rotary hearth furnace

The Rotary Hearth Furnace (RHF) is designed to convert green pellet made of iron ore fines and/or steel mill wastes into metallic iron using pulverized coal as a reductant. The end product is direct reduced iron. Concentrated iron ore and ground reductant are pelletized and dried before being sent to RHF. As the hearth rotates, the feed materials are heated to 1250-1350°C, and the iron oxide is reduced to metallic iron. Reduction of the iron oxide is accomplished by fixed carbon(C) reacting with the iron bearing materials to form metallic iron. Oxygen is removed from the iron ore while release carbon monoxide (CO) and carbon dioxide (CO2) gas. Residence time on the hearth is normally 20-30minuts and varies depending on deferent kind of iron ore and technical data. During this time 90-95% of the iron oxide is converted to direct reduced iron. Coal-based Rotary Hearth Furnace DRI process has basically no restrictions to the raw material ores, the iron concentrate, ore fines,ore bearing dust, iron containing sludge as well as laterite ore can all be used. Therequirementtothereducingcoaltobeusedisrelativelylower,thecommonnon-cokingcoalcanbeused.