PROCEDURE FOR LIXIVING MINERALS OF NICKEL OXIDES OF HIGH AND LOW LATERITES CONTAINED IN MAGNESIUM.

摘要

Hydrometallurgical method of leaching with sulfuric acid for the extraction of nickel and cobalt from laterite nickeliferous oxidic ore, comprising: a. provide an aqueous pulp of nickeliferous oxidic mineral with a low magnesium content; b. leach the aqueous pulp at a temperature of at least approximately 200 ° C and at an elevated pressure with an addition of sulfuric acid at least stoichiometrically sufficient to effect the leaching of the nickel and cobalt content and thereby provide a discharge of sulfate leach liquor from nickel, cobalt sulfate and a leaching residue, wherein the leaching liquor contains at least 76 g / l sulfuric acid; c. adding controlled amounts of high-magnesium raw nickel oxydelic ore to the leaching liquor from stage (b) at atmospheric pressure, to provide a final neutralization suspension, where (i) the raw mineral is added at temperatures ranging from 80 ° C to the boiling point at atmospheric pressure of the final neutralization suspension, (ii) sufficient agitation and time are provided to effect the extraction of nickel and cobalt from the raw mineral and (iii) an agent is not added reducer to the final neutralization suspension to control its oxidation / reduction potential; and d. adding a sufficient amount of a precipitating agent selected from the group consisting of alkali metal ions, ammonium ions and mixtures thereof, to the pulp of step (a), to the leaching liquor from step (b) or to the suspension of final neutralization of stage (c), to precipitate ferric iron as jarosite.