Mineralogical Heterogeneity Controls Dissolution-Front Instability and Reactive-Transport Scaling in Porous Media

However, most continuum reactive-transport models still rely on constitutive relations developed for single-mineral media, and the influence of insoluble mineral phases remains poorly understood. Here, we use three-dimensional pore-scale reactive transport simulations to investigate how the insoluble mineral fraction affects dissolution patterns and the evolution of hydraulic and reactive properties.

Mineralogical heterogeneity has regime-dependent effects on dissolution-front stability. At relatively low Péclet numbers, moderate insoluble mineral fractions enhance concentration heterogeneity and promote wormholing, whereas larger fractions disrupt connected reactive pathways and suppress flow focusing. At relatively high Péclet numbers, insoluble phases monotonically weaken preferential channel development and drive dissolution toward a more uniform pattern.