X-ray diffraction patterns of the same sample mixtures heated
at 550 ◦C for 60 min is shown in Fig. 4. In the pattern of the sample
without Ni(OH)2 addition, peaks of both starting sample, CaO and
dehydrochlorination product, CaClOH have been observed, indicating
that dehydrochlorination occurs by heating. Small peaks of
Ca(OH)2 have also been observed due to similarly the absorption
of water by CaO during sample handling.