Magnesia-carbon bricks are made of magnesia, re-burned magnesia, fused magnesia, high-purity magnesia, and high-quality graphite and bauxite additives. The price and performance of magnesia carbon bricks have a lot to do with the graphite content in the bricks. As the graphite content increases, the strength of the brick decreases, the thermal expansion rate decreases, and the residual expansion rate increases. Converter magnesia carbon brick
Therefore, magnesia carbon brick manufacturers should control the graphite content in the brick at about 20%. Magnesia carbon bricks have little wettability to molten slag, have excellent spalling resistance and corrosion resistance, and are suitable for the slag line of the ladle, especially in the occasion of multiple furnace continuous casting. In order to meet the needs of producing clean steel, when refining in the ladle, the application part of the magnesia carbon brick has been expanded from the slag line to the side wall. Electric furnace magnesia carbon brick
Converter magnesia carbon brick
When laying magnesia-carbon bricks on the ladle, care should be taken not to mix with bricks with high Si02 content. Otherwise, it will increase the local melting loss of the magnesia carbon brick, and the melting loss mechanism is:
Mainly used for lining and tapping of steel-making oxidation reformer, hot spots of high-power electric furnace wall, lining of refining furnace outside the furnace, and slag line of ladle, etc. Ladle magnesia carbon brick
The raw materials for making magnesia carbon bricks are high-quality sintered magnesia, fused magnesia, graphite, binders and antioxidants. The periclase particles in magnesia act as aggregates in refractory bricks. To produce high-quality magnesia-carbon bricks, you need to choose high-purity magnesia (MgO content is as high as possible, /SiO2≥2, bulk density ≥3.34g/cm3, crystal development is good, and magnesia itself has a porosity of ≤3%). Graphite is also the main raw material of magnesia carbon bricks. Its fixed carbon content, ash composition, oxidation resistance, particle size, shape, volatile content, moisture, etc. all directly affect the performance and use effect of magnesia carbon bricks. Select high-purity flake or flake graphite with high carbon content (C≥95-96%) to make bricks to obtain the corrosion resistance, spalling resistance, high temperature strength, oxidation resistance and other characteristics of magnesia carbon bricks.
The binder used in magnesia-carbon bricks is very important, and its quality largely affects the production and quality of refractory bricks. There are many types of materials that can be used as binders for magnesia-carbon bricks, such as coal tar, coal tar and petroleum pitch, special carbon resins, polyols, pitch-denatured phenolic resins, and synthetic resins. Due to the high carbon residue rate of phenolic thick. A purpose, it has good affinity with magnesia and graphite. It is easy to combine magnesia and graphite, and it is easy to spread in magnesia and graphite at room temperature. So far, phenolic Resin is still a better binder for the production of magnesia carbon bricks. Since magnesia-carbon bricks use high-purity graphite, the amount of liquid phase generated in the bricks is small, and oxygen can easily penetrate into the bricks to oxidize and decarburize the graphite, and the oxidation resistance of the bricks will deteriorate. Al-Mg alloy, SiC and other antioxidants. They can preferentially react with oxygen to form carbon compounds or oxides, and expand in volume, block or fill pores to densify the bricks, thereby improving the anti-oxygen performance of the refractory bricks.
