|
| Experiment of Kaolin Adsorption of Dissolved Uranium in Acidic Water |
|
Received:December 08, 2020
Revised:December 21, 2020
Accepted:December 23, 2020
Published Online:April 20, 2021
|
| View Full Text View/Add Comment Download reader |
| DOI：doi：10.3969/j.issn.1007-7545.2021.05.016 |
| KeyWord:kaolin; acid solution; uranium; adsorption; uranium hydrolytic precipitation |
| Author | Institution |
| ZENG Qin |
东华理工大学 核资源与环境国家重点实验室 |
| ZHOU Yi-peng |
东华理工大学 核资源与环境国家重点实验室 |
| LI Guang-rong |
东华理工大学 核资源与环境国家重点实验室 |
| XU Ling-ling |
东华理工大学 核资源与环境国家重点实验室 |
| ZHAO Kai |
东华理工大学 核资源与环境国家重点实验室 |
| MU Hai-lin |
东华理工大学核资源与环境国家重点实验室 |
|
| Hits: 1729 |
| Download times: 1976 |
| Abstract: |
| Clay minerals adsorption on uranium is one of influencing factors on uranium migration in acid in-situ leaching system. Kaolin was used as adsorption medium to carry out different L/S experiments on acidic uranium solution with pH value of 2.0 and uranium concentration of 55 mg/L at 17 ℃. The results show that after 97.5 h interaction with kaolin, uranium concentration in liquid phase drops to 0.06~48.76 mg/L under different L/S, and uranium concentration is positively correlated with L/S. Decrease of uranium concentration is not only due to adsorption, but also due to hydrolysis and precipitation of uranium. The smaller the L/S is, the larger the pH value of solution rising, and the more significant the uranium hydrolysis precipitation is. Critical limit of pH value for significant precipitation of dissolved uranium is 2.8~2.9. Adsorption capacity of kaolin to uranium is small and mainly occurs in initial short period within acidic conditions. Adsorption reaction is carried out for the first 0.5 h, and adsorption capacity of different L/S ranges from 44.8 μg/g to 57.04 μg/g, followed by desorption. Uranium adsorption capacity after desorption equilibrium is positively correlated with L/S in general. Occurrence of desorption is related to drops of uranium content in liquid phase, change of molecular structure and surface charge of kaolin, and change of hydrochemical composition. |
| Close |
|
|
|