method of increasing the proportion of scrap in steelmaking

摘要

Method of improving the heat balance and thus increasing the amt. of scrap that can be used in refining cast iron in a converter having oxygen tungenes below the bath surface with protective sheaths, and oxygen blowing devices above the bath level, is claimed in which during a large part of the refining period, 20-80% of the O2 is fed into the bath by jets directed toward the bath surface from above the bath surface, and the rest is blown in below the surface. The amount of O2 blown onto the surface from above is varied during the course of the refining. The properties of the steel produced are unaltered, despite the improved heat balance and the increased use of scrap. The axis of the free jets w.r.t. the surface of the bath make an angle with the axis of rotation of the converter of 35(45) degrees.