| Mineralogical Characterization and Thermal
Transformations of Talc-Carbonate Rocks
from Agoundis (High-Atlas, Morocco) |
M. Nciri1, M. Hajjaji* and A. Dekayir1
pages : 205-210
DOI : 10.1080/0371750X.2014.885387 |
| Abstract |
| Thermal transformations of talc-carbonate rocks consisting of talc, chlorite, mica/illite, quartz, feldspar and calcite
were investigated in the range of 900o-1100oC by X-ray diffraction, thermal analyses, scanning electron microscopy
and energy dispersive spectroscopy. Microstructural changes of heated decarbonated samples were also
investigated, and variations of some ceramic properties against temperature were followed. In the heated raw
samples, olivine and enstatite together with merwinite were formed at T1000oC from breakdown of chlorite. At
T1000oC, akermanite and monticellite were developed from talc, and shrinkage was almost unchanged. Heating of
decarbonated samples yielded olivine and enstatite together with Mg-spinel on the expense of talc. In this case, a
vitreous phase was also formed and shrinkage got increased. The neoformation processes in both the samples
were discussed based on the SiO2-MgO-CaO and SiO2-Al2O3-MgO phase diagrams. Considering the magnitudes of
the studied ceramic properties, the raw and carbonate-depleted materials could be suitable for manufacturing
insulating firebricks and extruded ceramic tiles (group AIII) respectively.
[Keywords: Talc-carbonate rock, Thermal transformation, Microstructure, Calcic-magnesian phases] |
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