Patent ID: 6379637
Filing Date: 2002-04-30
Classification: C22B

Abstract:
A process of leaching a highly-serpentinized saprolitic fraction of a nickel laterite ore profile and recovering metal values therefrom, comprising the steps of:preparing a finely ground highly-serpentinized saprolite ore; pulping said finely ground highly-serpentinized saprolite ore with water to produce a pulped ore with a density of between about 15% and 33% solids; heating said pulped ore; adding sulphuric acid to the heated pulped ore at atmospheric pressure in an amount of at least about 80% by weight of the finely ground highly-serpentinized saprolite ore on a dry weight basis, wherein heat released by mixing said sulphuric acid with said pulped ore raises the temperature of the mixture to a reaction temperature of at least about 80Â° C.; agitating the mixture for an effective period of time, whereby metal oxides are leached from the heated pulped ore mixed with sulphuric acid to produce a hot leach pulp; separating said hot leach pulp into liquid and solids, wherein said liquid contains sulphates of said metals; and recovering an intermediate product containing nickel and cobalt from said liquid.