Treatment method of oxygen reduction and stopping of blast furnace in heavy-load and high oxygen enriched smelting

Abstract

The invention discloses a treatment method of oxygen reduction and stopping of a blast furnace in heavy-load and high oxygen enriched smelting. The method is a blast furnace operation method mainly applied to heavy-load (coke load ranging from 5.30 to 5.95), high oxygen-enriched (oxygen enriching rate ranging from 5.0% to 6.0%), high coal ratio (coal ratio ranging from 155 kg / t to 205 kg / t) smelting condition after high oxygen reduction (oxygen enriching rate is decreased by more than 50%). The method mainly comprises the following steps: controlling blast humidity, blast temperature and blastquantity of a blast furnace in case of high oxygen reduction during smelting under a high oxygen enriching condition; controlling coke load and smelting intensity; controlling the coal injecting quantity of the blast furnace; controlling the furnace temperature and the gas flow distribution in the furnace. With the adoption of the operation method, the influence of high oxygen reduction on blastfurnace smelting can be effectively reduced; the blast furnace output loss can be decreased, and the influence of the furnace condition fluctuation on the service life of a blast furnace body device can be reduced.

Description

technical field [0001] The present application relates to the technical field of blast furnace smelting, in particular to a treatment method for reducing and stopping oxygen under heavy-duty high-oxygen smelting in a blast furnace. Background technique [0002] High oxygen-enriched smelting is one of the most important characteristics of today's modern large-scale blast furnace smelting, which to a certain extent represents the characteristics of enhanced smelting level and technological progress. With the development of large-scale domestic blast furnaces, blast furnace high oxygen-enriched smelting technology has been greatly developed. ) normalized production. [0003] However, if a large oxygen reduction occurs under this high-level smelting state, it will have a great impact on the blast furnace smelting system, which is mainly reflected in: [0004] 1) Affect the hearth temperature. A high oxygen enrichment rate is conducive to increasing the theoretical combustion ...

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Problems solved by technology

[0005] 2) Oxygen-enriched blast will increase the content of CO and H2 in the gas

When the oxygen enrichment is reduced or stopped, the air volume consumed by the production unit iron volume increases, resulting in an increase in the bosh gas volume, which affects the pressure-volume relationship in the furnace. If it is not handled properly, it will cause fluctuations in furnace conditions

[0006] 3) Reduce or stop oxygen enrichment, resulting in a decrease in the oxygen content in the blast, which will affect the fuel rate of the blast furnace pulverized coal, resulting in a decrease in the blast furnace coal ratio, and affect the smelting strength of the blast furnace

[0007] At present, there is no written operation specification and standard for large-scale blast furnace heavy-duty high-oxygen-enriched smelting to greatly reduce oxygen. If the blast furnace does not respond well, it will often cause unstable gas flow and abnormal furnace conditions, which will greatly affect pig iron production, quality and other major items. Indicators, the main economic indicators of the blast furnace have regressed sharply, seriously threatening the normal production of the blast furnace

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