PURPOSE: To reduce equipment cost by classifying powdered coal pulverized and classified to a prescribed particle size into coarse powder and fine powder with a specific classifier, then respectively storing the powders in storage bins and feeding the fine powder to a burner for a kiln and the coarse powder to a calcining burner.

CONSTITUTION: Coal 29 is fed from a coal hopper 27 into a fine pulverizing mill 30, pulverized and passed through a classifier 33 provided in a mill 30 to afford powdered coal 31, which is then fed to a classifier 34 installed independently of the mill 30 with a carrier gas 32 to separate coarse powder 10. The separated coarse powder 10 is then stored in a coarse powder storage bin 11. On the other hand, the classified fine powder 12 is separated with a dust collector 35 and stored in a fine powder storage bin 13 and the residual gas is then discharged from a chimney 26. The coarse powder 10 is subsequently passed through a weighing feeder 14 and a gas powder mixer 17 by introduction of carrier air 16 from a blower 15 to a calcining burner 18. The fine powder 12 is then fed through a weighing feeder 19 and a gas powder mixer 22 by introduction of carrier air 21 from a blower 20 to a burner 23 for a kiln.