| 摘要 |
A carbothermic process and apparatus for converting iron ore directly to sponge iron in a vertical retort is described. A reaction charge of iron ore, reducing agent, and additives if employed is charged to a vertical retort having in reciprocal cooperation and coordination as a first stage a pre-heating operation wherein the reaction mixture descends in the retort at a constant speed, the heating being by combustion gases of the retort stack; as a second stage a progressive heating operation utilizing burners to initiate reduction of the reaction mixture, the speed of descent of the mixture becoming progressively slower followed by, as a third stage, a heating operation wherein the temperature is maintained constant with the use of burners to complete the reduction of the reaction mixture, the speed of descent of the mixture becoming progressively slower, and wherein the maximum temperature is kept substantially constant in at least a part of the second stage and in the third stage, and wherein the withdrawal of the sponge iron is controlled to control the speed of descent in the various stages. The process and apparatus provides sponge iron of high grade at a reasonable cost and in reasonable operating times.
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