ATMOSPHERIC LIXIVIATION PROCEDURE FOR THE RECOVERY OF NICKEL AND COBALT FROM LIMONITA AND SAPROLITA MINERALS.

摘要

Hydrometallurgical process for extracting nickel and cobalt from a laterite mineral that includes at least one limonite mineral and one saprolite mineral, the process of which comprises: a. produce a pulp of limonite ore in water, where the pulp has a solids concentration between 5 and 35% by weight and where the limonite ore contains less than about 6% by weight of Mg; b. leach the pulp at a temperature below the boiling point and at atmospheric pressure, mixing it with sulfuric acid to form a thick leach suspension, where iron, cobalt and nickel dissolve in solution and virtually all of the acid is consumed sulfuric; c. adding an iron precipitating agent selected from the group consisting of sodium, potassium, ammonium ions and mixtures thereof to the pulp or thick leach suspension; and d. maintain the temperature of the thick leach suspension between approximately 85 ° C and the boiling point of the thick leach suspension and maintain the concentration of free acid in the thick leach suspension between approximately 5 and 15 gpl through the addition of mineral of saprolite to neutralize at least a portion of the acid generated by the precipitation of jarosite, where magnesium, cobalt and nickel dissolve simultaneously from the saprolite mineral to form a thick suspension of final leaching and where the final concentration of iron in a liquid component of the thick suspension of final leaching it is less than 3 gpl because iron precipitates as a jarosite compound.