Patent ID: 7666371

Claim:
A metal recovery process comprising the steps of: a) providing a metal-bearing material in a slurry form; b) subjecting said slurry to flotation to form a concentrated metal-bearing material; c) pressure leaching said concentrated metal-bearing material at a temperature in the range of about 170° C. to about 235° C. in an oxygen-containing atmosphere in a pressure leaching vessel to form a product slurry; d) separating said product slurry into a metal-bearing solution and a solids-containing residue; e) adjusting the pH of said metal-bearing solution to a pH of less than about 2.2 by combining said metal-bearing solution with a make-up diluting solution to yield a pH-adjusted metal-bearing solution, wherein the ratio of said metal-bearing solution to said make-up diluting solution is in the range of from about 1:4 to about 1:8; f) solvent extracting and electrowinning said pH-adjusted metal-bearing solution to yield an acid-containing raffinate solution; g) applying said acid-containing raffinate solution in a heap leaching operation.