Converter magnesia carbon brick has high fire resistance, good thermal shock resistance, anti-stripping, slag resistance. As a furnace lining material, it is widely used in converters. Compared with other furnace lining materials, the converter life is greatly improved. This article describes the production process, process flow application of magnesia-carbon brick in various parts of the converter. Magnesia carbon brick

Foreword The steel-making converter is an upright cylindrical furnace that does require an external heating source mainly uses liquid pig iron as a raw material for steelmaking. Its main characteristics are: the physical heat of the liquid pig iron in the converter the heat generated by the chemical reaction of various components in the pig iron (such as carbon, manganese, silicon, phosphorus, etc.) with the oxygen sent into the furnace, so that the metal reaches the tapping Required composition temperature. According to the properties of the furnace lining refractory, it can be divided into two types: acidic converter alkaline converter; according to the location of the gas blowing into the furnace, the converter is divided into bottom-blown, top-blown, side-blown, top-bottom composite converters. Magnesia carbon brick has high fire resistance, good resistance to slag invasion, strong thermal shock resistance, excellent stability at high temperatures, good thermal conductivity, wear resistance, good spalling resistance. It is widely used in electric furnace, converter refining furnace, its service life is greatly improved. At the same time, because magnesium carbon brick does require high temperature firing, saves energy, has a simple manufacturing process, it has been rapidly promoted applied by many countries in the world. China began to develop magnesium carbon bricks in the early 1980s. After using electric furnaces refining furnaces in small batches, they have received good results. Subsequently, iron steel plants such as Anshan Iron Steel, Wuhan Iron Steel, Shougang Baosteel successively tested magnesia-carbon bricks on large medium-sized converters. Now China has become the world's producer of shaped magnesium carbon bricks. With the continuous improvement of the grade of magnesium carbon bricks, the converter age has also been greatly improved, which has laid a foundation for reducing the cost of steelmaking.

Research practice show that the quality performance of raw materials has a greater impact on the use of magnesium-carbon bricks for converters. Therefore, various raw materials must be strictly selected. 1.1.1 Selection of magnesia During the use of magnesia-carbon bricks, the erosion process of magnesia particles is roughly as follows: ① The solid phase reaction of periclase particles graphite under high temperature vacuum is as follows: MgO + C → Mg ↑ + CO ↑ The generated steam CO are volatilized; ② the periclase particles are chemically melted by the slag, including the melting loss of various oxides in foreign slag magnesite impurities; ③ after the oxidative decarburization of the matrix of the magnesium carbon brick working layer, its combination Reduced strength. Under the infiltration scouring of the slag, the periclase particles leave the brick body are washed into the slag. Japanese scholars have conducted in-depth research on the relationship between the MgO content the depth of erosion in fused magnesia, the relationship between the slag resistance of magnesia-carbon bricks the size of periclase grains in magnesia. The production of magnesia-carbon bricks should only pay attention to the purity of magnesia, but also pay attention to the use of large-crystalline fused magnesia, hope that CaO / SiO2 ≥ 2. After fully considering the above factors, the magnesia-carbon bricks used as the main raw material are magnesite with large crystal grains, strong binding force, few impurities. The magnesite can only reduce the periclase The degree of crystal division by the silicate phase reduces the erosion rate of the slag on the grain boundaries, can also improve the stability of magnesia graphite when coexisting at high temperatures.