A novel hydrometallurgical approach to recover valuable metals from laterite ore

A novel hydrometallurgical process was developed to produce metal co-doped magnesium ferrites from saprolite and limonite laterite blends by using an atmospheric acid leaching–coprecipitation method. The effects of initial acid concentration, liquid to solid ratio and leaching time on the metal leaching efficiencies were investigated systematically. It is shown that extraction efficiencies of Fe, Ni, Mn, Co and Mg can reach 94.6%, 96.9%, 86.0%, 84.8% and 72.6%, respectively, after leaching for 60 min at 100 °C with the liquid (2.75 mol·L− 1 HCl acid) to solid (saprolite and limonite laterite blends) ratio of 10:1 mL·g− 1, and saprolite to limonite mass ratio (Msaprolite/limonite) of 5:5. Under the optimum leaching conditions, the influence of Msaprolite/limonite on the synthesis of metal co-doped magnesium ferrites from leaching solutions was also discussed. X-ray Diffraction (XRD) results showed that pure metal co-doped magnesium ferrites could be obtained when the Msaprolite/limonite was controlled at 7:3, with the initial acid concentration of 2.75 and 3.0 mol·L− 1, respectively.