1. Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, Liaoning, China; 2. School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China; 3. Research Institute, Hegang Technology of Materials, Shijiazhuang 050023, Hebei, China
Abstract:In order to investigate the flash reduction behavior of hematite fines under different reaction conditions, a mathematical model describing the flash reduction process of hematite fines in hydrogen atmosphere was established based on Euler-Lagrange method. The temperature distribution, velocity distribution and particle trajectories of gas-particle two-phase flow in the reactor were obtained by numerical calculation. The flash reduction process of hematite fines in the reactor was analyzed, and effects of operating conditions such as reactor temperature, hydrogen volume fraction and particle size on the flash reduction behavior were investigated. The results show that when the reactor temperature is not higher than 1 550 K, hematite fines undergo heating, thermal decomposition and gas-solid reduction during movement, while the reactor temperature is higher than 1 550 K, hematite fines also undergo gas-liquid reduction, and the gas-liquid reduction area expands with the increase of reactor temperature and hydrogen volume fraction. When the hydrogen volume fraction is 40%, the final reduction degree of hematite fines with particle size of 53-64 μm increases by 40 percentage point for every 150 K increase in reactor temperature. The establishment of model provides theoretical guidance for the development of flash reduction ironmaking technology.
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