A 4D in-situ tomography study of the evolution of porosity in fluid-driven reactive systems

The permeability of many rocks and ores is low but can increase dramatically during fluid-rock interaction via formation of connected porosity induced by mineral replacement reactions. Such reaction-induced porosity contributes to metasomatism, metal transport and ore deposition, as well as in situ metal recovery from orebodies. Our recent work has demonstrated that reaction-induced porosity is sensitive to reaction parameters such as pore pressure and temperature, but the dynamics of reaction-induced porosity remains poorly understood. We plan to perform in situ X-ray μCT experiment (up to 190 °C, 20 MPa) to investigate the effect of pore fluid pressure, confining pressure, and temperature on the dynamics of reaction-induced porosity during the replacement of calcite by magnesite, brucite, gypsum, and anhydrite. The new knowledge should help more accurate reactive transport modelling for minerals exploration, sustainable metal extraction, and CO2-sequestration.