Electric arc furnace refractory is an important part inside the electric arc furnace, which is subjected to extreme environments such as high temperature and high pressure. Therefore, the selection of refractory materials has a crucial impact on the production efficiency and safety of electric arc furnaces.
The electric furnace mainly uses steel scrap as the main raw material for steelmaking. Add scrap steel, lime, etc. into the furnace, and when the electricity is turned on, an electric arc occurs between the electrode and the scrap steel to heat the charge, and a series of metallurgical chemical reactions are carried out to turn the scrap steel into steel.
Electric furnaces mainly include DC electric arc furnaces, AC electric arc furnaces and induction furnaces.
DC Electric Arc Furnace Refractory
There are three basic types of DC EAF, namely ABB, Clecim and GHH. The life of the bottom electrode of the DC arc furnace is essentially the life of the refractory material.
The bottom electrode of the ABB type DC electric arc furnace is conductive with a conductive refractory material, and the bottom surface is cooled by wind;
In GHH, many small steel needles (thin steel rods with a diameter of 20-50mm) are buried at the bottom, and the bottom surface of metallurgical spare parts is also air-cooled;
The bottom electrode of Clecim is 1~4 thick steel rods, and the lower end is cooled with a copper water cooling jacket.
On the basis of these three types, various forms such as steel sheet type, water spray cooling bottom electrode steel rod type, and steel rod and copper rod composite bottom electrode type have been developed.
AC Electric Arc Furnace Refractory
The refractory material for the furnace bottom of the AC arc was rammed into the furnace bottom with pitch tar magnesia or brine magnesia binder in the early stage, and then more magnesia bricks and low-grade magnesia-carbon bricks were used to build the furnace bottom. By the 1990s, China began to use the furnace-bottom magnesia-calcium-iron dry vibrating ramming material.
The construction of metallurgical spare parts is simple and convenient, without baking. After construction, it can be directly made into steel and put into use.
The material is magnesium-calcium-iron dry vibrating ramming material. Utilizing the low melting point calcium ferrite it contains, when the temperature rises above 1000C, it can be rapidly sintered to generate strength.
Under the hydraulic pressure of molten steel, it can rapidly sinter and shrink, and its shrinkage can reach 4%-5%. It has particularly good corrosion resistance and good use effect.
Electric arc furnace is a commonly used furnace in the metallurgical industry. Its advantages lie in high production efficiency, low energy consumption, and environmental protection.
However, the use of electric arc furnaces also brings about a problem, that is, the wear of refractory materials.
At present, there are many kinds of refractory materials on the market, commonly used are refractory bricks, refractory cement and so on.
Refractory brick is a traditional refractory material. It has the advantages of high temperature resistance and wear resistance, but its manufacturing cost is high and it is easily affected by temperature changes.
Refractory cement is a new type of refractory material, which can be formulated according to different needs, and has the advantages of low manufacturing cost and long service life.
In addition to choosing the right refractory material, it is also very important for the maintenance and maintenance of the EAF Regular inspection and replacement of worn refractory materials, and timely cleaning of sundries in the furnace can effectively prolong the service life of the electric arc furnace.
In general, the selection and maintenance of electric arc furnace refractory materials are crucial to the production efficiency and safety of EAF.
When choosing refractory materials, it is necessary to choose according to different use environments and needs.
At the same time, attention should also be paid to the maintenance and maintenance of the electric arc furnaces to ensure its long-term stable operation.