(1. 東華理工大學(xué) 核資源與環(huán)境重點(diǎn)實(shí)驗(yàn)室，南昌 330013；
2. 東華理工大學(xué) 水資源與環(huán)境工程學(xué)院，南昌 330013；
3. 江西省勘查設(shè)計(jì)研究院，南昌 330095)
摘 要: 地浸采鈾數(shù)值模擬是研究場(chǎng)地尺度下鈾浸出遷移的重要手段。為準(zhǔn)確模擬浸出鈾的時(shí)空演化，以一組四注一抽現(xiàn)場(chǎng)地浸采鈾試驗(yàn)單元為例，探討模型中水巖反應(yīng)設(shè)置為熱力學(xué)平衡和反應(yīng)動(dòng)力學(xué)對(duì)模擬結(jié)果的影響。結(jié)果表明：1) 抽液井處浸出鈾的試驗(yàn)結(jié)果與反應(yīng)動(dòng)力學(xué)模型的模擬結(jié)果接近，與熱力學(xué)平衡模型的模擬結(jié)果相差較大，因此反應(yīng)動(dòng)力學(xué)模型相比熱力學(xué)平衡模型更能反映浸出鈾的開采過(guò)程；2) 同一時(shí)間內(nèi)，熱力學(xué)平衡模型相比反應(yīng)動(dòng)力學(xué)模型模擬得出的溶浸面積更大，溶浸鈾礦物量更多，鈾礦物完全浸出所需時(shí)間更短；3) 熱力學(xué)平衡模型預(yù)測(cè)的鈾礦物開采程度及浸出鈾濃度偏高，開采所需時(shí)間偏短，導(dǎo)致高估鈾礦物浸出率和低估開采時(shí)間。因此，在地浸采鈾數(shù)值模擬中，反應(yīng)動(dòng)力學(xué)相比熱力學(xué)平衡優(yōu)化了水巖反應(yīng)的反應(yīng)速率表達(dá)，使模擬更貼近實(shí)際。
關(guān)鍵字: 酸法浸鈾；溶質(zhì)運(yùn)移；PHAST；反應(yīng)速率；熱力學(xué)平衡；反應(yīng)動(dòng)力學(xué)
（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
