Precipitation-Induced Geometry Evolution During Reactive Transport: Experimental and Numerical Insights into Stochastic Dynamics of Mineral Growth

Abstract

Summary Crystal nucleation, precipitation, and growth during a reactive fluid flow and solute transport are critical in many natural and industrial systems. Mineral growth is a prime example where (geo)chemical reactions give rise to geometry evolution in porous media. Motivated by the importance of incorporating stochastic dynamics of nucleation, crystallization, and growth kinetics in studying a variety of multiphase and multiscale processes occurring in geo-environmental and geo-energy systems, this work presents experimental and numerical results delineating geometry evolution induced by mineral precipitation. A total of 27 microfluidic experiments (3×3×3 sets of supersaturation-temperature-time) extend the understanding of factors controlling crystal nucleation and growth rates, the impact of ambient and aqueous phase properties, and the substrate characteristics. For numerical simulations, we used the Lattice Boltzmann Method (LBM) to solve the advection-diffusion-reaction equation for tracking the concentration of different species. We developed a reactive transport model based on our recently proposed probabilistic nucleation and crystal growth theory. The results indicated the probabilistic nature of the process, which is affected by the physiochemistry of the aqueous phase and governed by fluid-solid surface interactions. We underscore the importance of theoretical reactive transport models considering the probabilistic nature of nucleation events before crystal formation.