Energy recovery system for preparing sponge iron by gasification of high-pressure pulverized coal and method thereof

Abstract

The invention provides an energy recovery method for preparing sponge iron by gasification of high-pressure pulverized coal and a system thereof. In the energy recovery method for preparing sponge iron through a coal-based shaft furnace process and the system thereof, oxygen, pulverized coal and water vapor are sent into a high-pressure pulverized coal gasification furnace for completing high-temperature pure oxygen gasification to generate synthesis gas with CO and H2 in a relatively high ratio; the synthesis gas is successively cooled to a specific temperature through a two-stage heat recovery plant after radiant cooling, and sulfur and nitrogen are removed from the synthesis gas through a dust remover and a gas purifier; the purified high-pressure low-temperature synthesis gas absorbs the sensible heat of coal gas through a secondary heat recovery plant and then is heated to a specific temperature and mixed with treated and recovered shaft furnace coal gas in a combustion chamber; the heated coal gas enters the shaft furnace and is reacted with sent-into iron ore to generate the sponge iron and the shaft furnace coal gas. The invention has the advantages that the gasification efficiency of coal is high, the invention is suitable for coal types of different tenors, and the invention greatly improves the recovery rate of the shaft furnace coal gas, simplifies the system for utilization of the shaft furnace coal gas, and synchronously realizes zero emission of sponge iron manufacture.

Description

technical field [0001] The invention relates to an energy recovery system and method for producing sponge iron by high-pressure pulverized coal gasification, which is used for improving the energy utilization efficiency of producing sponge iron by a coal-based shaft furnace method, and belongs to the technical field of iron and steel smelting equipment and methods. Background technique [0002] Although blast furnace ironmaking is the mainstream of ironmaking production at present, blast furnace production relies on coking coal. Blast furnace, coke oven and sintering will pollute the environment, and this production method will bring CO 2 Greenhouse gas emissions, these issues must be improved with the urgent requirements of sustainable development. [0003] At present, the output of sponge iron and sponge iron hot briquetting (collectively referred to as sponge iron) in the world is close to 60 million t / a. Sponge iron is a raw material used in electric furnace steelmaking...

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Problems solved by technology

[0010] In view of the defects or deficiencies in the above-mentioned background technology, the object of the present invention is to provide an improved high-pressure pulverized coal gasification shaft furnace method for producing sponge iron energy recovery system and method, which can not only overcome the disadvantages of natural gas production in the gas-based method Limitations, low heating efficiency of reducing gas, low heating tube life and low reduction efficiency of fine ore, etc., and can also solve the problems of low equipment efficiency, immature equipment, poor environmental performance and high coal quality requirements in the coal-based method

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