Abstract: A process for refining high-impurity blister copper to anode quality copper is disclosed. In an oxidation step of a blister copper refining stage, soda ash fluxing removes antimony and arsenic while also removing sulfur and iron. In a deoxidation step of the blister copper refining stage, sulfur hexafluoride is injected at a controlled oxygen concentration to remove bismuth while reducing the oxygen content. Slag is continuously or periodically skimmed from the surface of the molten blister copper to prevent re-entry of impurities. The process may be carried out in batch operation or, in a preferred embodiment, in continuous flow-through operation.