Mathematical modeling of refining of stainless steel in smelting reduction converter using chromium ore

Abstract

For predicting and controlling the process of chromium ore smelting reduction in a converter preferably, the coupling dynamic model is established for the first time based on the kinetic models of chromium ore dissolution and interfacial reducing reaction between the slag and the metal. It can decrease the refining time considerably and improve the production efficiency for producing 12 wt% Cr stainless steel crude melts in a converter when the initial hot metal contains the definite chrome metal at 1 560°C. Under the conditions of the mathematical model, the effect of chromium ore size on the process of producing stainless steel crude melts by chromium ore smelting reduction in a converter is great when the particle size of chromium ore increases to a certain value. In such condition, the dissolution of chromium ore in the slag is the rate controlling step at a certain stage of refining and the rate of chromium ore smelting reduction is controlled jointly by the dissolution and the reduction of chromium ore. The effect of temperature on the process of chromium ore smelting reduction in a converter is significant. The mean reduction rate of chromium ore increases from 0.052 wt%·min -1 to 0.175 wt%·min -1 with the increasing of temperature from 1 540°C to 1 580°C. © 2012 ISIJ.