Design of a furnace for refining copper prior to fusion

The design of a furnace for the removal of copper impurities prior to smelt ing is presented here. Impurities such as arsenic, antimony bismuth, lead, and zinc are removed by heating the concentrate below 1000 degrees C in an indirect way using the thermal energy fr om the gases effusion and conversi on. The concentrate heats up while sliding down along a hermetically, seale d vacuum tunnel After passing through filters, the volatilized substances a re conducted along a tunnel with a decreasing temperature profile which ind ices a step-wise condensation and recovery of the different substances. The main operating cost of the finance is due to the electric energy required by the vacuum pumps and the liquid air condensers. This cost turns out to b e very small as compared to the overall operating cost of the smelter. (C) 1999 Elsevier Science Ltd. All rights reserved.