Popis: |
Coke constitutes the major portion of ironmaking cost and its production causes the severe environmental concerns. So lower energy consumption, lower CO2 emission and waste recycling are driving the iron and steel industry to develop alternative, or coke-free, ironmaking process. Midrex and HYL Energiron are the leading technologies in shaft furnace direct reduction, and they account for about 76% of worldwide production. They are the most competitive ways to obtain high quality direct reduced iron (DRI) for steelmaking. Therefore, in the present paper, some detailed information about these two processes are given. Much attention has been paid on process scheme, the feedstock, DRI product, heat recovery, reforming gas, hot discharge and transportation, and by-product emission. Its very important for direct reduction development in both natural gas-rich counties and natural gas-poor counties. |