Reduction of pyrite cinder pellets mixed with coal powder

Direct reduction of pyrite cinder in a rotary hearth furnace (RHF) was studied under the condition of laboratory simulation. Effects of reduction temperature, reduction time, molar ratio of carbon to oxygen, and CaO addition on metallization rate as well as compressive strength of the pellets after reduction were discussed. The results showed that the metallization rate and compressive strength were 93.9% and 2160 N per pellet respectively under the conditions of the reduction temperature of 1200 °C, the reduction time of 16 min, and the molar ratio of carbon to oxygen (x_c/x_o) of 1.0; adding 2.5% CaO was beneficial to sulfur enrichment in slag phase of pellet, and metallization rate increased slightly while compressive strength decreased.