Method for treating combustible material and installation

A method for treating combustible material, comprising:

• providing a pipe which is opened to a molten substance surface above the molten substance surface of molten substance stored in a furnace body for smelting nonferrous metals, wherein the pipe is a double cylinder structure containing a mixing region from the end opening of the inner cylinder in the outer cylinder to the end opening of the outer cylinder;
• blowing combustible material containing valuable metals and oxygen-enriched air onto the molten substance surface from the pipe thereby immersing the combustible material in the molten substance, and burning and melting the combustible material while stirring the combustible material in the molten substance;
• and
• treating the molten substance in a post-process, and recovering the valuable metals with the smelting nonferrous metals, wherein
• supplying the oxygen-enriched air through a space between the inner cylinder and the outer cylinder,
• the pipe and an opening for discharging flue gas generated in the furnace body are provided on a ceiling wall of the furnace body,
• the opening is provided on the ceiling wall at a different position from the position of the pipe, and is connected to a waste heat boiler,
• a molten substance discharge port for discharging the molten substance from the furnace body is provided on a side wall of the furnace body, and
• the molten substance discharge port is provided on the side wall at a position opposite from the opening interposed therebetween the pipe.