"Ladle refractory life and reduce costs" has been the pursuit of the goal of the Bethlehem Steel Sparrows Point. Ladle refractories overall life expectancy is determined by the performance of the various parts of the ladle refractories, in order to achieve maximize the life of the ladle, select each of the parts of the refractory should consider the match between the various parts of the refractory performance . Improvement of the the Sparrows Point ladle refractory life by using the performance steel bobso brick while the remaining portion of the ladle refractories corresponding improvement.
Ladle Block brick: 1999, Block brick using low-temperature firing cement aluminum-magnesium spinel castable, increasing the height of the seat brick 62.5mm, the shape changes from square to round; following and then its ingredients do to improve the life of the plug brick furnace up to 135, is sufficient to maintain a complete furnace served. Table 1 shows do not burn and high temperature firing low cement magnesia spinel castable plug brick performance.
The Block Zhuanfeng: brick of life improved, the cracks between the blocks used in the refractory than Block Brick wear much faster; cracks between the blocks life enough to trial a 90% alumina plastic brick match, and later, due to this kinds of plastic curing time is longer, so replaced the 90% high alumina ramming mixes, it can meet the fast-curing and life with brick to match the dual requirements. Table 2 shows the 90% alumina plastic and 90% high alumina ramming mixes performance.
Ladle impact zone: At the same time, refractory ladle impact zone were systematically improve. The original design of the entire bottom of the ladle, including the impact zone, all on silicon carbide (225mm x 150mm x 75mm) puzzle; package wall of the lower part of the site close to the area of impact by increasing the thickness of the refractory bricks method to enhance the anti-splash molten steel erosion ; firebrick is 80% of the aluminum-magnesium-chrome brick. The end of the life of this ladle furnace 40 to 60. Later, the thickness of the bottom of the impact zone is increased to 340mm, life improvement. 1986, including the end try to 1200mm × 1250mm × 300mm low cement alumina impact of board castable used in conjunction with 225mm × 150mm × 75mm 80 high alumina brick, 74 furnace ladle life, and then gradually reached 82, 84 and 91 furnaces. In the 1990s, with a high temperature low cement cast aluminum-magnesium block, the entire ladle furnace life expectancy of 125 to 135, during which only the impact area to do some minor repair. Was developed to underwrite castable only two blocks, a prominent plate for the impact zone, away from the package wall 3 feet; another piece of refractory bricks underwrite the rest of the flat. The most recent test castable a complete precast block underwrite, is to be used for the prominent impact zone plate and underwrite the rest of the cast into a whole, and burn-in processing. This technology will be widely popularized. Designed such that the bottom of the package is expected to maintain 250 furnaces, ladle run during a stove service just do some small patches. By the calcination treatment, having a high thermal strength characteristics due to the impact zone, so the impact area may not need to increase the thickness.
