HIGH TEMPERATURE SOFTENING OF LEAD BULLION

摘要

A process for the refining of lead bullion containing lead and copper, plus one or more of the elements sulphur, arsenic, antimony, tin, silver, bismuth and other elements known to be contained in lead bullion is disclosed. The process comprises first desulphurizing and softening the lead bullion in a furnace at a temperature sufficiently high to prevent the formation of a separate copper containing phase, and then cooling of the softened bullion in a kettle or furnace to a temperature near 330 C to form a dross or matte containing substantially all the copper originally contained in the bullion.