Comparison of Different Coal Based Direct Reduction Processes

摘要

In this report coal-based direct reduction processes that are currently incommercial operation or under development are discussed and compared. The coal-based processes can be grouped into four categories according to their reduction reactors. The rotary kiln processes include ACCAR/OSIL, DRC, Krupp-CODIR and SL/RN processes. Kinglor Metor is a shaft furnace process, Circofer is a fluidized bed process and, further, rotary hearth processes include COMET, FASTMET and Inmetco processes. The Circofer, FASTMET, Inmetco and COMET processes seemed to be more attractive to produce DRI than the old rotary kiln processes. In the case of rotary hearth processes the reduction temperature is higher and thus retention time much lower compared to the other coal-based direct reduction processes. Also the production and investment costs of Circofer, FASTMET, Inmetco and COMET processes were found to be lower compared to the rotary kiln processes.