An improved micro–macro model of multicomponent reactive transport for multimineral systems

Abstract

The multiscale coupled reactive transport model has attracted increasing attention in recent years because it can reveal the different characteristics of the spatial structure evolution of porous media. A micro–macro model of multiscale coupled reaction transport has been derived from detailed pore-scale models by using the upscaling technique based on homogenization method. Because of its clear upscaling theory, it has been widely used. However, the current micro–macro model still has obvious defects in dealing with the geochemical reaction process in multimineral systems. To solve this problem, we coupled the model with existing geochemical models that have been widely verified so that the model has the ability to deal with multimineral reactions under complex hydrochemical conditions. The newly developed coupling model and the current model are used to simulate the same problem, which proves the superiority of the new model for geochemical reaction prediction. We extend the new model to a two-dimensional scanning electron microscope image, where a challenging medium geometry setup is handled well during simulation. At the same time, the new model also accurately captures the abrupt changes in macroscopic effective parameters caused by the change in geometric topological structure. Finally, we use the principle of mass conservation to quantify numerical errors caused by geometric evolution, ensuring the accuracy and validity of simulation results, which verifies the numerical scheme of the model to a certain extent.