Modern steel grades often require post-treatment in steel ladles to meet high purity requirements.
As a result, the demand for ladles has evolved; previously used exclusively for casting, nowadays, most metallurgical processes are carried out in the ladle.
The goals of secondary metallurgical treatment are to adjust the casting temperature, impurities level, and the finished steel’s chemical composition. To achieve these goals, numerous metallurgical activities are performed in the treatment ladle, such as homogenization of the melt, alloying, decarburization and desulfurization, degassing and deoxidization, and separation of non-metallic inclusions. All these operations require high-quality refractories, introducing as little contamination as possible into the process and allowing for the most extended possible operating times.
Different areas in the steel ladle, such as the slag line, bath area/sidewall, bottom, and impact area, are subject to various stresses.
The aim is to achieve the longest possible service life of all these areas with the proper selection of refractory products and thus optimize the costs for the entire lining, referred to as balanced lining. In cooperation with our customers, we develop appropriate solutions that offer the best price/performance ratio.
In the slag line, magnesia carbon bricks are state-of-the-art; in a few cases, dolomite-carbon bricks are also used. Depending on the steel produced, the product selection in the other areas may vary. In the case of aluminium-killed steels, alumina magnesia carbon bricks are often used in the bottom and wall areas, while carbon-bonded products based on magnesia and dolomite, or magdol, dominate in the case of silicon-killed steels.
Transport Ladle in Stainless Steel Production
In transport ladles for stainless steel production, concepts based on magnesia-alumina-carbon bricks are increasingly used and, depending on the slag chemistry, can lead to significantly higher ladle lining life than dolomite-carbon-based concepts.
Mayerton produces a wide range of high-quality MAC products that are already used by many customers and have significantly improved the price/performance ratio compared to traditional Doloma linings.
During tapping, the zone in which the steel stream from the converter hits the ladle bottom or the ladle side wall is subject to special thermomechanical requirements.
AMC bricks can withstand these conditions exceptionally well since their mineralogical composition causes them to form spinel when used in the ladle. Spinel is a very tough and hard mineral and thus improves resistance to mechanical impact. In addition, the spinel formation reaction is a space-demanding process, so it is associated with increased volume, further densifying and mechanically strengthening the bricks.
Mayerton offers specially developed brick grades with balanced alumina-magnesia-carbon ratios specifically for this lining area, which can withstand the mechanical challenges and thus contribute to better overall lining durability.
Mayerton generally recommends brick linings as safety linings, preferably made of fired magnesia or magnesia-chromite bricks.
In the bath area, materials based on non-basic raw materials, such as bauxite or mullite, are used as well. In any case, shapes should be used that guarantee high mechanical stability.
For this purpose, Mayerton offers different tongue and groove brick designs that can withstand the breaking out of worn working linings without damage and can be used for several ladle campaigns.