2018 Volume 58 Issue 6 Pages 1168-1174
Experiments were carried out in a slag cleaning electric furnace to reduce magnetite in copper smelting slag using petro-diesel or biodiesel produced from waste cooking oil, and the reduction effects using the two reducing agents were compared. The pyrolysis experiments of petro-diesel and biodiesel were carried out in a fixed bed reactor to study their pyrolysis characteristics and explore the reduction mechanism of magnetite in copper smelting slag. The experimental results showed that the primary crystalline phases in copper smelting slag were magnetite [Fe3O4] and silicate. And the content of fayalite [Fe2SiO4] increased while the magnetite [Fe3O4] decreased after reduction by petro-diesel and biodiesel. In the process of copper smelting slag reduction, the petro-diesel and biodiesel firstly cracked into coke, H2, CO and CH4, and then reacted with the magnetite in the slag. The reduction effect of biodiesel was better than petro-diesel because more reducing gases can be generated through pyrolysis of biodiesel, and its price should be much lower than petro-diesel. Therefore, magnetite reduction in copper smelting slag using biodiesel produced from waste cooking oil should be recognized as an economical and environment-friendly process for waste management and application.