Effect of the Addition of Calcium Carbide and Calcium Oxide to Melt on the Separation of Clogged Alumina in Continuous Steel Casting

Today, more than 90% of world steel production accounts for continuous casting method. One of the main problems of this method is alumina nozzle clogging. In this study, modification of alumina inclusions into the calcium aluminate phases was investigated. Calcium carbide and calcium oxide were added to the steel melt and hence chemical composition of secondary phases was studied using a Scanning Electron Microscope. Both qualitative and quantitative analyses were performed. The results showed that the addition of calcium oxide to the surface of the killed aluminum molten metal leads to the gradual formation of the calcium aluminate phases. Furthermore, the addition of calcium carbide does not have the considerable effect on the formation of calcium aluminate phases and in turn, calcium oxide in the top slag prevents the nozzle clogging problem.