Abstract: Microwave reduction roasting was used to modify the magnetic properties of pyrite cinder, and the effect of microwave reduction on the subsequent low intensity magnetic separation of the modified cinder was investigated. The results indicate that microwave reduction roasting is faster and more effective than conventional carbothermic reduction. The key factors affecting the modification of the magnetic properties are the reduction temperature and the dosage of accelerant while the dosage of reductant is not obvious. At a reduction temperature of 500℃ and an accelerant dosage of 10%, a concentrate grading 61.56% Fe and having a recovery of  86.13% can be obtained by magnetic separation of roasted cinder, rather good results.

Key words: Pyrite cinder, Microwave heating, Accelerant, Magnetic separation