title: Chloride chemical form in various types of fly ash.
abstract: Chloride content is a critical problem for the reuse of fly ash as a raw material in cement, and the method used by recyclers to reduce the fly ash chloride content depends on the chemical form of the chlorides. However, limited information is available on the quantitative distribution of chlorides and the identity of some chlorides such as Friedel's salt. We examined chloride forms and percentages using X-ray absorption near edge structure and X-ray diffraction analyses, as well as corresponding washing experiments. Approximately 15% of the chlorine in raw fly ash was estimated to be in the form of NaCI, 10% in KCl, 50% in CaCl2, and the remainder in the form of Friedel's salt. Fly ash collected in a bag filter with the injection of calcium hydroxide for acid gas removal (CaFA) contained 35% chlorine as NaCl, 11% as KCI, 37% as CaCl2, 13% as Friedel's salt, and the remaining 4% as CaClOH. In fly ash collected in a bag filter with the injection of sodium bicarbonate for acid gas removal (NaFA), approximately 79% of chlorine was in NaCl, 12% was in KCl, and 9% was in Friedel's salt.
authors.affiliation: Department of Urban and Environmental Engineering, Kyoto University, Kyoto City, Japan. zhufenfencb@envsolid.mbox.media.kyoto-u.ac.jp
authors.forename: Fenfen
authors.initials: F
authors.lastname: Zhu
authors.forename: Masaki
authors.initials: M
authors.lastname: Takaoka
authors.forename: Kenji
authors.initials: K
authors.lastname: Shiota
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Oshita
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kitajima
mesh_terms: D002244:Carbon / Q000032:analysis*; D002712:Chlorides / Q000032:analysis*; D060729:Coal Ash; D017745:Incineration; D052638:Particulate Matter / Q000032:analysis*; D013057:Spectrum Analysis; D014961:X-Ray Diffraction; D014965:X-Rays
chemical_list: D002712:Chlorides; D060729:Coal Ash; D052638:Particulate Matter; D002244:Carbon