A novel reagent-assisted mechanochemical method for nickel recovery from lateritic ore

A novel method for nickel recovery from lateritic ore was proposed. The method consisted of mechanochemical conversion in the presence of a reagent, ammonium carbonate or sodium hydroxide then followed by an acid leaching. The study presents the recovery of nickel from lateritic ore at low temperature and lower acid consumption to overcome the disadvantages of traditional metallurgical processes such as high temperature, high acid concentration, high cost and material requirements. Ore samples, both raw and mechanochemically treated, were characterized by different techniques such as Fourier transform infrared, X-ray diffraction, scanning electron microscope, thermogravimetry and differential scanning calorimetry. The leaching mechanism was defined as both chemically and diffusion controlled by shrinking core model. The optimization conditions for both mechanochemical conversion and atmospheric leaching processes were evaluated by response surface methodology to clearly demonstrate the advantages of the proposed method over conventional methods. The results of this study which included a combination of reactive-assisted mechanochemical process as a pretreatment and acid leaching reveal that high efficiency nickel recovery from the lateritic ore can be achieved with higher efficiency and lower iron content even at low temperatures and acid concentrations with shorter leaching time. (C) 2018 Elsevier Ltd. All rights reserved.