This paper presents a multiscale reactive flow model to simulate in-situ leaching of copper in heterogeneous porous microstructures. The introduced workflow combines fluid flow simulation with advection-diffusion-reaction simulation, both required to model reactive flow. The proposed workflow can include the fluid flow in resolved and unresolved pore structures and utilizes required parameters from molecular simulation (ionic diffusivity) and reaction databases (reaction rate parameters). The modeling approach is validated by comparing results to other open-source codes for a model calcite dissolution on acid injection. This model is applied to copper mining by leaching to analyze the reactive flow through a fractured digital rock model of a subsurface sample. Results are analyzed by tracking the concentration distribution along the pore space structure and calculating the outlet concentration of copper to conform the leaching path. Several sensitivity studies are performed to show the robustness of the modeling framework as well as to investigate the importance of each of these parameters on copper production. The complexity of the model is systematically increased from a single scale surface reaction model, to consider the influence of competitive bulk solution reactions, and finally to include flow through porous media to model multiscale reactive flow. This study shows that a multi-scale flow model with homogeneous bulk and heterogeneous surface reactions is required to accurately model copper leaching.

中文翻译：

---

异质多孔微结构中反应流的多尺度建模


本文提出了一种多尺度反应流模型来模拟异质多孔微结构中铜的原位浸出。引入的工作流程将流体流动模拟与平流扩散反应模拟相结合，两者都需要模拟反应流。所提出的工作流程可以包括已解析和未解析的孔隙结构中的流体流动，并利用分子模拟（离子扩散率）和反应数据库（反应速率参数）中所需的参数。通过将结果与酸注入方解石溶解模型的其他开源代码进行比较，验证了建模方法。该模型应用于浸出铜矿，通过地下样品的裂隙数字岩石模型分析反应流。通过跟踪沿孔隙空间结构的浓度分布并计算铜的出口浓度以符合浸出路径来分析结果。进行了几项敏感性研究，以显示建模框架的稳健性，并研究每个参数对铜生产的重要性。模型的复杂性从单尺度表面反应模型系统地增加到考虑竞争性本体溶液反应的影响，最后包括通过多孔介质的流动来模拟多尺度反应流。这项研究表明，需要具有均匀本体和非均匀表面反应的多尺度流动模型来准确模拟铜浸出。