General heat balance for oxygen steelmaking

Energy balances are a general fundamental approach for analyzing the heat requirements for metallurgical processes. The formulation of heat balance equations was involved by computing the various components of heat going in and coming out of the oxygen steelmaking furnace. The developed model was validated against the calculations of Healy and McBride. The overall heat losses that have not been analyzed in previous studies were quantified by back-calculating heat loss from 35 industrial data provided by Tata Steel. The results from the model infer that the heat losses range from 1.3% to 5.9% of the total heat input and it can be controlled by optimizing the silicon in hot metal, the amount of scrap added and the post-combustion ratio. The model prediction shows that sensible heat available from the hot metal accounts for around 66% of total heat input and the rest from the exothermic oxidation reactions. Out of 34% of the heat from exothermic reactions, between 20% and 25% of heat is evolved from the oxidation of carbon to carbon monoxide and carbon dioxide. This model can be applied to predict the heat balance of any top blown oxygen steelmaking technology but needs further validation for a range of oxygen steelmaking operations and conditions.