Tundish slag wall castables, first of all, should have good construction performance, construction body in the maintenance, baking process does not hydrate, do not crack, and has a high enough strength to meet the requirements of long-distance handling and hanging installation. At the same time, the slag retaining wall should have good resistance to bursting when baked on-line, not collapsing in the process of use, resistant to scouring, and able to meet the requirements of continuous casting of steel in multiple furnaces. For this reason, the raw materials are mainly high-purity sintered magnesium sand and electrofused magnesium sand, and appropriate binding agent, dispersant and anti-bursting agent are added.
The following purposes can be achieved by setting up a slag retaining wall in the continuous casting tundish:
(1) Prolong the time that molten steel stays in the tundish to purify the molten steel;
(2) Evenly distribute the molten steel to each water outlet so that the temperature of each flow remains consistent and the phenomenon of leakage and blockage is reduced;
(3) Make the fluid dynamic state of the molten steel reach the best;
(4) Reduce the stagnant flow area and increase the laminar flow area.
Slag Weir Wall Application:
Continuous casting intermediate package set slag weir (wall), can change the flow state of steel in the intermediate package, increase the residence time of steel, and promote the uplift of inclusions in the steel, play a role in purifying the steel. Slag weir (wall) has high aluminum and magnesium types. High-aluminum slag weir resistance to thermal shock, good resistance to slag erosion and resistance to steel scouring ability. Magnesium slag weir can absorb AI2O3, SiO2 inclusions in steel, improve the cleanliness of steel, will not make the steel secondary oxidation. Our magnesium slag weir adopts magnesium castables with electrofused or sintered magnesium sand and silica micropowder to form MgO-SiO2-H2O system cohesive bonding, and add explosion-proof agent and dispersant, and some of them add 2% steel fiber.
Magnesium slag weir use long time, easy to punch through, and aluminum-magnesium slag weir erosion resistance is better, but not as pure as magnesium slag weir for molten steel. The use of composite slag weir, that is, the slag line using aluminum-magnesium castables, steel area using magnesium castables, vibration molding, the two materials into one composite slag weir. It is very important to make the two kinds of castables well compounded and have good construction performance.
The tundish prefabricated parts include slag retaining wall, slag retaining weir, impact plate and flow stabilizer, etc. They are made of magnesia, alumina, white corundum, etc. as the main raw materials, combined with micro powder and ultra-fine powder, and added with appropriate amount of coagulant and dispersant, prefabricated and baked at medium temperature. It is suitable for continuous casting tundish, and prefabricated parts with different lifespans and materials can be designed according to different smelting requirements of users.
