| 摘要 |
<p>The present invention proposes a method for producing direct reduced iron in a vertical reactor (12) having an upper reducing zone (16) and a lower cooling zone (18), the method comprising the steps of: feeding iron oxide feed material (20) to an upper portion (22) of the vertical reactor (12), the iron oxide feed material (20) forming a burden flowing by gravity to a material outlet portion in a lower portion (24) of the vertical reactor (12); feeding hot reducing gas to a lower portion (26) of the reducing zone (16) of the vertical reactor (12), the hot reducing gas flowing in a counter flow to the burden towards a gas outlet port in the upper portion (22) of the vertical reactor (12); recovering direct reduced iron (27) at the lower portion (24) of the vertical reactor (12); recovering top gas at the upper portion (22) of the vertical reactor (12); submitting at least a portion of the recovered top gas to a recycling process; and feeding the recycled top gas back into the vertical reactor (12). According to an important aspect of the invention, the recycling process comprises heating the recovered top gas in a preheating unit before feeding it to a reformer unit (36); feeding volatile carbon containing material (38) to the reformer unit (36) and allowing the volatile carbon containing material (38) to devolatise and to react with the recovered top gas; feeding desulfurizing agent (40, 42) into the recovered top gas in or upstream of the reformer unit (36); heating the reformer unit (36); and feeding the reformed top gas recovered from the reformer unit (36) through a particle separation device (46)for removal of sulfur containing material (45).</p> |
