Oxygen-enriched blast furnace blow-in method

Abstract

The blowing-in method comprises the following steps: filling furnace charge after the furnace is dried, blowing and heating nitrogen at a tuyere for preheating, then feeding hot coal gas and oxygen at the tuyere, controlling the theoretical combustion temperature at 2350-2400 DEG C, and tapping when the theoretical iron amount in a hearth reaches 60% of the normal safe iron capacity; then, the in-furnace load is gradually increased, the in-furnace reduction gas amount and oxygen amount are increased, normal tapping and in-furnace load adjustment are organized, and the theoretical combustion temperature in the stage is 2400-2500 DEG C; according to the invention, heated nitrogen is used for purging materials, quickly and effectively drying and increasing the temperature of the materials, a blast furnace gas system is inerted, heated reducing gas and high-temperature and high-reducibility gas are injected into a tuyere, enter the furnace, immediately undergo a reduction reaction with upper furnace charge, and are combusted with injected oxygen to release a large amount of heat, so that the temperature of a hearth can be quickly increased; blow-in time is shortened, and raw fuel consumption is effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of blast furnace ironmaking, and in particular relates to a blast furnace opening method for oxygen-enriched gas injection. Background technique [0002] In the opening of a traditional blast furnace, sinter, pellets, coke and solvent are formed into the charge in a certain proportion. The charge is added to the furnace from the top of the furnace, and hot air is blown into the blast furnace tuyere. Heat transfer occurs when the charge moves in contact with the hot air in the blast furnace. It reacts with redox to generate gas, which moves upward from the riser and leaves the blast furnace. During the reaction, the blast furnace material melts and drops into molten iron and slag, and the liquid slag iron is discharged from the blast furnace from the iron hole. In the process of traditional blast furnace opening, there are difficulties in the initial hearth heat storage process, low gas calorific value, large...

AI Technical Summary

Problems solved by technology

During the start-up process of the traditional blast furnace, there are difficulties in the initial hearth heat storage process, low calorific value of gas, large fluctuations in gas utilization rate, and insufficient indirect reduction process. Blast furnace workers usually The furnace is started by increasing the amount of coke and using ultra-light load starting materials. This method consumes a lot of fuel and has a long reaction cycle. The furnace hearth usually needs to experience extremely cold and extremely hot processes. The operation in front of the furnace is difficult and risky.

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