Patent ID: 8361191

Claim:
A method for recovering nickel and cobalt from a lean ore comprising about 7% to about 40% iron, less than about 1.5% nickel and less than about 0.2% cobalt, the method comprising: leaching a slurry of the lean ore with about 50 to about 300 kg of an acid solution per tonne of lean ore for about 3 hours to about 72 hours at a temperature between ambient to about the boiling point of the solution to form a leach slurry, wherein less than about 3.5% of iron present in the lean ore is extracted during leaching; adding an alkali to the leach slurry to adjust the pH of the slurry to a range of about 3.5 to about 5 and to precipitate contaminating elements, wherein a neutralized slurry is formed; and either: (a) separating a nickel and cobalt-containing solution from the neutralized slurry; or (b) extracting nickel and cobalt from the neutralized slurry using a resin-in-pulp process to form a loaded resin; washing the loaded resin; and eluting nickel and cobalt from the loaded resin using a second acid to form a nickel and cobalt-containing solution; and recovering nickel and cobalt from the nickel and cobalt-containing solution, wherein about 60% to about 70% of the cobalt and about 30% to about 55% of the nickel present in the lean ore is recovered.