The copper content of blister copper is generally 95~98%, so the purpose of the fire-refining is to remove the sulfur and some other harmful impurities from the blister copper, produce a copper anode that can meet the requirement of electrolytic refining process and leave the precious metals in the copper anode.
If there are fewer precious metals, the resulting fine copper can be used in less demanding situations.
If there are more precious metals, cast the refined blister copper into anode plates for electrolysis.
The fire-refining process mainly includes the two stages of oxidation and reduction. The purity of copper can be increased to over 99%.
According to the type and content of impurities, relevant auxiliary materials are added to remove impurities.