System and technology for environmentally-friendly comprehensive treatment of iron making blast furnace gas

Abstract

The invention provides a system and a technology for environmentally-friendly comprehensive treatment of iron making blast furnace gas. The system comprises a blast furnace top uniform pressure gas full-recovery system, a gravity deduster and a dry bag filter, and further comprises a blast furnace gas hydrolysis tower and a blast furnace gas desulfurization tower. The blast furnace gas goes through the gravity deduster and the dry bag filter, and then is conveyed into the blast furnace gas hydrolysis tower, COS in the blast furnace gas is hydrolyzed by the blast furnace gas hydrolysis tower toform H2S; the treated blast furnace gas goes through a TRT / or pressure regulating valve group, and then is conveyed into the blast furnace gas desulfurization tower, and the blast furnace gas desulfurization tower desulfurizes and dechlorinates H2S and Cl<-> in the blast furnace gas; and the treated blast furnace gas is conveyed into a blast furnace gas user or is stored in a gas cabinet througha gas pipe network. The integral treatment technology which integrates blast furnace gas desulfurization, dechlorination and blast furnace top uniform pressure gas recovery has a high integration degree, and can run stably and reliably.

Description

technical field [0001] The invention relates to an environmental protection comprehensive treatment system and process for ironmaking blast furnace gas. The blast furnace gas environmental protection comprehensive treatment system and process can effectively remove sulfur and chlorine in the blast furnace gas, so that the flue gas discharged from the blast furnace gas after combustion can meet the national environmental protection requirements. . Background technique [0002] Blast furnace gas is a by-product combustible gas in the blast furnace ironmaking process. It has a large output and is widely used. It can be used as fuel for boilers in power plants, hot blast stoves in ironworks, and heating furnaces in steelworks. The main components of blast furnace gas are CO, CO 2 , N 2 , also contains a small amount of COS, H 2 S, Cl - , dust, etc. [0003] At present, there are two main treatment methods for blast furnace gas produced in ironworks. Most of them are used as...

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Problems solved by technology

[0006] Since there is no blast furnace gas desulfurization device in operation in China at present, the existing blast furnace gas treatment system only processes dust in blast furnace gas without desulfurization treatment, resulting in subsequent blast furnace gas users (power plant boilers, ironworks SO in flue gas discharged from hot blast furnace and heating furnace in steelmaking plant) 2 Content, Cl - None of the content can meet the national ultra-clean emission requirements, usually the SO in the flue gas emitted 2 Content greater than 50mg / m 3 , SO in the flue gas emitted by some production plants 2 The content is even as high as 250mg / m 3 above!

[0007] In order to meet the national environmental protection requirements, various blast furnace gas users (such as power plants, ironworks, and steel rolling mills) have added gas desulfurization equipment. However, the current gas desulfurization equipment mainly removes sulfur in blast furnace gas, that is, H 2 S, the sulfur in blast furnace gas is mainly COS. Therefore, for blast furnace gas, even if the gas desulfurization equipment is added, COS in blast furnace gas cannot be removed, and SO in the flue gas emission 2 The content still cannot meet the national environmental protection requirements

[0008] In addition, with the popularization of blast furnace gas dry dedusting, most domestic iron and steel enterprises adopt dry dedusting for blast furnace gas, and the chloride ions in the dry dedusted blast furnace gas exceed the standard, resulting in serious corrosion of the gas pipe network, generally without dechlorination treatment The gas pipelines of iron and steel enterprises are generally used for about 3 years, and there are different degrees of corrosion and perforation. Generally, the pipelines need to be replaced after about 6 years, which brings great safety hazards to the safe production of enterprises.

Since blast furnace gas pipelines generally have no spare pipelines or cut-off valves in the factory mains, replacing the mains often requires the company to stop production for replacement, seriously affecting the normal production of iron and steel companies, causing huge safety hazards, and replacing the pipelines also greatly increases the production cost of the company

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