synthetic slag process decreases sulfur and phosphorus contents of steel, improves inclusion removal, protects steel from atmosphere and prevents temperature drop of the liquid steel in the ladle. in this study, the synthetic slags of ternary cao-al2o3-sio2,and quaternary cao-al2o3-sio2-na2o and cao-al2o3-sio2-sro systems were pre-melted and then were kept in contact with the liquid steel in a ...