CHARACTERIZATION OF ABU KHRUQ NEPHELINE SYENITE AND ITS COMPENSATION WITH SODA-LIME-GLASS FOR PREPARATION OF GLASSCERAMIC

The Abu Khruq ring complex (ARC) is located in the Southern Eastern Desert of Egypt. It is composed
mainly of nepheline syenite, syenite and quartz syenite. Petrographical and chemical analysis (XRF) were
achieved to identify the mineral composition and to define the nature of the various rock types present in
the area.
Geochemically, the different types of alkaline syenitic rocks from margin and the center of the ring
show decrease of Na2O and enrichment of SiO2 toward the margin. The syenitic rocks have a considerable
value of Al2O3 (12.8 - 17.3 wt. %) and total alkalis are above 8.5 wt.% which might indicate magma
developed from deep crustal source of mixed material from the mantle. According to plate tectonic theory,
the different types of syenitic rocks placed in within plate anorogenic belts.
Sintered glass-ceramic was prepared from local nepheline syenite with soda-lime-silicate glass. B2O3
added to the glass batches to decrease the melting temperature as well as the glass melt viscosity. MgF2
and CaF2 were added to the glass batches as nucleation catalysts. Little nepheline, augite, xonotlite and
fluorite were developed in the samples after sintering process. Very little or traces of nepheline was
formed in boron-free and -containing sample. Although MgF2 enhance augitic pyroxene, CaF2 appropriate
the formation of xonotlite. In all samples nano- and micro-size rods were developed in the glassy matrix.
The Vickers microhardness and densities values were between ~ 396.5 to 676.2 kg/mm2 and ~ 2.14 to 2.52
g/cm3, respectively. The produced glass-ceramic can be used in building materials.