Abstract: An apparatus for fusing small articles of nonferrous metal comprises an molten metal chamber, for forming and containing molten metal, having burners for fusing a raw material such as ingot etc., and a fusing chamber disposed adjacent to the molten metal chamber for fusing small particles of the nonferrous metal. The molten metal discharged from the molten metal chamber is circulated through a swirl generation chamber and a suction passage and is introduced into a pump and discharged into to the molten metal chamber. The small particles of nonferrous metal are introduced into the upper side of a swirl generation chamber, in which a swirl stream is generated, mixed with the molten metal while dispersed in the molten metal and delivered to the molten metal chamber.

Abstract: A heat-treatment furnace for thermally treating materials such as iron or steel products therein has a plurality of burners selectively actuable in different combinations at successive stages of a predetermined combustion control pattern or one of such patterns. At least one of the selected burners is alternately turned on and off during its operation in each stage. The combustion control pattern may be selected which corresponds to one of a plurality of temperature distribution patterns as sensed by temperature sensors located in the furnace at different positions. With the method of the invention, the furnace can be heated efficiently according to a predetermined optimum combustion pattern without consuming an excess amount of fuel and discharging unwanted exhaust pollutants.