Process dynamics of electric arc furnace during direct reduced iron melting

Abstract

A phenomenological mathematical model to simulate steelmaking operations in an electric arc furnace (EAF) has been developed. This model has been validated with industrial data from a Mexican company that employs direct reduced iron (DRI) as the main iron unit. The slag and steel composition can be predicted in real time with the aid of several components integrated into the simulator. The model starts with the optimization of mass and energy balances that yields the requirement of materials to produce a given quality of steel with the minimum cost. The rate of reduction of iron oxide is computed based on two reactions occurring between the FeO and carbon dissolved in the metal and FeO with the carbon particles injected into the slag. A mechanism of consumption of carbon particles has been completed, which includes the effect of surfactant species in the slag and operational variables of the industrial practice of carbon injection. A new concept, called dynamic foaming index, (DFI) is proposed to quantify the actual foaming behavior of industrial slags throughout a commercial heat. The results prove the versatility and robustness of the present mathematical model and provide a knowledge base to assist in the design, operation, and optimization of metallurgical practices for EAF steelmaking.