Dissolution Kinetics for Colemanite Ore in Propionic Acid Solutions Saturated with Pyrite Roasting Gas

In this study, the dissolution kinetics for colemanite in propionic acid solutions saturated with pyrite roasting gas were investigated in a mechanically mixed system. The parameters were determined as temperature, particle size, solid/liquid ratio, acid concentration, gas flow rate, and stirring speed. The dissolution rate increased with increasing temperature, acid concentration, and pyrite roasting gas flow rate, while it reduced with increases in particle size and solid/liquid ratio. Compared to other parameters, stirring speed was found to have no significant effect on dissolution rate. The experimental data obtained were applied to homogeneous and heterogeneous reaction models by linear regression using the Statistica 10 Package Program to derive the appropriate model for the dissolution kinetics of colemanite. As a result, the dissolution rate was found to be controlled by a modified Avrami model. The activation energy for the process (E) was 38.66 kJ/mol and the Arrhenius constant was calculated as 9.6*104.