On Some Aspects of Basic Oxygen Steel Making with Prereduced Pellets

Abstract

Under normal circumstances, a BOF can consume upto 30% of scrap in the charge which otherwise consists of molten pig iron. In steel plants where the basic oxygen process has been adopted, this requirement of scrap is generally met by scrap generated within the plant and by that bought from external sources. The composition of scrap, espec-ially that purchased from dealers, is notorious for its variation from wagon to wagon, batch to batch and even from season to season. This is particularly true of the sulphur content of the scrap which is a factor of funda-mental importance in BOF steelmaking, This inconsistency in scrap composition tends to give rise to undesirable variations both in the final bath composition and in the general bath behaviour during blowing. To keep these fluctuations under control, BOF operators have to constantly monitor the blow and adopt corrective measures when necessary. A stricter control over the materials charged into the BOF would therefore appear to be nece-ssary before automation is possible and the process is rendered less subject to variations. To this end, the substitution of scrap by prereduced pellets could prove worthwhile.