Kinetics of Atmospheric Acid Leaching of a Limonitic Laterite

A limonitic nickel laterite was leached by sulfuric acid at atmospheric pressure. Kinetics of leaching within the temperature range of 75-100°C was studied. The leaching kinetics followed the shrinking core model. The diffusion through the liquid film could be negligible under the agitation speed of 600rpm or above. Surface chemical reaction was the rate-controlling step. The semi-empirical kinetic equation was determined and the activation energy was 52.843kJ/mol.