Thermal decomposition of Cd(OH)2 and formation of CdCO3 in CO2 atmosphere

The reaction which occurs in the process of thermal decomposition of Cd(OH)2 in the CO2 atmosphere was studied by means of DTA. X-ray diffraction pattern, TG, DSC, IR spectra and specific surface area were as well measured. A broad endothermic peak (240--3400C) and a narrow exothermic peak were observed on a micro-DTA curve. By the analysis of X-ray diffraction pattern of this process, it was recognized that the dehydration of Cd(OH)2 and the formation of CdCO3 proceeded within this temperature range. Furthermore, an endothermic peak around 4680C was considered to appear by the decomposition of CdCO3. Endothermic peak was observed only at 2440C and 3700C on a micro-DTA. By the result of X-ray diffractometric analysis, it was considered that the decomposition of Cd(OH)2 and the formation of CdCO3 took place under the same process as micro-DTA. (auth.)