Patent ID: 7718148

Claim:
A method for pressure leaching which comprises: supplying a slurry of material to be leached from a slurry source to a reaction zone, wherein the slurry of material comprises feed ore and leaching solution and the reaction zone being disposed relative to the slurry source such that slurry is resident in the reaction zone under gravity thereby providing at least 30% of the pressurisation required for the leaching operation, wherein in the reaction zone the slurry is passed downwardly through a first heat recovery exchanger and then through a second heat recovery exchanger to a first reaction vessel downstream of the second heat recovery exchanger; reacting the slurry in the first reaction vessel; reticulating the reacted slurry from the first reaction vessel back to the second heat recovery exchanger to provide sensible heat to the slurry passing downwardly through the second heat recovery exchanger from the first heat recovery exchanger; reticulating the reacted slurry emitted from the second heat recovery exchanger back to a second reaction vessel providing additional residence time for the leaching operation; reticulating the reacted slurry emitted from the second reaction vessel back to the first heat recovery exchanger to provide sensible heat to the slurry passing downwardly through the first heat recovery exchanger; and recovering leached slurry from the first heat recovery exchanger.