Reconstruction optimization of gas-based shaft furnace direct reduction ironmaking process
YU Heng1, ZHOU Ji-cheng2,3, LI Xiu-ping2,3, SHANGGUAN Fang-qin3
1. Tangsteel Company, HBIS Group, Tangshan 063016, Hebei, China; 2. Steel Industry Green and Intelligent Manufacturing Technology Center, China Iron and Steel Research Institute Group, Beijing 100081, China; 3. State Key Laboratory of Advanced Steel Processing and Products, Central Iron and Steel Research Institute, Beijing 100081, China
Abstract:Direct reduction iron (DRI) is a good raw material of electric arc furnace (EAF) steelmaking, which is purity and stable in chemical composition. The coking industry generates large quantities of coke oven gas (COG), which is suitable for the development of shaft furnace direct reduction ironmaking process with COG and the main processes are Midrex process and HYL-ZR process. In order to resolve the problems of Midrex process and HYL-ZR process, through process function analysis, the reconstruction optimization process of gas-based shaft furnace direct reduction ironmaking is proposed through the process function analysis. The main procedures include COG compression, TSA pretreatment, PSA decarbonization, PSA purification of CH4, hydrogen-rich gas heating, shaft furnace direct reduction ironmaking, and so on. The process can improve the reduction efficiency of shaft furnace because the COG purification is achieved, CH4 is separated, the ratio of H2 and CO reaches to 8 in the reduction gas, and the CH4 reforming is omitted. The process links the coking process and EAF, which is not only beneficial to the resource optimization of the integrated iron and steel works, but also can produce natural gas and improve energy utilization efficiency.