Application And Investigation Of Slag Splashing Technology For 50t Converter In Longsteel

The slag splashing technology for converter is a great break of converter lining maintenance technology in recent years,and widely developed and reaearched in steel industry around the world.The application of this technique has prolonged the converter lifespan greatly and obtained obvious economic benefits.In Longsteel,the slag splashing technology is applied in the 15t converter since 1997,and the campaign increases from 1000 to 3000.At present the technique is already applied for 50t converter,but it still exist a marked difference comparing with advanced level.Therefore,the further research on slag splashing technology plays an important role in Longsteel.In this paper,the slag splashing process system and material structure in Longsteel are adjusted,also the generated slag phase,melting properties,and lining bonding mechanism are researched.The results showed that:(1)The proper slag splashing parameters in Longsteel are as the follows:the suitable lance height is 0.8-2.2m,the quantity of slag is 2.5-3.5t,blowing pressure of nitrogen is 0.8-1.6MPa, gas blowing rate is 8000-10000Nm~3/h,and slag splashing time is 2 -3min.(2)By using slag splashing techniue in Longsteel,the refractory materials consumption decreased greatly and the cost reduced 3.8 Yuan/ton,the mean converter lifespan reached to 2000 and tha maximum is 21129.(3)The influence factors of final slag refractoriness are the slag basicity,∑FeO and MgO contents.For an adequate refractoriness,the adjustment of MgO content in slag is a main measure.The proper MgO content is 8wt%-12wt%,slag basicity is 3.0-3.5 and∑FeO is 10wt%-15wt%in final slag.(4)It can improve corrosion and scour resistance of slag splashing layers,the combination between slag splashing layer and converter lining by decreasing slag superheat,increasing slag melting point and viscosity.Meanwhile,with the cooling effects of additives,the slag splashing inoculation time is shortened,the gas gap is disappeared and the oxidation of graphite in converter lining is inhibited.All the above factors can accelerate the bonding of slag and lining.