Effect of preheat, bed porosity, and charge control on thermal response of submerged arc furnace producing ferrochromium

The temperature profile inside the submerged arc furnace is a critical factor influencing the process efficiency in the production of ferroalloys. The effect of a number of critical process parameters such as the charge preheat, bed porosity, and charge chemistry on the temperature profile was analysed by means of a mathematical model, It was found that preheating of the charge had a significant influence on the profile. Higher bed porosity tended to bring the various isotherms closer to the hearth of the furnace. Low bed porosity tended to expand the high temperature zone of the furnace. This can lead to diminished process efficiency under certain circumstances. The charge chemistry also altered the profile depending on the type of changes introduced. The influence of these parameters and their significance for the operation of the process are discussed in this paper.