(1. 东华理工大学 核资源与环境重点实验室，南昌 330013；
2. 东华理工大学 水资源与环境工程学院，南昌 330013；
3. 江西省勘查设计研究院，南昌 330095)
摘 要: 地浸采铀数值模拟是研究场地尺度下铀浸出迁移的重要手段。为准确模拟浸出铀的时空演化，以一组四注一抽现场地浸采铀试验单元为例，探讨模型中水岩反应设置为热力学平衡和反应动力学对模拟结果的影响。结果表明：1) 抽液井处浸出铀的试验结果与反应动力学模型的模拟结果接近，与热力学平衡模型的模拟结果相差较大，因此反应动力学模型相比热力学平衡模型更能反映浸出铀的开采过程；2) 同一时间内，热力学平衡模型相比反应动力学模型模拟得出的溶浸面积更大，溶浸铀矿物量更多，铀矿物完全浸出所需时间更短；3) 热力学平衡模型预测的铀矿物开采程度及浸出铀浓度偏高，开采所需时间偏短，导致高估铀矿物浸出率和低估开采时间。因此，在地浸采铀数值模拟中，反应动力学相比热力学平衡优化了水岩反应的反应速率表达，使模拟更贴近实际。
关键字: 酸法浸铀；溶质运移；PHAST；反应速率；热力学平衡；反应动力学
（1. Key Laboratory of Nuclear Resource and Environment, East China University of Technology, Nanchang 330013, China;
2. School of Water Resource and Environmental Engineering, East China University of Technology, Nanchang 330013, China;
3. Jiangxi Institute of Survey and Design, Nanchang 330095, China）
Abstract:Numerical simulation of in-situ leaching of uranium is an important method for studying uranium leaching migration at site scale. In order to accurately simulate the time and space evolution of leaching uranium, a group of in-situ leaching uranium mining test units with four injection and one pumping were taken as an example to discuss the impact of thermodynamic equilibrium and reaction kinetics of water-rock reaction in the numerical model on the simulation results of in-situ leaching uranium mining. The result show that the test results of uranium leaching at the production wells are close to the simulation results of the reaction kinetic model, but are quite different from the simulation results of the thermodynamic equilibrium model. Therefore, the reaction kinetic model can better reflect the extraction process of leaching uranium than the thermodynamic equilibrium model. At the same time, comparing the simulation results of thermodynamic equilibrium model and reaction kinetics model, it can be seen that the former simulation results in a larger leaching area, more leached uranium minerals amount, and a shorter time for complete leaching of uranium minerals. Furthermore, when predicting the degree of uranium mining and leaching uranium concentration in ore-bearing aquifer, the prediction result of thermodynamic equilibrium model is too high and the time needed for mining is too short, which lead to overestimate the uranium leaching rate and underestimate the mining time. Therefore, in the numerical simulation of in-situ leaching uranium mining, reaction kinetics optimizes the expression of reaction rate of water-rock reaction compared with thermodynamic equilibrium, which makes the simulation more practical.
Key words: acid leaching of uranium; reactive transport; PHAST; reaction rate; thermodynamic equilibrium; reaction kinetics
