Method of recovering copper from sulfidic copper ore

Claim 1

IN A PROCESS OF THE CHARTER DESCRIBED, IN WHICH A PULP OF SULFIDIC COPPER ORE SLIMES IN AN ACIDIC AQUEOUS MEDIUM CONTAINING DISSOLVED COPPER IS TREATED WITH METALLIC IRON TO PRECIPITATE THE DISSOLVED COPPER AS METALLIC CEMENT COPPER, AND IN WHICH THE ACIDIC PULP IS THEREAFTER SUBJECTED TO FROTH FLOTATION IN AN ACID CIRCUIT TO PRODUCE A CONCENTRATE OF SULFIDE COPPER AND CEMENT COPPER SUITABLE FOR SMELTING, THE IMPROVEMENT WHICH COMPRISES TREATING SAID ACIDIC PULP WITH AN AMOUNT OF GRANULAR METALLIC IRON SUBSTANTIALLY IN EXCESS OF THAT REQUIRED TO PRECIPITATE THE DISSOLVED COOPER, RETAINING SUCH EXCESS OF METALLIC IRON SUSPENDED IN THE ACIDIC PULP DURING SUBSEQUENT FLOTATION OPERATION, WHEREBY LOSS OF METALLIC COPPER BY RE-SOLUTION DURING PROGRESS OF THE FLOTATION OPERATION IS MINIMIZED, RECOVERING A TAILING CONTAINING UNCONSUMED METALLIC IRON FROM THE FLOTATION OPERATION, SEPARATING THE METALLIC IRON FROM SAID TAILING, AND EMPLOYING SUCH SEPARATED METALLIC IRON IN THE PRECIPITATION TREATMENT OF A FURTHER QUANTITY OF SAID PULP.