Behaviour of silver in the electric furnace for copper dross treatment.

The Chigirishima refinery produces electrolytic lead using a sintering-blast furnace-electrolysis route. Most of the copper and silver in the lead raw material migrates to the dross that forms when lead is decopperised. This is treated in an electric furnace to produce matte, speiss and crude lead. For recovery of silver it is important to improve its rate of migration to the lead. With this end, the distribution of silver between the crude lead, matte and speiss was examined. It was shown that decreasing the Cu to Cu+Fe ratio by adding iron leads to an increase in the migration of silver to the lead phase. For the recovery of silver from the speiss, melt equilibration of speiss and lead with no inclusion of silver is thought to be effective.
The Chigirishima refinery produces electrolytic lead using a sintering-blast furnace-electrolysis route. Most of the copper and silver in the lead raw material migrates to the dross that forms when lead is decopperised. This is treated in an electric furnace to produce matte, speiss and crude lead. For recovery of silver it is important to improve its rate of migration to the lead. With this end, the distribution of silver between the crude lead, matte and speiss was examined. It was shown that decreasing the Cu to Cu+Fe ratio by adding iron leads to an increase in the migration of silver to the lead phase. For the recovery of silver from the speiss, melt equilibration of speiss and lead with no inclusion of silver is thought to be effective.