焦炭溶损反应动力学及其模型研究

The kinetics of the reaction between coke and CO2 under the condition of blast furnace was studied by using the shrinking unreacted core model, and a relational expression of reaction kinetics was established with R, a determinable parameter. Reaction rate constant, effective diffusivity, apparent activation energy, effective diffusion activation energy and resistance in various steps of the reaction process were analyzed in this paper. The results show that the reaction of coke with CO2 is consonant with the shrinking unreacted core model, which has an apparent activation energy Ea=124.5kJ/mol, and an effective diffusion activation energy ED=642.4kJ/mol. With the increasing of reaction temperature, the resistance of surface chemical reaction increases, but the relative proportion of internal diffusion mass transfer resistance decreases in the residue ash layer. The coke reaction with CO2 is mainly controlled by the internal diffusion at lower temperatures, while with the increasing of reaction temperature, it is controlled by a combination of external diffusion, chemical reaction and internal diffusion. After a period of time at high temperatures the reaction turns to be controlled by the internal diffusion.