Steel making process

摘要

Residual materials which become available in metallurgy and contain oxides and volatilizable non-ferrous metals or compounds thereof are treated in a rotary kiln with solid carbonaceous reducing agents and are thus directly reduced in a high proportion to sponge iron whereas a substantial part of their non-ferrous metal content is volatilized. The solids discharged from the rotary kiln are sieved with a parting size of about 3 to 10 mm, depending on the feed grading of the residual materials and their disintegration characteristics, so that a major part of the unmagnetic material is included in the fine fraction. The coarse fraction is subjected to an electro-slag resistance process. The fine fraction is subjected to an electro-magnetic separation. The magnetic fraction is subjected to the resistance slag-refining process. The unmagnetic fraction is incorporated in and bonded to the feed mixture for the rotary kiln by a tumbling or pelletizing operation.