REMOVAL OF TIN DURING SCRAP MELTING IN A CONVERTER WITH A THICK LAYEROF SLAG

The authors previously found that tin was concentrated in iron dust in the pilot experiments of smelting reduction with a large amount of sl ag. In order to apply this phenomenon to the scrap melting process, 1 kg and 5 ton scale experiments were performed to clarify the mechanism of tin removal and to improve the tin concentration into iron dust. I t was found that tin could be removed from scrap efficiently in a scra p melting process with a thick layer of slag. In this method, a high e vaporation rate of tin can be achieved by using the high temperature o f hot spot with oxygen top blowing. From the experimental studies and theoretical analyses, it was supposed that most of tin vaporized as Sn S. The vapor of SnS could be highly concentrated in dust by suppressin g bubble burst dust. Therefore, in order to improve the tin removal ra tio, it is of great importance to separate oxygen jet from metal bath to suppress bubble burst dust. It was also found that the tin concentr ation ratio remarkably increased when pulvirized coke was blasted to t he hot spot. It might be possible to improve the tin concentration rat io by means of local centent of sulfur near the hot spot.