Method and device for producing direct reduced iron by using gas-based reduction shaft furnace

Abstract

The invention discloses a method and device for producing direct reduced iron by using a gas-based reduction shaft furnace. Coal reducing gas and coke oven gas are mixed and supplied to a shaft furnace so as to produce direct reduced iron. The method comprises the following steps: separating the coke oven gas into hydrogen gas and linde gas, mixing the hydrogen gas with the coal reducing gas and using as reducing gas to reduce iron ores, and using the linde gas as cooling gas to cool direct reduced iron. The device for realizing the method comprises a shaft furnace, a coke oven gas source, a coal gasification device, a coke oven gas hydrogen-extracting device and a gas heating device. In the invention, coal gasification devices of different sizes can be flexibly used with a coke oven gas supply device, thereby reducing the size of the coal gasification device and effectively using the coke oven gas. Meanwhile, the invention cancels the minor cycle of a cooling section of a common shaft furnace, saves the equipment and investment, and brings the heat of direct reduced iron to a reducing section, thereby saving the heating load of the system reducing gas.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a method and a device for producing direct reduced iron in a gas-based reduction shaft furnace. Background technique [0002] Direct reduced iron is directly reduced to iron by iron ore under solid condition. It has many advantages such as stable composition, low harmful impurities and uniform particle size. , powder metallurgy and other processes of iron-containing raw materials. [0003] At present, more than 75% of the world's direct reduced iron is produced by the gas-based shaft furnace method, and its typical processes include the MIDREX method and the HYL / Energiron method. Although the hot-charging and hot-delivery technology of direct reduced iron has been developed in recent years, it is only applicable to comprehensive iron and steel enterprises whose direct reduced iron plant is very close to the electric furnace plant, and the direct re...

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Problems solved by technology

[0005] The existing technology generally uses coal-based reducing gas alone to produce direct reduced iron, or uses coke oven gas alone to produce direct reduced iron, or uses other gases as reducing gases. Therefore, coal gasification equipment is large in scale and high in energy consumption, which cannot be flexibly adapted Energy equipment for steel plants

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