Patent ID: 11898221
Assignee: FLSMIDTH A/S
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  Y | IPC C

Claim 0:
1. A method of leaching a metal sulfide comprising:
providing a metal sulfide leach circuit 200 having therein, a reductive activation circuit 220 and an oxidative leach circuit 240; the reductive activation circuit 220 preceding the oxidative leach circuit 240 and being configured for performing metathesis reactions which are capable of producing an iron-depleted metastable phase on metal sulfide leach particles, wherein the reductive activation circuit 220 is configured such that the metathesis reactions produce the iron-depleted metastable phase at outer surface portions of the metal sulfide leach particles; the metal sulfide leach circuit 200 further being configured for controlling the metathesis reactions to limit the production of the iron-depleted metastable phase on the metal sulfide leach particles to between about 0.01% and about 10% by weight or volume of the metal sulfide leach particles;
maintaining the reductive activation circuit 220 at a pH between 2 and 6;
maintaining the oxidative leach circuit 240 at a pH below 1.8;
providing the metal sulfide leach particles to the reductive activation circuit 220;
producing an iron-depleted metastable phase on outer surface portions of the metal sulfide leach particles in the reductive activation circuit 220;
controlling metathesis reactions in the reductive activation circuit 220 to limit the production of the iron-depleted metastable phase on the metal sulfide leach particles to between about 0.01% and about 10% by weight or volume of the metal sulfide leach particles;
conveying the metal sulfide leach particles comprising the iron-depleted metastable phase to the oxidative leach circuit 240; and
leaching the metal sulfide leach particles comprising the iron-depleted metastable phase in the oxidative leach circuit 240.