Numerical simulation of coal mineral solubility under CO₂ partial pressure

Identification of the variation regularities of solubility of coal minerals under different temperature and CO₂ partial pressure can provide an important basis for the analysis of coal reservoir permeability during CO₂ injection. With the hydrogeochemistry software-PHREEQC, hydrochemical simulation was conducted for the solubility of coal minerals under the different temperature and CO₂ partial pressure conditions, the variation of coal mineral solubility under different temperature and CO₂ partial pressure was obtained. The results showed that when there was no CO₂ partial pressure, the solubility of the minerals increased with the rise of temperature, when CO₂ partial pressure of the solution increased to certain extent, the solubility of the minerals except for quartz decreased with the rise of temperature, at the same temperature and with the increase of CO₂ partial pressure, the solubility of all minerals except for quartz increased, the solubility of calcite showed rapid increase with the increase of CO₂ partial pressure, but other minerals showed slow increase in solubility.