Variable Surface Reactivity Model for Leaching Kinetics of Activated Ilmenite Particles

Current research was aimed at developing a variable surface reactivity kinetics model for leaching of activated particles. The geometrical surface of particles considered constant in a shrinking core model (SCM) was replaced by reactive surface. As a result, SCM was modified to a variable surface reactivity-shrinking core model, in good agreement with experimental measurements of the leaching of ilmenite-activated particles. Despite the slight increase in specific surface area with activation time, the significant increase in reactive surface indicated that the structural distortion had a more substantial effect on the leaching kinetics. The effect of crystal structure disordering on the leaching kinetics of activated ilmenite particles was assessed. The results revealed that leaching efficiency increases with an increase in lattice strain and amorphization degree and with a decrease in crystal size. For prolonged milling time, the crystal size effect on leaching efficiency was negligible, whereas lattice strain and amorphization degree became more influential on leaching kinetics.