Abstract: The present invention comprises a method of recovering copper minerals from ores containing both sulfide and oxidized copper sulfide minerals, such as found, for example, in surface oxidized porphyry ores. Accordingly, one embodiment of the present invention comprises first conditioning a pulp of an ore containing copper sulfide and oxidized copper sulfide minerals in the presence of an alkaline agent, next subjecting the so conditioned ore to a second conditioning step in the presence of a collector, subsequently adding a surface modifying agent to the so treated ore at a rate and in an amount sufficient to decrease the platinum electrode potential of the pulp when measured against a saturated calomel electrode to a minimum of -100 mV, then conditioning the ore only for a time sufficient to achieve intimate contact between the ore particles, and thereafter subjecting the so treated ore to conventional flotation.