In situ studies of the agglomeration phenomena for calcium–alumina inclusions at liquid steel–liquid slag interface and in the slag

Studies of inclusion behavior at the metal–slag interface are of great importance for the steel industry in order to obtain better control of the size and of inclusions as well as improving the steel quality and casting process. In this work the agglomeration of liquid Al2O3–CaO particles at the liquid steel–liquid slag interfaces are studied with a confocal scanning laser microscope. In addition, the agglomeration of liquid Al2O3–CaO inclusions already transferred to the slag is investigated. It is found that agglomeration of the liquid inclusions at the steel–slag interface could only take place when the inclusions were forced towards each other, while the agglomeration of liquid particles was seen to be noticeably enhanced when the particles were already in the slag.