What are the characteristic features of arc furnaces

Features of arc furnace

Electric arc steelmaking furnace takes electric energy as the main energy. The electric energy generates high temperature above 2000 ~ 6000 ℃ through the discharge arc between graphite electrode and furnace charge, and melts the scrap raw material in the way of arc radiation, temperature convection and heat conduction. In most of the time when the charge melts, the high-temperature heat source is surrounded by the charge, and the heat loss caused by high-temperature waste gas is relatively small, so the thermal efficiency is higher than that of other steelmaking equipment such as converter. In addition, the electric heating can easily and accurately control the furnace temperature, and the heating operation can be carried out under any conditions such as oxidation atmosphere or reduction atmosphere, atmospheric pressure or vacuum according to the process requirements.

Electric arc furnace steelmaking process is short, the equipment is simple, the operation is convenient, the pollution is easy to control, the construction investment is small, the floor area is small, and there is no need to rely on the complex ironmaking system like converter steelmaking.

Electric arc furnace steelmaking has strong adaptability to furnace charge. It takes scrap steel as the main raw material, but it can also use solid and liquid iron containing raw materials such as molten iron (molten iron of blast furnace or cupola), sponge iron (DRI), hot pressed block (HBI), pig iron block and so on.

Because the atmosphere in the EAF steelmaking furnace is controllable, the operation of slag adjustment or replacement is relatively easy, and the complex process operations of melting, decarburization, dephosphorization, degassing, inclusion removal, temperature control, composition adjustment (alloying) and other stages can be completed in the same set of operating system. EAF steelmaking can be produced intermittently, and the production varieties can be changed flexibly within a certain range. In addition, modern electric arc furnace can also use a lot of auxiliary energy, such as injecting heavy (light) oil, pulverized coal, natural gas and so on. Therefore, EAF steelmaking process has strong adaptability, flexible operation and wide application.

Electric arc furnace can not only smelt high-quality steel with low phosphorus, sulfur and oxygen content, but also use a variety of elements for alloying (including elements easy to be oxidized such as lead, boron, vanadium, titanium and rare earth) to produce all kinds of high-quality steel and alloy steel, such as ball bearing steel, stainless and acid resistant steel, tool steel, electrical steel, heat-resistant steel, magnetic materials and special alloys.

Although EAF steelmaking has many advantages, due to the problems of scrap steel and electricity price cost in China, EAF steelmaking cannot compete with converter steelmaking in common steel and long-term products. Electric arc furnace steelmaking only plays a leading role in the production of special steel with small batch, multiple varieties and high alloy ratio.

At present, some short process electric furnace production enterprises in the world generally use electric arc furnaces with high output power. Moreover, the traditional classical three-stage operation process with reduction period has been gradually replaced by combined process technologies such as out of furnace refining, electric arc furnace and

Its public and auxiliary facilities and equipment are also more perfect and reasonable. The proportion of electric furnace steel output in the world is increasing year by year.

China is a developing country. The capital construction has just started, and the large-scale scrap recovery period has not yet come. In addition, China's power development is unbalanced, and the current electricity price is still in a relatively high stage. Therefore, the development speed of EAF steelmaking in China is limited, not as fast as converter steelmaking. Although the total amount of EAF steel is also increasing, the proportion of EAF steel output in the total steel output is decreasing year by year, which is contrary to the development trend of electric arc furnace in the world.

With the development of electric power facilities and the accumulation of scrap resources in China, as well as the strengthening of national environmental protection and mineral resources management, the development trend of electric arc furnace steelmaking in China will be improved. At that time, China's electric arc furnace steelmaking technology will get a more comprehensive development.