Sintering energy-saving technique and system capable of removing multiple pollutants

Abstract

The invention discloses a sintering energy-saving technique capable of removing multiple pollutants. Flue gas discharged by a sintering wind box on the lower part of a sintering machine is sequentially divided into section A flue gas positioned at the head of the sintering machine, section B flue gas positioned in the middle of the sintering machine, and section C flue gas positioned at the tail of the sintering machine; the section A flue gas is discharged after being subjected to dust removal treatment; and the section C flue gas is used for preheating the section B flue gas, the preheated section B flue gas is denitrified and divided into two parts, one part is discharged after being subjected to desulfurization treatment, and the other part is sent into the sintering machine together with the section C flue gas to perform circulating sintering. The invention also discloses a sintering energy-saving system capable of removing multiple pollutants. The technique and system can treat dust, oxynitrides, sulfur dioxide, fluorides, heavy metals and many other pollutants in the sintering flue gas, can utilize the excess heat of the flue gas of the main flue of the sintering machine and the flue gas discharged by the cooling machine, and can lower the energy consumption of the sintering plant, thereby implementing energy saving and emission reduction.

Description

technical field [0001] The invention relates to the treatment of sintering flue gas pollutants and waste heat utilization in the iron and steel smelting industry, in particular to a process and system for sintering energy saving and removal of various pollutants. Background technique [0002] Iron ore sintering is an important process in steel plants. The sintered ore produced has high iron grade and less harmful impurities, which can reduce the coke ratio. After crushing and screening, the sintered ore has uniform particle size and high mechanical strength. However, the sintering process is the main source of pollutant emissions in iron and steel plants. The main pollutants include dust, sulfur dioxide, nitrogen oxides, fluorides, and dioxins. Oxygens account for most of the country's annual emissions, and the amount of flue gas in the iron ore sintering process is large, producing 4000-6000m3 per ton of sintered ore 3 Flue gas, so the total amount of pollutants discharged...

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Problems solved by technology

[0006] The low-energy sintering flue gas nitrogen oxide emission reduction system and method provided by the patent document with the publication number CN101829481A, uses a part of the flue gas with a high concentration of nitrogen oxides in the middle section of the sintering bellows for denitrification treatment, and part of it is used for cyclic sintering. However, this patent does not deal with other pollutants such as sulfur dioxide, and also fails to make good use of the waste heat of the flue gas from the sintering head;

[0007] And, the invention patent with publication number CN101376921A proposes a process for reducing sulfur dioxide emission in sintering flue gas. This method is to divide the sintering area into high SO2 area and areas other than high SO2 area, and treat them separately, which can be very good Treatment of sulfur dioxide, but the starting point of this patent is for sulfur dioxide, and it cannot handle pollutants such as nitrogen oxides and dioxins well. At the same time, this method divides the sintering area based on the data of the sintering cup test, which is not very appropriate. Divide pollutant concentration areas

[0008] It can be seen that the current technology in my country's sintering pollutant control and waste heat utilization is not mature enough, and further research and development are needed.

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