Chemical Characteristics of Steelmaking Slag in Aqueous Environments

The oxidizing slag discarded from the oxidation process in an electric arc furnace was analyzed using the tank leaching test based on the Japanese industrial standards. The dissolved concentrations of environmentally regulated substances from the oxidizing slag were lower than those stipulated in the environmental quality standards. Therefore, this slag could be used as soil. Ca, K, P, Mg, S, Fe, Mn, Zn, Cu, B and Mo, which are essential elements for plants, were dissolved in the slag. Si was also dissolved in the slag. The slag-containing aqueous solution exhibited buffering action, and its pH was approximately 8.5. This value was smaller than those of mortar and limestone solutions. The slag-free eluate also exhibited buffering action. The Fe(II) ion was dissolved in the slag, and therefore, it could reduce the Cr(VI) ion.

Keywords: Buffering Action, Cr(VI), Essential Nutrient, Environmental Quality Standard, Environmentally Regulated Substance, Leaching Test, pH.