Production of MgO in an electric arc furnace: thermal analysis

The computer simulation presented here is the response to an industrial challenge about how the electric are furnace, where the smelting process of magnesium oxide (MgO) takes place, should be charged to avoid shell overheating. If solid MgO is charged at a very high rate, the processing time becomes very long; on the other hand, if the feed rate is too slow, the external shell made of steel reaches temperatures above its melting point. Thus, it is necessary to reduce the electrode current or to charge more material to avoid shell overheating. With the aid of this model, a charge scheme for the furnace is proposed, having maximum production without shell overheating. Validation of the model has been carried out with temperature measurements along the external shell while the process was being conducted; the size and shape of the smelted zone after fusion were also compared with information obtained from the graphic results predicted by the model. Results from the model are in good agreement with the measurements. Calculation of the specific energy consumption can be provided with the input energy rate and the mass of the smelted MgO.