Patent ID: 7152741

Claim:
A method of separating iron sulfide mineral particles from other mineral sulfide value particles containing zinc, nickel and/or copper by using ozone during certain flotation steps to at least degrade the frothers and collectors in the slurry liquid and/or remove the collectors adsorbed on the surface of said particles, comprising: (a) obtaining a slurry comprised of less desirable iron sulfide mineral particles and more desirable mineral sulfide particles containing mineral values of zinc, nickel and/or copper, wherein said particles are of a preferred particle size; (b) adjusting and/or maintaining the pH of said slurry to a desired level between about pH 8.0 and pH 12 at least one time; (c) adding at least one collector to the slurry that adsorbs on at least a portion of said particles and adding at least one frother to said slurry; (d) conditioning the slurry during and/or after said collector is added to obtain flotation conditions for at least some of said particles; (e) subjecting the conditioned slurry to flotation and obtaining a flotation concentrate stream and a flotation tailings stream, wherein said concentrate stream comprises the more desirable mineral sulfide value particles and wherein the tailings stream comprises the less desirable iron sulfide particles; (f) treating the concentrate stream and/or the tailings stream with at least about 3.5%–15% ozone for a time and/or concentration sufficient to at least degrade the frother and collector in the liquid phase and/or to remove the collectors adsorbed on the surface of said particles; (g) further treating or supplying the concentrate stream and/or the tailings stream with at least about 3.5%–15% ozone for a time and/or concentration sufficient to oxidize the surface of iron sulfide minerals faster than the surface of the other more desired sulfide minerals; (h) agitating the concentrate and/or tailings stream during at least step (f); and (i) subjecting the agitated stream from step (h) to a second flotation to further separate the more desired mineral sulfide particles from the less desired iron sulfide particles in the concentrate and/or tailings stream.