| 摘要 |
A blast furnace where coke Is combusted with oxygen, Instead of air, and where a top gas comprising CO, CO2, H2, and without excess nitrogen is withdrawn from the upper part of the blast furnace, cleaned of dust, the H2/CO volume ratio adjusted to between 1.5 to 4.0 in a water shift reactor, water and CO2 are removed (increasing its reduction potential), heated to a temperature above 850°C, and fed back to the blast furnace above where iron starts melting (thereby Increasing the amount of metallic iron reaching the dead-man zone and decreasing the amount of coke used for reduction). Also carbon deposit problems caused by heating the CO-containing recycled gas are minimized by on-line cleaning of the heater tubes with steam without significantly affecting the reduction potential of the recycled reducing gas. |
