Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute tran...Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute transport within the leaching system. The governing equations are solved numerically using the COMSOL Multiphysics software for the coupled reactive flow and solute transport at micro-scale, meso-scale and macro-scale levels. At or near the surface of ore particle, the acid concentration is relatively higher than that in the central area, while the concentration gradient decreases after 72 d of leaching. The flow simulation between ore particles by combining X-ray CT technology shows that the highest velocity in narrow pore reaches 0.375 m/s. The air velocity within the dump shows that the velocity near the top and side surface is relatively high, which leads to the high oxygen concentration in that area. The coupled heat transfer and liquid flow process shows that the solution can act as an effective remover from the heap, dropping the highest temperature from 60 to 38 ℃. The reagent transfer coupled with solution flow is also analyzed. The results obtained allow us to obtain a better understanding of the fundamental physical phenomenon of the bioleaching process.展开更多
A model for liquid-gas flow （MLGF）, considering the flee movement of liquid surface, was built to simulate the wastewater velocity field and gas distribution in a full-scale Caroussel oxidation ditch with surface ae...A model for liquid-gas flow （MLGF）, considering the flee movement of liquid surface, was built to simulate the wastewater velocity field and gas distribution in a full-scale Caroussel oxidation ditch with surface aeration. It was calibrated and validated by field measurement data, and the calibrated parameters and sections were selected based on both model analysis and numerical computation. The simulated velocities of MLGF were compared to that of a model for wastewater-sludge flow （MWSF）. The results show that the free liquid surface considered in MLGF improves the simulated velocity results of upper layer and surface. Moreover, distribution of gas volume fraction （GVF） simulated by MLGF was compared to dissolved oxygen （DO） measured in the oxidation ditch. It is shown that DO distribution is affected by many factors besides GVF distribution.展开更多
基金Projects(50934002,51104011) supported by the National Natural Science Foundation of ChinaProject(IRT0950) supported by Program for Changjiang Scholars and Innovative Research Team in Chinese UniversityProject(20100480200) supported by China Postdoctoral Science Foundation
文摘Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute transport within the leaching system. The governing equations are solved numerically using the COMSOL Multiphysics software for the coupled reactive flow and solute transport at micro-scale, meso-scale and macro-scale levels. At or near the surface of ore particle, the acid concentration is relatively higher than that in the central area, while the concentration gradient decreases after 72 d of leaching. The flow simulation between ore particles by combining X-ray CT technology shows that the highest velocity in narrow pore reaches 0.375 m/s. The air velocity within the dump shows that the velocity near the top and side surface is relatively high, which leads to the high oxygen concentration in that area. The coupled heat transfer and liquid flow process shows that the solution can act as an effective remover from the heap, dropping the highest temperature from 60 to 38 ℃. The reagent transfer coupled with solution flow is also analyzed. The results obtained allow us to obtain a better understanding of the fundamental physical phenomenon of the bioleaching process.
基金Project supported by Visiting Scholar Foundation of Key Laboratory of the Resources Exploitation and Environmental Disaster Control Engineering in Southwest China (Chongqing University),Ministry of Education,China
文摘A model for liquid-gas flow （MLGF）, considering the flee movement of liquid surface, was built to simulate the wastewater velocity field and gas distribution in a full-scale Caroussel oxidation ditch with surface aeration. It was calibrated and validated by field measurement data, and the calibrated parameters and sections were selected based on both model analysis and numerical computation. The simulated velocities of MLGF were compared to that of a model for wastewater-sludge flow （MWSF）. The results show that the free liquid surface considered in MLGF improves the simulated velocity results of upper layer and surface. Moreover, distribution of gas volume fraction （GVF） simulated by MLGF was compared to dissolved oxygen （DO） measured in the oxidation ditch. It is shown that DO distribution is affected by many factors besides GVF distribution.
