METHOD FOR PRODUCING FINE PARTICLE OF NIOBIUM OXIDE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing fine particles of niobium oxide having a fine particle size suited for obtaining niobium oxide powder having a larger specific surface area per unit mass by sintering. SOLUTION: Fine particles of niobium oxide having a particle size of not more than 0.1μm are obtained by the steps of vaporizing niobium chloride at 170-240°C, hydrolyzing with steam added to the raw material gas stream comprising the obtained niobium chloride vapor and obtaining the fine particles of niobium oxide in the gas stream. Alternatively, they may be obtained by vaporizing niobium oxychloride at a temperature of 300-400°C. It is desirable that the vaporizing and the hydrolyzing are conducted in a vertical reactor and that the hydrolyzing part of it is at a temperature of not lower than 400°C. It is also desirable that the steam flows from a lower part toward an upper part in the gas stream of the raw material ascending in the vertical reactor and that the obtained fine particles of niobium oxide are recovered from the upper part of the vertical reactor by suction. COPYRIGHT: (C)2003,JPO