An electric arc furnace is a type of industrial furnace that uses an alternating electric current to produce heat. These furnaces serve as an alternative to traditional blast furnaces, and play a major role in global steelmaking. In an electric arc furnace, the electric current passes through the steel and other metals within, resulting in quick and efficient steel production. This type of furnace can also be used to process iron, metal alloys, and minerals.
A heavy stone shell forms the body of the furnace and keeps heat and molten materials contained within. The roof of the unit is generally removable so that raw materials can be added. Three metal electrodes protrude from the roof, and each can be adjusted to control the path of the electric arc. The finished metal exits the furnace through an opening high along one side of the unit, above the level of molten steel. Most electric arc furnace models are also built on a tilting platform so that the finished material can easily be dumped into nearby molds.
Traditionally, the electric arc furnace has been used to produce long steel products, including beams, steel bars, and piping. Flat goods, such as sheet metal or steel plates, are typically produced using a traditional blast furnace. Today, many steel mills produce a mix of these products, and the distinction between the two is no longer so well-defined.
One of the most important benefits to using an electric arc furnace is its ability to produce steel using only metal scraps. Workers drop the scrap metal into the roof of the furnace, where it is melted and used to form new steel. This feature helps to keep material costs low, and also maximizes recycling while lowering energy consumption. These furnaces are also smaller than traditional blast furnaces, and require a lower initial investment. This means that steel mills can be built locally as needed, helping to reduce transportation cost and time.
By nature, the electric arc furnace poses many dangers to workers. When the lid is removed to add material, the molten steel could splash up and out into the work area. Scrap material can also be sent out of the opened roof due to the high heat levels within. Finally, these furnaces require large volumes of cooling water, which is considered environmentally unfriendly.