Ladle furnace is a very important equipment in the steelmaking process. In particular, modern industry has increasingly higher requirements for the quality of steel. The demand for low-carbon, ultra-low-carbon and other pure steels is increasing, and converter ladle furnace steelmaking often fails to meet these requirements. Therefore, it is necessary to reduce the carbon content and other impurities in the molten steel by refining outside the furnace, so the requirements for the ladle furnace are getting higher and higher; and the traditional ladle refractory materials either cannot meet the requirements for use, or have a very low life span, and there is no cost competition. Advantage. Therefore, the development of high-efficiency and long-life
ladle refractories is an inevitable trend of development.
Ladle slag sticking is also a common problem in steel plants in my country. The main influencing factors are the composition of ladle slag and refractory material. In addition, due to the steelmaking process and operating factors, the ladle sticking to slag will also be aggravated.
The measures that can be taken to prevent the ladle furnace from sticking to slag include: 1) Increase the ladle thermal turnover rate and reduce the number of ladle turnover; 2) Strengthen the maintenance operation of the ladle, timely clean up the slagging along the ladle, and prevent the ladle slag from falling after the ladle edge is ringed. Endlessly, repair the obvious melting damage and spalling parts of the ladle wall in time to avoid the infiltration of slag and molten steel and aggravate slag sticking; 3) Pour the slag as soon as possible after the completion of the steel pouring, strengthen the production organization behind the furnace, and reduce the ladle from pouring. After the time to turn the tank, avoid the occurrence of ladle slag sticking; 4) Improve the converter tapping slag blocking operation level, reduce converter slag entering the ladle, add lime after the furnace and during refining to fully melt the ladle slag; 5) Control use Reduce the waiting time of the ladle; be heated by the steel front ladle; use the ladle cover in use; use the thermal insulation layer for the permanent layer of the ladle; use low thermal conductivity refractory material on the wall of the ladle; 6) In terms of refractory materials, improve the masonry quality and control The size of the brick joints reduces the thermal stress of the lining, improves the thermal shock resistance, and reduces cracking; 7) Use an effective ladle covering agent: improve the spreadability of the ladle covering agent, increase its thermal insulation performance, reduce the SiO2 content in the covering agent, and reduce its Viscosity, reduce ladle sticking slag.
The ideal configuration of the ladle refractory material should be: the thickness of the insulation layer of the ladle wall is 30 mm, the thickness of the permanent layer is 80-100 mm, and the overall thickness of the working layer is 180-210 mm; the slag line chooses low-carbon magnesia-carbon bricks with a thickness of 180 ~230 mm; the bottom of the package adopts integral casting. Choose the appropriate overall furnace lining thickness according to the size of the ladle. Draw lessons from the management experience of foreign advanced counterparts, and refer to the actual use of my country's ventilating bricks. At the same time, it is necessary to continue to strengthen the research and development of integral ladle castables and application technologies. The following two points are particularly important:
(1) Develop effective repair techniques to partially repair the worn-out part of the furnace lining instead of replacing the entire furnace lining with materials with good durability. This technology can not only ensure uniform wear of the furnace lining during the furnace campaign, but also produce as little residual refractories as possible.
(2) Develop continuous pouring and repair technology, and continuously construct lining without discarding the original residual lining refractories.
