PRODUCTION OF HIGH-PURITY MAGNESIA FINE POWDER

PURPOSE:To efficiently obtain an uniform high-purity magnesia fine powder product small in average particle diameter by varying the cross-sectional area of an ejector for a gaseous mixture of Mg vapor with an inert gas and the contact position of the Mg vapor with an oxygen containing gas in a producing method using vapor phase oxidation reaction. CONSTITUTION:The magnesia fine powder is obtained by jetting the gaseous mixture of the Mg vapor with the inert gas from the ejector 1 and bringing the mixture into contact with the oxygen containing gas introduced from two electors 2 upper the ejector 1, thereby oxidizing the Mg vapor. In this case, the particle diameter of the magnesia fine powder is reduced with the decrease of the cross-sectional area of the ejector 1 varied. And furthermore the particle diameter of the magnesia fine powder is controlled and the sticking and deposition of magnesia to the ejector 1 are prevented by making the fitting position of ejectors 2 adjustable and varying the contact position of the Mg vapor with the oxygen containing gas (distance H between the ejector 1 and the contact point of the Mg vapor with the oxygen containing gas).