Abstract:The feasibility to recover metal iron from copper slag and blast furnace ash by co-reduction followed by magnetic separation using blast furnace ash as reducing agent was verified. The process of recovering iron by co-reduction and magnetic separation was studied applying copper slag from Shandong with iron grade of 35.59% and four kinds of blast furnace ash from Shandong and Gansu province as raw materials. The results show that indexes of the direct reduced iron (DRI) are poor when blast furnace ash is only added into roasting system, while with the presence of CaF2, co-reduction followed by magnetic separation can make full use of reducibility of carbon in blast furnace ash and realize the recovery of iron resources in copper slag and blast furnace ash, and both the iron grade and iron recovery of reduced iron are more than 90%. Reducing agent type and dosage, CaF2 dosage, co-reduction temperature, co-reduction time, grinding fineness and magnetic field intensity has effects on indexes of DRI. DRI with Fe grade of 92.06% and Fe recovery of 92.65% is obtained under the conditions including roasting temperature of 1 250 ℃, roasting time of 60 min, mass ratio of G1 and CaF2 of 30% and 15%, respectively, grinding fineness of roasting product of -74 μm of 51.87%, and magnetic field intensity of 80 kA/m. This process can provide a reference for comprehensive utilization of copper slag and blast furnace ash.