On the Dephosphorization of Hot Metal in the Ladle

Abstract

Dephosphorization of hot metal in the ladle was investigated by mechanical stirring method with the dephosphorizing agent consisting of LD slag and Fe₂O₃ powder. The experiments were carried out both with a laboratory scale apparatus and 45t industrial ladles.
The following results have been obtained;
(1) Using LD slag with Fe₂O₃ powder, the phosphorus level of hot metal can be reduced to 20% to 40% of the initial content after 40 minutes treatment even when the slag is acidic.
(2) During the treatment, the extent of decarburization is small, although silicon and manganese are oxidized and removed from the hot metal.
(3) The low phosphorus steel, with less than 0.010%P, can be easily obtained in LD vessels starting with the dephosphorized hot metal.