Ironmaking in Rotary Hearth Furnace May17

Ironmaking in Rotary Hearth Furnace...

Ironmaking in Rotary Hearth Furnace Ironmaking in the rotary hearth furnace (RHF) is a direct reduction process which utilizes non-coking coal for the reduction of iron ore. The RHF is the process reactor which consists of a flat, refractory hearth rotating inside a stationary, circular tunnel kiln. Inside the RHF, direct reduction of iron ore or iron-bearing waste materials occurs, using coal as the reductant. RHF is not a new technology. It has been used successfully in a range of industrial applications which includes heat treatment, calcination of petroleum coke, waste treatment, and non-ferrous high-temperature metal recovery. The history of ironmaking in RHF goes back to the mid-1960s with the development of the ‘Heat Fast’ process by Midrex. Since then several ironmaking processes based on RHF have been developed. These include ‘Fastmet’ process/‘Fastmelt’ process, and ITmk3 process which were brought into commercial operation. These processes have been described in separate articles having links    http://ispatguru.com/fastmet-and-fastmelt-processes-of-ironmaking/, and http://ispatguru.com/itmk-3-process-of-making-iron-nuggets/. Other RHF processes are ‘Redsmelt’ process, ‘Inmetco’ process, ‘Iron Dynamics’ process, ‘DRyIron’ process, ‘Comet’ and ‘SidComet’ processes and Hi-QIP process. Redsmelt process The Redsmelt process technology has been developed to meet the growing demand for a low cost environmental friendly ironmaking alternative to the traditional blast furnace route. The plant with this process can be designed for a production capacity of 0.3 million tons per year to 1.0 million tons per year of hot metal. The process can treat a wide range of iron ore fines and waste materials from the steel plant. The Redsmelt process is based upon a RHF which reduces green pellets made out of iron ore, reductant fines and binders to produce hot, metallized direct reduced iron (DRI) which is charged to a submerged arc furnace (SAF). The process operates at high temperature and...