Lattice Gas Automata Model For Gas-Solid Reaction Flow In The Reduction Of Fe₂O₃

The process of CO reduction of Fe₂O₃ is the most representative basic reaction process in metallurgical reduction process.The reduction reaction characteristics of the process were discussed.The reaction mechanism is of great significance to the design of metallurgical reactor and the optimization of the process.The process is a multi-step reaction process,generally divided into Fe₂O₃ into Fe₃O₄,Fe₃O₄ into FeO,FeO into Fe three stages.Because of its flow,heat transfer and other transmission process coupling,the study of iron oxide reduction process is difficult.Aiming at this process,a single step reaction model was constructed based on the lattice gas automata method.The model was used to study the process of CO reduction of Fe₂O₃,and the experiment was carried out.Aiming at the multi-link coupling problem of gas-solid reaction process,the properties of gas particles in the region were expressed by the properties of the gas particles around the boundary of the solid particle boundary,and the concentration of the reaction gas in the region was expressed according to the multi-material,multi-energy reactant and product gas for temperature and other properties.The lattice gas cellular automata model of gas-solid reaction flow was established by combining the properties of gas-solid reaction.The numerical examples of CO reduction FeO were used to verify the rationality and practicability of the model.Based on the gas-solid reaction model constructed above,the reaction process of Fe₂O₃ to Fe₃O₄ was simulated,and the change characteristics of the reaction and particle were obtained under different reaction conditions.The results show that when the temperature and concentration increase,the reduction rate is faster,the time required for complete reaction is shortened,the nonuniform structure of the grain reaction interface shrinkage is more obvious,and the degree of reduction of the particle interface near the gas inlet is obviously high in the remaining parts;when the particle radius and the pipe inlet width increase,the rate of reduction slows down,the time required for complete reaction of the particles increases.In addition,when the height of the pipe increases,the effect on the reaction rate is not obvious.The reaction kinetics of CO-reduced Fe₂O₃ is studied by a micro-fluidized bed.The single-step reduction process of Fe₃O₄ conversion to FeO and FeO to Fe was simulated by the gas-solid reaction flow model.The multi-step reaction of the reduction process is coupled by the single-step reaction series combination.The results show that the higher the reaction temperature,the higher the reaction rate is.The apparent activation energy will increase with the increase of the reaction.The process of high temperature Fe₂O₃ conversion to Fe,at the same time,the reaction of Fe₂O₃ into Fe₃O₄ occurs at the initial stage of the reaction.The reaction rate of Fe₃O₄ conversion to FeO was higher than that of FeO,and the change of Fe₂O₃ conversion to Fe conversion is consistent with physical experiments.