Preparation of novel reducing agent and its application in copper pyrorefining

A novel tye of carbonaceous reagent was studied as a substitute for charcoal or heavy oil in copper pyrorefining. Several carbonaceous substances (metallurgical coke, petroleum coke, peat, anthracite and brown coal) were tested and brown coal was found to be the best. Treatment with HNO3, NaOH, H2O2 and H2SO4 was used to remove impurities from the brown coal. Most of the iron and sulphur was removed following treatment in H2O2 + HNO3 solution. After adding quartz sand flux to decrease the melting point of the brown coal ash, the reagent was applied in copper pyrorefining. The novel substitute has been used successfully instead of charcoal and heavy oil in two industrial plants.