Application case of magnesia carbon brick in steelmaking converter
Application case of magnesia carbon brick in steelmaking converter:
1、 Background information
1. Product features
Magnesia carbon brick is mainly composed of magnesia sand and graphite. Magnesia sand provides excellent fire resistance and can withstand high temperature environments. Its melting point is relatively high, generally around 2800 ℃, which can effectively resist the erosion of molten steel and slag. Graphite has good thermal conductivity and thermal shock resistance, which can make magnesia carbon bricks less prone to cracking and other damage in steelmaking environments with rapid temperature changes.
The apparent porosity of magnesia carbon bricks is relatively low, which makes it difficult for molten steel and slag to penetrate into the interior of the brick, thereby extending its service life.
2. Background of demand in the steel industry
In steelmaking converters, the furnace lining needs to withstand the erosion of high-temperature molten steel, chemical erosion of slag, and frequent temperature changes. Traditional refractory materials are difficult to meet the requirements of efficient and long-term operation of converters. In the process of converter steelmaking, the temperature can reach 1600-1700 ℃, and the chemical reactions inside the furnace are intense, which puts high demands on the chemical stability and physical properties of the furnace lining.
2、 Application process
1. Installation process
During the process of lining the converter furnace, magnesia carbon bricks are precisely cut and laid according to the shape and size of the converter. For example, for large converters (with a capacity of 100-300 tons), the thickness of the furnace lining is generally around 600-800mm. Magnesia carbon bricks are laid in a staggered manner, with brick joints controlled between 1-2mm, and special refractory mortar is used for jointing to ensure the integrity and sealing of the furnace lining.
2. Use phase
During the steelmaking process, magnesia carbon bricks have demonstrated their advantages in high temperature resistance and corrosion resistance. After the molten steel is poured into the converter, magnesia carbon bricks can effectively block the erosion of the furnace lining by the molten steel. A protective film is formed on its surface by the reaction between magnesia sand and slag, which further prevents the erosion of slag and molten steel. For example, in a typical BOF (Basic Oxygen Converter) steelmaking process, the oxygen blowing time is about 15-20 minutes, and the temperature changes frequently. Magnesia carbon bricks can withstand this intense thermal shock. After each steelmaking cycle, it is found through inspection of the furnace lining that the loss rate of magnesia carbon bricks is within a reasonable range. Compared with traditional refractory materials, their service life can be increased by 30% to 50%.
3. Maintenance and replacement
Regularly inspect and maintain the furnace lining according to the usage of the converter. When the erosion of magnesia carbon bricks reaches a certain degree (such as the remaining thickness being less than 30% of the original thickness), it is necessary to replace some of the furnace lining. During the replacement process, use specialized tools to remove damaged magnesia carbon bricks, and then reinstall new magnesia carbon bricks according to the masonry requirements to ensure the normal operation of the converter.
3、 Application effect
1. Economic benefits
Due to the extended service life of magnesia carbon bricks, the frequency of replacing converter lining has been reduced. This not only reduces the procurement cost of refractory materials, but also reduces the downtime caused by replacing furnace lining. For example, in a medium-sized steelmaking enterprise, after using magnesia carbon bricks, the number of furnace lining replacements per year has been reduced from 4-5 times to 2-3 times, and the downtime for each lining replacement is about 2-3 days. This greatly improves the production efficiency of the enterprise, while reducing maintenance costs and refractory material costs.
2. Product quality improvement
The excellent performance of magnesia carbon bricks ensures the stability of the steelmaking environment inside the converter. A stable furnace lining can make the temperature and composition control of molten steel more precise, thereby improving the quality of steel. For example, in the production of high-quality alloy steel, the application of magnesia carbon bricks reduces the impurity content in the molten steel, makes the mechanical properties and chemical composition of the steel more uniform, and increases the product qualification rate by about 10% -15%.
In summary, there are application cases of magnesia carbon bricks in steelmaking converters. If you have any questions, please feel free to contact us at any time. Thank you.