Kinetic Simulation of Hot Metal Pretreatment: Desulfurization Using Powder Injection

A kinetic model for hot metal pretreatment process was developed. The co-injection of soluble magnesium and insoluble lime, and both of the transitory and permanent contact reaction zones were considered in the present model. That is, the model covers all the general features of hot metal desulfurization in the submerged powder injection, practiced at steel plants. The model was based on the effective equilibrium reaction zone approach in combination with FactSage thermodynamic databases. The process was divided into a finite number of reaction zones, and effective reaction volumes of each reaction zone were determined as a function of process parameters based on physical descriptions of reactions’ mechanisms. The present model can be applied to a wide range of HM and top slag chemistries, and can calculate compositional evolution of both hot metal and slag during the process. The accuracy of model was compared to the sampled plant data. The current model was also utilized to study the potential for further optimization of the existing hot metal pretreatment process at a steel plant.