減圧下における炭素飽和溶融Fe-Sn-S合金からのSnSの蒸発速度

Abstract

The recycling of valuable resources has currently became a major worldwide subject in the industries from the viewpoint of saving energy and protection of environment. Since the accumulated amount of steel product is reaching almost one billion ton in Japan, it is very important to develop the technology for the removal of tramp-elements such as tin, copper and zinc from steel scrap. In the present work, the rate of tin removal by the evaporation from carbon saturated liquid Fe-Sn-S alloy has been studied at 1, 673 K under reduced pressure.Tin evaporates from molten iron and equimolar amount of sulfur is also removed together with tin. The evaporation rate of tin increases with increasing initial sulfur content in the melt. It is confirmed that tin dissolved in liquid iron is removed in the form of SnS under the presence of sulfur in the metal. The rate of tin evaporation becomes faster with reducing the pressure in the reaction chamber. This indicates that the rate is controlled mainly by the mass transfer of SnS in the gas phase.