Geologia Croatica, Vol. 72 No. 3, 2019.
Other
https://doi.org/10.4154/gc.2019.18
Chemical, mineralogical and structural features of native and expanded perlite from Macedonia
Arianit A. Reka
orcid.org/0000-0002-6419-2270
; Department of Chemistry, Faculty of Natural Sciences and Mathematics, University of Tetova
Blagoj Pavlovski
orcid.org/0000-0003-0662-5995
Kiril Lisichkov
; Faculty of Technology and Metallurgy, Ss. Cyril and Methodius Universit
Ahmed Jashari
; aFaculty of Natural Sciences and Mathematics, University of Tetovo
Blažo Boev
; Faculty of Natural and Technical Sciences, Goce Delčev University
Ivan Boev
; Faculty of Natural and Technical Sciences, Goce Delčev University
Maja Lazarova
; Faculty of Natural and Technical Sciences, Goce Delčev University
Volkan Eskizeybek
; Department of Materials Science and Engineering, Çanakkale Onsekiz Mart University
Ayhan Oral
; Department of Materials Science and Engineering, Çanakkale Onsekiz Mart University
Petre Makreski
orcid.org/0000-0003-0662-5995
; Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University
Abstract
The physico-mechanical, chemical and mineralogical characteristics of volcanic glass (perlite) from the Mariovo region (Macedonia) as well as the mineralogical changes that occur during its thermal treatment were investigated to demonstrate its utilization for industrial use. The native perlite was characterized by chemical analysis, X-ray powder diffraction (XRPD), infrared (IR) spectroscopy, thermal analysis (TGA/DTA), scanning electron microscopy (SEM-EDX), transmission electron microscopy (TEM), and solid- state NMR. The chemical examination suggests that the perlite represents an acidic volcanic rock with a high percentage of SiO2 (72.45%), high in alkali metal oxides (4.21 wt.% K2O, 3.56 wt.% Na2O), with a loss of ignition 3.54 wt.%. Results from the XRPD indicated major amorphous behaviour, with low amounts of feldspars, quartz, and cristobalite. SEM examinations revealed glassy structure with presence of certain pores (dimensions ranging from 50–100 μm). The determined expansion coefficient was 20 times its original volume. XRPD of expanded perlite compared to the native perlite depicted new intensive peaks of cristobalite. SEM and TEM revealed irregular morphology with broken or ragged edges. On the basis of the chemical and mineralogical composition, the studied perlite is classified as an appropriate material suitable as ceramic flux to lower the sintering temperature.
Keywords
perlite; volcanic rocks; chemical and mineralogical characterization; expansion coefficient
Hrčak ID:
228278
URI
Publication date:
31.10.2019.
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