Influence of precipitation conditions of magnesium hydroxide on its thermal decomposition in the preparation of active MgO

Thermal decomposition of magnesium hydroxide, prepared by its precipitation from a magnesium salt solution with ammonium hydroxide using different salts and different conditions (concentration of Mg salt, mode of mixing of the Mg salt and ammonium hydroxide solution, pH and temperature of precipitation, and the ageing period of the precipitate) has been investigated by TG, DTG and DTA techniques in the temperature range 30–600°C. The thermal analysis showed that the preparation conditions of magnesium hydroxide have a strong influence on its thermal decomposition to active magnesium oxide. An exothermic DTA peak was observed in the decomposition for only a few of the magnesium hydroxide samples.