Oxygen-Rich Side-Blown Bath Smelting of Copper Dross: A Process Study

A complex copper dross containing Bi, Pb, Cu, As and Sb was processed in a 3.6 m2 industrial-scale oxygen-rich side-blown bath smelting furnace (OSBF). The products were collected and analyzed by chemical and mineralogical methods. Industrial statistical data showed that recoveries of Cu, Pb, Bi and Sb reached 87%, 96%, 97% and 60%, respectively. Slag composition indicated that the process can be divided into 2 steps, i.e., oxidative smelting and reductive smelting, due to the use of different oxygen-rich gas flow rate and enrichment. The effect of oxygen partial pressure (PO2) on the element partitioning was simulated by Factsage. The results indicated that increase of PO2 between 10–5 atm and 10–7 atm would significantly increase the partitioning of Cu, Pb, As and Sb to the slag; while element partitioning became almost independent of PO2 between 10–7.5 atm to 10–9.5 atm. Phase analysis for the slag indicated that the bath in the furnace was a “FeO”–CaO–SiO2–Al2O3–ZnO slag coexisting with solid spinels.