Methods of copper extraction

Abstract

The hydrometallurgical copper extraction processes of the present teachings generally including two steps: a conditioning or activating step using low concentrations of ammonia and ammonium in an aqueous solution; and an acid leaching step. The processes of the present teachings can be performed at low temperature, for example, at ambient temperature, and at atmospheric pressure.

What is claimed is: 
     
         1 . A method of extracting copper from a copper ore or a copper concentrate, the method comprising:
 contacting a copper ore or a copper concentrate with an aqueous solution comprising ammonia and ammonium in the presence of an oxygen gas-containing fluid to provide a solid activated copper ore or a solid activated copper concentrate, wherein the aqueous solution has a pH between about 8 to 9.5; and   leaching the solid activated copper ore or the solid activated copper concentrate with an acid to provide a pregnant leaching solution.   
     
     
         2 . The method of  claim 1 , further comprising recovering copper from the pregnant leaching solution. 
     
     
         3 . (canceled) 
     
     
         4 . The method of  claim 1 , wherein the ammonium is derived from one or more of ammonium carbonate, ammonium chloride, ammonium hydroxide, ammonium nitrate, and ammonium sulfate. 
     
     
         5 . The method of  claim 1 , wherein the ammonia is derived in situ from the ammonium. 
     
     
         6 . The method of  claim 1 , wherein the contacting step is carried out at atmospheric pressure. 
     
     
         7 . The method of  claim 1 , wherein the contacting step is carried out at a temperature ranging from ambient temperature to about 90° C. 
     
     
         8 . The method of  claim 1 , wherein the oxygen gas-containing fluid comprises air. 
     
     
         9 . (canceled) 
     
     
         10 . The method of  claim 1 , wherein the copper ore or cooper concentrate comprises chalcopyrite. 
     
     
         11 .- 20 . (canceled)