NDA@SZTAKI

Optimization of activator solution and heat treatment of ground lignite type fly ash geopolymers

MolnĂĄr, ZoltĂĄn

SzabĂł, Roland

Råcz, Ádåm

Lakatos, JĂĄnos

Debreczeni, Ákos

Mucsi, GĂĄbor

IOP Publishing

2017

TN Mining engineering. Metallurgy / bĂĄnyĂĄszat, kohĂĄszat, fĂŠmipar

Geopolymers are inorganic polymers which can be produced by the reaction between silico aluminate oxides and alkali silicates in alkaline medium. Materials containing silica and alumina compounds are suitable for geopolymer production. These can be primary materials or industrial wastes, i. e. fly ash, metallurgical slag and red mud.
In this paper, the results of the systematic experimental series are presented which were
carried out in order to optimize the geopolymer preparation process. Fly ash was ground for
different residence time (0, 5, 10, 30, 60 min) in order to investigate the optimal specific
surface area. NaOH activator solution concentration also varied (6, 8, 10, 12, 14 M).
Furthermore, sodium silicate was added to NaOH as a network builder solution. In this last
serie different heat curing temperatures (30, 60, 90°C) were also applied. After seven days of
ageing the physical properties of the geopolymer(compressive strength and specimen
density)were measured. Chemical leaching tests on the rawmaterial and the geopolymers were
carried out to determine the elements which can be mobilized by different leaching solutions. It
was found that the above mentioned parameters (fly ash fineness, molar concentration and
composition of activator solution, heat curing) has great effect on the physical and chemical
properties of geopolymer specimens. Optimal conditions were as follows: specific surface area
of the fly ash above 2000 cm2/g, 10 M NaOH, 30o C heat curing temperature which resulted in 21 MPa compressive strength geopolymer.

angol

Article

PeerReviewed

info:eu-repo/semantics/article

text

http://real.mtak.hu/63368/1/Moln%C3%A1r_2017_IOP_Conf._Ser....

Molnår, Zoltån and Szabó, Roland and Råcz, Ádåm and Lakatos, Jånos and Debreczeni, Ákos and Mucsi, Gåbor (2017) Optimization of activator solution and heat treatment of ground lignite type fly ash geopolymers. IOP CONFERENCE SERIES: MATERIALS SCIENCE AND ENGINEERING (175). pp. 1-8. ISSN 1757-8981

http://real.mtak.hu/63368/

https://doi.org/10.1088/1757-899X/175/1/012046

doi:10.1088/1757-899X/175/1/012046