How to reduce slag sticking in ladle
Ladle is an important equipment for continuous casting in the iron and steel smelting process. It is a container for containing and carrying molten steel and refining molten steel outside the furnace from tapping to pouring. It can be used for deoxidation and alloying operations, adjust the temperature and uniform composition of molten steel, and float non-metallic inclusions in molten steel. At the same time, the flow of molten steel can be controlled during the casting process.
Slag sticking in the ladle has puzzled the steel plant for many years. After slag sticking in the ladle, the following problems will be caused:
1. After the slag is stuck on the bottom of the ladle, the surface of the ladle vent brick is adhered by the slag, which makes it difficult to clean the vent brick in hot repair, seriously affects the bottom blowing effect of the ladle vent brick, and poses a threat to production.
2. The volume of the ladle is reduced, the molten steel rises, and the steel slag will float to the ladle mouth during refining, which will result in slagging and cold steel at the ladle mouth, seriously affecting the cleaning of the ladle casting slag.
3. It will increase the weight of the ladle and directly affect the operation safety of the crane.
4. As the slag is very hard and firmly combined with the ladle lining, it is very difficult to remove, and the removal time is long, resulting in long ladle repair cycle and tight ladle turnover. Therefore, it is necessary to better understand the mechanism of slag sticking and find a suitable way to solve the problem.
Generally, two kinds of bricks are used for the working layer of ladle wall: alumina magnesia carbon brick and corundum spinel carbon free prefabricated brick. The slag layer is often mixed with cold steel. As the melting loss at the lower slag line is fast, a thick slag layer is often formed below the upper slag line and above the lower slag line. The reasons for slag sticking in the ladle generally include refractory material, converter slag composition, smelting steel, ladle turnover speed, ladle maintenance and insulation methods, among which the refractory material is the main factor for slag sticking. Slag sticking will occur in the use of alumina magnesia carbon brick ladle and carbon free brick ladle. It can be seen from the use process that with the increase of the number of times of use, the lining surface becomes uneven. In the process of frequent cold and hot alternate use of the ladle, there are many micro cracks in the lining of the ladle, which makes the slag and cold steel slag very easy to adhere and penetrate. Such a cycle and long-term accumulation make the lining surface more and more serious. Most of the reasons are related to the different materials of the lining materials and their corrosion resistance.
Slag sticking in the ladle seriously affects production. To reduce slag sticking, on the one hand, try to reduce converter slag entering the ladle, speed up the turnover of the ladle, and strengthen the thermal insulation measures of the ladle; In addition, a high temperature non stick coating can also be sprayed on the refractory surface of the ladle.