Dissolution kinetics of sphalerite in acidic ferric chloride leaching

Abstract

Abstract This paper presents a study for leaching kinetics of sphalerite concentrate in FeCl3–HCl solution. The shrinking core model was applied to the results of experiments investigating the effects of stirrer speed of 200–600 rpm, ferric ion concentration in range of 0–1 M, solid/liquid ratio in range of 1/100–1/5, leaching temperature range of 40–80 °C and particle size on zinc dissolution rate. The activation energy for the leaching process was found to be 45.30 kJ/mol and the Arrhenius constant was calculated to be 5.454 s−1. The order of reaction for ferric ion concentration, solid/liquid ratio and particle size were also obtained. The rate of the reaction based on reaction-controlled process can be expressed as, [ 1 − ( 1 − α ) 1 / 3 ] = k 0 ( F e 3 + ) 0.36 ( ρ S / L ) − 0.33 r 0 − 0.97 exp ( − 45300 / R T ) t . The dissolution of sphalerite with acidic ferric chloride solution was found to be controlled by reaction-controlled process.