An electric arc furnace is an electric furnace that uses the high temperature generated by electrode electric arcs to smelt ores and metals. When an electric arc is formed via gas discharge, energy is highly concentrated, and the temperature in the arc zone exceeds 3000°C. For metal smelting, electric arc furnaces feature greater process flexibility than other steelmaking furnaces. They can effectively remove impurities such as sulfur and phosphorus, deliver easy furnace temperature control, and occupy a small floor area, making them suitable for smelting high-quality alloy steel.
Industrial furnaces heated by electric arcs generated through metallic or non-metallic electrodes are defined as electric arc furnaces. Based on arc forms, they are categorized into three-phase electric arc furnaces, consumable electrode arc furnaces, single-phase electric arc furnaces and resistance arc furnaces.
The furnace body of an electric arc steelmaking furnace consists of a furnace roof, furnace door, tapping spout and furnace shell. The furnace bottom and furnace walls are lined with basic or acidic refractory materials. In accordance with the transformer capacity configured per ton of furnace capacity, electric arc steelmaking furnaces are classified into regular power, high-power and ultra-high-power types.
Electric arc steelmaking transmits electric energy into the furnace through graphite electrodes, and relies on the electric arcs formed between electrode tips and furnace charge as the heat source for steel smelting. Using electric energy as the heat source, electric arc furnaces allow adjustable furnace atmosphere, which is extremely beneficial for smelting steel grades rich in easily oxidizable elements. Shortly after the invention of electric arc furnaces, they were applied to alloy steel smelting and achieved rapid development.
Thanks to the upgrading of electric arc furnace equipment, advances in smelting technology and the growth of the power industry, the production cost of electric arc furnace steelmaking has kept declining. Nowadays, electric arc furnaces are not only used for alloy steel production, but also widely adopted to manufacture ordinary carbon steel. Their output proportion in the total steel output of major industrial countries keeps rising year by year.