Experimental study on iron recovery by microwave carbon heat reduction-magnetic separation from red mud

Abstract

To explore new ways to recycle red mud, this paper study on iron recovery by microwave carbon heat reductionmagnetic separation from red mud. Using orthogonal experimental method，study the effect of carbon to oxygen ratio, microwave power, heating time and slag former ratio on recovery of iron. The results show that microwave power is the main factor affecting iron recovery. After optimized by orthogonal experimental results, in the case when carbon to oxygen ratio is 1,5, microwave power is 3 000 W, heating time is 45 min, slag former ratio is 5 %, the grade and recovery of iron reach to 64,58 % and 90,64 % respectively. Analyzed comprehensivly by X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS), Fe2O3 in red mud is reduced to Fe3O4 and Fe by microwave carbon heat reduction.

Keywords

• red mud
• microwave
• carbon heat reduction
• magnetic separation