title: Efficiency of fly ash belite cement and zeolite matrices for immobilizing cesium.
abstract: The efficiency of innovative matrices for immobilizing cesium is presented in this work. The matrix formulation included the use of fly ash belite cement (FABC-2-W) and gismondine-type Na-P1 zeolite, both of which are synthesized from fly ash of coal combustion. The efficiency for immobilizing cesium is evaluated from the leaching test ANSI/ANS 16.1-1986 at the temperature of 40 degrees C, from which the apparent diffusion coefficient of cesium is obtained. Matrices with 100% of FABC-2-W are used as a reference. The integrity of matrices is evaluated by porosity and pore-size distribution from mercury intrusion porosimetry, X-ray diffraction and nitrogen adsorption analyses. Both matrices can be classified as good solidify systems for cesium, specially the FABC-2-W/zeolite matrix in which the replacement of 50% of belite cement by the gismondine-type Na-P1 zeolite caused a decrease of two orders of magnitude of cesium mean Effective Diffusion Coefficient (D(e)) (2.8e-09 cm(2)/s versus 2.2e-07 cm(2)/s, for FABC-2-W/zeolite and FABC-2-W matrices, respectively).
authors.affiliation: Instituto de Ciencias de la Construcción Eduardo Torroja, CSIC, C/Serrano Galvache, 4, 28033 Madrid, Spain. sgoni@ietcc.csic.es
authors.forename: S
authors.initials: S
authors.lastname: Goñi
authors.forename: A
authors.initials: A
authors.lastname: Guerrero
authors.forename: M P
authors.initials: MP
authors.lastname: Lorenzo
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002586:Cesium / Q000737:chemistry*; D060729:Coal Ash; D005899:Glass Ionomer Cements / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D052638:Particulate Matter / Q000737:chemistry*; D016062:Porosity; D014961:X-Ray Diffraction; D017641:Zeolites / Q000737:chemistry*
chemical_list: D060729:Coal Ash; D005899:Glass Ionomer Cements; D052638:Particulate Matter; C516482:belite; D017641:Zeolites; D002586:Cesium; D002244:Carbon