Seamless ladle lining can reduce the unit consumption of refractory materials by 50%

Source: | Author:ChangXing Refractory | Published time: 1061 days ago | 803 Views | Share:

Magnesia carbon brick (MgO-C) has been used for many years as a refractory lining for ladle. In the 1980s, Japan developed a magnesia-aluminum spinel castable amorphous lining containing prefabricated spinel for use in ladle. In the 1990s, an in-situ spinel composition was formed in the second generation lining with fine magnesia and activated alumina added to the matrix. Different spinel castables are used in different ladle areas. At the bottom of the ladle, especially the ladle purging plug and wall bricks, the volume stability under high temperature and high pressure is the most important. High corrosion resistance and thermal shock resistance are also important in the process of high-speed molten steel production and when blowing in low-temperature stirring gas. Castables containing prefabricated spinel have become the standard for this application and provide optimal performance. The requirements for the side wall of the ladle vary. Since each steel cladding shell has some deformation after transportation, storage and processing, and because the inner lining is not absolutely rigid, one of the advantages is that stress relaxation can be used to avoid stress peaks causing cracks. Adding silicon powder to the castable formed by spinel to form a liquid phase will cause the castable to soften (a sharp drop in the RUL curve) to release thermal stress. The volume expansion caused by the in-situ spinel formation can close the seams on the surface. Therefore, the castable formed by spinel brings some advantages to the side wall of the ladle. This article believes that the combination of spinel and spinel is the best solution. This article provides a quick review of the ladle unshaped lining and innovative installation technology.

Advantages of unshaped lining for ladle:

(1) The replacement of magnesia carbon bricks with amorphous linings at the bottom and side walls of the ladle brings many advantages to the steelmaking process, mainly as follows:
(1) The use time of ladle is extended;
(2) The total number of ladle operations is reduced by 20%;
(3) Compared with MgO-C bricks containing toxic and carcinogenic substances (phenolic resin, coal tar pitch, etc.), the castable does not have any harmful materials;
(4) Reduce the unit cost of steel production;
(5) Produce ultra-low carbon steel in a better operating environment, because there is no carbon increase in the ladle refractories;
(6) The unit consumption of refractory materials is reduced by more than 50%.

Compared with other amorphous linings, the last advantage is the most important. Technically, the unit consumption of refractory materials is reduced by more than 50%, which is based on the concept of seamless lining. When magnesia-carbon bricks are used as the lining of the ladle and the service life of the bricks is reached, it will be replaced by a new set of MgO-C bricks. However, for amorphous linings, the situation is completely different. In the first installation, the amount of castable is the same as that of bricks. Subsequent replacement of the lining at the bottom and side walls, if brick lining is used, all need to be replaced. If unshaped refractory is used, only the part of the lining (about 40% to 60%) in contact with molten steel needs to be replaced, and the undamaged the lining will remain in place. Until the end of the ladle operation and before the complete renewal of all the inner linings of the ladle, including the necessary safe working layer, refractory materials can be saved by using the unshaped inner lining.