Chemical state analysis of high-temperature molten slag components by using high-energy XAFS

Okamoto, Yoshihiro  ; Osugi, Takeshi  ; Akabori, Mitsuo; Kobayashi, Toru ; Shiwaku, Hideaki   

High energy XAFS measurement using cerium K-edge was performed to study the chemical state of cerium in high-temperature molten slag (SiO-CaO-FeO-CeO). It was found from the change in the nearest Ce-O distance obtained from EXAFS analysis and the energetic shift of the white line peak observed in XANES analysis that oxidation state of cerium was tetravalent in the molten state and trivalent in solid state. The Debye-Waller factor of the nearest Ce-O pair in solid slag was very large even at room temperature, and the change in its value upon heating and melting was very small. This result suggests that cerium is highly disordered and stable in solid slag.