PURPOSE: To facilitate the handling of oil-mixed coal, to avoid an instability attending upon pheumatic conveyance and to provide complete combustion by enabling the oil-mixed coal to be conveyed as it is in the state of a slurry to a burner.

CONSTITUTION: Oil-mixed coal fed from a fuel feed pipe 2 is injected from an injection port 12 into a space formed by a deoiling cup 1 and a separation feeder 8 rotating at high speed. The oil-mixed coal injected into the deoiling cup 1 is imparted with a centrifugal force due to the rotation of the cup 1, so that a coal layer and an oil layer are formed on the inside wall surface of the cup 1. In this case, due to the difference in the specific gravity between the coal and oil, the oil layer is formed directly on the inside wall surface of the cup 1 and the coal layer is formed on the oil layer. The coal layer (deoiled coal) is gradually moved toward a nozzle 7 by the difference in the revolution rate between the feeder 8 and the cup 1, diffused and sprayed from the nozzle 7 into a combustion chamber, and burnt by the primary air and secondary air which are fed from a primary-air passage 17 and from the outside of a burner casing 3, respectively.