| 摘要 |
In the process for the production of liquid pig iron 943) or liquid steel pre-products from charging substances comprising iron ore (5) and fluxes and at least partially containing a portion of fines, the iron ore is directly reduced to sponge iron in at least two reduction stages (1, 2) by the fluidized bed method, the sponge iron is melted in a melt-down gasifying zone (39) under the supply of carbon carriers and an oxygen-containing gas, and a CO- and H2-containing reducing gas is produced which is injected into reduction zones of the reduction stages (1, 2), is reacted there, is withdrawn as a top gas and optionally is supplied to a consumer. To achieve uniform reduction of the iron ore at optimum exploitation of the reducing gas, the iron ore (5) in a first reduction stage (1) by aid of the reducing gas is fractionated into at least two fractions having different grain size distributions each, each fraction is reduced by the reducing gas in a separate fluidized bed (6, 15), wherein the reducing gas maintains a first fluidized bed (6) containing the coarse-grain fraction and separates the fine-grain fraction from the same, and wherein, further, reducing gas is additionally introduced into the further fluidized bed (15) directly reduced iron ore (5) is discharged both from the first and from the further fluidized bed (6, 15) and the fine- and the coarse-grain fraction reduced in the first reduction stage (1) are further reduced in at least one further reduction stage (2) operating in the same manner as the first reduction stage (1) and from the last reduction stage (2) the fine-grain fraction is introduced into the melt-down gasifying zone (39) while being agglomerated by provision of oxygen, and the coarse-grain fraction is fed directly into the melt-down gasifying zone (39) gravitationally (FIG. 1).
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