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Crystallization of (Na 2 O–MgO)–CaO–Al 2 O 3 –SiO 2 Glassy Systems Formulated from Waste Products
Author(s) -
Barbieri Luisa,
Ferrari Anna Maria,
Lancellotti Isabella,
Leonelli Cristina,
Rincòn Jesus Maria,
Romero Maximina
Publication year - 2000
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2000.tb01584.x
Subject(s) - devitrification , glass recycling , crystallization , mineralogy , aluminosilicate , materials science , anorthite , wollastonite , chemical engineering , ceramic glaze , nucleation , vitrification , nepheline , gehlenite , silicate , feldspar , metallurgy , ceramic , glaze , raw material , geology , thermodynamics , phase (matter) , chemistry , quartz , andrology , engineering , biochemistry , catalysis , organic chemistry , physics , medicine
Aluminosilicate and silicate glass‐ceramics were obtained from controlled devitrification of CaO–Al 2 O 3 –SiO 2 glassy systems starting from Spanish and Italian coal fly ash or Italian municipal incinerator slag mixed with other byproducts, such as glass cullet and dolomite. The nucleation mechanism and the crystallization kinetics were investigated by thermal, diffractometric, and microstructural measurements. Moreover, the experimentally observed devitrification and the identification of the crystalline phases formed were compared with the indications derived from Ginsberg, Raschin‐Tschetveritkov, and Lebedeva diagrams used for petrological glass‐ceramics. All the glasses showed a good crystallization tendency with the formation of dendritic pyroxene and acicular wollastonite together with feldspar and iron spinels starting from the surface. The activation energy values for crystallization ranging from 472 to 832 kJ ·mol −1 were found to be close to those typical for aluminosilicate glasses; moreover, the possibility to vitrify and devitrify up to 100 wt% of slag and up to 40–50 wt% of ash mixed with glass cullet and dolomite makes the vitrification treatment a suitable disposal procedure.