Semi-Empirical Modelling for Dissolution of Calcium from Ironmaking Slag in Ammonium Acetate for CO₂ Utilization

Using iron and steel slags as feedstock for a mineral carbonation reaction using carbon dioxide gas is an excellent technique because they are easily accessible, contribute to land pollution, and have a reasonable quantity of lime and magnesia. The rate at which ironmaking blast furnace slag dissolves in an aqueous solution of ammonium acetate was investigated in relation to pH, stirring speed, solvent concentration, and temperature. A one-factor-at-a-time experiment was conducted, pH was monitored to the maximum value of 11, stirring speed ranged from 100 to 200 rpm, solvent concentration was adjusted from 0.01 to 1 M, whereas the reaction temperature was maintained between 25 and 80 °C. The dissolution kinetics of ironmaking slag were calculated by fitting experimental data to a model of a diminishing core. Using Atomic Absorption Spectroscopy, the leach liquor was characterized under various experimental conditions. The results of the trial revealed that this reaction is driven by a chemical reaction model equation. A semi-empirical model was also developed from the experimental data to better describe the dissolution kinetics.