Process Analysis of the Electric Arc Furnace Melting for Alumina Spinel Production

Alumina spinel is widely used as a refractory material in metallurgy industries. Arc furnace melting method is suitable to produce high quality alumina spinel. However, the high melting temperature (> 2200 °C) and high electric energy consumption limit the application of this method. There exists huge opportunity for energy saving through process optimization. A newly designed 2400 kVA electric arc furnace is used as melting facility to produce alumina spinal in this study. It shows from the experiments and analysis that melting voltage has much effect on electric power input and electric efficiency. At voltages higher than 150V, stable electric power input and adequate efficiency can be maintained. Stable melting voltage is difficult to maintain at 100-150V range and power efficiency are also apparently lower. For voltage less than100V, the process is very difficult to control and energy efficiency are very poor. Too high voltage on the other hand can lead the electric arc expose directly to the surroundings and increase the energy loss. In practical melting process, controlling the melting voltage at 140-160V range is suitable for high quality alumina spinel production.