PREPARATION OF HIGH PURITY MAGNESIUM OXIDE

PURPOSE:To prepare magnesium oxide having low impurity content, in high yield, by spraying a clear aqueous solution of magnesium bicarbonate repeatedly in gaseous or liquid phase at a specific temperature, and filtering and calcining the resultant magnesium carbonate. CONSTITUTION:A magnesium-containing basic mineral such as calcined dolomite or a basic magnesium compound such as magnesium hydroxide is made to react with carbon dioxide gas in the state of aqueous suspension, and insoluble impurities are removed from the resultant aqueous solution of magnesium bicarbonate to obtain clear aqueous solution of magnesium bicarbonate. The solution is sprayed repeatedly in a vapor phase or via a vapor phase in a liquid phase with a pump, etc. at