| Budget Amount *help |
¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1996: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Research Abstract |
In 1995, some preliminary experiments were carried out. Temperature behaviors of some oxides, such as CaO,SiO_2, Al_2O_3, FeO,Fe_2O_3, with microwave (2.45GHz, 500W) irradiation were investigated. After a new apparatus for 1.6kW microwave was built up, synthesized steelmaking slags (CaO-SiO_2-Fe_tO system) were exposed to microwave and the effect of slag composition was investigated. The heating rate was strongly dependent on Fe^<3+>/Fe^<2+> ratio and the existence of CaFe_3O_5 seemed to be the key of the heating mechanism, which was also found to have high dielectric losses
In 1996, the behaviors of iron and phosphorus of the steelmaking slags coexisting with carbon under microwave irradiation as well as temperature change have been investigated. The aim of this experiment is to clarify the possibility of extracting some resources such as iron and phosphours from steelmaking slags and dust, which are seldom recycled as beneficial materials. Temperature was raised up to 1700ﾟC in 4-6 min. and the heating rate was shown to increase with increasing amount of carbon mixed with the slags. Iron-carbon melts were formed and more than 90% of iron in the slags were recovered. When the carbon equivalent which we defined as the fractional amount of carbon required for the reduction of iron oxide in the slags to pure iron with the formation of carbon monoxide is more than unity, 50-60% of phosphorus in the slags was brought into the metal phase and about 20% disappeared probably into gas phase.
Accordingly, steelmaking slags coexisting with carbon were found to heat up effectively by means of microwave irradiation, and iron and phosphorus could be recovered from the slags. This new process is proposed as an effective one for recycling steelmaking slags and dust.
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