3.1.2. X-ray diffraction spectra and carbonates
PB revealed more crystalline characteristics as indicated by
more peaks in the X-ray diffraction spectrogram than PBa (Fig. 2).
Common peaks appeared in both spectra at 3.05, 3.36, and 4.30 Å
and resulted from the effect of carbonates and SiO2. The peaks of
the PB spectrum at 1.88, 1.92, 2.09, 2.28, and 2.50 Å were mainly
caused by the presence of carbonates. Thus, more significant
carbonate features were found in PB than in PBa. Carbonate
contents in PB and PBa were 14.86 and 7.16 g kg1, respectively,
according to the volumetric analysis method.