Preparation method, product and application of NH3-SCR catalyst

Abstract

The invention provides a preparation method, a product and application of an NH3-SCR catalyst, and belongs to the technical field of catalyst preparation. The preparation method comprises the following steps: grinding and sieving the electrolytic manganese residues, and drying to obtain an original sample of the electrolytic manganese residues; roasting the electrolytic manganese residue original sample to obtain an electrolytic manganese residue roasted sample; the electrolytic manganese residue original sample is added into acid liquor to be leached, and leachate is collected; and the electrolytic manganese residue roasting sample is soaked in the leachate and then dried, and the NH3-SCR catalyst is obtained. According to the method provided by the invention, dilute nitric acid is adopted for activating and self-modifying the electrolytic manganese residues, the denitration performance of the electrolytic manganese residues is effectively improved, and the catalyst has the denitration efficiency of 77% or above at the temperature interval of 25-150 DEG C and can reach the denitration efficiency of 100% at the temperature interval of 150-450 DEG C; meanwhile, the problems that an existing bulk solid waste treatment technology is high in cost, a commercial catalyst is poor in thermal stability and the like are solved, and the purpose of treating waste with waste is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst preparation, and particularly relates to a preparation method, product and application of an NH 3 -SCR catalyst. Background Art

[0002] Currently, the catalysts gradually applied to the selective catalytic reduction (NH 3 -SCR) denitration of thermal power generation flue gas are V 2 O 5 -WO 3 / TiO 2 series catalysts. Although they have the characteristic of high denitration efficiency, they have a high denitration temperature, high denitration cost, and poor thermal stability of the catalyst, which limits their application in low-temperature flue gas industries such as glass, rubber, and steel. With the rapid development of the electrolytic manganese industry, the anode mud generated near the electrolytic anode during the electrolytic manganese process, after solid-liquid separation and pressure filtration, produces electrolytic manganese slag. Electrolytic manganese production enterprises must requisition a large amount of special sites to store these solid wastes. This not only increases the production cost of the enterprises, but also a large amount of stacking occupies land resources. At the same time, the leachate generated during the stacking process contains a large amount of ammonia nitrogen elements, seriously polluting the environment and affecting human health. Therefore, using electrolytic manganese slag to prepare a catalyst for catalytic reduction (NH 3 -SCR) denitration, turning waste into treasure and realizing waste treatment with waste, has important application value. Summary of the Invention

[0003] Based on the above, the purpose of the present invention is to provide a preparation method, product and application of an NH 3 -SCR catalyst. The method provided by the present invention uses dilute nitric acid to activate and self-modify electrolytic manganese slag, effectively improving the denitration performance of electrolytic manganese slag, and at the same time solving the problems of high cost of existing bulk solid waste treatment technologies and poor thermal stability of commercial catalysts, achieving the purpose of waste treatment with waste.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] The first aspect of the present invention provides a preparation method of an NH 3 -SCR catalyst, including the following steps:

[0006] After grinding and sieving electrolytic manganese slag, dry it to obtain the original electrolytic manganese slag sample (E);

[0007] Roast the original electrolytic manganese slag sample to obtain the roasted electrolytic manganese slag sample (xE-i);

[0008] Add the original electrolytic manganese slag sample to an acid solution for leaching, and collect the leachate (y% H m E n );

[0009] Immerse the roasted electrolytic manganese slag sample in the leaching solution, and then dry it to obtain NH 3 -SCR catalyst ((y% H m E n )) z -xE j -i).

[0010] In a preferred embodiment of the present invention, the drying temperature is 80°C - 160°C, and the time is 8h - 24h.

[0011] In a preferred embodiment of the present invention, the drying temperature is 80°C, 100°C, 120°C, 140°C or 160°C; the time is 8h, 12, 16h or 24h.

[0012] In a preferred embodiment of the present invention, the roasting temperature is 400°C - 600°C, and the time is 2h - 6h.

[0013] In a preferred embodiment of the present invention, the roasting temperature is 400°C, 450°C, 500°C, 550°C or 600°C, and the time is 2h, 3h, 4h, 5h or 6h.

[0014] In a preferred embodiment of the present invention, the acid solution is nitric acid; the mass concentration of the nitric acid is 2.5% - 10%; the mass-to-volume ratio of the original electrolytic manganese slag to the acid solution is 1g:10 - 25mL.

[0015] In a preferred embodiment of the present invention, the mass concentration of the nitric acid is 2.5%, 3%, 4%, 5%, 7.5% or 10%.

[0016] In a preferred embodiment of the present invention, the leaching process is as follows: first stir, and then let it stand. The stirring time is 30 - 90min; the standing time is 2h.

[0017] In a preferred embodiment of the present invention, the leaching time is 30min, 60min or 90min.

[0018] In a preferred embodiment of the present invention, the mass-to-volume ratio of the roasted electrolytic manganese slag sample to the leaching solution is 2 - 8g:1mL.

[0019] In a preferred embodiment of the present invention, the impregnation time is 12h.

[0020] The second aspect of the present invention provides an NH 3 -SCR catalyst prepared by the above preparation method.

[0021] The third aspect of the present invention provides an above-mentioned NH3 -SCR catalyst in the application of catalytic flue gas denitrification; the flue gas contains NH 3 , NO, N 2 and O 2 .

[0022] The present invention discloses the following technical effects:

[0023] 1. The dilute nitric acid-activated and self-modified electrolytic manganese slag NH 3 -SCR catalyst provided by the present invention has cheap and easily available raw materials, which can greatly reduce the production cost, and treat waste with waste to realize the resource utilization of solid waste.

[0024] 2. The dilute nitric acid-activated and self-modified electrolytic manganese slag NH 3 -SCR catalyst provided by the present invention impregnates the leaching solution (y% H m E n ) onto the roasted electrolytic manganese slag sample (xE-i) during the preparation process, improving the content of active elements such as Fe and Mn in the roasted electrolytic manganese slag sample, thereby improving the denitrification performance of the electrolytic manganese slag.

[0025] 3. The dilute nitric acid-activated and self-modified electrolytic manganese slag NH 3 -SCR catalyst provided by the present invention has a simple preparation method. The electrolytic manganese slag as-received is leached with dilute nitric acid, and only the obtained leaching solution (y% H m E n ) needs to be mixed and impregnated with the roasted electrolytic manganese slag sample (xE-i) to activate and self-modify the electrolytic manganese slag.

[0026] 4. The dilute nitric acid-activated and self-modified electrolytic manganese slag NH 3 -SCR catalyst provided by the present invention can be used for simulated tail gas with a composition of 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 . For flue gas denitrification under the conditions of a total flow rate of 200 mL / min, an airspeed of 70771 h -1 , and a test temperature of 25 - 450 °C. Its denitrification efficiency reaches over 77% in the range of 25 - 150 °C, and the denitrification effect is significant under the conditions of 150 - 450 °C, reaching 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 SEM image of the catalyst sample in Example 1;

[0029] Figure 2 XRD pattern of the catalyst sample in Example 1;

[0030] Figure 3 SEM image of the catalyst sample in Example 2;

[0031] Figure 4 XRD pattern of the catalyst sample in Example 2;

[0032] Figure 5 SEM image of the catalyst sample in Example 3;

[0033] Figure 6 XRD pattern of the catalyst sample in Example 3;

[0034] Figure 7 SCR denitration efficiency diagrams of Example 1 and Examples 4 - 7 under the conditions of Experimental Example 1 and Experimental Examples 4 - 7 respectively;

[0035] Figure 8 For Example 1 and Examples 4 - 7, the N 2 selectivity change trend diagram;

[0036] Figure 9 SCR denitration efficiency diagrams of Example 2 and Examples 8 - 11 under the conditions of Experimental Example 2 and Experimental Examples 8 - 11 respectively;

[0037] Figure 10 For Example 2 and Examples 8 - 11, the N 2 selectivity change trend diagram;

[0038] Figure 11 SCR denitration efficiency diagrams of Example 3 and Examples 12 - 16 under the conditions of Experimental Example 3 and Experimental Examples 12 - 16 respectively;

[0039] Figure 12 For Example 3 and Examples 12 - 16, the N 2 selectivity change trend diagram;

[0040] Figure 13 SCR denitration efficiency diagrams of Example 1, Example 2, Example 3 and Examples 17 - 19 under the conditions of Experimental Example 1, Experimental Example 2, Experimental Example 3 and Experimental Examples 17 - 19 respectively;

[0041] Figure 14 For Example 1, Example 2, Example 3, and Examples 17-19, the N 2 selectivity change trend diagrams under the conditions of Experimental Example 1, Experimental Example 2, Experimental Example 3, and Experimental Examples 17-19;

[0042] Figure 15 For Example 1, Example 2, Example 3, and Examples 20-22, the SCR denitration efficiency diagrams under the conditions of Experimental Example 1, Experimental Example 2, Experimental Example 3, and Experimental Examples 20-22;

[0043] Figure 16 For Example 1, Example 2, Example 3, and Examples 20-22, the N 2 selectivity change trend diagrams under the conditions of Experimental Example 1, Experimental Example 2, Experimental Example 3, and Experimental Examples 20-22;

[0044] Figure 17 The SCR denitration efficiency diagram of the catalysts of Example 3 and Comparative Example 1;

[0045] Figure 18 For the catalysts of Example 3 and Comparative Example 1, the N 2 selectivity change trend diagram. Detailed implementation manners

[0046] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0047] It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0048] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0049] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the description of the present invention, which will be obvious to those skilled in the art. Other embodiments obtained from the description of the present invention will be obvious to those skilled in the art. The description and examples of the present invention are merely exemplary.

[0050] Regarding the use of "comprising", "including", "having", "containing", etc. in this article, they are all open-ended terms, meaning including but not limited to.

[0051] The sources of manganese slag mainly include solid wastes in the process of manganese ore smelting, mainly from the production processes such as blast furnace ferromanganese and silicomanganese alloy. The manganese content varies due to different smelting processes and raw materials, usually between 10% and 30%, and the manganese content in some high-grade manganese slag can even reach more than 50%. Due to the high manganese grade, it is relatively easy to carry out activation modification during reprocessing, and the modified manganese slag has better application effects. Electrolytic manganese slag is the waste residue generated through processes such as acid leaching, neutralization, and pressure filtration of manganese carbonate ore during the production of electrolytic manganese. It has a low manganese grade and a high acidity of the waste residue, making it difficult to reuse. Even if the low-grade electrolytic manganese slag is modified and reused, its application effect is often relatively low and it is difficult to achieve the expected effect. With the increasing annual stockpile of electrolytic manganese slag, how to realize the resource treatment of electrolytic manganese slag is an urgent problem to be solved.

[0052] Since electrolytic manganese slag also contains Fe element and Mn element, if the electrolytic manganese slag is used to make Mn-Fe-based NH 3 -SCR catalyst, the cost of the denitration catalyst can be reduced, thus achieving the purpose of treating waste with waste. Therefore, the NH 3 -SCR catalyst prepared by activating and self-modifying electrolytic manganese slag with dilute nitric acid provided by the present invention has important application value.

[0053] The present invention uses dilute nitric acid to leach the original electrolytic manganese slag, and after standing, the leachate containing manganese ions and iron ions is separated from the solid-liquid. Then it is loaded onto the calcined sample of electrolytic manganese slag, and after drying and grinding and sieving, the NH 3-SCR catalyst. In the present invention, the process of loading the leaching solution containing manganese ions and iron ions obtained by leaching the original electrolytic manganese residue with dilute nitric acid onto the calcined electrolytic manganese residue sample is a process of modifying the electrolytic manganese residue by utilizing the characteristics of Mn and Fe elements contained in the electrolytic manganese residue itself, so as to achieve the purpose of improving the low-temperature catalytic effect while ensuring the high-temperature denitrification effect. In the range of 50-150 °C, the denitrification efficiency is nearly 80%, and in the range of 150-450 °C, the denitrification efficiency is nearly 100%, and no other foreign elements are introduced for modification. Secondly, the calcination activation process of the present invention is to calcine the electrolytic manganese residue before loading the leaching solution, and no longer calcine after loading, which is different from the prior art of drying and then calcining and activating after leaching modification.

[0054] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art. The reagents or raw materials used, unless otherwise specified, are all purchased from commercial channels or are publicly available.

[0055] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments.

[0056] Example 1

[0057] Put the electrolytic manganese residue (EMR) after grinding and screening into an oven and dry it at 120 °C for 12 h to obtain the original electrolytic manganese residue catalyst, named E.

[0058] SEM, XRD and XRF analyses were carried out on the catalyst sample E of this example. As Figure 1 shown, the microscopic morphology of the catalyst is mainly composed of rod-shaped and irregular blocky stacks. Figure 2 There are obvious diffraction peaks of CaSO 4 ·2H 2 O, FeS 2 and SiO 2 in the XRD of, while no obvious diffraction peaks of manganese oxides were detected, which may exist in sample E in an amorphous state. The XRF results in Table 1 show that the original electrolytic manganese residue contains elements such as Fe (52.314%), S (21.461%), Ca (8.163%), Mn (7.308%), Si (5.799%), etc., and the Fe content is relatively high.

[0059] Table 1 Main element composition (wt, %) of the original electrolytic manganese residue (E)

[0060]

[0061] Example 2

[0062] The E in Example 1 was calcined in a muffle furnace at 500 °C for 4 h to obtain an electrolytic manganese slag calcined sample catalyst, named 500E-4.

[0063] SEM, XRD, and XRF analyses were performed on the catalyst sample 500E-4 of this example. As Figure 3 shown, compared with the SEM image of the catalyst sample E, the microscopic morphology of the calcined catalyst is mainly composed of rod-like and irregular blocky stacks, but metal oxide lattice stripes appear on the rod-like structure, indicating that the metal elements in the sample undergo oxidation reactions after calcination, and metal oxides appear. Figure 1 Figure 4 There are obvious diffraction peaks of CaSO 4 , and SiO 2 in the XRD pattern of the catalyst sample 500E-4 in Figure 2 . Compared with the catalyst sample E, the diffraction peak of FeS 2 disappears, and the diffraction peak of Fe 2 O 3 appears. No obvious diffraction peak of manganese oxide was detected, which may be in an amorphous state. The XRF results in Table 2 show that the contents of elements such as Fe (56.54%) and Mn (7.54%) in the catalyst sample 500E-4 increase after calcination compared with the catalyst sample E (Table 1), and the content of S (16.304%) decreases compared with the catalyst sample E (Table 1).

[0064] Table 2 Main element composition (wt, %) of electrolytic manganese slag calcined sample (500E-4)

[0065]

[0066] Example 3

[0067] Take 20 mL of 5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (5% H 20 E 1 ). Then take 4 ml of the leaching solution and mix it with 1 g of the electrolytic manganese slag calcined sample (500E-4), impregnate for 12 h, and then put it into an oven and dry at 120 °C for 12 h to obtain a catalyst, named ((5% H 20 E 1 ) 4 -500E 1 -4).

[0068] SEM, XRD, and XRF analyses were performed on the catalyst sample ((5% H 20 E 1 ) 4 -500E 1 -4) of this example. As Figure 5 ​As shown, compared with the catalyst sample E( Figure 1 ) and the catalyst sample 500E-4( Figure 4 ), the rod-like structure of the catalyst made from electrolytic manganese slag modified by dilute nitric acid disappears and becomes stacked with irregular blocks. Figure 6 There are obvious diffraction peaks of CaSO 4 and SiO 2 in the XRD pattern of Figure 4 , and compared with the catalyst sample 500E-4( 2 ), the diffraction peak of Fe 3 O 20 E 1 ) 4 -500E 1 -4) shows that the contents of Fe (57.82%) and Mn (10.31%) elements in the catalyst sample ((5% H

[0069] Table 3 Main element composition (wt, %) of the electrolytic manganese slag sample modified by dilute nitric acid ((5% H 20 E 1 ) 4 -500E 1 -4)

[0070]

[0071] Example 4

[0072] Roast E of Example 1 in a muffle furnace at 400 °C for 4 h to obtain a roasted electrolytic manganese slag sample catalyst, named 400E-4.

[0073] Example 5

[0074] Roast E of Example 1 in a muffle furnace at 450 °C for 4 h to obtain a roasted electrolytic manganese slag sample catalyst, named 450E-4.

[0075] Example 6

[0076] Roast E of Example 1 in a muffle furnace at 550 °C for 4 h to obtain a roasted electrolytic manganese slag sample catalyst, named 550E-4.

[0077] Example 7

[0078] Roast E of Example 1 in a muffle furnace at 600 °C for 4 h to obtain a roasted electrolytic manganese slag sample catalyst, named 600E-4.

[0079] Example 8

[0080] The E of Example 1 was calcined in a muffle furnace at 500 °C for 1 h to obtain an electrolytic manganese slag calcined sample catalyst, named 500E-1.

[0081] Example 9

[0082] The E of Example 1 was calcined in a muffle furnace at 500 °C for 2 h to obtain an electrolytic manganese slag calcined sample catalyst, named 500E-2.

[0083] Example 10

[0084] The E of Example 1 was calcined in a muffle furnace at 500 °C for 3 h to obtain an electrolytic manganese slag calcined sample catalyst, named 500E-3.

[0085] Example 11

[0086] The E of Example 1 was calcined in a muffle furnace at 500 °C for 5 h to obtain an electrolytic manganese slag calcined sample catalyst, named 500E-5.

[0087] Example 12

[0088] Take 20 mL of 2.5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (2.5% H 20 E 1 ), then take 4 ml of the leaching solution and mix it with 1 g of the electrolytic manganese slag calcined sample (500E-4), impregnate for 12 h, then put it in an oven and dry at 120 °C for 12 h to obtain a catalyst, named ((2.5% H 20 E 1 ) 4 -500E 1 -4).

[0089] Example 13

[0090] Take 20 mL of 3% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (3% H 20 E 1 ), then take 4 ml of the leaching solution and mix it with 1 g of the electrolytic manganese slag calcined sample (500E-4), impregnate for 12 h, then put it in an oven and dry at 120 °C for 12 h to obtain a catalyst, named ((3% H 20 E 1 ) 4 -500E 1 -4).

[0091] Example 14

[0092] Take 20 mL of 4% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag sample (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (4% H 20 E 1 )), then take 4 mL of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E-4), impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain a catalyst, named ((4% H 20 E 1 ) 4 -500E 1 -4).

[0093] Example 15

[0094] Take 20 mL of 7.5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag sample (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (7.5% H 20 E 1 )), then take 4 mL of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E-4), impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain a catalyst, named ((7.5% H 20 E 1 ) 4 -500E 1 -4).

[0095] Example 16

[0096] Take 20 mL of 10% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag sample (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (10% H 20 E 1 )), then take 4 mL of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E-4), impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain a catalyst, named ((10% H 20 E 1 ) 4 -500E 1 -4).

[0097] Example 17

[0098] Take 10 mL of 5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag sample (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (5% H 10 E 1 )), then take 4 mL of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E-4), impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain a catalyst, named ((5% H 10 E1 ) 4 -500E 1 -4)

[0099] Example 18

[0100] Take 15 mL of 5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (5% H 15 E 1 ), then take 4 mL of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E - 4), impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain the catalyst, named ((5% H 15 E 1 ) 4 -500E 1 -4)

[0101] Example 19

[0102] Take 25 mL of 5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (5% H 25 E 1 ), then take 4 mL of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E - 4), impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain the catalyst, named ((5% H 25 E 1 ) 4 -500E 1 -4)

[0103] Example 20

[0104] Take 20 mL of 5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (5% H 20 E 1 ), then take 2 mL of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E - 4), impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain the catalyst, named ((5% H 20 E 1 ) 2 -500E 1 -4)

[0105] Example 21

[0106] Take 20 mL of 5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag (E), stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain the leaching solution (5% H 20 E 1), then take 6 ml of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E-4) and impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain a catalyst named ((5% H 20 E 1 ) 6 -500E 1 -4).

[0107] Example 22

[0108] Take 20 mL of 5% dilute nitric acid and mix it with 1 g of the original electrolytic manganese slag sample (E) and stir for 30 min, then let it stand for 2 h, and then separate the solid and liquid to obtain a leaching solution (5% H 20 E 1 ), then take 8 ml of the leaching solution and mix it with 1 g of the roasted electrolytic manganese slag sample (500E-4) and impregnate for 12 h, then put it into an oven and dry at 120 °C for 12 h to obtain a catalyst named ((5% H 20 E 1 ) 8 -500E 1 -4).

[0109] Above, Example 1 is prepared from the original electrolytic manganese slag sample (E); Examples 2 and 4-11 are prepared from the roasted electrolytic manganese slag sample (xE-i); Examples 3 and 12-22 are prepared from the dilute nitric acid-activated and self-modified electrolytic manganese slag ((y% H m E n ) z -xE j -i).

[0110] Experimental Example 1

[0111] The E catalyst of Example 1 was fixed in a tubular furnace, and simulated tail gas (with components of 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and an airspeed of 70771 h -1 , and the test temperature was 25-450 °C. The denitrification efficiency of the E catalyst was 61% in the temperature range of 25-150 °C, and the N 2 selectivity remained above 100%. The highest denitrification efficiency was 97% in the temperature range of 150-450 °C, and the N 2 selectivity remained above 85%.

[0112] Experimental Example 2

[0113] The 500E-4 catalyst of Example 2 was fixed in a tubular furnace, and simulated tail gas (with components of 500 ppm NO, 500 ppm NH 3 , 5 vol.% O2 and N 2 ), with a total flow rate of 200 mL / min and an airspeed of 7077 1 / h -1 , and the test temperature was 25 - 450 °C. The denitrification efficiency of the 500E-4 catalyst was approximately 80% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. In the temperature range of 150 - 450 °C, the denitrification efficiency was around 96%, and the N 2 selectivity remained above 94%.

[0114] Experimental Example 3

[0115] The ((5% H 20 E 1 ) 4 -500E 1 -4) catalyst was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and an airspeed of 7077 1 / h -1 , and the test temperature was 25 - 450 °C. The ((5% H 20 E 1 ) 4 -500E 1 -4) catalyst had a denitrification efficiency of approximately 80% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. In the temperature range of 150 - 450 °C, the denitrification efficiency reached 100%, and the N 2 selectivity remained above 96%.

[0116] Experimental Example 4

[0117] The 400E-4 catalyst of Example 4 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and an airspeed of 7077 1 / h -1 , and the test temperature was 25 - 450 °C. The 400E-4 catalyst had a maximum denitrification efficiency of 69% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. In the temperature range of 150 - 450 °C, the maximum denitrification efficiency was 94%, and the N 2 selectivity remained above 94%.

[0118] Experimental Example 5

[0119] The 450E-4 catalyst of Example 5 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and a space velocity of 70771 h -1 . The test temperature was 25 - 450 °C. The maximum denitrification efficiency of the 450E-4 catalyst was 74% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. The maximum denitrification efficiency was 96% in the temperature range of 150 - 450 °C, and the N 2 selectivity remained above 95%.

[0120] Experimental Example 6

[0121] The 550E-4 catalyst of Example 6 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and a space velocity of 70771 h -1 . The test temperature was 25 - 450 °C. The maximum denitrification efficiency of the 550E-4 catalyst was 78% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. The maximum denitrification efficiency was 95% in the temperature range of 150 - 450 °C, and the N 2 selectivity remained above 85%.

[0122] Experimental Example 7

[0123] The 600E-4 catalyst of Example 7 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and a space velocity of 70771 h -1 . The test temperature was 25 - 450 °C. The maximum denitrification efficiency of the 600E-4 catalyst was 59% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. The maximum denitrification efficiency was 90% in the temperature range of 150 - 450 °C, and the N 2 selectivity remained above 95%.

[0124] Experimental Example 8

[0125] The 500E-1 catalyst of Example 8 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH3 , 5 vol.% O 2 and N 2 ), total flow rate 200 mL / min, space velocity 7077 1 / h -1 , and the test temperature was 25 - 450 °C. The 500E-1 catalyst had the highest denitration efficiency of up to 90% at 350 °C in the temperature range of 25 - 450 °C, and the N 2 selectivity was maintained above 91%.

[0126] Experimental Example 9

[0127] The 500E-2 catalyst of Example 9 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and a space velocity of 7077 1 / h -1 , and the test temperature was 25 - 450 °C. The 500E-2 catalyst had the highest denitration efficiency of up to 90% at 350 °C in the temperature range of 25 - 450 °C, and the N 2 selectivity was maintained above 92%.

[0128] Experimental Example 10

[0129] The 500E-3 catalyst of Example 10 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and a space velocity of 7077 1 / h -1 , and the test temperature was 25 - 450 °C. The 500E-3 catalyst had the highest denitration efficiency of up to 90% at 350 °C in the temperature range of 25 - 450 °C, and the N 2 selectivity was maintained above 91%.

[0130] Experimental Example 11

[0131] The 500E-5 catalyst of Example 11 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and a space velocity of 7077 1 / h -1 , and the test temperature was 25 - 450 °C. The 500E-5 catalyst had the highest denitration efficiency of up to 90% at 350 °C in the temperature range of 25 - 450 °C, and the N 2 selectivity was maintained above 92%.

[0132] Experimental Example 12

[0133] The ((2.5% H 20 E 1 ) 4 -500E 1 -4) catalyst was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced. The total flow rate was 200 mL / min, and the space velocity was 70771 h -1 . The test temperature was 25 - 450 °C. The ((2.5% H 20 E 1 ) 4 -500E 1 -4) catalyst had a maximum denitrification efficiency of 61% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. In the temperature range of 150 - 450 °C, the maximum denitrification efficiency was 95%, and the N 2 selectivity remained above 87%.

[0134] Experimental Example 13

[0135] The ((3% H 20 E 1 ) 4 -500E 1 -4) catalyst was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced. The total flow rate was 200 mL / min, and the space velocity was 70771 h -1 . The test temperature was 25 - 450 °C. The ((3% H 20 E 1 ) 4 -500E 1 -4) catalyst had a maximum denitrification efficiency of 62% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. In the temperature range of 150 - 450 °C, the maximum denitrification efficiency was 90%, and the N 2 selectivity remained above 93%.

[0136] Experimental Example 14

[0137] The ((4% H 20 E 1 ) 4 -500E1 -4) The catalyst was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and an airspeed of 70771 h -1 . The test temperature was 25 - 450 °C. ((4% H 20 E 1 ) 4 -500E 1 -4) The denitrification efficiency of the catalyst was up to 72% at the temperature range of 25 - 150 °C, and the N 2 selectivity was maintained above 100%. At the temperature range of 150 - 450 °C, the denitrification efficiency was up to 95%, and the N 2 selectivity was maintained above 94%.

[0138] Experimental Example 15

[0139] For the ((7.5% H 20 E 1 ) 4 -500E 1 -4) catalyst in Example 15, it was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and an airspeed of 70771 h -1 . The test temperature was 25 - 450 °C. ((7.5% H 20 E 1 ) 4 -500E 1 -4) The denitrification efficiency of the catalyst was up to 44% at the temperature range of 25 - 150 °C, and the N 2 selectivity was maintained above 100%. At the temperature range of 150 - 450 °C, the denitrification efficiency was up to 94%, and the N 2 selectivity was maintained above 93%.

[0140] Experimental Example 16

[0141] For the ((10% H 20 E 1 ) 4 -500E 1 -4) catalyst in Example 16, it was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2), total flow rate 200 mL / min, space velocity 7077 1 / h -1 , the test temperature is 25 - 450 °C. ((10% H 20 E 1 ) 4 -500E 1 -4) The denitrification efficiency of the catalyst is up to 55% at the temperature range of 25 - 150 °C, and the N 2 selectivity remains above 100%. At the temperature range of 150 - 450 °C, the denitrification efficiency of the catalyst is up to 85%, and the N 2 selectivity remains above 89%.

[0142] Experimental Example 17

[0143] The ((5% H 10 E 1 ) 4 -500E 1 -4) The catalyst is fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) is introduced. The total flow rate is 200 mL / min, and the space velocity is 7077 1 / h -1 , the test temperature is 25 - 450 °C. ((5% H 10 E 1 ) 4 -500E 1 -4) The denitrification efficiency of the catalyst is up to 49% at the temperature range of 25 - 150 °C, and the N 2 selectivity remains above 100%. At the temperature range of 150 - 450 °C, the denitrification efficiency of the catalyst is up to 99%, and the N 2 selectivity remains above 91%.

[0144] Experimental Example 18

[0145] The ((5% H 15 E 1 ) 4 -500E 1 -4) The catalyst is fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) is introduced. The total flow rate is 200 mL / min, and the space velocity is 7077 1 / h -1 , the test temperature is 25 - 450 °C. ((5% H 15 E 1 ) 4 -500E 1-4) The denitration efficiency of the catalyst is up to 52% at the temperature range of 25 - 150 °C, and the N 2 selectivity remains above 100%. At the temperature range of 150 - 450 °C, the denitration efficiency is up to 93%, and the N 2 selectivity remains above 92%.

[0146] Experimental Example 19

[0147] The ((5% H 25 E 1 ) 4 -500E 1 -4) The catalyst was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced. The total flow rate was 200 mL / min, and the space velocity was 70771 h -1 . The test temperature was 25 - 450 °C. The ((5% H 25 E 1 ) 4 -500E 1 -4) The denitration efficiency of the catalyst is up to 60% at the temperature range of 25 - 150 °C, and the N 2 selectivity remains above 100%. At the temperature range of 150 - 450 °C, the denitration efficiency is up to 93%, and the N 2 selectivity remains above 94%.

[0148] Experimental Example 20

[0149] The ((5% H 20 E 1 ) 2 -500E 1 -4) The catalyst was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced. The total flow rate was 200 mL / min, and the space velocity was 70771 h -1 . The test temperature was 25 - 450 °C. The ((5% H 20 E 1 ) 2 -500E 1 -4) The denitration efficiency of the catalyst is up to 59% at the temperature range of 25 - 150 °C, and the N 2 selectivity remains above 100%. At the temperature range of 150 - 450 °C, the denitration efficiency is up to 92%, and the N 2 selectivity remains above 89%.

[0150] Experimental Example 21

[0151] The ((5% H 20 E 1 ) 6 -500E 1 -4) catalyst of Example 21 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and a space velocity of 70771 h -1 , and the test temperature was 25 - 450 °C. The ((5% H 20 E 1 ) 6 -500E 1 -4) catalyst had a maximum denitrification efficiency of 57% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. In the temperature range of 150 - 450 °C, the maximum denitrification efficiency was 95%, and the N 2 selectivity remained above 93%.

[0152] Experimental Example 22

[0153] The ((5% H 20 E 1 ) 8 -500E 1 -4) catalyst of Example 22 was fixed in a tubular furnace, and simulated tail gas (composition: 500 ppm NO, 500 ppm NH 3 , 5 vol.% O 2 and N 2 ) was introduced, with a total flow rate of 200 mL / min and a space velocity of 70771 h -1 , and the test temperature was 25 - 450 °C. The ((5% H 20 E 1 ) 8 -500E 1 -4) catalyst had a maximum denitrification efficiency of 63% in the temperature range of 25 - 150 °C, and the N 2 selectivity remained above 100%. In the temperature range of 150 - 450 °C, the maximum denitrification efficiency was 97%, and the N 2 selectivity remained above 94%.

[0154] The results of Experimental Example 1 and Experimental Examples 4 - 7 are as Figure 7 and Figure 8, the E catalyst was calcined at 400 °C, 450 °C, 500 °C, 550 °C and 600 °C for 4 h to obtain 400E-4, 450E-4, 500E-4, 550E-4 and 600E-4 catalysts. The N of the calcined catalyst xE-i within the temperature range of 25 - 450 °C 2 selectivity was all above 90%. Compared with the E catalyst, the denitrification efficiency of the 500E-4 catalyst reached above 81% within the temperature range of 25 - 150 °C, and the denitrification efficiency within the temperature range of 150 - 450 °C was slightly lower than that of the E catalyst, but all above 90%, higher than other calcined catalysts. While the denitrification efficiency of the E, 400E-4, 450E-4, 550E-4 and 600E-4 catalysts was only up to 78% at most within the temperature range of 25 - 150 °C, and their denitrification efficiencies within the temperature range of 150 - 450 °C were all lower than that of the 500E-4 catalyst. The reason may be that calcination can make the metal generate metal oxides beneficial to the NH 3 -SCR reaction, and at the same time improve the synergy between metals. By comparing Figure 2 catalyst sample E and Figure 5 the XRD patterns of catalyst sample 500E-4, it can be seen that Fe 2 O 3 diffraction peaks appeared during calcination, which may enhance the synergy between Fe and Mn. And Mn, as an important element of the low-temperature NH 3 -SCR catalyst, makes the low-temperature denitrification efficiency of the 500E-4 catalyst increase. Therefore, calcination can not only improve the low-temperature denitrification efficiency of the E catalyst, but also improve the N 2 selectivity of the E catalyst. However, it is difficult to maintain the high-temperature denitrification efficiency of the E catalyst. Therefore, while improving the low-temperature denitrification efficiency of the E catalyst, it is necessary to ensure the high-temperature denitrification efficiency.

[0155] The results of Experimental Example 2, 8 - 11 are as Figure 9 and Figure 10 . Different calcination times have a great influence on the denitrification efficiency of the calcined 500E-i catalyst. The E catalyst was calcined at 500 °C for 1, 2, 3, 4 and 5 h respectively to prepare 500E-1, 500E-2, 500E-3, 500-4 and 500E-5 catalysts. The denitrification efficiency of the 500E-4 catalyst was higher than that of the E, 500E-1, 500E-2, 500E-3 and 500E-5 catalysts in the whole temperature range, and the N 2 selectivity was also higher than that of the 500E-1, 500E-2, 500E-3 and 500E-5 catalysts, all above 90%.

[0156] The results of Experimental Example 3, Experimental Example 12 - 16 are as Figure 11 and Figure 12, ((y% H m E n ) z -xE j -i) catalyst N 2 The selectivities are all above 85%. ((2.5% H 20 E 1 ) 4 -500E 1 ), ((3% H 20 E 1 ) 4 -500E 1 -4), ((4% H 20 E 1 ) 4 -500E 1 -4), ((7.5% H 20 E 1 ) 4 -500E 1 -4), ((10% H 20 E 1 ) 4 -500E 1 -4) catalyst, compared with E catalyst and 500E-4 catalyst, only ((4% H 20 E 1 ) 4 -500E 1 -4) catalyst has a higher denitration efficiency than E catalyst in the temperature range of 25 - 150 °C, but it is difficult to maintain the denitration efficiency in the temperature range of 150 - 450 °C, and its denitration efficiency is only higher than that of 500E-4 catalyst in the temperature range of 200 - 300 °C. For the ((5% H 20 E 1 ) 4 -500E 1 -4) catalyst, its denitration efficiency is higher than that of E catalyst in the whole temperature range of 25 - 450 °C. Not only does the denitration efficiency increase from 62% to 77% in the temperature range of 25 - 150 °C, but while maintaining the denitration efficiency of E catalyst greater than 97% in the temperature range of 150 - 450 °C, it also increases the denitration efficiency by 2 - 5% and reaches 100% denitration efficiency. And the N 2 selectivity remains above 97% in the whole test range. ((5% H 20 E 1 ) 4 -500E 1-4) Compared with the 500E-4 catalyst, the denitrification efficiency of this catalyst is slightly lower than that of the 500E-4 catalyst in the temperature range of 25 to 150 °C, but it is significantly better than that of the 500E-4 catalyst in the temperature range of 150 to 450 °C, and the N 2 selectivity is better than that of the 500E-4 catalyst.

[0157] The results of Experimental Example 1, Experimental Example 2, Experimental Example 3 and Experimental Examples 17-19 are as Figure 13 and Figure 14 , ((y% H m E n )) z -xE j -i) The N 2 selectivity of the catalyst is above 85% in the temperature range of 25 to 450 °C. The ratios of the amount of nitric acid used to E are 10 ml / g, 15 ml / g, and 25 ml / g respectively to prepare ((5% H 10 E 1 )) 4 -500E 1 ), ((5% H 15 E 1 )) 4 -500E 1 ), ((5% H 25 E 1 )) 4 -500E 1 ) Compared with the E catalyst and the 500-4 catalyst, only ((5% H 10 E 1 )) 4 -500E 1 -4), ((5% H 15 E 1 )) 4 -500E 1 -4) The denitrification efficiency of the catalyst is higher than that of the E catalyst and the 500E-4 catalyst in the temperature range of 200 to 250 °C, and lower than that of the E catalyst and the 500E-4 catalyst at other temperature points. The ((5% H 20 E 1 )) 4 -500E 1 -4) catalyst has a denitrification efficiency higher than that of the E catalyst in the entire temperature range of 25 to 450 °C. Not only does the denitrification efficiency increase from 62% to 77% in the temperature range of 25 to 150 °C, but while maintaining the denitrification efficiency of the E catalyst greater than 97% in the temperature range of 150 to 450 °C, it also increases the denitrification efficiency by 2 to 5% and reaches a denitrification efficiency of 100%, and in the entire test range N2 The selectivity is maintained above 97%. ((5% H 20 E 1 ) 4 -500E 1 -4) Compared with the 500E-4 catalyst, the denitration efficiency of this catalyst in the temperature range of 25 - 150°C is slightly lower than that of the 500E-4 catalyst, but in the temperature range of 150 - 450°C, its denitration efficiency is significantly better than that of the 500E-4 catalyst, and the N 2 selectivity is better than that of the 500E-4 catalyst.

[0158] The results of Experimental Example 1, Experimental Example 2, Experimental Example 3 and Experimental Examples 20 - 22 are as Figure 15 and Figure 16 , ((y% H prepared with different usage amounts of leaching solution m E n ) z -xE j -i) Catalyst N 2 selectivity is all above 85%. The ratios of the usage amount of leaching solution to 500E-4 are 2 ml / g, 6 ml / g, and 8 ml / g respectively for the prepared ((5% H 20 E 1 ) 2 -500E 1 -4), ((5% H 20 E 1 ) 6 -500E 1 -4), ((5% H 20 E 1 ) 8 -500E 1 -4) Compared with the E catalyst and the 500E-4 catalyst, in the entire temperature range of 25 - 450°C, only ((5% H 20 E 1 ) 2 -500E 1 -4), ((5% H 20 E 1 ) 8 -500E 1 -4) The denitration efficiency of the catalyst is higher than that of the E catalyst and the 500E-4 catalyst in the temperature range of 200 - 250°C, and lower than that of the E catalyst and the 500E-4 catalyst at other temperature points. And for the ((5% H prepared with the ratio of the usage amount of leaching solution to 500E-4 being 4 ml / g 20 E 1 ) 4 -500E 1-4) The catalyst has a denitrification efficiency higher than that of catalyst E throughout the temperature range of 25 to 450 °C. Not only does the denitrification efficiency increase from 62% to 77% in the temperature range of 25 to 150 °C, but while maintaining a denitrification efficiency of greater than 97% in the temperature range of 150 to 450 °C for catalyst E, the denitrification efficiency is increased by 2 to 5% to reach a denitrification efficiency of 100%, and the N 2 selectivity remains above 97%. ((5% H 20 E 1 ) 4 -500E 1 -4 catalyst, when compared with the 500E-4 catalyst, has a slightly lower denitrification efficiency in the temperature range of 25 to 150 °C, but significantly better denitrification efficiency in the temperature range of 150 to 450 °C, and the N 2 selectivity is better than that of the 500E-4 catalyst.

[0159] Comparative Example 1

[0160] 1) After grinding, sieving, and drying electrolytic manganese slag, the original electrolytic manganese slag (E) is obtained;

[0161] 2) Add 1 g of the original electrolytic manganese slag to 20 ml of dilute nitric acid with a mass concentration of 5% for leaching, and collect the leaching solution (5% H 20 E 1 );

[0162] 3) Immerse 1 g of the original electrolytic manganese slag (E) in 4 ml of the above leaching solution (5% H 20 E 1 ), let it stand, then dry and calcine (500 °C, 4 h) to obtain the catalyst ((5% H 20 E 1 ) 4 -E 1 -500 °C - 4).

[0163] Comparative Example 1 is a scheme of calcining after loading the leaching solution on the original electrolytic manganese slag (E). Compared with the scheme of the present application of calcining first and then loading (Example 3), the denitrification performance is as Figure 17 、 18 shown (the test process refers to Test Example 3). For the catalyst ((5% H 20 E 1 ) 4 -E 1 -500 °C - 4) of the scheme of calcining after loading, its denitrification efficiency is lower than that of the catalyst (5% H 20 E 1 ) 4 -500E 1-4), and its N 2 Selectively in the range of 50 - 450 °C is also lower than that of the catalyst ((5% H 20 E 1 ) 4 -500E 1 -4).

[0164] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing an NH3-SCR catalyst, characterized in that: The following steps are involved: Grinding and sieving the electrolytic manganese slag, and drying it to obtain the electrolytic manganese slag original sample; calcining the electrolytic manganese slag original sample to obtain an electrolytic manganese slag calcined sample; adding the electrolytic manganese slag as is into the acid solution for leaching, and collecting the leaching solution; The calcined electrolytic manganese slag sample is immersed in the leaching solution and then dried to obtain an NH3-SCR catalyst.

2. The method for preparing the NH3-SCR catalyst according to claim 1, characterized in that: The drying temperature is 80° C.-160° C., and the drying time is 8 h-24 h.

3. The method for preparing the NH3-SCR catalyst according to claim 1, characterized in that: The calcination temperature is 400° C.-600° C., and the calcination time is 2 h-6 h.

4. The method for preparing the NH3-SCR catalyst according to claim 1, characterized in that: The acid solution is nitric acid; the mass concentration of the nitric acid is 2.5%-10%; the mass volume ratio of the electrolytic manganese slag original sample to the acid solution is 1g:10-25mL.

5. The method for preparing the NH3-SCR catalyst according to claim 1, characterized in that: The leaching process is as follows: stirring first and then standing still; the stirring time is 30-90 minutes; and the standing still time is 2 hours.

6. The method for preparing the NH3-SCR catalyst according to claim 1, characterized in that: The mass volume ratio of the electrolytic manganese slag roasted sample to the leaching solution is 2-8g:1mL.

7. The method for preparing the NH3-SCR catalyst according to claim 1, characterized in that: The immersion time is 12 hours.

8. An NH3-SCR catalyst prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the NH3-SCR catalyst according to claim 8 in catalytic flue gas denitrification; the flue gas contains NH3, NO, N2 and O2.

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