CN105833655A - Method for preparing agglomeration liquid for restraining iron mine sintering flue gas fine particle emissions - Google Patents

Abstract

The invention discloses a preparation method of an agglomeration liquid for suppressing the emission of fine particles of iron ore sintering flue gas, and belongs to the technical field of pollutant emission reduction in the iron ore sintering process. The specific steps of the present invention are: (A) mix 20-40 parts of polyacrylamide, 0-20 parts of polyaluminium chloride, 20-40 parts of sodium carboxymethyl cellulose, and 20-40 parts of polyacrylamide to obtain Mixture A; (B) take 2-5 parts of additives by mass parts, add in mixture A, mix uniformly, obtain composite agglomerating agent; (C) mix the composite agglomerating agent in step (B) with water, and agglomerating agent The mass ratio to water is 1:2000‑10000, and the reunion liquid is prepared. The present invention enables the agglomerated liquid droplets adsorbed with fine particles to nucleate, collide, and grow up under low pressure to form large particle agglomerates, and uses a dust removal device to remove the agglomerated and grown fine particles, thereby inhibiting the discharge of pollutants , providing a new emission reduction approach for the reduction of fine particulate matter in the iron ore sintering process.

Description

A preparation method of agglomeration liquid for suppressing emission of fine particles in iron ore sintering flue gas

technical field

The invention relates to the technical field of pollutant emission reduction in the iron ore sintering process, in particular to a preparation method of an agglomeration liquid for suppressing the emission of fine particles in iron ore sintering flue gas.

Background technique

Inhalable particulate matter refers to the general term for particulate matter that can enter the human respiratory tract through the nose and mouth, represented by PM10 (particles with an aerodynamic diameter of less than 10 microns in the ambient air). PM2.5 refers to particulate matter in the ambient air with an aerodynamic equivalent diameter less than or equal to 2.5 microns. It can be suspended in the air for a long time, and the higher its concentration in the air, the more serious the air pollution. Although PM2.5 is only a small component of the earth's atmospheric composition, it has an important impact on air quality and visibility. Compared with coarser atmospheric particles, PM2.5 has a small particle size, large area, strong activity, and is easy to attach toxic and harmful substances (such as heavy metals, microorganisms, etc.), and has a long residence time in the atmosphere and a long transportation distance. Therefore, it has a greater impact on human health and the quality of the atmospheric environment. Moreover, it can enter the alveoli of the human body and even the blood circulation system, directly causing cardiovascular diseases and other diseases. At present, inhalable particulate matter pollution has become a prominent atmospheric environmental problem, which has attracted great attention from all countries in the world. It is a serious hazard to human health and is also an important factor leading to major environmental problems such as reduced atmospheric visibility, acid deposition, global climate change, and photochemical smog. The air quality standards of the United States, the European Union, and the United Kingdom have successively made clear requirements for PM2.5; PM2.5 average concentration limit.

The iron and steel industry is not only an important pillar industry of the national economy, but also a major energy-consuming and polluting household. At present, the annual output of crude steel in my country has exceeded 800 million tons, which is close to 50% of the global output. According to the "2012 China Environmental Statistical Annual Report", the smoke (powder) dust emission of ferrous metal smelting and rolling processing industry was 1.813 million tons, accounting for 18.9% of the emissions of key surveyed industrial enterprises, ranking third. Source apportionment of PM10 (particles with a particle size ≤ 10 μm) and PM2.5 (particles with a particle size ≤ 2.5 μm) shows that the iron and steel metallurgical industry has become one of the main sources of PM10 and PM2.5 in the atmosphere in my country. The sintering process is an essential link in the modern steel production process, but it is also the largest source of PM10 and PM2.5 emissions in the steel industry, accounting for about 40% of its total emissions ^[1-3] . Since iron ore sintering is a drafting process and the humidity of the flue gas is high, currently the sintering plant mainly uses an electrostatic precipitator to purify the particulate matter in the sintering flue gas. For fine particles with a diameter less than 10 μm, due to their high specific resistance and poor charging capacity, the dust removal efficiency is significantly reduced. After the sintering flue gas is subjected to electrostatic dust removal, more than 90% of the particulate matter in the flue gas is PM10, and more than 80% of the particulate matter is PM2.5 ^[4] .

Sintering flue gas is formed by air passing through the sintering material layer during the draft sintering process and undergoing a series of complex physical and chemical changes. Due to the influence of raw material conditions, mixture ratio, process parameters and other factors, the chemical composition of sintering flue gas is complex and changeable, and flue gas flow rate, temperature and the concentration of various pollutants fluctuate greatly. To sum up, sintering flue gas has the following typical characteristics ^[5-7] :

(1) The air leakage rate in the sintering process can reach 40-50%, resulting in a large amount of flue gas. According to statistics, the production of 1 ton of sinter can produce 4000-6000m ³ of flue gas; and the flue gas amount depends on the raw material composition and process parameters. The difference changes, making the flue gas volume fluctuate greatly;

(2) Flue gas temperature fluctuates in a wide range, which changes with process conditions and fuel ratio, flue gas temperature fluctuates at: 80-160°C;

(3) The moisture content of the flue gas is relatively large, and the moisture content is about 10%. During the sintering and mixing process, it is necessary to add an appropriate amount of water for mixing and granulation, so as to ensure the air permeability of the material layer;

(4) There is a large amount of dust in the flue gas, which contains a large amount of fine particles, and 20-40kg of dust is produced per ton of sinter;

(5) The composition of flue gas is complex, which contains a variety of pollutants, such as: fine particles, SO ₂ , COx, NOx, HCl, HF and dioxins.

It is precisely because of the characteristics of complex composition of sintering flue gas, large flow rate and low concentration of pollutants that although dust removal equipment with high purification efficiency is adopted for sintering flue gas, the removal effect on fine particles is not ideal.

Due to the large specific surface area and strong surface activity, the fine particles in the sintering flue gas can enrich the alkali metals (K, Na), heavy metals (Hg, Pb, Cr, Cu, Cd, As) and organic pollutants (VOCs) generated during the sintering process. , PCDD/Fs) and other toxic and harmful substances ^[8] , which have strong carcinogenic, mutagenic and teratogenic effects, and the aerosols formed by discharging into the atmosphere are important factors that induce smog, acid rain, ozone layer destruction, etc. The pollution problem is directly related to It is related to the living environment and quality of life of the people. It is imminent to realize the emission reduction of fine particles in the sintering process.

After searching, there are already technical solutions for emission reduction of fine particulate matter in flue gas. Such as: the name of the invention: industrial kiln flue gas PM _2.5 dust and heavy metal treatment and removal device ^[9] , (Chinese patent number: ZL201220721358.X, application date: 2012-12-24), by setting the flue gas path filter bag, and the bag is caged inside the filter bag to reduce the emission of PM _2.5 dust in the flue gas; this technology has a better emission reduction effect on large particle pollutants, but the reduction effect of PM _2.5 in the flue gas limited. In addition, the titles of the inventions are: a method for segmental circulation of iron ore sintering flue gas ^[10] (China Patent No.: ZL201310443223.0, application date: 2013-09-26), an energy-saving and emission-reducing method for iron ore sintering method ^[11] (Chinese patent number: ZL201510137762.0, application date: 2015-03-27), etc. These technical solutions can realize the synergistic emission reduction of various pollutants in the sintering flue gas, although they can reduce the Emission of large particles of dust; but the effect of reducing emission of fine particles in sintering flue gas is extremely limited. In addition, compared with other waste gases, sintering flue gas has complex composition and huge flue gas flow rate, so that effective emission reduction technologies suitable for fine particulate matter in sintering flue gas have not yet been developed. There is an urgent need to find a suitable way to reduce emissions to achieve the emission reduction of fine particles in the sintering process.

references:

[1] Lu Yan. Talking about the current situation and prevention measures of my country's iron and steel industry pollution [C]. 2014 Beijing-Tianjin-Hebei Iron and Steel Industry Clean Production Environmental Protection Exchange Conference. 2014, 95-96.

[2] Yan Xianghong. Characteristics and Source Apportionment of Atmospheric Fine Particle Aerosol PM2.5 in Baoshan District, Shanghai [D]. Shanghai: East China University of Science and Technology, 2011, 42-50.

[3]S.JAGATHLAL.Assessing the PM10footprint of an iron and steel plant on ambient air quality:Modelling PM10emissions from the Arcelormittal Vanderbijlpark works iron and steel plant[D].University of the Witwatersrand,Johanesburg,2012,1-5.

[4] Ma Jinghua. Research on Particulate Matter Emission Characteristics of Typical Production Processes of Iron and Steel Enterprises [D]. Southwest University, 2009, 24-28.

[5] Shen Xiaolin, Liu Daoqing, Lin Yu, et al. Development and Application of Baosteel Sintering Flue Gas Desulfurization Technology [J]. Baosteel Technology, 2009(3): 7-11.

[6]Fuzhong W, Wenhao W.Study on Flue Gas Desulfurization ofSintering in Pilot-ScaleExperiment[C]//Computer Distributed Control and Intelligent Environmental Monitoring(CDCIEM),2011International Conference on.IEEE,2011:1737-1741.

[7] Chen Kaihua, Song Cunyi, Zhang Donghui, etc. Comparison of sintering flue gas combined desulfurization and denitrification process [J]. Sintering pellets, 2008, 33(5): 29-32.

[8]C.PENG,Z.C.GUO,F.L.ZHANG.Discovery of potassium chloride in the sintering dust bychemical and physical characterization[J].ISIJ International,2009,48(10):1398-1403.

[9] Liaoning Wanhe Environmental Protection Industry Co., Ltd. Industrial kiln flue gas PM2.5 dust and heavy metal treatment and removal device: China, ZL201220721358.X[P]. 2013-09-11.

[10] Central South University. A method of segmental circulation of iron ore sintering flue gas: China, ZL201310443223.0[P]. 2014-01-08.

[11] General Institute of Iron and Steel Research, Steel Research Shenghua Engineering Technology Co., Ltd. A method for energy saving and emission reduction of iron ore sintering: China, ZL201510137762.0[P]. 2015-07-01.

Contents of the invention

1. The technical problem to be solved by the invention

The purpose of the present invention is to overcome the deficiency in the prior art that the iron ore sintering process is the main emission source of fine particles, and the existing emission reduction methods are difficult to effectively remove the fine particles in the sintering flue gas, and provide a method for suppressing iron ore sintering fume The preparation method of the agglomeration liquid discharged from the gas fine particles, so that the fine particles are agglomerated by the agglomeration liquid, and then the dust is removed by the dust removal equipment, so as to realize the effective removal of the fine particles in the sintering process.

2. Technical solution

In order to achieve the above object, the technical scheme provided by the invention is:

A kind of preparation method of the agglomeration liquid of the present invention suppresses the emission of fine particles of iron ore sintering flue gas, the components such as sodium carboxymethyl cellulose, polyacrylamide and additives are mixed evenly, and the agglomeration agent is prepared, and the agglomeration agent is mixed with water Mix to prepare an agglomeration liquid.

Furthermore, the agglomerating agent including polyaluminum chloride, sodium carboxymethylcellulose, polyacrylamide and additives is uniformly mixed to prepare an agglomerating agent, and the agglomerating agent is mixed with water to prepare an agglomerating liquid.

Furthermore, the preparation method is as follows:

(A) mix polyaluminum chloride, sodium carboxymethyl cellulose, and polyacrylamide uniformly to obtain mixture A;

(B) adding the additive into the mixture A, mixing uniformly to obtain a composite agglomerating agent;

(C) Mix the composite agglomerating agent in step (B) with water, and stir and mix evenly to prepare an agglomerating liquid.

Further, the specific steps are:

(A) Weigh 0-20 parts of polyaluminum chloride, 20-40 parts of sodium carboxymethyl cellulose, and 20-40 parts of polyacrylamide by mass parts, and take 0-20 parts of polyaluminum chloride, carboxymethyl fiber Mix 20-40 parts of plain sodium and 20-40 parts of polyacrylamide to obtain mixture A;

(B) Take 2-5 parts of additives by mass parts, add in the mixture A, mix evenly, obtain composite agglomerating agent;

(C) Mix the composite agglomerating agent in step (B) with water, stir and mix evenly, and the mass ratio of the agglomerating agent to water is 1:2000-10000 to prepare an agglomerating liquid.

Furthermore, _Ca (OH) powder is added to the agglomeration liquid to adjust the pH value of the agglomeration liquid to 8-9.

Furthermore, the additive is a solid additive.

Furthermore, the additive is composed of activated carbon and coke powder, and the additive is composed in the following mass percentages: 70-90% of activated carbon and 10-30% of coke powder.

Furthermore, the activated carbon particle size requirement: 74 μm≤activated carbon particle size≤100 μm, coke powder particle size requirement: 74 μm≤coke powder particle size≤100 μm.

Furthermore, the additive is composed of activated carbon and zeolite, and the additive is composed in the following mass percentages: 85-95% of activated carbon and 5-15% of zeolite.

Furthermore, the activated carbon particle size requirement: 74 μm≤activated carbon particle size≤100 μm, and the zeolite particle size requirement: 74 μm≤zeolite particle size≤100 μm.

3. Beneficial effect

Compared with the existing known technology, the technical solution provided by the invention has the following remarkable effects:

The invention creatively proposes to add a small amount of additives to the agglomerating agent, which significantly improves the agglomeration efficiency of the agglomeration liquid, thereby eliminating the process of fine particle adhesion and nucleation, accelerating the agglomeration speed of the particles, and the high-speed fine particles are difficult to penetrate Through the agglomerated liquid droplets, the effective collision probability is improved.

Since activated carbon and coke have a porous structure, they can adsorb fine particles. When the fine particles collide with the agglomeration liquid droplets and enter the agglomeration liquid, they will be adsorbed on the activated carbon and coke, so that the surface of the agglomeration liquid droplets is exposed. The new particles can fully contact with the liquid surface of the agglomeration liquid mist, thereby improving the agglomeration efficiency. With the addition of a small amount of additives, the emission reduction efficiency of PM10 and PM2.5 has been significantly improved. The emission reduction efficiency of PM10 has reached 65.9%, and the emission reduction efficiency of PM2.5 has reached 53.6%. A significant emission reduction effect has been achieved. Moreover, while reducing the emission of fine particles, the emission concentrations of SO ₂ and NO _X in the sintering flue gas are also significantly reduced, realizing the coordinated control of various pollutants.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the emission reduction system of embodiment 1-9 application;

Fig. 2 is a schematic diagram of the layout of the agglomeration liquid nozzle of the shrinkage tube of the emission reduction system used in embodiments 1-9;

Fig. 3 is the schematic diagram of the sintering machine and emission reduction system applied in Examples 1-9;

Fig. 4 is the flow chart of fine particulate matter emission reduction method of the present invention;

Fig. 5 is a flowchart of the preparation method of the agglomeration liquid of the present invention.

Explanation of the labels in the schematic diagram:

1. Main flue; 2. Atomization and agglomeration device; 21. Shrink tube; 22. Cylindrical connecting tube; 23. Expansion tube; 3. Reunion liquid adding device; 31. Reunion liquid storage parts; 32. Air compressor; 33 , Agglomeration liquid nozzle; 4. Dust removal device; 5. Fan; 6. Sintering trolley; 7. Bellows; 8. Ring pipe; 9. Stirring device.

detailed description

In order to further understand the contents of the present invention, the present invention will be further described below in conjunction with the examples.

Example 1

As shown in Fig. 4 and Fig. 5, a method for preparing an agglomeration liquid for suppressing the emission of fine particulate matter in iron ore sintering flue gas in this embodiment: a composite agglomerating agent for emission reduction of fine particulate matter in flue gas, each component is composed according to the following mass: polymerized chlorine Aluminum 10g, sodium carboxymethylcellulose 30g, polyacrylamide 30g, additive 2g. The additive is a solid additive, and the additive is composed of activated carbon and coke powder. The additive is composed of the following mass percentages: 90% activated carbon and 10% coke powder. 100μm, coke powder particle size requirement: 74μm≤coke powder particle size≤100μm.

The preparation method of the present embodiment reunion liquid is:

(A) Weigh 10 g of polyaluminum chloride, 30 g of sodium carboxymethyl cellulose, and 30 g of polyacrylamide in parts by mass, and mix 10 g of solid particle polyaluminum chloride, 30 g of sodium carboxymethyl cellulose, and 30 g of polyacrylamide , to get mixture A;

(B) Take 2g of the additive by mass parts, the additive is a solid additive, add in the mixture A, mix uniformly, and obtain the composite agglomerating agent;

(C) Mix the composite agglomerating agent in step (B) with water, and stir and mix evenly, and the mass ratio of the agglomerating agent to water is 1:5000, then add Ca(OH) ₂ powders to adjust the pH of the solution to be 8.5, Prepare a conglomerate solution.

During the iron ore sintering process, the agglomeration liquid is sprayed into the flue gas channel of the sintering flue gas, and the fine particles in the sintering flue gas are agglomerated and grown under the action of the agglomeration liquid, and the dust removal device 4 is used to remove the agglomerated fine particles. The flue gas channel is the main flue 1 of the sintering flue gas, and the atomization and agglomeration device 2 is installed on the main flue 1, and the atomized agglomeration liquid droplets are sprayed into the atomization and agglomeration device 2, and the flue gas The fine particles and the agglomeration liquid reunite in the atomization agglomeration device 2 to nucleate, collide and grow up.

The specific steps of applying the agglomerating agent of this embodiment to reduce the emission of fine particles are:

Step 1: Prepare the reunion solution: prepare the reunion solution according to the above method;

Step 2: Agglomeration of fine particles

During the iron ore sintering process, the agglomeration liquid is added to the agglomeration liquid storage part 31, and the atomization agglomeration device 2 is installed on the main flue 1, and the agglomeration liquid in the agglomeration liquid storage part 31 is transported to the agglomeration liquid nozzle by the air compressor 32 33. The agglomeration liquid nozzle 33 sprays mist agglomeration liquid into the shrink tube 21 of the atomization agglomeration device 2, and the particles in the flue gas and the agglomeration liquid reunite, contact, wet, adhere and nucleate in the atomization agglomeration device 2 , collide, grow up. Wherein: the droplet size of the sprayed agglomeration liquid is 30-150 μm, and the injection amount of the agglomeration liquid per cubic meter of sintering flue gas is 15ml.

The atomization agglomeration device 2 includes a shrinkage tube 21, a cylindrical connecting tube 22 and an expansion tube 23. The flue gas enters the atomization agglomeration device 2 from the inlet end of the shrinking tube 21, and then flows into the expansion tube 23 through the cylindrical connecting tube 22, and enters the main flue 1 The flue gas flows into the shrink tube 21 from the inlet end of the shrink tube 21. Since the diameter of the shrink tube 21 decreases rapidly, the flow rate of the smoke in the shrink tube 21 increases rapidly. 21 is sprayed into misty agglomeration liquid, so that the agglomeration liquid contacts, wets and adheres to the fine particles in the flue gas. Since the speed of the flue gas increases when it passes through the cylindrical connecting pipe 22, there is a gap between the cylindrical connecting pipe 22 and the expansion pipe. 23 Low pressure is generated, so that the agglomerated liquid droplets adsorbed with fine particles nucleate, collide and grow up under low pressure to form large particle agglomerates.

Step 3: Dust removal device captures

Use an electrostatic precipitator to remove the large particle agglomerates formed by agglomeration, that is, use the strong electric field in the electrostatic precipitator to ionize the gas, that is, generate a corona discharge, and then separate the particle agglomerates from the gas, thereby suppressing fine particles emissions to achieve emission reduction of fine particles in flue gas.

Detect the emission concentrations of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and record them as shown in Table 1. Detect the emission concentrations of SO ₂ and NO _X in the sintering flue gas after the dedusting device 4, and record them as shown in Table 2.

Comparative example 1

This comparative example is used as a benchmark test. The basic process of this comparative example is the same as that of Example 1. The difference is that no atomization agglomeration device 2 is installed on the main flue, nor is the agglomeration liquid sprayed into the main flue 1 to detect dust removal. The emission concentrations of PM2.5 and PM10 in the sintering flue gas after device 4 are recorded in Table 1. Detect the emission concentrations of SO ₂ and NO _X in the sintering flue gas after the dedusting device 4, and record them as shown in Table 2.

Comparative example 2

The emission reduction process of this comparative example is the same as that of Example 1, the difference being that the atomization agglomeration device 2 is not installed on the main flue, but the agglomeration liquid is sprayed into the main flue 1, and the agglomeration agent only consists of polyaluminum chloride, carboxylate Composed of sodium methylcellulose and polyacrylamide, the agglomerating agent does not contain solid additives, the emission concentrations of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4 are detected, and the records are shown in Table 1.

Comparative example 3

The emission reduction process of this comparative example is the same as in Example 1, and the mass percentages of polyaluminum chloride, sodium carboxymethylcellulose and polyacrylamide are the same as in Example 1, except that the agglomerating agent is only composed of polychlorinated Composed of aluminum, sodium carboxymethyl cellulose and polyacrylamide, the agglomerating agent does not contain solid additives, the emission concentrations of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4 are detected, and the records are shown in Table 1.

The experiment evaluates the agglomeration effect of PM10 (PM2.5) by the agglomeration efficiency, which is defined as the percentage reduction of the concentration of PM10 (PM2.5) in the flue gas after agglomeration, namely:

η=(1-N1/N0)×100%

Where N0 is the concentration of PM10 (PM2.5) in the initial flue gas (mg/m ³ ), and N1 is the concentration of PM10 (PM2.5) in the flue gas after agglomeration (mg/m ³ ).

Table 1 PM10, PM2.5 emission concentration in flue gas of sintering test

PM10(mg/m ³ ) PM10 emission reduction efficiency (%) PM2.5(mg/m ³ ) PM2.5 emission reduction efficiency (%) Comparative example 1 12.6 —— 6.9 —— Comparative example 2 9.2 27.0% 5.8 15.9% Comparative example 3 6.9 45.2% 4.8 30.4% Example 1 4.3 65.9% 3.2 53.6%

(1) Through the comparison of Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1, it can be seen that no matter how the agglomeration liquid is added to the flue gas, the emission of fine particles in the flue gas can be reduced.

(2) Comparative Example 2 Compared with Comparative Example 1, the emission reduction efficiency of PM10 is 27.0%, the emission reduction efficiency of PM2.5 is 15.9%, and the emission reduction efficiency of fine particles is poor. The reason is that the flue gas flow rate in the sintering process is large. The general method of adding agglomeration liquid makes it difficult for the agglomeration liquid to fully contact and wet the particles in the flue gas, and it is also difficult to realize the nucleation and growth of the particles. In addition, the composition of the sintering flue gas is complex, and the flue gas flow and composition fluctuate greatly, making The emission reduction effect of fine particulate matter is very limited.

(3) The PM10 emission reduction efficiency of comparative example 3 is 45.2%, and the PM2.5 emission reduction efficiency is 30.4%. Compared with comparative example 2, the PM10 and PM2.5 emission reduction efficiency are all significantly improved, and the atomization agglomeration device 2 is significantly improved. The agglomeration efficiency of the agglomeration liquid is improved. The reason for the analysis of the mechanism is that the atomization agglomeration device 2 includes a shrinkage tube 21, a cylindrical connecting tube 22 and an expansion tube 23, and the flue gas enters the atomization agglomeration device 2 from the inlet end of the shrinkage tube 21. Since the diameter of the shrinkage tube 21 becomes smaller rapidly, The flue gas velocity in the shrink tube 21 increases rapidly, and the agglomeration liquid spray nozzle 33 sprays misty agglomeration liquid into the shrink tube 21 of the atomization agglomeration device 2, so that the agglomeration liquid contacts and moistens the fine particles in the flue gas. Wet and sticky, because the speed of the flue gas increases when passing through the cylindrical connecting pipe 22, a low pressure is generated in the cylindrical connecting pipe 22 and the expansion pipe 23, so that the agglomerated liquid droplets adsorbed with fine particles nucleate, collide, and grow under low pressure. Large, large particle agglomerates formed. The electrostatic precipitator is used to remove the large particle agglomerates formed by agglomeration and growth, so that the emission concentration of fine particles in the flue gas is significantly reduced.

What needs to be clearly stated here is that existing researchers generally believe that the venturi tube has a poor emission reduction effect on fine particles, and due to the large resistance loss of the venturi tube, the application of the venturi tube to fine particles in sintering flue gas There are few reports on emission reduction studies. The applicant designed the atomization agglomeration device 2 by using the Venturi effect, so that the emission concentration of fine particles in the flue gas is significantly reduced. Break the technical bias of the existing technology.

(4) Compared with comparative example 3, the PM10 emission reduction efficiency of embodiment 1 has reached 65.9%, and the PM2.5 emission reduction efficiency is 53.6%. The solid additive in the agglomeration agent has significantly improved the agglomeration efficiency of the agglomeration liquid, and electrostatic dust removal is adopted The device removes the large particle agglomerates formed by agglomeration and growth, so that the emission concentration of fine particles in the flue gas is significantly reduced, which makes the applicant very surprised; but its kinetic collision and adhesion mechanism are still unclear. Discuss its reaction mechanism through several workshops, and think that the reason may be:

1) When the flue gas passes through the cylindrical connecting pipe 22, the speed increases, forming a low-pressure environment, so that the agglomeration liquid collides with the fine particles and grows up under low pressure. When the agglomeration liquid mist contains solid additives, the solid additives are agglomerated A stable nucleation matrix is formed inside the liquid mist. After the fine particles contact the surface of the agglomerated liquid mist, large particle agglomerates are formed directly, which saves the process of fine particle adhesion and nucleation, thus speeding up the agglomeration speed of the particles. .

2) The agglomeration of fine particles mainly depends on the contact and collision between the droplets of the reunion liquid and the fine particles to grow up, but the gas flow rate in the shrink tube 21 increases rapidly, although the probability of collision between the droplets of the reunion liquid and the fine particles is increased, However, due to the high speed of the fine particles in the flue gas and the droplets of the agglomeration liquid, some fine particles directly penetrate the droplets of the agglomeration liquid during the contact and collision process, making it difficult for the agglomeration liquid to effectively absorb the fine particles and form a large number of invalid collisions; When the agglomerated liquid mist droplets contain solid additives, it is difficult for high-speed fine particles to penetrate the agglomerated liquid mist droplets, which increases the effective collision probability.

3) When the fine particles collide with the agglomeration liquid droplets and enter the agglomeration liquid, due to the influence of the viscous resistance in the agglomeration liquid droplets, the fine particles will stay on the surface of the agglomeration liquid droplets again instead of being in the agglomeration liquid droplets. Internally; while the adhesion of the agglomerated liquid droplets to the particles mainly depends on the surface layer of the agglomerated liquid droplets. surface and cannot be adhered; when the agglomeration liquid droplets contain solid additives, because the solid additive has a porous structure, it can adsorb fine particles. When the fine particles collide with the agglomeration liquid droplets and enter the agglomeration liquid, they will be adsorbed on On the activated carbon and coke, the liquid surface on the surface of the agglomerated liquid mist is exposed, and the new particles can fully contact with the liquid surface of the agglomerated liquid mist, thereby improving the agglomeration efficiency.

The atomization agglomeration device 2 of the present invention includes a shrinkage tube 21, a cylindrical connecting tube 22 and an expansion tube 23. The flue gas enters the atomization agglomeration device 2 from the inlet end of the shrinking tube 21, and then flows into the expansion tube 23 through the cylindrical connecting tube 22. The main smoke The flue gas in the channel 1 flows into the shrinking tube 21 from the inlet end of the shrinking tube 21. Since the diameter of the shrinking tube 21 decreases rapidly, the flow rate of the flue gas in the shrinking tube 21 increases rapidly. Spray a mist-like agglomeration liquid into the shrink tube 21, so that the agglomeration liquid contacts, wets and adheres to the fine particles in the flue gas. Since the speed of the flue gas increases when it passes through the cylindrical connecting pipe 22, the air in the cylindrical connecting pipe 22 and expansion tube 23 to generate low pressure, so that the agglomerated liquid droplets adsorbed with fine particles nucleate, collide and grow up under low pressure to form large particle agglomerates. And the dust removal device is used to remove the agglomerated fine particles, which realizes the efficient emission reduction of fine particles, and provides a new emission reduction method for the emission reduction of fine particles in the iron ore sintering process.

The invention creatively proposes to add a small amount of additives to the agglomerating agent, which significantly improves the agglomeration efficiency of the agglomeration liquid, thereby eliminating the process of fine particle adhesion and nucleation, accelerating the agglomeration speed of the particles, and the high-speed fine particles are difficult to penetrate Through the agglomerated liquid droplets, the effective collision probability is improved.

Since activated carbon and coke have a porous structure, they can adsorb fine particles. When the fine particles collide with the agglomeration liquid droplets and enter the agglomeration liquid, they will be adsorbed on the activated carbon and coke, so that the surface of the agglomeration liquid droplets is exposed. The new particles can fully contact with the liquid surface of the agglomeration liquid mist, thereby improving the agglomeration efficiency. With the addition of a small amount of additives, the emission reduction efficiency of PM10 and PM2.5 has been significantly improved. The emission reduction efficiency of PM10 has reached 65.9%, and the emission reduction efficiency of PM2.5 has reached 53.6%. A significant emission reduction effect has been achieved.

The emission reduction efficiency of SO ₂ and NO _X is calculated using the following formula:

Where C0 is the concentration of PM10 (PM2.5) in the initial flue gas (mg/m ³ ), and C1 is the concentration of PM10 (PM2.5) in the flue gas after agglomeration (mg/m ³ ).

Table 2 The emission concentration of SO ₂ and NO _X in the flue gas of the sintering test

SO ₂ (mg/m ³ ) SO ₂ emission reduction efficiency (%) NO _X (mg/m ³ ) NO _X emission reduction efficiency (%) Comparative example 1 659 —— 322 —— Example 1 378 42.6% 256 20.5%

As can be seen from Table 2, after injecting the agglomerating agent of the present invention, the SO in the flue gas _The emission concentration dropped from 659mg/m to ^378mg / ^m , and the NO _X emission concentration dropped from 322mg/ ^m to 256mg/m ^3. It not only has adsorption effect on fine particles, but also has adsorption effect on SO ₂ , NOx, and dioxin in flue gas, so as to realize the coordinated control of various pollutants. The reason is that the sprayed agglomerating agent solution contains activated carbon and coke with a porous structure, which not only has an adsorption effect on fine particles, but also has an adsorption effect on SO ₂ , NOx, and dioxin in the flue gas, and the agglomeration liquid Adding Ca(OH) ₂ powder can absorb SO ₂ , NOx and other acid gases in the flue gas; and promote the contact, wetting and adhesion of fine particles and agglomeration liquid droplets, thereby improving the agglomeration efficiency.

As shown in Figures 1, 2 and 3, the emission reduction system applied in the present invention includes a fine particle atomization and agglomeration device 2, a reunion liquid adding device 3 and a dust removal device 4, and the sintered mixture is mixed and granulated by a distribution device, Lay it on the sintering trolley 6. After the sintering mixture is ignited, it is ventilated and sintered. The sintering smoke passes through the sintering material layer. The bottom of the sintering trolley 6 is connected with the main flue 1 through the bellows 7. The bottom of the car 6 flows into the main flue 1 through the bellows 7, and the main flue 1 is provided with an atomization agglomeration device 2, an agglomeration liquid adding device 3 and a dust removal device 4, and the flue gas flows from the main flue 1 into the atomization agglomeration device 2, After being dedusted by the dust removal device 4, it is discharged into the chimney by the fan 5; the fine particles in the flue gas are reunited and nucleated in the atomization agglomeration device 2, and the nucleation grows up, and the agglomerated and grown fine particles are removed in the rear dust removal device 4. particulates.

The above-mentioned atomization agglomeration device 2 includes a shrinkage tube 21, a cylindrical connecting tube 22 and an expansion tube 23; wherein: the shrinkage tube 21 and the expansion tube 23 are tapered tubes with different inner diameters at both ends, and the shrinkage tube 21 is connected to the main flue 1 is the inlet end of the shrink tube 21, the inner diameter of the inlet end of the shrink tube 21 is the same as the inner diameter of the main flue 1, the end of the shrink tube 21 close to the expansion tube 23 is the outlet end of the shrink tube 21, and the outlet end of the shrink tube 21 is connected to the expansion tube 23 inlet ends have the same internal diameter; the outlet end of the shrink tube 21 is connected to the inlet end of the expansion tube 23 through a cylindrical connecting tube 22, and the end of the expansion tube 23 away from the shrink tube 21 is the outlet end of the expansion tube 23, and the inner diameter of the outlet end of the expansion tube 23 is the same as The inner diameter of the main flue 1 is the same, and it is connected with the main flue 1; the centerlines of the above-mentioned shrinking tube 21, cylindrical connecting tube 22 and expansion tube 23 are on the same straight line; the smoke enters the atomization from the inlet end of the shrinking tube 21 The agglomeration device 2 flows into the expansion pipe 23 through the cylindrical connecting pipe 22, and flows out of the atomization agglomeration device 2 from the outlet end of the expansion pipe 23. The flue gas in the main flue 1 flows into the shrinking tube 21 from the inlet end of the shrinking tube 21. Since the diameter of the shrinking tube 21 decreases rapidly, the flow rate of the flue gas in the shrinking tube 21 increases rapidly. When the flue gas passes through the cylindrical connecting tube 22 The speed increases, and a low pressure is generated near it, which makes the particle collision in the flue gas more intense.

The described agglomeration liquid adding device 3 comprises an agglomeration liquid storage part 31, an air compressor 32 and an agglomeration liquid nozzle 33, wherein the agglomeration liquid storage part 31 is provided with a stirring device 9, so that the agglomeration liquid composition in the agglomeration liquid storage part 31 is uniform Stable, preventing component segregation of the prepared agglomeration liquid, thus affecting the emission reduction effect of fine particles. The agglomeration liquid storage part 31 is connected to the inlet end of the air compressor 32 through a pipeline, and the outlet end of the air compressor 32 is connected to the agglomeration liquid nozzle 33 through a pipeline, wherein: the agglomeration liquid storage part 31 is used to store the agglomeration liquid, and the air compressor 32 is The agglomeration liquid enters the agglomeration liquid nozzle 33 to provide power, and the agglomeration liquid nozzle 33 is used to atomize the agglomeration liquid and spray it into the atomization agglomeration device 2 , and the agglomeration liquid nozzle 33 is arranged on the shrink tube 21 . The agglomeration liquid containing the agglomeration agent is driven by the air compressor 32, flows into the agglomeration liquid nozzle 33 from the agglomeration liquid storage part 31, and the agglomeration liquid nozzle 33 sprays the atomized agglomeration liquid into the atomization agglomeration device 2, and the atomized mist The diameter of the droplet is 30-150 μm; the diameter of the shrinkage tube 21 of the atomization agglomeration device 2 becomes smaller rapidly, so that the speed of the flue gas increases when it passes through the cylindrical connecting tube 22, and a low pressure is generated near it, so that the agglomeration liquid has a strong impact on the fine particles. Adsorption, the particles in the flue gas fully contact, wet, adhere, and nucleate with the atomized agglomeration liquid, and continue to agglomerate and collide to grow, making the fine particles continue to agglomerate and grow.

The agglomeration liquid nozzle 33 is evenly arranged on the circumferential tangent line of the cross section of the shrink tube 21, the flow rate of the smoke in the shrink tube 21 is continuously increasing, and the agglomeration liquid droplets atomized by the agglomeration liquid nozzle 33 can be mixed with the smoke in the shrink tube 21. The gas is fully and uniformly mixed; the cross section is a vertical section perpendicular to the centerline of the shrink tube 21, the horizontal distance between the plane where the agglomeration liquid nozzle 33 is located and the inlet end of the shrink tube 21 is L1, and the plane where the agglomeration liquid nozzle 33 is located is in the same plane as the shrink tube 21 The horizontal distance of the outlet end is L2, L2=0.5L1, that is, the horizontal distance between the plane where the agglomeration liquid nozzle 33 is located and the inlet end of the shrink tube 21 is greater than the horizontal distance between the plane where the agglomeration liquid nozzle 33 is located and the outlet end of the shrink tube 21, so that the flue gas enters the shrink tube After 21, during the process of increasing the flue gas flow rate, it is mixed and contacted with the atomized agglomerated liquid droplets.

The outside of the shrink tube 21 is arranged with an annular pipe 8, the inlet end of the annular pipe 8 is connected with the outlet end of the air compressor 32, and 16 outlets are arranged on the annular pipe 8, and the outlet of the annular pipe 8 is connected with the agglomeration liquid nozzle 33, and the agglomeration liquid It flows into the agglomeration liquid nozzle 33 from the annular pipe 8; the annular pipe 8 is provided with 16 outlets, which can uniformly and stably transport the agglomeration liquid from the agglomeration liquid storage part 31 to the agglomeration liquid nozzle 33, so that the agglomeration liquid nozzle 33 is uniform and stable Spray into the agglomeration liquid.

The dust removal device 4 is an electrostatic precipitator. The fine particles in the flue gas are wetted and adhered to the agglomeration liquid droplets in the atomization and agglomeration device 2. The removal of particulate matter can realize the agglomeration and emission reduction of fine particulate matter in the sintering process.

Example 2

The basic content of this embodiment is the same as that of Example 1, except that the additive is composed of activated carbon and zeolite, and the additive is composed of the following mass percentages: 85% of activated carbon and 15% of zeolite, and the particle size of the activated carbon requires: 74μm≤activated carbon particle size≤100μm, zeolite particle size requirement: 74μm≤zeolite particle size≤100μm.

Detect the emission concentration of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and calculate the emission reduction efficiency of PM2.5 and PM10. The emission reduction efficiency of PM2.5 is 56.4%, and the emission reduction efficiency of PM10 is 49.0%.

Example 3

The basic content of this embodiment is the same as that of Example 1, except that the additive is composed of activated carbon and zeolite, and the additive is composed of the following mass percentages: 95% of activated carbon and 5% of zeolite.

Detect the emission concentration of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and calculate the emission reduction efficiency of PM2.5 and PM10. The emission reduction efficiency of PM2.5 is 60.2%, and the emission reduction efficiency of PM10 is 48.8%.

Example 4

The basic content of this embodiment is the same as that of Embodiment 1, except that the additive is composed of activated carbon and zeolite, and the additive is composed of the following mass percentages: 90% of activated carbon and 10% of zeolite.

Detect the emission concentration of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and calculate the emission reduction efficiency of PM2.5 and PM10. The emission reduction efficiency of PM2.5 is 55.9%, and the emission reduction efficiency of PM10 is 48.6%.

Example 5

The basic content of this embodiment is the same as that of Example 1, except that the additive is composed of activated carbon, coke powder, bentonite and Suzhou clay, and the additive is composed of the following mass percentages: 90% of activated carbon, 8% of coke powder %, bentonite 1%, Suzhou soil 1%, the bentonite particle size requirement: 74 μm ≤ bentonite particle size ≤ 100 μm, Suzhou soil particle size requirement: 74 μm ≤ Suzhou soil particle size ≤ 100 μm.

Detect the emission concentration of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and calculate the emission reduction efficiency of PM2.5 and PM10. The emission reduction efficiency of PM2.5 is 63.8%, and the emission reduction efficiency of PM10 is 54.2%.

Example 6

The basic content of this embodiment is the same as that of Example 1, except that the additive is composed of activated carbon, coke powder and kaolin, and the additive is composed of the following mass percentages: 90% of activated carbon, 7% of coke powder, kaolin 3%, the kaolin particle size requirement: 74μm≤kaolin particle size≤100μm.

Detect the emission concentration of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and calculate the emission reduction efficiency of PM2.5 and PM10. The emission reduction efficiency of PM2.5 is 64.2%, and the emission reduction efficiency of PM10 is 51.1%.

Example 7

The basic content of this embodiment is the same as that of Example 1, except that the additive is composed of activated carbon, coke powder, kaolin and zeolite, and the additive is composed of the following mass percentages: activated carbon 90%, coke powder 7% , Kaolin 2%, Zeolite 1%.

Detect the emission concentration of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and calculate the emission reduction efficiency of PM2.5 and PM10. The emission reduction efficiency of PM2.5 is 62.6%, and the emission reduction efficiency of PM10 is 51.7%.

Example 8

The basic content of this embodiment is the same as that of embodiment 1, the difference being: the composite agglomerating agent for emission reduction of flue gas fine particles, each component is composed according to the following mass: sodium carboxymethyl cellulose 20g, polyacrylamide 20g, polypropylene Amide 20g, additive 4g. The specific steps of applying the agglomerating agent of this embodiment to reduce the emission of fine particles are:

Step 1: Prepare the reunion solution

(A) Weigh 20 g of sodium carboxymethyl cellulose and 20 g of polyacrylamide in parts by mass, and mix 20 g of solid particle sodium carboxymethyl cellulose and 20 g of polyacrylamide to obtain mixture A;

(B) Take 4g of the additive by mass parts, add it in the mixture A, and mix evenly to obtain a composite agglomerating agent;

(C) Mix the composite agglomerating agent in step (B) with water, and stir and mix evenly, and the ratio of the mass of the agglomerating agent to water is 1:2000, then add _Ca (OH) Powder to adjust the pH of the solution to be 8, Prepare the reunion liquid;

Step 2: Agglomeration of fine particles

During the iron ore sintering process, the agglomeration liquid is added to the agglomeration liquid storage part 31, and the atomization agglomeration device 2 is installed on the main flue 1, and the agglomeration liquid in the agglomeration liquid storage part 31 is transported to the agglomeration liquid nozzle by the air compressor 32 33. The agglomeration liquid nozzle 33 sprays mist agglomeration liquid into the shrink tube 21 of the atomization agglomeration device 2, and the particles in the flue gas and the agglomeration liquid reunite, contact, wet, adhere and nucleate in the atomization agglomeration device 2 , collide, grow up. Wherein: the droplet size of the sprayed agglomeration liquid is 30-150 μm, and the injection amount of the agglomeration liquid per cubic meter of sintering flue gas is 20ml.

The atomization agglomeration device 2 includes a shrinkage tube 21, a cylindrical connecting tube 22 and an expansion tube 23. The flue gas enters the atomization agglomeration device 2 from the inlet end of the shrinking tube 21, and then flows into the expansion tube 23 through the cylindrical connecting tube 22, and enters the main flue 1 The flue gas flows into the shrink tube 21 from the inlet end of the shrink tube 21. Since the diameter of the shrink tube 21 decreases rapidly, the flow rate of the smoke in the shrink tube 21 increases rapidly. 21 is sprayed into misty agglomeration liquid, so that the agglomeration liquid contacts, wets and adheres to the fine particles in the flue gas. Since the speed of the flue gas increases when it passes through the cylindrical connecting pipe 22, there is a gap between the cylindrical connecting pipe 22 and the expansion pipe. 23 Low pressure is generated, so that the agglomerated liquid droplets adsorbed with fine particles nucleate, collide and grow up under low pressure to form large particle agglomerates.

Step 3: Dust removal device captures

The bag filter is used to remove the large particle agglomerates formed by agglomeration, that is, the bag filter is used to separate the particle agglomerates from the gas, so as to reduce the emission of fine particles in the flue gas.

The additives are composed according to the following mass percentages: 70% of activated carbon and 30% of coke powder.

Detect the emission concentration of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and calculate the emission reduction efficiency of PM2.5 and PM10. The emission reduction efficiency of PM2.5 is 60.7%, and the emission reduction efficiency of PM10 is 43.5%.

Example 9

The basic content of this embodiment is the same as that of Embodiment 1, the difference being that: the composite agglomerating agent for emission reduction of flue gas fine particles, each component is composed according to the following mass: 20g of polyaluminium chloride, 40g of sodium carboxymethyl cellulose, poly Acrylamide 40g, additive 5g. The specific steps of applying the agglomerating agent of this embodiment to reduce the emission of fine particles are:

Step 1: Prepare the reunion solution

(A) Weigh 20g of polyaluminum chloride, 40g of sodium carboxymethyl cellulose, and 40g of polyacrylamide in parts by mass, mix 20g of solid particle polyaluminum chloride, 40g of sodium carboxymethyl cellulose, and 40g of polyacrylamide , to get mixture A;

(B) 5g of the additive is weighed in parts by mass, added to the mixture A, and mixed uniformly to obtain a composite agglomerating agent;

(C) Mix the composite agglomerating agent in step (B) with water, and stir and mix evenly, and the mass ratio of the agglomerating agent to water is 1:10000, then add Ca(OH) ₂ powders to adjust the pH of the solution to be 9, Prepare the reunion liquid;

Step 2: Agglomeration of fine particles

During the iron ore sintering process, the agglomeration liquid is added to the agglomeration liquid storage part 31, and the atomization agglomeration device 2 is installed on the main flue 1, and the agglomeration liquid in the agglomeration liquid storage part 31 is transported to the agglomeration liquid nozzle by the air compressor 32 33. The agglomeration liquid nozzle 33 sprays misty agglomeration liquid into the shrink tube 21 of the atomization agglomeration device 2, and the particulate matter in the flue gas and the agglomeration liquid reunite in the atomization agglomeration device 2 for contact, wetting, adhesion, nucleation, Collide and grow up. Wherein: the droplet size of the sprayed agglomeration liquid is 30-150 μm, and the injection amount of the agglomeration liquid per cubic meter of sintering flue gas is 10ml.

The atomization agglomeration device 2 includes a shrinkage tube 21, a cylindrical connecting tube 22 and an expansion tube 23. The flue gas enters the atomization agglomeration device 2 from the inlet end of the shrinking tube 21, and then flows into the expansion tube 23 through the cylindrical connecting tube 22, and enters the main flue 1 The flue gas flows into the shrink tube 21 from the inlet end of the shrink tube 21. Since the diameter of the shrink tube 21 decreases rapidly, the flow rate of the smoke in the shrink tube 21 increases rapidly. 21 is sprayed into misty agglomeration liquid, so that the agglomeration liquid contacts, wets and adheres to the fine particles in the flue gas. Since the speed of the flue gas increases when it passes through the cylindrical connecting pipe 22, there is a gap between the cylindrical connecting pipe 22 and the expansion pipe. 23 Low pressure is generated, so that the agglomerated liquid droplets adsorbed with fine particles nucleate, collide and grow up under low pressure to form large particle agglomerates.

Step 3: Dust removal device captures

The bag filter is used to remove the large particle agglomerates formed by agglomeration, that is, the bag filter is used to separate the particle agglomerates from the gas, so as to reduce the emission of fine particles in the flue gas.

The additives are composed in the following mass percentages: 85% of activated carbon and 15% of coke powder.

Detect the emission concentration of PM2.5 and PM10 in the sintering flue gas after the dust removal device 4, and calculate the emission reduction efficiency of PM2.5 and PM10. The emission reduction efficiency of PM2.5 is 61.9%, and the emission reduction efficiency of PM10 is 52.6%.

The above schematically describes the present invention and its implementation, which is not restrictive, and what is shown in the drawings is only one of the implementations of the present invention, and the actual structure is not limited thereto. Therefore, if a person of ordinary skill in the art is inspired by it, without departing from the inventive concept of the present invention, without creatively designing a structural mode and embodiment similar to the technical solution, it shall all belong to the protection scope of the present invention .

Claims (10)

1. A method for preparing an agglomeration liquid that suppresses the discharge of iron ore sintering flue gas fine particles, characterized in that: components such as sodium carboxymethyl cellulose, polyacrylamide and additives are mixed uniformly to prepare an agglomerating agent, and the agglomerated The agent is mixed with water to prepare the agglomeration liquid. 2. the preparation method of a kind of agglomeration liquid that suppresses iron ore sintering flue gas fine particles according to claim 1 is characterized in that: the agglomeration agent comprises polyaluminum chloride, sodium carboxymethyl cellulose, polyacrylamide It is uniformly mixed with additives to prepare an agglomerating agent, and the agglomerating agent is mixed with water to prepare an agglomerating liquid. 3. a kind of preparation method of the agglomeration liquid that suppresses iron ore sintering flue gas fine particulate matter discharge according to claim 2, is characterized in that: preparation method is as follows: (A) mix polyaluminum chloride, sodium carboxymethyl cellulose, and polyacrylamide uniformly to obtain mixture A; (B) adding the additive into the mixture A, mixing uniformly to obtain a composite agglomerating agent; (C) Mix the composite agglomerating agent in step (B) with water, and stir and mix evenly to prepare an agglomerating liquid. 4. a kind of preparation method of the agglomeration liquid that suppresses iron ore sintering flue gas fine particulate matter discharge according to claim 3 is characterized in that: concrete steps are: (A) Weigh 0-20 parts of polyaluminum chloride, 20-40 parts of sodium carboxymethyl cellulose, and 20-40 parts of polyacrylamide by mass parts, and take 0-20 parts of polyaluminum chloride, carboxymethyl fiber Mix 20-40 parts of plain sodium and 20-40 parts of polyacrylamide to obtain mixture A; (B) Take 2-5 parts of additives by mass parts, add in the mixture A, mix evenly, obtain composite agglomerating agent; (C) Mix the composite agglomerating agent in step (B) with water, stir and mix evenly, and the mass ratio of the agglomerating agent to water is 1:2000-10000 to prepare an agglomerating liquid. 5. a kind of preparation method of the agglomeration liquid that suppresses iron ore sintering flue gas fine particles discharge according to claim 4 is characterized in that: in agglomeration liquid, add _Ca (OH) Powder, the pH value of adjustment agglomeration liquid 8-9. 6. A method for preparing an agglomeration liquid for suppressing emission of fine particulate matter in iron ore sintering flue gas according to any one of claims 1-5, characterized in that: the additive is a solid additive. 7. a kind of preparation method of the agglomeration liquid that suppresses iron ore sintering flue gas fine particle emission according to claim 6 is characterized in that: described additive is made up of activated carbon and coke powder, and additive is made up of following mass percentage: activated carbon 70-90%, coke powder 10-30%. 8. A method for preparing an agglomeration liquid for suppressing the emission of fine particulate matter in iron ore sintering flue gas according to claim 7, characterized in that: the particle size requirement of the activated carbon: 74 μm≤particle size of activated carbon≤100 μm, coke powder Diameter requirement: 74μm≤coke powder particle size≤100μm. 9. A method for preparing an agglomeration liquid for suppressing the discharge of iron ore sintering flue gas fine particles according to claim 6, characterized in that: the additive is composed of activated carbon and zeolite, and the additive is composed of the following mass percentage: activated carbon 85 -95%, Zeolite 5-15%. 10. A method for preparing an agglomeration liquid for suppressing the emission of fine particles in iron ore sintering flue gas according to claim 9, characterized in that: the particle size requirement of the activated carbon: 74 μm≤particle size of activated carbon≤100 μm, particle size of zeolite Requirements: 74μm≤zeolite particle size≤100μm.