1983 Volume 69 Issue 15 Pages 1886-1892
K-BOP, one of combined blowing processes, is favorable for refining stainless steel by diluting gas practice because of its inherent advantage of preferential carbon oxidation suppressing excessive chromiun oxidation. In K-BOP, application of dephosphorized hot metal to production of stainless steel can realize energy saving.
One of the application technique is a duplex process in which crude molten metal is produced by mixing dephosphorized hot metal with optimum chromium bearing molten steel from electric melting furnace (EF). This crude molten metal has higher heat energy i.e. sensible heat and heat of oxidation of C, Si, Mn, Cr than that from overall EF practice. Consequently it is possible to refine stainless steel at higher temperature and this leads to the benefits of higher chromium yield.
The other technique is "Hot Metal Process" in which dephosphorized hot metal are decarburized and all ferro alloys must be charged in converter. Consequently input heat energy is not enough to raise temperature of molten steel to aim point. For the compensation of the shortage of heat, the use of small size coke which is surplus and cheap material in works is found to be beneficial. To countermeasure the sulfur pick up by coke addition, K-BOP practice is associated with remarkable gaseous desulfurization and slag/metal desulfurization reaction. In "Hot Metal Process" production cost is decreased by 3.4% due to saving electric power for EF
