Acidic Oxygen Top-Blown Steelmaking with Small Amount of Slag

The purified low sulphur and low phosphorus semi-finished hot metal obtained by pretreating molten Vanadiu(?)n-bearing pig iron with sodium salt is the most suitable material to be used in acidic steelmaking process. Experimental investigation on steelmaking of this semi finished hot metal has been carried out in a 100 KVA middle frequency induction furnace, with slag-forming material added in amount of 1.5—2% of the weight of the semi-finished hot metal. The refining operation is very smooth and the low alloy structural steel can be easily made. During therefining process the average remains rate of vanadium in metal is about 36% while it raises to about 53% after deoxidation in bath. During the refining process the phosphorus content and the sulphur content altered slightly with the average phosphorus conteng of finished steel after deoxidation in the bath being 0.006% higher than that bEfore deoxidation, and the average sulphur content decreasing by 0.0013%. Analysis on thermal balance and two simple farmulas for calculating the temperature increment due to oxidation of carbon in metal and the quantity of scrap addition have also been made in this paper.