Effect of Grinding Fineness of Fly Ash on the Properties of Geopolymer Foam

Abstract

Present paper deals with the development of geopolymer foam prepared from ground F class power station fly ash. The effect of the fly ash fineness on the rheology of the geopolymer paste and the foam properties have been investigated. The raw fly ash was ground in a ball mill for various duration, 5, 10, 20, 30, 60 and 120 min. Geopolymer paste was prepared from the raw and ground fly ash with NaOH -sodium silicate mixture as alkaline activator. Geopolymer foam production was made using H 2 O 2 as foaming agent. Additionally, the geopolymer material structure was investigated by Fourier transform infrared spectrometer, the foam cell structure was monitored using optical microscopy. The rheological behaviour of the geopolymer paste changed due to the grinding of fly ash (from Bingham plastic to Newtonian liquid). Grinding of fly ash has a significant effect on the physical properties as well as on the cell structure of the geopolymer foam.

Rigid polyurethane–polyisocyanurate foams modified with grain fraction of fly ashes

“…Putting this rule into perspective, as a result of long-term research and production experiments in Poland and in the world, basic directions for utilizing the byproducts of energetics and their wide usage have been determined. 12–18 The utilization of fly ash is not significantly varied in different parts of the world. In Poland, the unused part of the ash is gathered on landfills, which also affects the pollution of the environment, especially its dust contamination and exhaustion of dissolvable compounds into ground waters.…”

Functionalized geopolymers: A review

“…The foam formation is based on the fact that H2O2 is thermodynamically unstable and easily separates into water and oxygen gas (Szabó et al, 2017). Increasing H2O2 concentration increases the amount of oxygen resulting in increased bubble formation, which is greatly influenced by the pH of the solution.…”

Influence of Particle Size on Compressive Strength of Alkali Activated Refractory Materials

“…Influence of particle size on compressive strength of AAM was published in several papers stating that smaller the precursor's particles, higher the compressive strength [12][13][14][15][16][17][18][19]. This effect was also investigated in connection to the synthesis of alkali activated foam, where the same dependence was found, i.e., smaller the particles, higher the compressive strength [20,21]. In addition with small enough particles in the slurry, slurry goes from Bingham plastic to Newtonian liquid, viscosity decreases and larger pores form (easier escape of the gasses from the slurry).…”