Abstract: A method of combusting a coal-water mixture fuel. The mixture is atomized into a conically-shaped primary pre-combustion chamber. Primary air is supplied, at a rate smaller than that required for complete burning of the mixture and in the form of a swirl about the axis of the jet of the atomized mixture, from the peripheral portion of the primary pre-combustion chamber into a secondary pre-combustion chamber connected to said primary pre-combustion chamber, thus forming a region of low pressure around the jet of the mixture. The region of low pressure serves to induce the atmosphere gas from the secondary pre-combustion chamber of higher temperature back into the primary pre-combustion chamber of a lower temperature, so that the water content of the mixture is evaporated and the mixture is ignited by the heat of the hot atmosphere gas.