Powder-classifying apparatus

This powder-classifying apparatus classifies a starting material powder having a particle size distribution, into fine powder and coarse powder. The apparatus has: a disk-shaped centrifugal separation chamber constituted as a space between two facing members; a plurality of air nozzles that supply a gas into the centrifugal separation chamber and generate a spiral flow; a starting material spray nozzle for supplying a starting material powder into the spiral flow generated in the centrifugal separation chamber; a fine powder recovery pipe passing through the center portion of one of the members of the centrifugal separation chamber, for discharging to outside of the centrifugal separation chamber a gas that includes a fine powder classified in the centrifugal separation chamber; a cylindrical first wall part provided to the opening made by the fine powder recovery pipe; and a cylindrical second wall part facing the first wall part, and provided to the other member, leaving a prescribed gap therebetween. 本发明的粉