title: Vaporization Mechanisms of Water-Insoluble Cs in Ash During Thermal Treatment with Calcium Chloride Addition.
abstract: The vaporization mechanisms of water-insoluble Cs in raw ash and Cs-doped ash during thermal treatment with CaCl2addition was systematically examined in a lab-scale electrical heating furnace over a temperature range of 500-1500 °C. The results indicate that the water-insoluble Cs in the ash was associated with aluminosilicate as pollucite. Addition of 10% CaCl2caused the maximum vaporization ratio of Cs in the raw ash to reach approximately 80% at temperatures higher than 1200 °C, whereas approximately 95% of Cs was vaporized at temperatures higher than 1300 °C when 30% CaCl2was added. The formation of an intermediate compound, CsCaCl3, through the chemical reaction of Cs with CaCl2was responsible for Cs vaporization by means of the subsequent decomposition of this intermediate upon the increase in temperature. The indirect chlorination of Cs by the gaseous chlorine released from the decomposition of CaCl2was insignificant. A high CaCl2content in the resulting annealed products with 30% CaCl2addition delayed the decomposition of CsCaCl3and thus lowered the Cs vaporization ratio compared to that with 10% CaCl2addition at 900-1250 °C. Thermal treatment with CaCl2addition is a proposed method to remove Cs from Cs-contaminated incineration ash.
authors.affiliation: Department of Applied Chemistry, Chubu University , 1200 Matsumoto-Cho, Kasugai, Aichi 487-8501, Japan.
authors.forename: Facun
authors.initials: F
authors.lastname: Jiao
authors.affiliation: Department of Applied Chemistry, Chubu University , 1200 Matsumoto-Cho, Kasugai, Aichi 487-8501, Japan.
authors.forename: Norie
authors.initials: N
authors.lastname: Iwata
authors.affiliation: Institute of Technology, Shimizu Corporation , 3-4-17 Etchujima Koto-ku, Tokyo 135-8530, Japan.
authors.forename: Norikazu
authors.initials: N
authors.lastname: Kinoshita
authors.affiliation: Institute of Technology, Shimizu Corporation , 3-4-17 Etchujima Koto-ku, Tokyo 135-8530, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kawaguchi
authors.affiliation: Institute of Technology, Shimizu Corporation , 3-4-17 Etchujima Koto-ku, Tokyo 135-8530, Japan.
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Asada
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Honda
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sueki
authors.affiliation: Department of Applied Chemistry, Chubu University , 1200 Matsumoto-Cho, Kasugai, Aichi 487-8501, Japan.
authors.forename: Yoshihiko
authors.identifier: 0000-0002-3523-9666
authors.initials: Y
authors.lastname: Ninomiya
mesh_terms: D002122:Calcium Chloride; D060729:Coal Ash / Q000737:chemistry*; D017745:Incineration; D014835:Volatilization; D014867:Water
chemical_list: D060729:Coal Ash; D014867:Water; D002122:Calcium Chloride