| 摘要 |
A process for direct reduction of iron oxide in a shaft furnace. The furnace has a pre-reduction zone near its uppermost portion, a metallization zone below the pre-reduction zone, an intermediate zone which separates the pre-reduction zone from the metallization zone and which includes a restriction to inhibit rich fuel gas from passing from the pre-reduction zone to the metallization zone, and a cooling zone below the metallization zone at the lowest portion of the furnace. The process includes feeding iron oxide to the furnace, passing the iron oxide successively downwardly through the pre-reduction zone, the transition zone, the metallization zone, and the cooling zone while passing rich fuel gas produced by external partial combustion with a sub-stoichiometric volume of air upwardly through the pre-reduction zone in counter-current flow so as to partially reduce the iron oxide, and passing reducing gas downwardly through the metallization zone in co-current flow so as to substantially complete the reduction of the iron oxide to metallic iron. The reducing gas is first pre-heated in a gas heater and then subjected to partial combustion with oxygen to further increase its temperature. The process includes removing a metallized iron product from the cooling zone. |
| 主权项 |
1. A process for effecting direct reduction of iron oxide in a shaft furnace having a pre-reduction zone near its uppermost portion, a metallization zone below the pre-reduction zone, an intermediate zone which separates the pre-reduction zone from the metallization zone and which includes a restriction to inhibit rich fuel gas from passing from the pre-reduction zone to the metallization zone, and a cooling zone below the metallization zone at the lowest portion of the shaft furnace, the process comprising feeding an iron oxide burden to the shaft furnace, passing the iron oxide burden successively downwardly through the pre-reduction zone, the intermediate zone, the metallization zone, and the cooling zone of the shaft furnace while passing rich fuel gas produced by external partial combustion with a sub-stoichiometric volume of air upwardly through the pre-reduction zone in counter-current flow so as to partially reduce the iron oxide burden, and passing reducing gas downwardly through the metallization zone in co-current flow so as to substantially complete the reduction of the iron oxide burden to metallic iron, the reducing gas having first been preheated in a gas heater and then subjected to partial combustion with oxygen to further increase its temperature, and removing metallic iron from the cooling zone.
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