Hydrometallurgical process for extracting copper from chalcopyrite or bornite concentrates

A process for the extraction of copper from copper containing minerals such as chalcopyrite and bornite comprising the steps of:

• comminuting the concentrate, having a particle size of at least 40 .mu.m, in a conventional attrition grinder and in the presence of a liquid dispersing agent, selected from the class consisting of ammonium hydroxide, potassium hydroxide and sodium hydroxide for a period of time ranging from about 5 to 15 minutes so as to form a pulp having particles the size of which range from 3 .mu.m to substantially less than 3 .mu.m, and leaching said pulp in the presence of a silver catalyst and oxygen gas at a pressure of approximately 1 kg/sq.cm. at a temperature of approximately 110.degree.C. and for a period of time of from about 15 minutes to about 30 minutes wherein more than 90 per cent of the copper is brought into solution.