichuan, PR China; Key Laboratory of Solid Waste Treatment and Resource Recycle, Southwest University of Science and Technology, Ministry of Education, Mianyang 621010, Sichuan, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: Institute of Mineral Materials and Application, Southwest University of Science and Technology, Mianyang 621010, Sichuan, PR China; Key Laboratory of Solid Waste Treatment and Resource Recycle, Southwest University of Science and Technology, Ministry of Education, Mianyang 621010, Sichuan, PR China. Electronic address: tjpeng@swust.edu.cn.
authors.forename: Tongjiang
authors.initials: T
authors.lastname: Peng
authors.affiliation: Key Laboratory of Solid Waste Treatment and Resource Recycle, Southwest University of Science and Technology, Ministry of Education, Mianyang 621010, Sichuan, PR China.
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Sun
authors.affiliation: Key Laboratory of Solid Waste Treatment and Resource Recycle, Southwest University of Science and Technology, Ministry of Education, Mianyang 621010, Sichuan, PR China.
authors.forename: Huanjuan
authors.initials: H
authors.lastname: Yue
mesh_terms: D002681:China; D060587:Groundwater / Q000737:chemistry; D008906:Mining; D011834:Radiation Monitoring; D012990:Soil Pollutants, Radioactive / Q000032:analysis; D014501:Uranium / Q000032:analysis*; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D012990:Soil Pollutants, Radioactive; D014875:Water Pollutants, Radioactive; D014501:Uranium
keywords: Desorption; Mineral dissolution; Mobility; Release behavior; Uranium mill tailings