In the ladle refining furnace, the selection of the appropriate refractory lining is key to maintaining stable furnace operation. This process often involves furnaces such as the Vacuum Arc Degassing VAD furnace and the ASEA-SKF furnace. They form the ladle refining equipment when started together.
Introduction to Ladle Refine Equipment
The operation of the VAD furnace involves injecting molten steel into the ladle and sending it into the vacuum chamber. This area is heated by an electric arc while the vacuum is being drawn. The ASEA-SKF furnace, in addition to refining the ladle like the VAD furnace and heating the molten steel with an electric arc. Besides, it needs to perform electromagnetic stirring. The development of ladle refining technology has completely changed the previous requirements for refractory materials in the ladle lining. To choose the best refractory material, we sincerely recommend the following information to you.
Key Points about Choosing Refractory Lining for Ladle Refining Equipment
- Even with the use of a ladle furnace cover insulation board, the heat cycle of the refining ladle is still quite large. Therefore, the damage to the refractory material will be greater than that of a one-time steelmaking furnace.
- When the ladle is moved and lifted, thermal mechanical cracks will appear inside the thinner refractory working lining;
- High steel tapping temperature and erosion of certain types of stirring belts;
- Overheated slag caused by lime, calcium aluminate, and fluorite causes high erosion of the refractory lining;
- There is usually a lack of slag protection layer and spray repair layer. This is the same as those used to extend the life of a one-time steelmaking furnace;
- Vacuum causes the volatilization of refractory material components. The reaction of C, Si, Al, Ti and Mn in the steel water with the components of the refractory material is also the cause of refractory material erosion.
Requirements on Refractory Lining for Ladle Refining Equipment
The refining ladle is very strict in terms of temperature and time, and the highest temperature often reaches above 1750℃. At this stage, the corundum brick is a good choice. Moreover, during the refining operation process, the slag alkalinity changes within 0.6% – 4.0%. Therefore, the lining refractory material is eroded by the highly penetrating acidic slag. It accelerates the erosion speed of the refractory material.
Strongly penetrating slag easily penetrates the pores of the refractory material, causing the refractory material to deteriorate, produce structural peeling, and cause premature damage to the refractory material.
Forced stirring stirs up the steel liquid to carry the slag flow, which has a very significant scouring and high temperature wear effect on the refractory material lining, which leads to its premature erosion. Therefore, it is required that the fire brick refractory products has high strength and high wear resistance characteristics.
The refractory material used under vacuum operation conditions should have good vacuum stability. Al2O3, ZrO2, and CaO refractory materials are stable, while MgO, SiO2, and Cr2O3 refractory materials are unstable and have a large weight loss. However, actual operation proves that low temperature has little effect on the vacuum volatility of refractory materials, and its volatilization loss will only be obvious when it is at high temperature.
The container of the refining ladle is the ladle, so it is frequently quenched and heated, and it is intermittent operation and the use conditions are harsh. To adapt to these harsh use conditions, refractories and monolithics materials with high thermal shock resistance should be selected to build the lining.
Kerui offers a complete guide about choosing suitable refractory lining for ladle lining equipment. Moreover, you can find high quality related products in our company. If you have any needs, please contact Kerui now.