  Effects of heterogeneity of mineral distribution and reaction rate on the
rock dissolution process are investigated using a pore-scale reactive transport
model based on the lattice Boltzmann method. Coupled fluid flow, species
transport, chemical reaction and solid structure alternation due to dissolution
are simulated. Effects of mineral distributions and chemical heterogeneity on
the dissolution behaviors and evolutions of hydrologic properties are studied
under different reactive transport conditions. Simulation results show that the
coupling between advection, diffusion and reaction as well as the mineralogical
heterogeneity leads to complex reactive transport behaviors and complicated
temporal evolutions of hydrologic properties including porosity, permeability
and reactive surface. Diverse relationships between surface area and volume are
predicted, which cannot be described by simple models such as the
spherical-grain model. Porosity-permeability relationships also differ under
different mineral distributions and reactive transport conditions. Simulation
results indicate that it is extremely challenging to propose general
relationships for hydrologic properties for dissolution of rocks with
mineralogical heterogeneity, due to the complicated interactions between
reactive transport and mineralogical heterogeneity.
