Study On Effect Of Additives On Properties Of Al₂O₃-SiC-C Castable For Iron Trough

With the development of metallurgical technology of blast furnace,In order to improve its' production,various metallurgical technology of blast furnaces have been adopted extensively,the working environment of iron runner refractory becomes worse day by day,so the more higher requirement to the use performance of Al₂O₃-SiC-C based tastable has led to a higher demand.In this paper,using new type sub-corundum, silicon carbide,ultrafine SiO₂,α-Al₂O₃ micropowder,silicon powder,and spherical pitch as starting materials,the influences of the amount of MgAl₂O₄ and Fe-Si₃N₄, different binders to the castable properties were studied;physical performances at normal temperature and slag resistance were deeply analyzed both on macrostructure and microstructure.The reason and mechanism that appropriate MgAl₂O₄ addition(10mass%)on the Al₂O₃-SiC-C castable possesses high physical performance and good resistance were discussed.The results show that:appropriate MgAl₂O₄ addition improves bulk density and accelerates the sintering,on the other hand,because of the larger specific surface area,it also prevent the slag penetrating.So the material has a better slag resistance.Using different binders,the performances of the samples change greatly.The Al₂O₃-SiC-C based castable which add 10mass%MgAl₂O₄ used calcium aluminate cement as binder has the better physical performance,while the slag resistance of the samples usedρ-Al₂O₃ because of no melt point phase under high temperature is much batter.As the addition of the Fe-Si₃N₄,physical performances and the slag resistance of the castable are improved.The result is that:the silicon nitride oxidizes and forms N₂ and SiO₂,which can prevent the slag and iron penetrating,and also prevent the carbon and silicon carbide oxidizing.From this experiment,when the addition of Fe-Si₃N₄ is 8mass%,the material is batter.