Discussion - Snyder, Ernest B. - Marblehead Lime Company

I strongly endorse Mr. Jackson's (Inland Steel Company) oral comment on the authors' paper that, as blast furnace slag is removed from the BOF charge, lime solution may be retarded. After two or three pourings, the blast furnace slag will contain some iron oxide and considerable manganese oxide, and it is hot and possibly still liquid. A few thousand pounds of this slag will speed up the slag development rate considerably and could be considered a good auxiliary flux. Although the removal of blast furnace slag from the BOF charge lowers the total sulfur load by 40 to 50%, we must have a good, quick slag development in the BOF to bring .030 to .035% sulfur hot metal to .020%, a requirement on a high percentage of our steels today. In discussions at off-the-record meetings and one not published at last year's annual meeting as well as discussions with many operators over the past 1-1/2 years, I predicted that the removal of blast furnace slag could slow down lime dissolution and that, if a shop had dissolution problems before, the problem could be quite serious.