During alteration of actinolite to talc, Fe and Ca decreased, but conversely Mg and Si increased.
EDX
analysis of the Emirdağ talc samples was characterized
by high SiO2
(44.35–59.56 wt.%) and MgO (24.08–28.88
wt.%), but low Al2
O3
(0.49-3.29 wt.%). On the other
hand, high Ni (0.21–0.26 wt.%), and Cr (0.20–0.35 wt.%)
contents of the Emirdağ samples in chemical analyses are
conformable to the composition of talc deposits related to
ultramafic origin. Fe2
O3
content affecting the whiteness
of talc varies between 5.40 and 6.10 wt.%. The correlative
results obtained from EDX studies conducted on the talc
crystals and chemical analyses of the pure talc samples
indicated that iron takes place in the crystal lattice structure
of talc minerals. Accordingly, high IS (1.26 mm/s) and QS
(2.72 mm/s) values obtained from Mössbauer studies also
confirm the results of EDX and chemical analysis and
indicate that iron in the Emirdağ talc is thought to be Fe+2.
On the other hand, it was observed that the strong peak
intensities of the talc on the FT-IR spectra decrease with
reduction of the talc content in the samples, and different
endothermic/exothermic peaks and mass loss arose in the
DTA and TG curves consistently with the mineralogical
composition. According to the results of color analysis, the
WI and L values increase proportionally with talc content
but are inversely proportional to the iron and titanium
element contents of the talc samples. Taking into account
the physiochemical values, the talc from the Emirdağ
region does not have the qualities in its current form, such
as high purity, chemical content (particularly Fe2
O3
and
CaO), and other physical properties, especially whiteness,
that are required in industries like cosmetics, paint, or
paper. However, there might be a possibility of using it as a
secondary raw material in these industries.