Improvement of carbothermic reduction of nickel slag by addition of CaCO3
(1. School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China;
2. Shaanxi Engineering Research Center of Metallurgy, Xi’an University of Architecture and Technology, Xi’an 710055, China)
2. Shaanxi Engineering Research Center of Metallurgy, Xi’an University of Architecture and Technology, Xi’an 710055, China)
Abstract: The effect of CaCO3 addition on the carbothermic reduction of nickel slag was studied, and the mechanism of CaCO3 in improving the reduction was analyzed. The results showed that when the CaCO3 content added to the slag was increased from 0 to 8 wt.%, initiation temperature of the carbothermic reaction decreased from 1100 to 1000 °C, the temperature reaching the maximum reduction rate decreased from 1150 to 1100 °C, and the reduction degree of the nickel slag increased from 58% to 88%. The iron particles in the reduced nickel slag were coarsened and the X-ray diffraction intensity of metallic iron peaks increased, confirming that the addition of CaCO3 was beneficial to the reduction of nickel slag and recovery of iron.
Key words: nickel slag; fayalite; carbothermic reduction; CaCO3