Potential Reuse of Slag from the Kambara Reactor Desulfurization Process of Iron in an Acidic Mine Drainage Treatment

Kambara reactor desulfurization slag (KR slag) is a solid waste generated from the desulfurization process of molten iron by a KR mechanical stirring process in a steel factory. Most of the KR slag is sent to landfills or stored on-site. The KR slag may be potentially used in an acidic mine drainage (AMD) treatment process as a replacement of lime due to its high CaO content. This research focused on the physicochemical properties of the KR slag samples collected from a steel corporation in China and its potential treatment of AMD. Two samples were analyzed for major minerals by X-ray diffraction (XRD), particle size distribution, chemical compositions, and morphology by scanning electron microscope (SEM). The results showed that the chemical compositions of the KR slag were CaO, SiO2, Fe, Al2O3, MgO, S, and F, and the mineral components were portlandite, calcite, carbon, and calcium silicate. The CaO and Fe contents were high and much of the CaO was still unreacted. The main particles of the KR slag were irregular and there was a wide particle size distribution from <0.045 to <10 mm. The neutralization investigation indicated that the KR slag could neutralize AMD effectively even with low free lime content, and the dissolution of toxic elements was very low. (C) 2014 American Society of Civil Engineers.