Concerted mineral carbonation and selective leaching of laterites

A process for extracting values from a mineralized silicate material, wherein the mineralized silicate material comprises a total amount of each of a mineralized nickel, a mineralized cobalt, a mineralized iron and a mineralized magnesium, wherein the process comprises:

• a) heating the mineralized silicate material in an aqueous H2CO3(a)/HCO3− buffered extraction medium in the presence of a gaseous carbon dioxide supply and a selective Ni/Co ligand;
• b) providing extraction conditions to:
• i) selectively leach nickel and cobalt from the silicate material into the extraction medium in the form of complexes with the selective Ni/Co ligand, to form solubilized Ni complexes and solubilized Co complexes;
• and,
• ii) react magnesium and iron in the silicate material with dissolved carbon dioxide provided by the carbon dioxide supply to form a solid carbonate product comprising a solid magnesium carbonate and a solid iron carbonate;
• and,
• c) in a solid liquid separation, separating the solid magnesium carbonate and the solid iron carbonate from the solubilized Ni complexes and the solubilized Co complexes, to form a Ni/Co pregnant leach solution;
• wherein providing extraction conditions comprises:
• providing the Ni/Co ligand in a molar ratio to the total amount of mineralized Ni in the mineralized silicate material of greater than 1:1, so as to extract at least 50%, 60%, 70% 80% or 90% of the total amount of mineralized Ni and Co in the mineralized silicate material into the Ni/Co pregnant leach solution, and so that less than 20%, 15% or 10% of the total amount of the mineralized Fe and Mg in the mineralized silicate material is leached into the Ni/Co pregnant leach solution.