PURPOSE: To reduce the generation of flue cinder by specifying the size of the straight-pipe passage of a concentrate burner and supplying a specified amt. of the material to be refined while blowing in reaction air.
CONSTITUTION: The average radius of the cross section of a straight-pipe passage 17 formed between the outer surface of an oxygen blowing pipe 16 and its inner surface at the lower end of a concentrate chute 14 is controlled to ≤60mm in the concentrate burner 4, and the width of the passage 17 in its radial direction is adjusted to ≥20mm. The reaction air 3 supplied into the main body of the burner 4 is passed through a venturi part 18 and blown into a reaction tower, and the material 2 to be refined is supplied into the reaction tower with the amt. at the passage 14 of the chute 14 controlled to 2.3-5kg/cm2/ min. When the radius of the cross section of the passage 17 exceeds 60mm, the material 2 is not collected at the center at the outlet of the burner, and the generation of flue cinder is not reduced. The passage 17 is likely to be clogged when the width of the passage 17 is less than 20mm.
NAGAI KATSUHIKO
KONDO YASUHIRO
