 Flotation then separates the gangue from the metalliferous particles, which float off as a 28-percent concentrate of copper along with lesser amounts of silver, gold, lead, molybdenum, platinum and palladium.A selective flotation step separates the molybdenite (molybdenum disulfide) from the chalcopyrite.The filtered concentrate slurry is piped to the smelter, where it is dried, and then injected along with oxygen into a flash smelting furnace to oxidize the iron and sulfur.