The Role of Open and Closed Curing Conditions on the Leaching Properties of Fly Ash-Slag-Based Geopolymers

Abstract

This study deals with the synthesis of geopolymers from co-fired fly ash and blast furnace slags. Geopolymer bodies were simultaneously synthesized in open and closed curing conditions in order to elucidate the role of this parameter on their resultant properties. Open curing conditions produce solid bodies characterized by high porosity, low compressive strength and exacerbated leaching of certain oxyanionic metalloids. By contrast, protected curing promotes the binder development, giving rise to higher strength and less porous systems. This imposes physical restrictions to leaching which decreases and/or retards releases of oxyanionic metalloids in comparison to open curing conditions. Fly ash-slag-based geopolymers may immobilize a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, REE, Sn, Th, U, Y and Zr, regardless of the curing conditions. Due to geopolymers displaying weak assimilation capacity for oxyanionic species, their successful regarding oxyanionic retention is strongly dependent on porosity and therefore on curing conditions applied. © 2009 Elsevier B.V. All rights reserved.

Department(s)

Chemical and Biochemical Engineering

Comments

European Commission, Grant GEOASH RFC-CR-04005

International Standard Serial Number (ISSN)

0304-3894

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Elsevier, All rights reserved.

Publication Date

15 Apr 2010

PubMed ID

20005626

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