The kinetic study of limonitic low grade nickel ore leaching using hydrochloric acid

The leaching kinetic ore from Pomalaa (Southeast Sulawesi, Indonesia) using hydrochloric acid solution was investigated in a batch reactor. Variables studied were temperature, pH and particle size. To evaluate the kinetic parameters, the experimental data were fitted with a shrinking core model of a constant particle size. The experimental data fit very well with the proposed model and the overall rate is controlled by dissolution rate of nickel through product layer. The activation energy (E<inf>De</inf>) for the dissolution of nickel is 22.5 kJ/mol. The maximum nickel recovery is 41.5 at pH 1, reaction temperature of 90°C, particle size of -200 mesh, solid to liquid ratio at 0.2 (w/w) and stirring speed of 400 rpm for 240 minutes. © Published under licence by IOP Publishing Ltd.