CN111036073A - Sintering flue gas denitration process - Google Patents

Sintering flue gas denitration process Download PDF

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CN111036073A
CN111036073A CN201911292668.7A CN201911292668A CN111036073A CN 111036073 A CN111036073 A CN 111036073A CN 201911292668 A CN201911292668 A CN 201911292668A CN 111036073 A CN111036073 A CN 111036073A
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denitration
flue gas
sintering flue
catalyst
iron
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CN111036073B (en
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周建安
王怡
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Wuhan University of Science and Engineering WUSE
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8621—Removing nitrogen compounds
    • B01D53/8625—Nitrogen oxides
    • B01D53/8628—Processes characterised by a specific catalyst
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/745—Iron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases

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Abstract

The invention discloses a sintering flue gas denitration process, and belongs to the technical field of sintering flue gas treatment. The SCR denitration catalyst is prepared by taking iron ore as a raw material, crushing, grinding and screening the iron ore, and then reducing and calcining the iron ore by hydrogen to obtain iron-based powdery particles; during denitration, the prepared SCR denitration catalyst powder is fixed in a denitration tower and is subjected to selective catalytic reduction with ammonia steam introduced into the denitration tower under the action of an iron-based catalyst, so that sintering flue gas denitration is realized. The SCR denitration catalyst disclosed by the invention has the advantages of wide raw material source, convenience in production, simplicity in use, high strength, low cost and the like, has a good denitration effect at a low temperature, and can well solve the problems of low denitration efficiency and slightly high use temperature section of the existing denitration catalyst, thereby being conductive to prolonging the service life of the catalyst and saving the cost.

Description

Sintering flue gas denitration process
Technical Field
The invention relates to the technical field of sintering flue gas treatment, in particular to a sintering flue gas denitration process.
Background
With the rapid development of the steel industry in China, the crude steel yield leaps the first world. But the contradiction of the steel industry is more and more prominent, the iron ore sintering process is a main pollution source of smoke pollutants in the steel industry, and the amount of the discharged waste gas accounts for 40% of the total waste gas amount in the steel industry, so the pollutant discharge is an important subject to be solved urgently. Research shows that 1 ton of agglomerate is producedAbout 4000-6000 m3The flue gas, wherein fine dust, oxysulfide, nitric oxide, dioxin and the like are main atmospheric pollutants, and how to realize low-cost and high-efficiency purification of the flue gas has important value for improving iron and steel enterprises and the surrounding environment. The sintering flue gas treatment, especially the discharge of nitrogen oxides in the steel industry, has increasingly strict industrial discharge standards required by China along with the improvement of environmental awareness, and the steel industry faces new challenges.
In the sintering flue gas denitration process, Selective Catalytic Reduction (SCR) denitration is one of common methods, the denitration principle is that nitrogen oxides are converted into nitrogen and water which are naturally contained in the air by a reducing agent at a proper temperature in the presence of a catalyst, and the SCR technology is widely applied due to a low reaction temperature range and high denitration efficiency. The catalyst is the core of the SCR technology, and the performance of the catalyst is directly related to the overall denitration efficiency. The catalyst widely used at present is mainly TiO2As a carrier, V2O5As the main active substance, with the aid of WO3And the like, and the activity of the medium-temperature catalyst is increased, and the catalyst has the characteristics of high denitration efficiency and good stability. However, the use of the above-mentioned catalysts has the following disadvantages: firstly, the preparation cost of the catalyst is high; secondly, the preparation conditions of the catalyst are strict and are not easy to control; and thirdly, under the influence of an active temperature window of the catalyst, the SCR denitration reactor is usually required to be arranged at a high-temperature (300-400 ℃) and high-dust section between a boiler economizer and an air preheater, the operation temperature is high and is strictly controlled, and the catalyst is easy to block and neutralize, so that the activity of the catalyst is reduced, and the service life of the catalyst is short. In addition, because the temperature of the flue gas of the existing power plant in China after desulfurization and dust removal is relatively low, which is usually 120-240 ℃, the existing denitration catalyst is not suitable for the actual situation in China and cannot be used for full and effective denitration. More importantly, vanadium in the vanadium-titanium oxide catalyst is a heavy metal element with high toxicity, and can cause great harm to human health and environment in the processes of catalyst preparation, catalytic reactor installation, and treatment and disposal after failure.
Therefore, the temperature of the molten metal is controlled,the development of the low-temperature catalyst can ensure that the reaction is carried out at a lower temperature, not only can reduce the energy consumption reaction and reduce the cost, but also can consider placing the SCR denitration reactor after an ESP (electric precipitation process), thereby reducing or completely eliminating SO2The influence on the catalyst can prevent the catalyst from being blocked and poisoned, and the cost is saved.
For example, the Chinese patent application number is: 200810120648.7, the invention discloses a low temperature SCR catalyst using nitrogen doped active carbon as carrier and its preparation process, the invention uses nitrogen doped active carbon prepared by ammonia gas burning method as carrier, and one of Mn, V, Fe, Co, Cu metal element oxides is impregnated and loaded as active component, thereby improving the denitration activity of the low temperature SCR catalyst using active carbon as carrier to a certain extent, and widening the active window of the catalyst. For another example, the invention patent with Chinese patent application No. 200710056741.1 discloses a catalyst for SCR denitration of boiler low-temperature flue gas and a preparation method thereof, the application uses active carbon fiber as a carrier, adopts an impregnation method, and loads a catalyst component MnO/CeO of manganese and cerium oxides on the carrier2Thereby improving the denitration efficiency of the catalyst at low temperature to a certain extent. In summary, the catalyst prepared by using the active carbon as the carrier is beneficial to the dispersion of the active components because the active carbon carrier has larger specific surface area, and has certain SO resistance2However, the high-temperature burning phenomenon of the activated carbon in the activation and regeneration process is too serious, so that the catalyst loss is too large, and the method is not suitable for industrial popularization and application.
For another example, chinese patent publication No. CN 104971736 a discloses a natural ferrimanganic composite oxide SCR denitration catalyst and a method for denitration of flue gas using the same, the catalyst provided by the present invention is obtained by crushing and sieving natural ferrimanganic oxide ore containing nano iron oxide and nano manganese oxide and having a nano-micron hierarchical pore structure as a raw material. During denitration, the catalyst and ammonia gas are simultaneously fed into flue gas flow at the temperature of 200-350 ℃, so that the SCR denitration catalyst and the flue gas are absorbed on the surface of a polar plate or a filter bag of an electric dust remover, and are collected into an ash hopper in an ash removal mode; the SCR denitration catalyst can be separated from the materials discharged from the ash bucket through screening and then recycled; the deactivated catalyst can be regenerated after being washed by dilute ammonia water. The denitration catalyst in the application has a certain denitration effect, the denitration efficiency in the temperature section is good, but the denitration effect in the temperature section lower than 200 ℃ is relatively poor, and the denitration catalyst still has high and stable denitration efficiency at lower temperature (120 plus 200 ℃), so that the denitration catalyst cannot be used for effectively denitration after flue gas desulfurization and dust removal in the existing power plant in China. In addition, the denitration catalyst in the invention is used in a mode of spraying the catalyst into the flue gas flow, and the spraying amount of the solid is not easy to control, so that the contact reaction with the flue gas flow is unstable, and the denitration efficiency is limited.
Disclosure of Invention
The invention aims to solve the problems that the prior denitration catalyst is influenced by an active temperature window of the catalyst, the service temperature section of the prior common denitration catalyst is higher, so that the prior common denitration catalyst is not suitable for the condition that the temperature is lower after the desulfurization and the dedusting of the flue gas of the prior power plant in China, the catalyst is easy to block and poison, and the denitration efficiency is lower, and provides a sintering flue gas denitration process, wherein iron ore is used as a raw material, an iron-based catalyst is obtained by crushing, grinding and screening the iron-based catalyst and is subjected to hydrogen reduction and calcination with ammonia steam introduced into a denitration tower to realize the catalytic denitration of the sintering flue gas at a low temperature. And the cost is saved.
In order to achieve the purpose, the invention adopts the technical scheme that:
a sintering flue gas denitration process comprises the following steps:
s1, crushing and grinding the collected iron ore and then sieving the crushed iron ore;
s2, under the protection of inert gas, putting the iron ore particles sieved in the step S1 into a vacuum tube furnace, heating, introducing hydrogen for reduction, naturally cooling along with the furnace, and discharging to obtain the iron ore particlesIn sintering flue gas NH3-an iron based catalyst for SCR denitration;
and S3, introducing the desulfurized sintering flue gas into a denitration tower internally provided with an iron-based catalyst, and carrying out selective catalytic reduction on the desulfurized sintering flue gas and ammonia steam introduced into the denitration tower under the action of the iron-based catalyst to realize denitration of the sintering flue gas.
As a further limitation of the above technical means, in step S1, the collected iron ore is ground to a specific surface area of 20 to 50m2/g。
As a further limitation of the above technical solution, in step S1, a 100 mesh sieve is used for sieving, and the particle size of the finally obtained iron-based catalyst is less than 100 μm.
As a further limitation of the above technical means, in step S2, the temperature is raised to 600 to 800 ℃.
As a further limitation of the above technical solution, in step S2, the flow rate of hydrogen is 400-600 mL/min, and the reduction time is 1-3 h.
As a further limitation of the technical scheme, the iron-based catalyst is dried for 6-8 hours at 100-120 ℃ before use.
As a further limitation of the technical scheme, the ratio of the addition mass of the iron-based catalyst in the denitration tower to the sintering flue gas treatment amount is 0.02-0.05 g/Nm3。
As a further limitation of the above technical means, the NH3The volume ratio of the introduced amount to NO in the flue gas is (0.8-1.2): 1.
as a further limitation of the above technical solution, in step S3, the catalytic reduction temperature is 120 to 240 ℃.
Compared with the prior art, the invention has the beneficial effects that:
(1) the SCR denitration catalyst has simple production process, and the iron-based denitration catalyst is prepared by using cheap resource iron ore tailings which have abundant reserves and serious environmental pollution as raw materials through hydrogen reduction to effectively remove NO harmful to air environmentxThe purpose of treating pollution by using pollution is achieved, and the SCR denitration catalyst has good performance at low temperature (120-240℃)The denitration effect is further favorable for reducing energy consumption, reducing iron ore tailing accumulation and improving NOxThe method has the advantages of reducing the cost and prolonging the service life of the catalyst on the environmental pollution, having very important research significance on solid waste utilization and pollutant emission reduction, having higher economic benefit, being suitable for the condition of low temperature after flue gas desulfurization and dust removal of the existing power plants in China, and ensuring the flue gas denitration effect.
(2) The specific surface area of the iron ore adopted by the invention is 20-50 m2And/g, and the crushed catalyst is sieved by using a 100-mesh sieve, so that the denitration effect of the catalyst can be further improved, and the denitration reaction can be fully performed.
(3) The iron-based catalyst prepared by reducing the iron ore through the hydrogen is simple in preparation method, green and environment-friendly, and meanwhile, the components in the iron ore can better perform synergistic action, so that the low-temperature denitration effect of the iron ore can be guaranteed.
(4) The catalytic reduction temperature of the iron ore is 600-800 ℃, and the inventor optimally designs the reduction temperature and the reduction time through a large number of experiments, so that the content of mineral impurities in the iron ore can be effectively reduced, the influence of the mineral impurities on the denitration of the catalyst is reduced, the content of iron in the denitration catalyst is increased, the catalytic efficiency of the obtained catalyst is further improved, the denitration effect of the finally obtained catalyst is ensured, and the full play of the synergistic effect among the components is facilitated.
Drawings
Fig. 1 is a graph showing denitration efficiency results of the SCR denitration catalyst obtained in example 1 at different temperatures.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly apparent, the present invention is further described in detail with reference to the following embodiments; it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.
The present invention will be described in further detail below with reference to specific embodiments and with reference to the attached drawings.
Example 1
The embodiment provides a sintering flue gas denitration process, which comprises the following steps:
s1, crushing and grinding the collected iron ore to a specific surface area of 40m2Sieving the powder with a 100-mesh sieve after per gram;
S2、N2under protection, putting the iron ore particles sieved in the step S1 into a vacuum tube furnace, heating to 700 ℃, introducing hydrogen at the flow rate of 500mL/min for reduction for 2h, naturally cooling along with the furnace, discharging, and obtaining NH for sintering flue gas3-an iron based catalyst for SCR denitration;
s3, introducing the desulfurized sintering flue gas into a denitration tower internally provided with an iron-based catalyst, and carrying out selective catalytic reduction on the desulfurized sintering flue gas and ammonia vapor introduced into the denitration tower under the action of the iron-based catalyst to realize denitration of the sintering flue gas;
wherein the ratio of the addition mass of the iron-based catalyst in the denitration tower to the sintering flue gas treatment amount is 0.04g/Nm3(ii) a The NH3The volume ratio of the introduced amount to NO in the flue gas is 1: 1.
controlling the temperature range to be between room temperature and 450 ℃ through a heating furnace program, and detecting the temperature by a K-type thermocouple; gas sampling ports are arranged in front of and behind the reactor, smoke components are measured by a smoke analyzer, and data are recorded on a storage card in real time. As shown in fig. 1, the SCR denitration catalyst of the present embodiment has a high denitration efficiency within a temperature range of 120 to 240 ℃, the denitration efficiency at 180 ℃ can reach 98%, the denitration efficiency at a temperature as low as 140 ℃ is still above 90%, the low-temperature denitration effect is good, and the SCR denitration catalyst can be applied to the conditions of flue gas desulfurization and dust removal of the existing power plant in China.
It is worth to be noted that, through a great deal of experimental research, the inventors found that the specific surface area of the ground iron ore is crucial to the low-temperature denitration effect of the obtained SCR denitration catalyst, and the good low-temperature denitration effect can not be obtained by selecting any iron ore with any specific surface area. According to the invention, the collected iron ore is ground, so that the SCR denitration catalyst has a good denitration effect at a low temperature (120-240 ℃), further, the energy consumption is reduced, the cost is reduced, the service life of the catalyst is prolonged, the SCR denitration catalyst can be suitable for the condition that the temperature is low after the flue gas desulfurization and dust removal of the existing power plant in China, and the flue gas denitration effect is ensured.
In addition, the selection of the reduction temperature and the reduction time when the iron ore is reduced by hydrogen is also crucial to the denitration efficiency of the catalyst, the inventor carries out optimization design on the reduction temperature and the reduction time through a large amount of experimental research, finally determines that the calcination temperature is 600-800 ℃, and the reduction time is 1-3 hours, so that the content of mineral impurities in the iron ore can be effectively reduced, the influence of the mineral impurities on the denitration of the catalyst is reduced, the content of iron oxide in the denitration catalyst is increased, the catalytic efficiency of the obtained catalyst is further improved, the denitration effect of the finally obtained catalyst is ensured, and the full play of the synergistic effect among the components in the iron ore is facilitated.
Example 2
Embodiment 2 provides a sintering flue gas denitration process, which is different from embodiment 1 in that, in step S2, the temperature of the tube furnace is raised to 600 ℃, and other operations are the same, and are not described herein again.
The method of embodiment 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in this embodiment, and the denitration efficiency of the SCR denitration catalyst in this embodiment in the temperature range of 120 to 240 ℃ is close to that of embodiment 1, and has a better low-temperature denitration effect.
Example 3
Embodiment 3 provides a sintering flue gas denitration process, which is different from embodiment 1 in that, in step S2, the temperature of the tube furnace is raised to 800 ℃, and other operations are the same, and are not described herein again.
The method of embodiment 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in this embodiment, and the denitration efficiency of the SCR denitration catalyst in this embodiment in the temperature range of 120 to 240 ℃ is close to that of embodiment 1, and has a better low-temperature denitration effect.
Example 4
Embodiment 4 provides a sintering flue gas denitration process, which is different from embodiment 1 in that in step S3, the ratio of the added mass of the iron-based catalyst in the denitration tower to the sintering flue gas treatment amount is 0.02g/Nm3Other operations are the same and are not described herein.
The method of example 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in this example, and the denitration efficiency of the SCR denitration catalyst of this example is 83.2% at 120 ℃, and the denitration efficiency is as high as 98.1% at 180 ℃.
Example 5
Embodiment 5 provides a sintering flue gas denitration process, which is different from embodiment 1 in that in step S3, the ratio of the added mass of the iron-based catalyst in the denitration tower to the sintering flue gas treatment amount is 0.05g/Nm3Other operations are the same and are not described herein.
The method of example 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in this example, and the denitration efficiency of the SCR denitration catalyst of this example is 86.1% at 120 ℃, and the denitration efficiency is as high as 98.9% at 180 ℃.
Example 6
Embodiment 6 provides a sintering flue gas denitration process, which is different from embodiment 1 in that in step S2, the flow rate of hydrogen is 400mL/min, and other operations are the same and are not described herein again.
The denitration efficiency of the SCR denitration catalyst prepared in this example was tested by the method in example 1, and the denitration efficiency of the SCR denitration catalyst in this example was 83.9% at 120 ℃, and was as high as 97.8% at 180 ℃.
Example 7
Embodiment 7 provides a sintering flue gas denitration process, which is different from embodiment 1 in that in step S2, the flow rate of hydrogen is 600mL/min, and other operations are the same and are not described herein again.
The method of example 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in this example, and the denitration efficiency of the SCR denitration catalyst of this example is 85.2% at 120 ℃, and the denitration efficiency is as high as 98.3% at 180 ℃.
Comparative example 1
The comparative example provides a sintering flue gas denitration process, which is different from that of example 1 in that in step S3, the ratio of the addition mass of the iron-based catalyst in the denitration tower to the sintering flue gas treatment amount is 0.01g/Nm3Other operations are the same and are not described herein.
When the denitration efficiency of the SCR denitration catalyst prepared in the present comparative example is tested by the method in example 1, the denitration efficiency of the SCR denitration catalyst in the present comparative example can only reach 71% at 120 ℃, and the denitration efficiency of the SCR denitration catalyst in the present comparative example can not reach 90% until the temperature reaches 180 ℃, whereas the denitration efficiency of the catalyst obtained in example 1 has reached 98%. It can be seen that changing the ratio of the amount of the catalyst to the amount of the sintering flue gas in step S3 has a significant effect on the denitration effect. The inventor discovers through a large number of experiments that the ratio of the adding mass of the iron-based catalyst in the denitration tower to the sintering flue gas treatment amount is controlled to be 0.02-0.05 g/Nm3Within the range, better denitration effect can be achieved.
Comparative example 2
Compared with the embodiment 1, the difference of the denitration process for sintering flue gas is that in the step S2, the flow rate of hydrogen is 380mL/min, and other operations are the same, and are not described herein again.
The method of example 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in the present comparative example, and the denitration efficiency of the SCR denitration catalyst in the present comparative example can only reach 72% at 120 ℃, and can not reach 85% until the temperature reaches 180 ℃. It can be seen that the denitration effect of the denitration catalyst prepared from the iron ore of example 1 is much better than the denitration effect of the denitration catalyst prepared from the iron ore of comparative example 1, which indicates that changing the flow rate of hydrogen in the catalytic reduction reaction of the iron ore in step S2 has a significant effect on the denitration effect.
Comparative example 3
Compared with the embodiment 1, the difference of the denitration process for sintering flue gas is that in the step S2, the flow rate of hydrogen is 610mL/min, and other operations are the same, and are not described herein again.
The method of example 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in the present comparative example, and the denitration efficiency of the SCR denitration catalyst in the present comparative example can only reach 74% at 120 ℃, and can not reach 89% until the temperature reaches 180 ℃. This is probably because the too large flow rate of hydrogen in the catalytic reduction reaction of iron ore in step S2 increases the content of mineral impurities in the prepared iron-based catalyst, thereby reducing the denitration effect thereof.
Comparative example 4
Compared with the embodiment 1, the difference of the denitration process for sintering flue gas is that in the step S2, the temperature of the tube furnace is raised to 580 ℃, and other operations are the same, and are not described again.
The method of example 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in the present comparative example, and the denitration efficiency of the SCR denitration catalyst in the present comparative example can only reach 75% at 120 ℃, and can not reach 90% until the temperature reaches 180 ℃. It is explained that lowering the temperature of the hydrogen catalytic reduction reaction in step S2 is not favorable for the reduction of the catalytic activity of the iron catalyst to be obtained, and is not favorable for the optimum denitration effect.
Comparative example 5
Compared with the embodiment 1, the difference of the denitration process for sintering flue gas is that in the step S2, the temperature of the tube furnace is raised to 850 ℃, and other operations are the same, and are not described again.
The method of example 1 is adopted to test the denitration efficiency of the SCR denitration catalyst prepared in the present comparative example, and the denitration efficiency of the SCR denitration catalyst in the present comparative example at 120 ℃ can only reach 73%, and the denitration efficiency thereof can not reach 87% until the temperature reaches 180 ℃. This is probably because the too high temperature of the hydrogen catalytic reduction reaction in step S2 increases the content of mineral impurities in the prepared iron catalyst, thereby reducing the denitration effect thereof.
While the invention has been described with respect to specific embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes, omissions and deviations in the form and detail thereof may be made without departing from the scope of this invention; those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the spirit and scope of the invention; meanwhile, any equivalent changes, modifications and alterations of the above embodiments according to the spirit and techniques of the present invention are also within the scope of the present invention.

Claims (9)

1. A sintering flue gas denitration process is characterized by comprising the following steps:
s1, crushing and grinding the collected iron ore and then sieving the crushed iron ore;
s2, under the protection of inert gas, putting the iron ore particles sieved in the step S1 into a vacuum tube furnace, heating, introducing hydrogen for reduction, naturally cooling along with the furnace, and discharging to obtain NH for sintering flue gas3-an iron based catalyst for SCR denitration;
and S3, introducing the desulfurized sintering flue gas into a denitration tower internally provided with an iron-based catalyst, and carrying out selective catalytic reduction on the desulfurized sintering flue gas and ammonia steam introduced into the denitration tower under the action of the iron-based catalyst to realize denitration of the sintering flue gas.
2. The denitration process for sintering flue gas of claim 1, wherein in step S1, the collected iron ore is ground to a specific surface area of 20-50 m2/g。
3. The denitration process for sintering flue gas as claimed in claim 1, wherein in step S1, a 100 mesh screen is adopted for screening, and the particle size of the finally obtained iron-based catalyst is less than 100 μm.
4. The sintering flue gas denitration process according to claim 1, wherein in step S2, the temperature is raised to 600-800 ℃.
5. The denitration process for sintering flue gas as claimed in claim 1, wherein in step S2, the flow rate of hydrogen is 400-600 mL/min, and the reduction time is 1-3 h.
6. The sintering flue gas denitration process of claim 1, wherein the iron-based catalyst is dried at 100-120 ℃ for 6-8 h before use.
7. The sintering flue gas denitration process according to claim 1, wherein the ratio of the addition mass of the iron-based catalyst in the denitration tower to the sintering flue gas treatment amount is 0.02-0.05 g/Nm3。
8. The denitration process for sintering flue gas as claimed in claim 1, wherein said NH is3The volume ratio of the introduced amount to NO in the flue gas is (0.8-1.2): 1.
9. the sintering flue gas denitration process according to claim 1, wherein in step S3, the catalytic reduction temperature is 120-240 ℃.
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