Parameters Optimization, Sticking Mechanism and Kinetics Analysis of Fine Iron Ore in Fluidized-Reduction Process

抄録

ORD-S fine iron ore is reduced in fluidized bed, and fine iron ore particles are evaluated through mechanical and dynamic analyses. This study aims to obtain the changing direction of the operating parameters by synthetically analyzing the effect of temperature, velocity of reducing gas, reducing gas atmosphere, size of fine iron ore particle, and coating oxide composition on the fluidized reduction sticking process; draw economic, convenient, and effective operating parameters; and provide theoretical and technical basis for the economical and rational use of the ORD-S fine iron ore. The optimal operating parameters require to reduce ORD-S fine iron ore include 923 K to 1023 K temperatures, particle size range of 0.63 mm to 1.0 mm, linear velocity of 0.6 m/s, hydrogen accounting for 80 vol.% of the total carbon monoxide and hydrogen mixture, and coating MgO accounting for 2 mass% of the total quality of fine iron ore. Under the optimal experimental conditions, the critical radius of solid bridge is 90–105 nm, the apparent activation energy E of the chemical reaction is 22.48 kJ/mol, and the limit link of chemical reaction speed is the internal diffusion speed.