Process for refining molten iron by directly using low-grade iron ores

Abstract

The invention provides a process for refining molten iron by directly using low-grade iron ores. The process comprises the following steps that: 1, low-grade iron ores are magnetically roasted in a fluidized bed reactor to obtain iron ores with stronger magnetism; 2, the fine ores obtained after roasting enter a hot magnetic separator to obtain hot iron ores with higher grade by hot magnetic separation; 3, the high-quality hot iron ores, which are obtained by magnetic separation, are added into a pre-reduction multi-stage fluidized bed to obtain pre-reduction iron ores with a higher reductiondegree, wherein the pre-reduction multi-stage fluidized bed is combined by a 2 to 4-stages circulating fluidize bed and a bubbling fluidized bed reactor, and after being reduced by the pre-reduction multi-stage fluidized bed, the metallization rate of the fine ores is over 60 percent; and 4, the pre-reduced iron ores are directly injected in a final reduction furnace or fusion gasification furnaceby a hot-pressed block for final reduction refining so as to obtain the molten iron. In the process, the refining process of the low-grade iron ores is completed by fully using energy in the technological process and the low-grade iron ores avoids repeated heating and cooling when being refined into the molten iron, so the energy consumption is greatly reduced.

Description

technical field [0001] The invention relates to a smelting reduction ironmaking process in the field of ironmaking, in particular to a process and a device for directly using low-grade iron ore to smelt molten iron. Background technique [0002] The blast furnace ironmaking process is currently the main ironmaking process, but the overall process of the blast furnace ironmaking process is long, the pollution is serious, and the dependence on coking coal is the bottleneck that the process itself cannot break through. The smelting reduction ironmaking process is expected to overcome the limitations of the blast furnace ironmaking process , in the case of increasingly scarce resources and increasing pressure on environmental protection, the smelting reduction ironmaking process has increasingly highlighted its importance. Moreover, blast furnace ironmaking requires the use of high-grade iron ore resources. With the increasing depletion of rich ore resources, the ironmaking proc...

AI Technical Summary

Problems solved by technology

However, the current process of using lean iron ore to smelt molten iron is magnetization roasting→magnetic separation→sintering or pelletizing→blast furnace smelting. High consumption, serious pollution

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