Patent ID: 10648060

Abstract:
Provided herein is a process of fire refining blister copper, comprising the steps of (a) providing molten blister copper into an anode furnace; (b) when sulfur concentration of the molten blister copper provided in step (a) is above a first prescribed target value, oxidizing sulfur in the molten blister copper by blowing oxygen containing gas into the molten blister copper until the first prescribed target value has been reached; (c) subsequently lowering the sulfur and oxygen content in blister copper by blowing inert gas into the molten blister copper until a second prescribed target value has been reached, wherein the inert phase (c) is continued until the second prescribed target value of the oxygen concentration is below 4000 ppm, and the second prescribed target value of the sulfur concentration is below 500 ppm; (d) when certain condition(s) occur, subsequently reducing oxygen in the blister copper; and (e) optionally casting.