Selection of Refractories for Metallurgical Furnace
Posted by adela li on October 21st, 2016
Metallurgical electric furnace is mainly scrap steel as the main raw material and steel-making. The scrap, lime, etc. to the furnace, the power, the electrode and the scrap between the arc and heating charge, metallurgy spare parts for a series of metallurgical refractory brick for sale chemical reactions, the scrap steel into steel. EAF mainly DC arc furnace, AC arc furnace and induction furnace and so on.
Refractories for direct current arc furnaces
There are three basic types of DC arc furnaces, ABB, Clecim and GHH. Different types of DC arc furnaces are classified according to the structure of the bottom ladle refractory electrode, which shows the importance of the bottom electrode. The bottom electrode of the ABB type DC electric arc furnace is electrically conductive with a conductive refractory and the bottom surface is air-cooled. The GHH is the bottom of which many small steel pins (20-50 mm diameter steel rods) are buried. Air cooling; and Clecim the bottom electrode is 1 to 4 crude steel rods, and the lower end of copper refractory castable cooling jacket cooling. On the basis of these three types, the development of the steel-type, water-cooled cooling bottom electrode rods and steel rod and copper rod composite bottom electrode type and other forms.
DC arc furnace bottom electrode life, in essence, the life of refractories. For the Clecim bottom electrode, the electrode bricks have magnesia, magnesium carbon, magnesia-alumina and magnesia-chrome refractories. Europe generally use carbon-free Zang bricks, and Japan that the thermal shock stability is a big problem, should use high-carbon tt containing magnesium carbon brick. Metallurgical spare parts In order to further improve the thermal shock resistance and corrosion resistance of briquettes, Europe began to use magnesia-alumina spinel materials and magnesia-chrome bricks. Clecim bottom electrode is to rely on heat to maintain a high life-span, so repair materials and Refractory company construction results is critical, the current repair materials used mainly magnesium dry ramming material. For the steel needle or steel bottom electrode conductive type of DC electric arc furnace, steel needle or between the steel with dry material, but also made of prefabricated parts, mainly magnesia refractories. In order to improve the life, now useful in Japan MgO-C material. It is impossible to raise the life of the bottom electrode significantly by improving the performance of the refractory. Therefore, the metallurgical spare parts abroad in recent years to carry out the hot work, the use of hot feed requirements are conductive refractories (the conductive steel needle and steel buried), mainly mahogany conductive ramming material, magnesia carbon brick conductive ramming Materials, magnesium calcium carbonate conductive ramming expected.
Standard Specification for Refractories for Alternating Current Arc Furnaces
AC arc furnace refractory early use of tar magnesite or brine magnesia knotting material ramming into the bottom, and then more use of magnesia brick and low-grade magnesia brick brick masonry, to the 20th century 90 years, China began to use the bottom of the magnesium-calcium-iron Department of dry vibrating ramming material. Metallurgical spare parts It is simple and convenient construction, without baking, construction is good, can be directly used in steelmaking. The material is Mg-Ca-Fe series dry vibrating ramming compound. Use it contains low-melting point of calcium ferrite, when heated to UOO'C or more, can quickly sintered to produce strength. In the molten steel under the hydraulic sintering rapid contraction, the contraction of 4% -5%, the bulk density increased to 3.0 ycm3 above, with a particularly good anti-erosion and good use of the results.
General small electric arc furnace silica ramming mass wall refractories mainly used asphalt magnesium bricks, magnesia carbon brick, magnesia fill charge. For high-power high-power electric furnace, electric furnace wall with high-quality magnesium carbon brick, especially the slag and hot spots with very high performance of high-quality magnesium carbon brick, furnace wall repair is mainly used Magnesian gunning material. Its role is to heat and protect the environment, in order to prevent dust escape. Metallurgical spares have strong thermal shock and erosion on the arc-covered lid area when the arc radiation and the electrode are pulled out and inserted in the range of more than 2000 , resulting in a great thermal stress which further promotes the appearance of the electrode hole surface and the lower part of the triangle Layer by layer peeling, which is the main reason for the destruction of arc furnace cover.
Small electric arc furnace top is generally used to burn high alumina bricks, its service life is generally within the range of 60 ~ 120 furnace. In recent years, there are not burning high-alumina bricks, high-alumina castable prefabricated parts, the life of some reached more than 150 furnaces; while saving energy and construction is simple, metallurgy spare parts to reduce labor intensity. So high aluminum prefabricated parts gradually occupy the main position, the proportion of high alumina brick less and less.
High-power, ultra-high-power electric arc furnace top electrode triangle corundum, metallurgical spare parts chrome corundum and corundum magnesia castables and precast. Peripheral roof generally used to burn high alumina brick or do not burn high alumina brick, magnesia brick and magnesia chrome brick.
Generally use the side of the trough, China generally used high-alumina, wax stone, magnesia and other unshaped ramming material or casting the overall prefabricated trough, but also useful magnesium bricks, silicon carbide brick Masonry.
The 20th century, the development of the eccentric tapping hole 80 years. From the tilting to the fixed tapping tapping, tapping brick brick for the asphalt baked sintered magnesium bricks, metallurgical spare parts for the magnesium brick brick tube, the end of the Al203-SiC-C brick or magnesium bricks. Commonly used forsterite as the matrix of coarse sand as a drainage material.
Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.
