A submerged arc furnace-also known as an electric arc furnace or electric resistance furnace-is primarily used for the reductive smelting of raw materials such as ores, carbonaceous reducing agents, and fluxes. It is a key piece of industrial equipment for producing ferroalloys (such as ferrosilicon, ferromanganese, ferrochrome, ferrotungsten, and silicomanganese alloys) and chemical raw materials like calcium carbide.
The furnace operates using a carbonaceous or magnesia refractory lining and self-baking electrodes. It functions through a continuous process involving submerged-arc operation-where electrodes are inserted into the furnace charge-and utilizes both arc energy and resistance heating (generated as current passes through the charge) to smelt the metal; charging is performed continuously, while tapping of molten metal and slag occurs intermittently. The transformer serving the furnace operates under a continuous, stable load and features low impedance voltage, multiple voltage regulation steps with small increments, and high overload capacity. These transformers are available in two types: on-load voltage regulation and off-circuit (no-excitation) voltage regulation. Typically, they provide constant power output at the initial voltage steps and constant current output at the subsequent steps.