Utilisation of municipal solid waste incinerator (MSWI) fly ash with metakaolin for preparation of alkali-activated cementitious material
Journal article, 2021

The proper treatment on hazardous municipal solid waste incineration fly ash (MSWIFA) is important. The application of alkali-activation technology to prepare alkali-activated MSWIFA (AAFA) material provides a potential not only to immobilise the heavy metals, but also to trigger its pozzolanic property in manufacturing building material. In this study, in addition to investigate the feasibility of alkaline activation technology in preparing AAFA with sodium silicate activator, the effect of metakaolin in AAFA (AAFM) was also explored to enhance its performance. The results showed that, compared to the AAFA, blending 10 % metakaolin in AAFA significantly improved both 28-day and 90-days compressive strengths, which was almost 200 % higher than that of AAFA. The compressive strength was increased with increasing the dosage of sodium silicate. The C-S-H gel was observed as the main hydration product of AAFA and AAFM. Moreover, the ettringite was observed in AAFM due to the reaction between the CaSO4 in MSWIFA and aluminate phase from metakaolin. Finally, the 28 and 210-day leaching behaviours of AAFM on Zn, Cu, Pb, Cd, Cr and Ni were successfully suppressed to less than 1 % of that originally from MSWIFA, which can meet the requirement from Chinese standards.

Alkali-activated cementitious material

Compressive strength

Metakaolin

MSWI fly ash

Leaching toxicity

Author

Jun Liu

Shenzhen University

Lu Hu

Shenzhen University

Luping Tang

Chalmers, Architecture and Civil Engineering, Building Technology

Jun Ren

Shenzhen University

Harbin Institute of Technology

Journal of Hazardous Materials

0304-3894 (ISSN) 18733336 (eISSN)

Vol. 402 123451

Subject Categories

Inorganic Chemistry

Other Environmental Engineering

Materials Chemistry

Other Chemical Engineering

DOI

10.1016/j.jhazmat.2020.123451

PubMed

32688190

More information

Latest update

8/5/2020 2