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用木炭还原沸腾钢铁鳞,可获得含铁>98.5%,适合于粉末冶金用的优质铁粉.在1000℃左右的还原过程中,在金属铁出现之前,在数分钟内Fe_2O_3和Fe_3O_4几乎都已全部还原成浮士体,但后者还原成金属铁的阶段,则须经历数十分钟之久,因此后一阶段便成为还原过程中控制的一步.在浮士体还原成金属铁的阶段,所生成的多孔性金属铁并不阻碍气相的扩散;还原的速率由浮士休-金属铁相界面的表面反应所控制,而表面反应的速率则受CO的生长速率所限制。浮士体表面的金属铁层成长所需的激活能约为57000卡/克分于,与用固体碳发生CO的反应所需的激活能相同。实验的结果更指出,不同温度下浮士体还原速率个同的原因,是由温度对CO发生速率的影响所引起。
With the reduction of boiled steel scale with charcoal, we can get the high-quality iron powder containing 98% of iron, which is suitable for powder metallurgy.In the reduction process of about 1000 ℃, Fe 2 O 3 and Fe 3 O 4 are almost all within a few minutes before the metal iron appears All of which are reduced to the form of a flotation body but the latter is reduced to the metallic iron phase, which takes tens of minutes, so that the latter stage becomes a control step in the reduction process.In the stage of reduction of the fusilli into metallic iron, The resulting porous metallic iron does not impede the diffusion of the gas phase; the rate of reduction is controlled by the surface reaction at the Faustian-metallic interface, whereas the rate of surface reaction is limited by the growth rate of CO. The activation energy required for the growth of the metal iron layer on the surface of the float body is about 57,000 cal / g min., Which is the same as that required for the reaction of CO with carbon on solid carbon. The results of the experiment also point out that the reason why the reduction rates of the floating bodies are the same at different temperatures is caused by the effect of temperature on the rate of occurrence of CO.