Next Article in Journal
Spontaneous Serpentine Carbonation Controlled by Underground Dynamic Microclimate at the Montecastelli Copper Mine, Italy
Previous Article in Journal
The High-Pressure Structural Evolution of Olivine along the Forsterite–Fayalite Join
Previous Article in Special Issue
Effects and Mechanism of Different Grinding Media on the Flotation Behaviors of Beryl and Spodumene
Open AccessArticle

Synthesis of Geopolymers from Mechanically Activated Coal Fly Ash and Improvement of Their Mechanical Properties

1
Department of Chemical, Energy and Environmental Engineering, Faculty of Environmental and Urban Engineering, Kansai University, 3-3-35 Yamate-cho, Suita-shi, Osaka 564-8680, Japan
2
Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita-shi, Osaka 564-8680, Japan
3
Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
*
Author to whom correspondence should be addressed.
Minerals 2019, 9(12), 791; https://doi.org/10.3390/min9120791
Received: 18 November 2019 / Revised: 12 December 2019 / Accepted: 12 December 2019 / Published: 16 December 2019
Coal fly ash is a spherical fine powder by-product discharged from coal-fired power plants. When coal fly ash is used as raw materials for the synthesis of geopolymers, there are practical problems associated with the stable surface of the particles that do not allow the production of geopolymers with sufficient strength. A long-time is also required for the curing. In this study, we aim to promote the curing reaction of geopolymers by activating the surface of coal fly ash particles. By mechanically activating the surface of coal fly ash particles using an attrition-type mill, the dissolution of Si4+ and Al3+ in coal fly ash is promoted, and the acceleration of the reaction taking place during curing is also anticipated. The surface morphology and crystal phase of coal fly ash particles change with the use of an attrition-type mill. The mechanical activation results in improvement of the compressive strength and the acid resistance under milder curing conditions by the densification of the hardened body. Thus, it is clearly shown that mechanical activation is effective for the production of geopolymers with beneficial mechanical properties under milder curing conditions. View Full-Text
Keywords: coal fly ash; mechanical activation; geopolymerization; compressive strength coal fly ash; mechanical activation; geopolymerization; compressive strength
Show Figures

Figure 1

MDPI and ACS Style

Matsuoka, M.; Yokoyama, K.; Okura, K.; Murayama, N.; Ueda, M.; Naito, M. Synthesis of Geopolymers from Mechanically Activated Coal Fly Ash and Improvement of Their Mechanical Properties. Minerals 2019, 9, 791.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop