Selective leaching of a copper ore by an electromembrane process using ammonia solutions

A new method of copper extraction from its ore is examined in this paper. Based on the electrokinetic processes used for soil remediation, the technique envisaged consists in the copper dissolution by ammonia solution using an electric field. The ore is mixed with NH4+/NH3 solution and it is inserted in a five compartment cell between two ion exchange membranes. Then the system acts as an electrodialyser where the ore represents the solution which should be demineralised. Moreover, ammonium crosses the membrane from an adjacent compartment to increase the dissolution giving rise to 98% of extraction yield after 400 h. The role of the current and the transport mechanisms have been examined through this interesting process which reduces the number of operation units and saves energy by the fact that it does not need oxygen pressure for an alkaline leaching.