REFINING COPPER PYROMETALLURGICALLY BY TWO-STAGE SUBATMOSPHERIC TREATMENT

摘要

Copper precipitated from solution is melted in air to slag iron and to form a copper bath containing sulfur and oxygen, with the oxygen content being at least in excess of the sulfur content without producing a separate cuprous oxide phase, and at least one other volatile impurity selected from the group consisting of arsenic, bismuth, lead, selenium, tellurium, tin and zinc. The copper bath is subjected to a subatmospheric pressure treatment while passing a purge gas, that can contain free oxygen, through the bath to rapidly remove sulfur from the bath. The flow of the inert gas through the bath is terminated and the bath is then subjected to even lower subatmospheric pressures to remove other volatile impurities.