Publication detail

Effect of Ammonium ion content in Fly Ash after Selective Non-catalytic Reduction (SNCR) on Physical and Mechanical Properties of Autoclaved Aerated Concrete (AAC)

LÉDL, M. GALVÁNKOVÁ, L. DROCHYTKA, R.

Original Title

Effect of Ammonium ion content in Fly Ash after Selective Non-catalytic Reduction (SNCR) on Physical and Mechanical Properties of Autoclaved Aerated Concrete (AAC)

Type

conference paper

Language

English

Original Abstract

After introducing SNCR in coal combustion process in power plants, the valuable by-product such as fly ash remains contaminated with amount of ammonia in form of NH 4 HSO 4 , (NH 4 ) 2 SO 4 respectively, which became undesirable in AAC technology because the toxic ammonia is released in the air during the mixing process. This paper deals with the effect of varying ammonia content in fly ash after selective non-catalytic reduction (SNCR) on the physical-mechanical properties of the fly ash based autoclaved aerated concrete (AAC) with the main focus on determination of the impact of the various content of ammonium ion in fly ash on the initial consistency of fresh slurry, the residual content of ammonium ion in hardened aerated matrix and also the impact on the bulk density, compressive strength and tobermorite formation after hydrothermal treatment. Seven batches of AAC, made out of fly ash with rising content of ammonium ion from 0 ppm to 250 ppm, were tested and based on the results obtained it was found out that ammonia is released during the mixing process entirely and doesn‘t remain in AAC after autoclaving, moreover it doesn‘t affect the properties of both fresh slurry (no apparent foaming effect noticed) and thermally treated samples of AAC. Formation of tobermorite wasn’t negatively affected.

Keywords

Autoclaved aerated concrete; fly ash; selective non-catalytic reduction; tobermorite; ammonia; compressive strength

Authors

LÉDL, M.; GALVÁNKOVÁ, L.; DROCHYTKA, R.

Released

20. 6. 2018

Publisher

Trans Tech Publications

Location

Switzerland

ISBN

1662-9779

Periodical

Solid State Phenomena

Year of study

276

State

Swiss Confederation

Pages from

148

Pages to

153

Pages count

6

BibTex

@inproceedings{BUT144911,
  author="Matěj {Lédl} and Lucie {Dlabajová} and Rostislav {Drochytka}",
  title="Effect of Ammonium ion content in Fly Ash after Selective Non-catalytic Reduction (SNCR) on Physical and  Mechanical Properties of Autoclaved Aerated Concrete (AAC)",
  booktitle="Solid State Phenomena",
  year="2018",
  journal="Solid State Phenomena",
  volume="276",
  pages="148--153",
  publisher="Trans Tech Publications",
  address="Switzerland",
  doi="10.4028/www.scientific.net/SSP.276.148",
  issn="1662-9779"
}