The ladle lining of a steelmaking plant is made of aluminum-magnesium castables, the pouring thickness is 160mm, each ladle uses 13 tons of castables, and the average service life of the ladle is 58 furnaces. Inspection of the ladle used found that the refractory material at the upper slag line of the ladle was slightly corroded, with a thickness of 140mm left, but the bottom of the ladle was severely corroded, which was the direct cause of the unusable ladle. After each ladle is used, there is still about 10 tons of residual lining, and several ladles need to be re-lined every day, and the removed lining waste reaches 40-50 tons.
Using waste aluminum and magnesium castables lining the ladle as raw materials, the slag and iron sheet in the waste are manually sorted out, crushed by a jaw crusher, passed through a 10mm sieve, and the aggregate under the sieve is used as aggregate, with a particle size smaller than The mixed powder of 0.088mm first-grade high-alumina bauxite clinker and sintered magnesia is used as powder, and water glass with a modulus of 2.8~3.3 and a density of 1.40~1.45g/cm3 is used as a binder, and sodium fluorosilicate is used Used as a coagulant to prepare aluminum-magnesium recycled castables for reuse.
When batching, first weigh the refractory aggregate, powder and sodium fluorosilicate, pour them into a forced mixer and dry mix them evenly; then weigh the water glass solution and water, pour them into the ingredients and mix them wet for 2-4 minutes before use , The well-mixed material needs to be formed within 30mm. After forming, it should be cured for 1 day before the mold can be removed, and then cured for 2 days. During the maintenance period, the ambient temperature should be higher than 10°C, and no water should be allowed
Since the aggregate used is the used ladle lining waste, it is inevitably mixed with harmful impurities such as steel slag and iron sheet, and the batching is made of unified materials, which leads to high porosity and bulk density of the ladle waste castable. Lower, larger shrinkage after burning. Casting 340mm thick with ladle waste castables is used as the inner lining of the water jacket of the mixed iron furnace, which can fully meet the requirements. Using ladle waste castables to cast 150mm thick high-alumina brick permanent layer instead of the original small plate tundish can be used for about 60 heats, which is about 40 heats longer than the permanent layer built with high-alumina bricks. The use effect is good. It is in There is still a large amount of surplus in the above two aspects, and the production preparation workshop is used to cast the bottom of the slag basin. In order to prevent steel slag from adhering to the slag basin, a layer of building red bricks was originally placed in the slag basin, and red bricks had to be built every time it was used, which required a large amount of work. After using it instead of red bricks, it can be used more than ten times, which greatly reduces the workload of workers, but the cost has increased.