Peer-reviewed articles 17,970 +



Title: METHOD FOR RAPID VERIFICATION OF THE PRESENCE OF AMMONIUM SALTS IN FLY ASH AT A CONCRETE PLANT

METHOD FOR RAPID VERIFICATION OF THE PRESENCE OF AMMONIUM SALTS IN FLY ASH AT A CONCRETE PLANT
Daniel Dobias; Stanislav Rehacek; Petr Hunka; Karel Hurtig; David Citek
10.5593/sgem2022/6.1
1314-2704
English
22
6.1
•    Prof. DSc. Oleksandr Trofymchuk, UKRAINE 
•    Prof. Dr. hab. oec. Baiba Rivza, LATVIA
Requirements relating to the quality of the flue gases produced have become more and more stringent in recent years. This is why the electricity producers, especially those using coal-fired units, have been forced to introduce additional environmental technologies. However, most of the coal-fired power plants and waste incineration plants in the Czech and Slovak Republics are following the same path, in particular for economic reasons. They are introducing the selective non-catalytic reduction of nitrogen oxides (SNCR). This method is based on the reduction of nitrogen oxides by injecting a solution of urea or ammonia water into the combustion chamber of the combustion unit.
The captured fly ash is thus in direct contact with the injected agent. Direct contact of the high-temperature fly ash with the injected medium results in increased amounts of ammonium salts in the fly ashes that have undergone the SNCR process. The ammonium salts contained in fly ash then react very quickly with alkaline substances, such as cement in a concrete mix, producing gaseous NH3. This gas is characterized by a very unpleasant odour. Therefore, when the fly ash is used the hygiene limits might beexceeded.
Very often, but it is not clear whether the fly ash brought to the concrete plant has passed the SNCR mechanism or not. That is why a quick orientation method for detecting the presence of ammonium ions in fly ash was designed and verified. Based on the result of the analysis using this method, it is possible to decide at the concrete plant whether or not the fly ash will be admitted to the silo of the concrete plant. The article briefly describes the methodology of the analysis, highlighting the advantages of the proposed method.
[1] Decree No. 415/2012 Coll. on the permissible level of air pollution and on the implementation of certain other provisions of the Air Protection Act.
[2] Machac, P., Vavrova, J., What we know about the non-catalytic reduction of nitrogen oxides (in Czech), University of Chemistry and Technology Prague, Czech Republic, 2013.
[3] Snop, R., The influence of SNRC technology from the perspective of the ash processor and distributor (in Czech), Ash in Construction 2015, Brno University of Technology, pp 189-195, 2015.
[4] Government Regulation No. 361/2007 Coll., Which lays down the conditions for health protection at work - PART A List of chemical substances and their permissible exposure limits (PEL) and maximum permissible concentrations (MPC).
[5] Sulc, R., Snop, R., Neruda, J., Skvara, F., Peterova, A., Report on the issue of fly ash after SNCR technology as an admixture in concrete, Prague, 2017.
[6] Hela, R., Tazky, M., Influence of SNCR on the properties of fly ash in terms of its applicability to concrete, 24th International Conference Concrete Days 2017, Litomysl, Czech Republic, 2017.
[7] ISO 7150-1 Water quality. Determination of ammonium. Part 1: Manual spectrometric method.
The paper has been written with the support of the TACR grant project FW01010539.
conference
Proceedings of 22nd International Multidisciplinary Scientific GeoConference SGEM 2022
22nd International Multidisciplinary Scientific GeoConference SGEM 2022, 04 - 10 July, 2022
Proceedings Paper
STEF92 Technology
International Multidisciplinary Scientific GeoConference SGEM
SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Serbian Acad Sci and Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts and Letters; Acad Fine Arts Zagreb Croatia; Croatian Acad Sci and Arts; Acad Sci Moldova; Montenegrin Acad Sci and Arts; Georgian Acad Sci; Acad Fine Arts and Design Bratislava; Turkish Acad Sci.
187-192
04 - 10 July, 2022
website
8651
concrete plant, fly ash, ammonium salts, rapid verification