Method for recovering metal values from metal-containing materials using high temperature pressure leaching
View Patent ↗The present invention relates generally to a process for recovering copper and other metal values from metal-containing materials through pressure leaching operations. In accordance with the various aspects of the present invention, metal-containing pregnant leach solutions from pressure leaching operations need not be significantly diluted to facilitate effective metal recovery using solvent extraction and electrowinning.
1. 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.
2. The process of claim 1 wherein said step of providing a metal-bearing material comprises providing a copper containing material.
3. The process of claim 2 wherein said step of solvent extracting and electrowinning comprises solvent extracting and electrowinning said pH-adjusted copper containing solution to yield an acid containing raffinate solution and copper cathode.
4. The process of claim 3 , wherein said step of adjusting the pH of said metal-bearing solution comprises 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 and the pH of said pH-adjusted metal-bearing solution is from about 1.4 to about 1.8.