Characterization of alkali-activated thermally treated incinerator bottom ash

X. C. Qiao, M. Tyrer, Chi Sun Poon, C. R. Cheeseman

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)

Abstract

The fine fraction (<14 mm) of incinerator bottom ash (IBA) obtained from a UK energy from waste plant has been milled and thermally treated at 600, 700, 800 and 880 °C. Treated materials have been activated with Ca(OH)2(10 wt%) and the setting times and compressive strengths at different curing times measured. In addition to decomposition of CaCO3to CaO, thermal treatment increases the content of gehlenite (Ca2Al2SiO7), wollastonite (CaSiO3) and mayenite (Ca12Al14O33). Thermally treated samples were significantly more reactive than milled IBA and heating to 700 °C produced a material which rapidly set. Silica, gehlenite and wollastonite were the main crystalline phases present in hydrated samples and a mixed sulphate-carbonate AFm-type phase (Ca4Al2O6(CO3)0.67(SO3)0.33· 11H2O) formed. Significant volumes of gas were generated during curing and this produced a macro-porous microstructure that limited strength to 2.8 MPa. The new materials may have potential for use as controlled low-strength materials.
Original languageEnglish
Pages (from-to)1955-1962
Number of pages8
JournalWaste Management
Volume28
Issue number10
DOIs
Publication statusPublished - 31 Jul 2008

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology
  • Management, Monitoring, Policy and Law
  • Pollution
  • Waste Management and Disposal

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