KR20180076390A - Method for Rematerializing Waste De-NOx Catalyst Using Inorganic Acid - Google Patents

Abstract

The present method relates to a method of rematerializing a de-NO_x catalyst, the method which uses an organic acid to remove poisoning materials of the waste de-NO_x catalyst discarded after being used in a power plant or the like, thereby enabling the waste catalyst to be reused. A method of rematerializing the waste de-NO_x catalyst using the inorganic acid comprises: a step of collecting a waste catalyst component from a waste de-NO_x catalyst module; a pretreatment step of crushing the waste catalyst component and removing metallic foreign materials from the crushed waste catalyst component by using a magnet to obtain a pretreated waste catalyst; a step of reacting the pretreated waste catalyst with the inorganic acid to remove the poisoning materials in the waste catalyst; a step of filtering the poisoning material-removed waste catalyst to obtain a filtered waste catalyst and washing the filtered waste catalyst to obtain a washed waste catalyst; a step of firing the washed waste catalyst to obtain a fired waste catalyst; and a step of milling the fired waste catalyst to produce a fine powder from the fired waste catalyst. Since the method of the present invention is a method of removing the poisoning materials in the waste catalyst, the method can reduce preparation costs of the catalyst by minimizing loss amounts of effective catalyst components contained in the waste catalyst, and particularly enabling titanium dioxide and tungsten trioxide occupying most of a de-NO_x catalyst to be recovered such that the recovered titanium dioxide and tungsten trioxide can be rematerialized. Further, since the method of the present invention is a method of recovering titanium dioxide and tungsten trioxide by removing the poisoning materials such as sodium, potassium calcium, sulfur trioxide and the others that inhibit catalytic activities instead of performing a process of separating and extracting tungsten and vanadium, the process being expensive in the recovery of titanium dioxide and tungsten trioxide from the waste catalyst, the method reduces costs required in the rematerialization process. The method can reduce a rematerializing manufacturing process since the recovered titanium dioxide and tungsten trioxide can be reused as catalyst raw materials even without passing through a separate processing process.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for remineralizing a waste denitration catalyst using an inorganic acid,

The present invention relates to a method for remanufacturing a waste denitration catalyst which enables the reuse of spent catalyst by removing inorganic poisons of a waste denitration catalyst that is discarded after being used in a power plant.

With rapid economic development, industrialization requires enormous amount of energy. As a result, the amount of fossil fuels has increased and the emission of a large amount of environmental pollutants has been made indiscreetly. As a result, serious environmental destruction has been caused, and in recent years, It is an opportunity to re-recognize the importance of

As the problem of air pollution among environmental pollution sources becomes more serious and the risk of nitrogen oxides in air pollution becomes important, regulation of emission of nitrogen oxides is strengthened. Most of domestic power generation facilities are equipped with deNOx system have.

The domestic market for NOx catalysts is gradually increasing from 40,000 ㎥ in 2011 to 45,000 ㎥ in 2015, and the cost of catalysts is gradually increasing from 150 billion won annually.

The denitration catalyst is contaminated by various routes such as dust, sulfur, alkali metal, arsenic, and phosphorus compounds contained in the exhaust gas and thereby the catalytic activity is gradually lowered. In general, the replacement cycle of the catalyst used in the exhaust- It has been replaced every three to five years.

The waste catalyst, which is replaced with depletion, is separated into waste and disposed of at the designated site. However, the recycled value of the waste catalyst is high because the waste catalyst contains valuable metals and various kinds of valuable metals. It is necessary to acquire the technology of recycling the spent catalyst because it can increase the competitiveness due to the reduction and increase the competitiveness with foreign companies.

The composition of the denitration catalyst varies depending on the manufacturer and the application, but most of the initial raw materials are composed of 80 to 90% of titanium dioxide, 5 to 10% of tungsten trioxide, and 1 to 2% of vanadium pentoxide. There is known a valuable metal recovering technique in which tungsten and vanadium metal classified as rare metals in the denitrification catalyst components (titanium dioxide, tungsten trioxide, vanadium pentoxide, etc.) are individually extracted by an alkaline wet leaching method.

The alkaline wet leaching method is a technique of extracting and reusing high value added tungsten and vanadium. Such a valuable metal recovery technology has a low recovery rate of tungsten and vanadium and a very difficult extraction process, and recovery of titanium dioxide Therefore, it is costly to apply to the field of catalyst materialization, and thus the efficiency of resource recycling is not satisfied.

In order to solve such a problem, Korean Patent Registration No. 1360292 discloses a method for recovering valuable metals from a spent catalyst by using a thermophilic strain, wherein the oil component of the waste catalyst generated in the petroleum refining step is removed first Fermenting a fermenting strain which oxidizes iron and sulfur in a non-ferrous 9K medium and inoculating the spent catalyst to recover biologically leached ferrous metal.

The present invention can be economically achieved by using a biological method and can raise the leaching rate of nickel (Ni) and vanadium (V) in a short time, and can recover iron (Fe), molybdenum (Mo) and aluminum However, titanium (Ti) and tungsten (W), which are the most abundant components in the catalyst, are difficult to be recovered and thus are not effective in terms of recycling the spent catalyst.

Korean Patent Publication No. 1452179 discloses a method for recovering vanadium and tungsten from a leach solution of a denitrification catalyst. The leaching of the denitrification catalyst produced by the soda roasting process, the alkali atmospheric pressure leaching process or the alkali pressure leaching process Acid (hydrochloric acid, nitric acid, sulfuric acid) and a calcium compound are added to the solution to convert vanadium to Ca (VO ₃ ) ₂ And then the acid and calcium compounds were added to the remaining leach solution to remove tungsten from CaWO ₄ And precipitated and recovered.

The present invention can selectively recover vanadium and tungsten contained in the denitrification catalyst, but can not recover valuable metals that are not leached into the alkali solution of the valuable metals contained in the waste catalyst, and can not recover the same The separation of vanadium and tungsten is difficult. In order to recycle the recovered Ca (VO ₃ ) ₂ and CaWO ₄ as a catalyst, it is necessary to reprocess it again.

DISCLOSURE Technical Problem Accordingly, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a waste denitration catalyst which efficiently removes poisonous substances contained in a waste denitration catalyst, instead of a conventional method of separating and recovering valuable metals in a waste denitration catalyst, And to provide a method of materialization.

In order to solve the above problems, the present invention provides a method for removing NOx from a waste denitration catalyst module, A pretreatment step of pulverizing the waste catalyst component and removing a metallic foreign substance using a magnet; Reacting the pretreated spent catalyst with an inorganic acid to remove poisonous materials in the spent catalyst; Filtering the waste catalyst from which the poisoning material has been removed to wash it; Firing the washed spent catalyst; And finely pulverizing the calcined waste catalyst. The present invention also provides a method of remineralizing a waste denitration catalyst using an inorganic acid.

At this time, it is preferable that the waste catalyst component collected is pulverized to a particle size of 100-2000 mu m, and then a metallic foreign substance in the waste catalyst component is removed with a magnet of 7000-12000 Gauss strength.

In addition, the removal of the poisoning material is preferably performed by reacting the spent catalyst and the inorganic acid at a temperature of 120 ° C to 300-500 rpm for 30-120 minutes.

The inorganic acid is preferably an aqueous sulfuric acid solution having a concentration of 0.1 to 2.0 M, an aqueous hydrochloric acid solution having a concentration of 0.1 to 2.0 M, a hydrogen peroxide aqueous solution having a concentration of 0.1 to 1.0 M, or a mixed solution thereof.

The step of removing the poisoning material may be performed by reacting the waste catalyst with a pretreated waste catalyst by adding an organic acid to the inorganic acid, or reacting the pretreated waste catalyst with an inorganic acid, followed by further reaction with an organic acid reaction solution or a mixed reaction solution of an inorganic acid- More preferably, the organic acid is 0.1 to 1.5 M aqueous citric acid solution or 0.1 to 1.0 M aqueous EDTA solution, and the organic acid reaction solution or mixed reaction solution of inorganic acid-organic acid is citric acid, EDTA, hydrogen peroxide and citric acid, It is most preferable that hydrogen peroxide and EDTA are mixed in a volume ratio of 4: 6: 4 to 6:

In the firing step, it is preferable that the washed spent catalyst is heated at 140 to 160 ° C. for 40 to 80 minutes and then calcined at 300 to 450 ° C. for 10 to 150 minutes.

Since the method of remanufacturing the waste denitration catalyst according to the present invention is a method of removing poisonous substances in the spent catalyst, the amount of effective catalyst component contained in the waste catalyst is minimized, and titanium dioxide and tungsten trioxide, which occupy most of the denitration catalyst, Most of the catalyst can be recovered and recycled to reduce the manufacturing cost of the catalyst.

In addition, instead of separating and extracting tungsten and vanadium, which are costly to recover from waste catalysts, removing poisoning substances such as sodium, potassium, calcium, and sulfur trioxide, which inhibit catalytic activity, to recover titanium dioxide and tungsten trioxide Titanium dioxide and tungsten trioxide, which have a low cost of materialization and are recovered, can be reused as a catalyst material without any separate processing steps, thereby reducing the manufacturing process of the materialization.

1 is a flowchart showing a method of removing a poisonous substance from a waste denitration catalyst according to the present invention and a method for recovering a waste catalyst.
FIG. 2 is a process diagram showing a pretreatment process during the materialization process of the waste denitration catalyst according to the present invention. FIG.
FIG. 3 is a process diagram showing a process of removing a poisonous substance from a pretreated waste denitration catalyst to make it a material.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for remanufacturing a waste denitration catalyst based on tungsten trioxide (WO ₃ -TiO ₂ ) used in domestic and overseas power plants and the like. The waste catalyst module is disassembled and air- Separating and pulverizing the waste catalyst component, collecting the waste catalyst component, pretreating the waste catalyst component using a magnet to remove metallic foreign substances, and removing the poisoning substance in the spent catalyst by reacting the pretreated waste catalyst with inorganic acid , Filtering and washing the waste catalyst and the reaction solution using pressure or vacuum, firing the washed spent catalyst, and finely dividing the fired waste catalyst to a fine size. Provides a method of materialization.

The present invention is the main component of the catalyst material by removing the causative factors of sodium that instead of extracting a specific component of the waste removal catalyst decreases the NOx removal efficiency (Na), potassium (K), calcium (Ca), sulfur trioxide (SO _3), etc. By recovering titanium dioxide, tungsten trioxide, and vanadium pentoxide, it is possible to minimize the loss of these waste catalysts during the reconditioning of spent catalysts.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

It is to be understood, however, that the invention is not to be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Will be apparent to those skilled in the art to which the present invention pertains.

FIG. 1 is a flow chart showing a method for remanufacturing a waste denitration catalyst using inorganic acid according to the present invention.

The method for remineralizing a waste denitration catalyst according to the present invention includes a pretreatment step (S10) for collecting waste catalysts from a waste denitration catalyst module to remove metallic foreign substances. The waste denitration catalyst module is disassembled and air- And the spent catalyst is collected, and the metallic foreign substance in the spent catalyst is removed using a magnet.

FIG. 2 is a flow chart of the preprocessing step S10 included in the flow chart.

In the pretreatment step S10, the wastewater denitration catalyst module 11 based on tungsten trioxide-WO ₃ -TiO ₂ , which is supplied to domestic and overseas power plants, is separated, and then an air compressor 15 Air brushing at a flow rate of ~ 400 L / min, metal mesh separation and crushing, and metallic or foreign materials are removed using magnets or electromagnets.

The waste denitration catalyst module may be applied to heavy fuel oil power generation, coal-fired power generation waste denitration catalyst and combined-cycle power generation waste denitration catalyst, and may be applied to all of the waste denitration catalysts based on tungsten trioxide-titanium dioxide.

The module type of the waste denitration catalyst can be divided into a plate type 13 and a honeycomb type 14. In the case of a plate type, a canister 12 is separated from a waste denitration catalyst module 11 The plate catalyst 13 is separated from the canister 12, and then the catalyst is separated from the metal net of the plate catalyst 13 and pulverized. In the case of the honeycomb type, the entire catalyst is crushed.

The pulverized spent catalyst 16 preferably has a particle size of 100 to 2,000 mu m and is preferably made of a metallic foreign substance in the spent catalyst 16 or a metallic contaminant 19 in the spent catalyst 16 by using a magnet or electromagnet 18 having a strength of 7000 to 12000 Gauss, To obtain a pretreated spent catalyst (17).

Next, an inorganic acid solution is reacted with the pretreated spent catalyst 17 to remove poisonous substances in the spent catalyst (S20).

The pretreated spent catalyst 17 may be reacted with an appropriate inorganic acid solution because the type and content of the poisonous substance are different depending on the catalyst type of the power plant, the fuel, and the control conditions of the selective catalytic reduction (SCR) Remove poisonous substances and react by adjusting temperature (room temperature ~ 120 ℃), stirring speed (300 ~ 500 rpm) and time (30 ~ 120min).

At least one of hydrogen peroxide (H ₂ O ₂ ), sulfuric acid (H ₂ SO ₄ ) and hydrochloric acid (HCl) is used as the inorganic acid and hydrogen peroxide is an aqueous solution having a concentration of 0.1 to 1.0 M Preferably, sulfuric acid and hydrochloric acid are aqueous solutions having a concentration of 0.1 to 2.0 M, and sulfuric acid and hydrogen peroxide or hydrochloric acid and hydrogen peroxide are preferably combined with the spent catalyst 17 in these reaction solutions, and sulfuric acid: hydrogen peroxide (or hydrochloric acid : Hydrogen peroxide) = 4 to 6: 4 to 6 volume ratio, and it is most preferable that they are mixed in the same amount in terms of volume.

For example, citric acid (C ₆ H ₈ O ₇ ) or ethylenediaminetetraacetic acid (EDTA) may be added to the aqueous hydrogen peroxide solution to remove the toxic substance It is preferable to mix the hydrogen peroxide solution with citric acid (or EDTA) = 4 to 6: 4 to 6 by volume, and the hydrogen peroxide solution and citric acid (or EDTA) It is more preferable that they are mixed in the same amount.

Most substances that degrade the denitrification performance of spent catalysts are alkaline (earth) metal oxides and metal oxides of phosphorus and arsenic.

EDTA has four carboxyl groups and a negative charge can be generated in the oxygen due to the drop of H ⁺ ion. As a result, EDTA is adsorbed on the waste catalyst when EDTA is added to a ligand-binding metal and most heavy metals, As the metal ions are combined with the metal ions to form complex ions, the metal component acting as a poisoning substance can no longer coordinate with the waste catalyst component. Therefore, the waste catalyst reacted with EDTA is filtered to remove the poisonous substance from the waste catalyst can do.

The poisoning material removal step (S20) may be further decrypted as an inorganic acid reaction solution as described above, and further decrypted as a mixed reaction solution of an organic acid reaction solution or an inorganic acid-organic acid. In addition, 0.1 to 1.5 M citric acid aqueous solution or 0.1 to 1.0 M aqueous EDTA solution may be used as the organic acid to be used, and hydrogen peroxide, sulfuric acid and hydrochloric acid are used as the inorganic acid used for further decryption.

Further, the organic acid or inorganic acid-organic acid used for the further decryption is preferably a combination of citric acid and EDTA, hydrogen peroxide and citric acid, or hydrogen peroxide and EDTA, and the mixing ratio of these combined substances is 4 to 6: 4 to 6 More preferably, they are mixed in the same amount as each other on a volume basis.

The mixture amount of the waste catalyst and the reaction solution during the removal of the poisonous material and / or the additional detoxification is such that the poisonous substances contained in the waste catalyst are sufficiently removed, and the waste catalyst and the reaction solution are mixed at a volume ratio of 1: 5 to 10 desirable.

Next, the filtering and washing step (S30) for removing the inorganic acid as the reaction solution from the poisoned material-removed spent catalyst is performed. First, the waste catalyst is filtered to remove the reaction solution in the spent catalyst, Water is removed with the reaction solution.

It is preferable that the pore size of the filter is selected according to the particle size of the spent catalyst and the filter having a pore size of 1 to 50 탆 is used in consideration of the size of the normal spent catalyst particle. It is preferable to perform filtration using pressure or vacuum.

Also, it is preferable to use distilled water of 2 to 10 times the volume of the spent catalyst so that the reaction solution is sufficiently removed.

Next, the waste catalyst from which the reaction solution is removed is calcined and finely pulverized (S40). The calcination is preferably performed at 140 to 160 ° C. for 40 to 80 minutes and then at 300 to 450 ° C. for 10 to 150 minutes. The temperature and time can be controlled depending on the use of the catalyst.

The method of remanufacturing a waste denitration catalyst according to the present invention can reduce the cost of importing tungsten trioxide and titanium dioxide, the cost of manufacturing the catalyst, and the waste treatment cost of the spent catalyst, It also helps.

Example 1 Method for Reconstruction of Waste Denitration Catalyst Using Hydrochloric Acid

FIG. 3 is a process diagram according to an embodiment of the present invention showing a process of removing a poisoning substance of a waste catalyst and recovering a material for recovery of tungsten trioxide and titanium dioxide catalyst materials in a waste denitration catalyst.

2, the waste denitration catalyst pretreated in FIG. 2 is stored in a storage silo 21 and 50 kg of the spent catalyst in the storage silo 21 and 500 l of distilled water in the distilled water tank 23 are introduced into the primary washing tank 22, The waste catalysts were firstly washed with distilled water and then filtered through a primary filter 24 having a pore size of 23 탆. The generated wastewater was transferred to a wastewater treatment tank 25 and treated.

The distilled water from the distilled water tank 23 and the hydrochloric acid in the chemical solution storage tank 27 were transferred to the primary filtration catalyst to obtain a mixed solution of 500 ml of a 1.92 mole hydrochloric acid aqueous solution and 100 ° C And the mixture was stirred at 300 rpm for 1 hour.

After the reaction was completed, the reaction solution was removed from the secondary filter 31 having a pore size of 23 μm, and 500 L of the distilled water in the distilled water tank 23 was transferred from the secondary washing tank 33 to the second wash water. The generated wastewater was transferred to the chemical treatment tank 32 for treatment.

The waste water that has been washed secondarily was again filtered by a tertiary filter 34 having a pore size of 23 μm and the generated wastewater was transferred to a wastewater treatment tank 35 for treatment. , And then heated at a temperature of 150 DEG C for one hour while supplying air to the firing furnace 41, and then calcined at a temperature of 400 DEG C for two hours.

The calcined spent catalyst was transferred to a pulverizing mill (42) to be finely divided into less than 45 탆 and made into a material.

<Example 2> Reconstitution of a waste denitration catalyst using mixed reaction solution of hydrochloric acid and hydrogen peroxide

50 kg of the waste denitration catalyst in the storage silo 21 pretreated in FIG. 2 and 500 L of distilled water in the distilled water tank 23 are transferred to the primary washing tank 22 and stirred. The spent catalyst is firstly rinsed with distilled water, And filtered through a primary filter 24 having a diameter of 23 mu m.

The distilled water in the distilled water tank 23 and the hydrochloric acid and hydrogen peroxide in the chemical solution storage tank 27 were transferred to the primary filtered catalyst, and 250 L of a hydrochloric acid aqueous solution having a concentration of 1.90 mole and 250 L of a hydrogen peroxide solution having a concentration of 1.0 mole were mixed And reacted with the reaction solution in a chemical solution tank 26 at a temperature of 100 ° C for 1 hour at 300 rpm.

After the reaction was completed, the reaction solution was removed from the secondary filter 31 having a pore size of 23 μm, and then 500 L of the distilled water in the distilled water tank 23 was transferred to the second washing tank 33, The waste catalyst washed with water was filtered through a tertiary filter (34) having a pore size of 23 mu m.

The third filtered catalyst was heated at a temperature of 150 ° C. for one hour while being supplied with air from a calcining furnace 41 and then calcined at a temperature of 400 ° C. for two hours. The calcined spent catalyst was passed through a differentiator (42) By weight.

<Example 3> Reconstitution of waste denitration catalyst using sulfuric acid

The waste denitration catalyst pretreated in FIG. 2 is stored in the storage silo 21 and then 60 kg of the spent catalyst in the storage silo 21 and 600 L of distilled water in the distilled water tank 23 are transferred to the primary washing tank 22, The waste catalyst was firstly washed with distilled water and then filtered through a first filter 24 having a pore size of 23 μm. The generated wastewater was transferred to a wastewater treatment tank 25 for treatment.

The distilled water from the distilled water tank 23 and the sulfuric acid in the chemical solution storage tank 27 were transferred to the primary filtration catalyst and mixed with 600 liters of a 2.0 mole aqueous sulfuric acid solution mixed together. And the mixture was stirred at 350 rpm for 1 hour.

After the reaction was completed, the reaction solution was removed from the secondary filter 31 having a pore size of 23 μm, and 600 L of the distilled water in the distilled water tank 23 was transferred to the secondary washing tank 33 to be secondly washed with water. The generated wastewater was transferred to the chemical treatment tank 32 for treatment.

The waste water that has been washed secondarily was again filtered by a tertiary filter 34 having a pore size of 23 μm and the generated wastewater was transferred to a wastewater treatment tank 35 for treatment. , And then heated at a temperature of 150 DEG C for one hour while supplying air to the firing furnace 41, and then calcined at a temperature of 400 DEG C for two hours.

The calcined spent catalyst was transferred to a pulverizing mill (42) to be finely divided into less than 45 탆 and made into a material.

<Example 4> Reconstitution of a waste denitration catalyst using mixed reaction solution of sulfuric acid and hydrogen peroxide

60 kg of the waste denitration catalyst of the storage silo 21 pretreated in FIG. 2 and 600 L of distilled water of the distilled water tank 23 are transferred to the primary washing tank 22, and the waste catalyst is firstly rinsed with distilled water, And filtered through a primary filter 24 having a diameter of 23 mu m.

The distilled water of the distilled water tank 23 and the sulfuric acid and the hydrogen peroxide of the chemical solution storage tank 27 were transferred to the primary filtered catalyst, and 300 L of a 2.0 M concentration sulfuric acid aqueous solution and 300 L of a 1.0 M concentration hydrogen peroxide solution were mixed And the mixture was reacted with the reaction solution in a chemical solution tank 26 at a temperature of 100 ° C for one hour at 350 rpm.

After the reaction was completed, the reaction solution was completely removed from the secondary filter 31 having a pore size of 23 μm, and then 600 L of the distilled water in the distilled water tank 23 was transferred to the secondary washing tank 33, The waste catalyst washed with water was filtered through a tertiary filter (34) having a pore size of 23 mu m.

The third filtered catalyst was heated at a temperature of 150 ° C. for one hour while being supplied with air from a calcining furnace 41 and then calcined at a temperature of 400 ° C. for two hours. The calcined spent catalyst was passed through a differentiator (42) By weight.

&Lt; Test Example > Analysis of poisoning substance removal efficiency and denitrification efficiency

3 shows the results of analyzing the components of the waste denitration catalyst before and after the poisoning material removal process. The results are shown in Table 1 below.

XRF (X-Ray Flourescence Spectrometry, ZSX Primus II, Rigaku, Japan) was used for the analysis of the components.

XRF analysis results (% by weight) before and after the poisoning material removal ingredient Waste Denitration Catalyst (Before Removing Poisonous Substance) Reformatization denitration catalyst (after removal of poisonous substance) Hydrochloric acid Hydrochloric acid + hydrogen peroxide Sulfuric acid Sulfuric acid + hydrogen peroxide Na ₂ O 0.1368 0.0470 0 0.0382 0 MgO 0.2073 0.1470 0.1043 0.1175 0.0945 Al ₂ O ₃ 1.9636 1.7852 1.6132 1.6933 1.5120 SiO ₂ 6.2274 6.6408 6.1492 5.9417 5.7602 P ₂ O ₅ 1.8495 1.9071 1.3972 1.9359 1.5550 SO ₃ 2.6675 0.8600 0.7302 0.8400 0.7990 K ₂ O 0.0465 0.0191 0.0204 0.0133 0.0113 CaO 1.7383 1.2000 1.1000 1.0188 0.8510 TiO ₂ 78.5337 82.0700 83.7225 82.4921 83.3004 V ₂ O ₅ 1.4658 0 0 0.6722 0.7986 Fe ₂ O ₃ 0.1978 0.1767 0.1728 0.1993 0.2012 NiO 0.0398 0 0 0 0 SrO 0.0205 0.0206 0.0225 0.0184 0.0131 ZnO 0.0155 0 0 0 0 Nb ₂ O ₅ 0.1025 0.1052 0.1002 0.0970 0.1005 MoO ₃ 0.2048 0.3519 0.1842 0.2007 0.1961 WO ₃ 4.5827 4.6694 4.6833 4.7216 4.8071 system 100 100 100 100 100

Poisonous substance removal rate (%) ingredient Hydrochloric acid Hydrochloric acid + hydrogen peroxide Sulfuric acid Sulfuric acid + hydrogen peroxide Na ₂ O (%) 65.6 100.0 72.0 100.0 K ₂ O (%) 58.9 56.1 71.3 75.6 CaO (%) 30.9 36.7 41.3 51.0 SO ₃ (%) 67.7 72.6 68.5 70.0

Table 1 and Table 2 show that the removal rate of sulfuric acid poison is slightly higher than that of hydrochloric acid, and it is more efficient to use hydrogen peroxide together than hydrochloric acid or sulfuric acid alone. Vanadium pentoxide, when treated with hydrochloric acid, It can be seen that the use of sulfuric acid and hydrogen peroxide more than hydrochloric acid is most advantageous for removing poisonous substances since all of them are removed from the flue gas denitration catalyst.

The reformate denitration catalyst from which the poisoning substance was removed was placed in a fixed-bed reactor filled with nitrogen, and a flow rate of 600 cc, a space velocity of 60000 h ^-1 , an O ₂ content of 3 vol.%, An NO content of 800 ppm, NH ₃ / NO mole ratio of 1.0, and a reaction temperature of 350 ° C. The denitration efficiency was 80% or more on average in all of Examples 1 to 4 above.

From the test results, it can be seen that the denitration catalyst that has been reformed by the method of the present invention economically recycles the waste catalyst and can exert a denitrification effect to a certain level or more, thereby enabling the waste denitration catalyst to be efficiently restored.

11: a waste denitration catalyst module, 12: a canister separated from the module, 13: a plate catalyst separated from the canister, 14: a honeycomb catalyst separated from the module, 15: an air compressor, 16: A pretreatment waste catalyst from which metallic foreign substances have been removed, 18: a magnet, 19: a metallic foreign matter, 21: a spent catalyst storage silo, 22: a primary washing tank, 23: a distilled water tank, 24: A chemical solution tank, a chemical solution tank, a chemical tank, a chemical tank, a chemical tank, a chemical tank, a chemical tank, Calcination furnace, 42: differentiator

Claims (9)

Collecting spent catalyst components from the waste denitration catalyst module;
A pretreatment step of pulverizing the waste catalyst component and removing a metallic foreign substance using a magnet;
Reacting the pretreated spent catalyst with an inorganic acid to remove poisonous materials in the spent catalyst;
Filtering the waste catalyst from which the poisoning material has been removed to wash it;
Firing the washed spent catalyst; And
And finely pulverizing the calcined waste catalyst. The method of claim 1, The method according to claim 1,
Wherein the pre-treating step is a step of pulverizing the collected catalyst component to a particle size of 100 to 2,000 mu m and then removing a metallic foreign substance in the waste catalyst component with a magnet having a strength of 7000 to 12000 Gauss strength. How to do it. The method according to claim 1,
Wherein the poisoning material is removed by reacting the waste catalyst and the inorganic acid at a temperature of 120 ° C to 300-500 rpm while stirring for 30-120 minutes. The method according to claim 1,
Wherein the inorganic acid is a sulfuric acid aqueous solution having a concentration of 0.1 to 2.0 M, an aqueous hydrochloric acid solution having a concentration of 0.1 to 2.0 M, a hydrogen peroxide aqueous solution having a concentration of 0.1 to 1.0 M, or a mixed solution thereof. . The method according to claim 1,
Wherein the step of removing the poisoning material comprises reacting an inorganic acid with an organic acid to react with a pretreated waste catalyst. The method according to claim 1,
Wherein the step of removing the poisoning material comprises reacting the pretreated waste catalyst with an inorganic acid, and further reacting the waste catalyst with an organic acid reaction solution or a mixed reaction solution of an inorganic acid-organic acid. The method according to claim 5 or 6,
Wherein the organic acid is 0.1 to 1.5 M citric acid aqueous solution or 0.1 to 1.0 M aqueous EDTA solution. The method of claim 7,
Wherein the mixed reaction solution of the organic acid reaction solution or the inorganic acid-organic acid is mixed with citric acid, EDTA, hydrogen peroxide and citric acid, or hydrogen peroxide and EDTA in a volume ratio of 4-6: 4-6. Materialization method. The method according to claim 1,
Wherein the calcining step comprises heating the washed spent catalyst at 140 to 160 DEG C for 40 to 80 minutes and then calcining at 300 to 450 DEG C for 10 to 150 minutes.

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