| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for improving both of the dephosphorization efficiency and the iron yield by supplying a solid oxygen source with a carrier gas.SOLUTION: In the dephosphorization treatment of molten pig iron using reaction vessels 1A and 1B of upper bottom blowing converter type, in parallel with supply of a dephosphorization agent mainly composed of CaO, a gas oxygen source is supplied from one supply system, and a solid oxygen source is supplied from another supply system, using a carrer gas having a discharge rate of 50 Nm/s or more at the outlet. In blowing the solid oxygen source, the blowing height is set to 1 to 3.3 m; the blowing position Hsatisfies: 1/6D≤H*tan (&thetas;)≤1/2D; and the blowing rate Fsatisfies: 0<F*C/100/&egr;≤0.40. Herein, &thetas; (°) represents the discharge angle of nozzle for blowing solid oxygen source; D (m) represents the diameter of vessel; F(kg/min/t) represents the blowing rate of solid oxygen source; C(mass%) represents the O concentration in solid oxygen source, and &egr;(kW/t) represents the agitation power density of bottom blowing gas. |
