To produce molten pig iron at a low coke ratio in a specified vertical melting furnace.
When ferrous scrap, iron-containing dust/iron-containing sludge agglomerate, and coke are charged from a furnace top and air is blasted from a main tuyere and an upper tuyere, air is blasted from the main tuyere and the upper tuyere, so that the position Lu/H of the upper tuyere, the blast volume ratio Vu/(Vm+Vu) at the upper tuyere, and the flow velocity Vc at the furnace center position of the blast at the upper tuyere satisfy any one of the conditions (1): Lu/H=0.25 to 0.80, Vu/(Vm+Vu)=0.21 to 0.37, Vc=10 to 25, (2): Lu/H=0.35 to 0.70, Vu/(Vm+Vu)=0.15 to 0.43, Vc=10-25, and (3): Lu/H=0.35-0.70, Vu/(Vm+Vu)=0.21 to 0.37, Vc=8 to 25, where Lu: the distance in the furnace height direction from the main tuyere to the upper tuyere, H: the distance in the furnace height direction from the main tuyere to the stock line, Vm: blast volume at the main tuyere, Vu: blast volume at the upper tuyere.
ISHIWATARI NATSUO
MURAI RYOTA
SAWA YOSHITAKA
| JPH07278635A | 1995-10-24 | |||
| JPH10237518A | 1998-09-08 | |||
| JP2008150668A | 2008-07-03 |