<p>A fluidized-bed classifier has a vessel (20) defining a space divided into an upper fluidized-bed chamber (22) and a lower gas chamber (23) by a perforated dispersion plate (21) having the shape of a funnel. Rising currents of a gas, such as air, are blown through the dispersion plate (21) into the upper fluidized-bed chamber to produce a fluidized bed of a particulate material over the dispersion plate. The lower gas chamber (23) is divided into a first gas chamber (23a) and a second gas chamber (23b) by a partition plate (29). The gas is supplied into the first air chamber (23b) so that rising gas currents of a velocity necessary for fluidizing coarse particles contained in the particulate material red into the vessel are blown from the first air chamber (23a) through the dispersion plate (21) into the fluidized-bed chamber. The gas is supplied into the second air chamber(23b) so that rising gas currents of a velocity lower than the velocity of the rising gas currents blown from the first air chamber (23a) into the fluidized-bed chamber (22) are blown into the fluidized-bed chamber so that coarse particles contained in the particulate material are not fluidized and does not flow together with fine particles into a fine particle discharge chute (28). <IMAGE></p>
