Study On Reclaiming Of Used Refractory Castable Of Desulfurization Stirring Equipment

This paper uses the used castable of KR pretreatment of hot metal desulfurization stirrer as material, adopt the methods include crushing, grinding, screening and immersing in the acid, which proceed the regeneration research of the used castable. Using these methods include XRD, SEM and chemical analysis to compare these differences of mineral composition, microstructures and chemical composition between material and regeneration material. Testing the part of properties of simples include the regeneration permanent layer of tundish and the regeneration stirrer production. Analyzing the regeneration used meaning of the used refractory. This paper respectively research on the influence of grinded time, the immersed time in acid on the quality of regeneration materials. It researches the influence of addition of regeneration material and the form of particle size on regeneration materials’ properties. The conclusion include:(1) the quality of material is worse after crushing, and the B.D of particle is between 2.45 and 2.62, and the content of false particle is above 50%. The content of false particle abruptly drops, after being grinded. The best time is between 25 min and 40 min, at this point the B.D up to 2.70~2.80g/cm3, the content of false particle down to 10~15%. The 99% iron fibers get rid of particle after being grinded.(2) By immersing in the HCl can effectively descend the content of false particle in the regeneration material, and enhance the quality of regeneration material. The longer the time of immersing is, the higher the concentration is, the lower the content of false particle is. The content of false particle can drop 2.0~2.5% after being immersed 60 h.(3) Using the regeneration material 3~1mm、1~0mm and powder as the material to produce permanent layer of tundish. After 110℃×24h drying: The B.D, A.P and cold strength is above contrasted simples. When respectively add 3~1mm、1~0mm and powder to produce three groups simples. Their B.D, A.P and cold strength are close to contrasted simples.(4) The all simples be produced used regeneration material, every property is best after being burnt at 1350℃×3h.(5) Using the regeneration material 8~5mm、5~3mm、3~1mm as the material to produce regeneration stirrer simples: With the increasing the addition, the HMOR of simples appears the trend is increase first and then decrease: When the addition is 45%, the strength is biggest is 1.59 MPa, but the addition is 55% the strength is smallest is 0.69 MPa. So the regeneration material 8~5mm、5~3mm、3~1mm after being recycled and treated can as regeneration stirrer’s material.