Electrode Erosion due to High‐Current Electric Arcs in Silicon and Ferrosilicon Furnaces

Abstract

The role of the electric arc in the consumption of electrodes in submerged arc furnaces has long been discussed. The environment does not make direct measurement possible, so simulation has been used to evaluate the arcs contribution to the erosion. Magnetofluiddynamic (MFD) electric arc simulations and a cathode / anode sub‐model developed in order to provide boundary conditions to the arc model have been used for this purpose. In the case of high‐current industrial AC arcs, arc currents are typically ~100 kA, phase voltages ~100 V and total furnace power ~10 ‐ 60 MW. The results show that although enormous amounts of material is evaporated, due to recondensation of vapour, less than half of the total electrode consumption in an industrial furnace can be attributed to the arc. The largest contributor is chemical corrosion. Results from this analysis indicated that there are probably more than one arc present in the crater.