Method for supplying oxygen to blast furnace oxygen-enriched coal spray

Abstract

The invention discloses a method for supplying oxygen to blast furnace oxygen-enriched coal spray. The method comprises the following steps of: a) supplying oxygen, namely supplying high-pressure oxygen of which the pressure is between 0.3 MPa to 0.6 MPa; and b) injecting the oxygen, namely dividing the high-pressure oxygen into two parts, injecting one part of the high-pressure oxygen into a cold air pipeline of a hot blast furnace from an air blower in front of the hot blast furnace, and injecting the other part of the high-pressure oxygen into a blast furnace from an oxygen-coal gun at a tuyere of the blast furnace. According to the method for supplying oxygen to the blast furnace oxygen-enriched coal spray, in order to ensure a high coal spray ratio of 200 to 300kg / t, an oxygen enrichment mode of injecting the high-pressure oxygen into the hot blast furnace from the air blower in front of the hot blast furnace and injecting the high-pressure oxygen into the blast furnace from the tuyere of the blast furnace is adopted, so that the coke consumption of the blast furnace is reduced and the iron-making cost is reduced under the condition that an oxygen supply system is safe and stable.

Description

technical field [0001] The invention relates to an oxygen adding method in the technical field of ironmaking, in particular to an oxygen supply method for blast furnace oxygen-enriched coal injection in the blast furnace oxygen-enriched injection technology. Background technique [0002] In recent years, the shortage of coking coal resources, large investment in new coke ovens, environmental pollution, and rising coke prices have led to the rapid development of blast furnace coal injection technology. Blast furnace coal injection is good for saving coke, but with the usual ironmaking process, the amount of coal injection is limited. Due to the large injection of coal, the theoretical temperature in the tuyere swirl area of ​​the blast furnace will drop too much, which will cause the deterioration of the blast furnace condition. Correspondingly, the coal injection replacement ratio decreases, which is not conducive to blast furnace smelting. Therefore, the increase in the amo...

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Problems solved by technology

Among them, adding oxygen before the blower in front of the hot blast stove, although low-pressure oxygen can be used, can save energy, but due to the large diameter of the low-pressure oxygen delivery pipeline, this requires a relatively short distance between the oxygen generator and the blower. The long distance not only increases the investment in oxygen pipelines, but also limits the transmission capacity; in addition, the current coal injection ratio of blast furnaces at home and abroad is basically 100-200kg / t, and the corresponding reasonable oxygen enrichment rate is about 2-5%. To further increase the coal injection ratio (for example, to 300kg / t), the oxygen enrichment rate should be increased accordingly. If all the oxygen passes through the hot blast stove, and there are leakage points in the valves and hot blast pipes of the hot blast stove system, the high oxygen-enriched hot air will easily blow the leak point The equipment burns through, and the hot air duct of the hot blast stove system has potential safety hazards

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