Recovery of metals from EAF dust with rapid system

The dust generated from the electric arc furnace steel making process is classified as hazardous material by Korean Environmental Protection Acts, mainly because of the existence of water leachable Pb, Zn and Cd. Thus the treatment of EAF dust is being carried out to fulfill both the environmental aspect and recovery of valuable metals. To recover the valuable metals (Fe, Zn, Pb and Cd) and to produce the non-toxic slag from EAF dust, using the plasma furnace system developed by RIST combined with Zn-condenser, the reduction, vaporization and condensation mechanism of Fe,Zn,Pb,Cd in EAF dust were investigated with prototype RAPID system. The optimum conditions for the melting and reduction of EAF dust with RAPID system were found to be 1300? f'ce temperature, 1.7 C/S ratio, 180 wt.% of carbon reduction equivalent. Zn and Fe recovery was revealed to be higher than 98 wt% and 87 %, respectively. Electricity consumption for the system was 1280KWH per ton dust. After toxicity test, slags after tapping from the furnace lies within the regulation. Construction of RAPID-10 (RIST Arc Plasma Industrial Device) system for treating 10,000 ton of EAF dust per year is now underconstruction. Overall plan for treating EAF dust generated in KOREA will be setup after successful operation (June,1999) of RAPID-10 system.