Process of extracting gold and other metals from ores, concentrates, residues and the like containing principally cobalt, nickel, iron, arsenic and gold

Claim 1

A PROCESS OF EXTRACTING GOLD FROM ARSENIURETED AND SUPLHARSENIURETED ORES, CONCENTRATES, RESIDUES AND THE LIKE CONTAINING SMALL AMOUNTS OF GOLD AND SUBSTANTIAL AMOUNTS OF IRON AND ARSENIC, WHICH COMPRISES FORMING A SLURRY OF THE ORE IN A MINERAL ACID, ADDING AN OXIDING AGENT TO A SLURRY AT A GIVEN RATE TO CAUSE A GRADUAL RISE IN THE OXIDATION POTENTIAL OF THE SLURRY TO DISSOLVE THE METAL EXCEPT GOLD, CONTINOUSLY MEASURING THE OXIDATION POTENTIAL OF THE SLURRY DURING THE ADDITION OF THE OXIDIZING AGENT, PROGRESSIVELY ADDING A CHLORINATING AGENT UNTIL AN AXCESS OF THE AGENT OVER THAT REQUIRED TO OXIDIZE THE GOLD HAS BEEN ADDED TO THE SLURRY, MAINTAINING SAID EXCES OF THE OXIDIZING AGENT, AS REVEALED BY AN INCREASE IN THE OXIDATION POTENTIALM IN THE SLURRY BY ADDITION OF THE AGENT AT A REDUCED RATE UNTIL SUBSTANTIALLY ALL OF THE GOLD AS BEEN DISSOLVED, PRECIPITATING IRON AND ARSENIC COMPOUNDS GY REDUCING THE ACTIDITY OF THE SLURRY, SEPARATING THE PRECIPITATE TOGETHER WITH INSOLUBLE RESIDUE FROM THE SOLUTION AND RECOVERING GOLD FROM THE LAST MENTIONED SOLUTION.