Method for preparing catalyst using aluminum ore tailings, catalyst and application method thereof

Abstract

The present invention relates to the field of waste resource utilization, and discloses a method for preparing a catalyst using aluminum ore tailings, and its catalyst, application, and application method. The method comprises: (1) crushing the aluminum ore tailings and then ball milling to obtain aluminum ore tailings powder; (2) ultrasonically mixing the aluminum ore tailings powder with a precursor solution, followed by stirring, and then solid-liquid separation, and calcining the obtained solid phase; the precursors are copper salts and manganese salts. The method uses aluminum ore tailings to prepare a catalyst, and the aluminum ore tailings are mixed with a precursor solution containing copper salts and manganese salts and then calcined to prepare a catalyst that simultaneously catalyzes the synergistic removal of CO and NO in exhaust gas. The catalyst of the present invention has a wide active temperature range, a high conversion efficiency of CO and NO in the catalytic gas, and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the field of waste resource utilization, and in particular to a method for preparing a catalyst by utilizing aluminum ore tailings, the catalyst and an application method thereof. Background Art

[0002] CO is a common air pollutant, the most abundant and widely distributed in the atmosphere. It is a product of the incomplete combustion of carbon-containing substances such as coal and petroleum. High concentrations of CO can cause symptoms such as fatigue, nausea, hallucinations, inability to move, general weakness, and drowsiness. It is generally irritating, persistent, highly toxic, and has "tri-hazard" effects, making it extremely biotoxic. Similar to CO, NO is also an air pollutant. NO can bind to human hemoglobin, causing suffocation. It is corrosive and physiologically irritating to the human body, and inhalation into the lungs can cause respiratory infections. Furthermore, large-scale emissions of CO and NO not only contribute to the formation of acid rain and corrode metals and plants, but also create air pollution such as photochemical smog and atmospheric haze, seriously affecting human health. Therefore, reducing atmospheric CO and NO is of paramount importance.

[0003] Among the atmospheric pollutant control technologies, selective catalytic reduction technology (SCR denitrification method) is currently the mainstream technology for reducing oxide emissions from combustion engines due to its advantages such as high efficiency, stable performance, and strong load adaptability. Selective catalytic reduction refers to the selective catalytic reduction of NOx into N2 and H2O using a reducing agent (such as NH3, H2, CO or hydrocarbons) in the presence of a catalyst and oxygen. Among them, ammonia selective catalytic reduction (NH3 selective catalytic reduction, NH3-SCR) technology, as one of the efficient technologies in the field of denitrification, is widely used in fields such as reducing NOx in flue gas from coal-fired boilers. However, the currently commonly used SCR denitrification catalysts are not ideal for the removal of CO, and in recent years, there have been an increasing number of research reports on the removal of NO or CO alone, but the development of catalysts that can simultaneously remove NO and CO with efficient synergistic performance is still lacking.

[0004] Aluminum ore tailings are a byproduct of aluminum mining and utilization, with an annual discharge volume of 3 to 4 million tons. If these tailings are not properly handled and utilized, they will inevitably lead to significant resource waste and serious environmental pollution. Currently, aluminum ore tailings are primarily used as raw materials for building materials. This extensive utilization method fails to fully utilize the valuable elements in the tailings, such as aluminum, and its many excellent properties are not fully utilized, failing to fully utilize them. Furthermore, in existing technologies, aluminum ore tailings are often subjected to acid leaching, which produces large amounts of waste acid containing metal ions during the treatment process. This poses challenges in the purification and treatment of secondary wastewater, making industrial implementation difficult. Summary of the Invention

[0005] The present invention aims to overcome the problems existing in the prior art, such as the difficulty in resource utilization of aluminum ore tailings and the difficulty in simultaneously treating NO and CO. A method for preparing a catalyst using aluminum ore tailings, a catalyst, and an application method thereof are provided. The method uses aluminum ore tailings to prepare a catalyst, wherein the aluminum ore tailings are mixed with a precursor solution containing a copper salt and a manganese salt, and then calcined to prepare a catalyst for simultaneously removing CO and NO from tail gas. The catalyst of the present invention has a wide active temperature range, a high removal effect of CO and NO from gas, and broad application prospects.

[0006] In order to achieve the above object, the present invention provides a method for preparing a catalyst using aluminum ore tailings, the method comprising the following steps:

[0007] (1) crushing the aluminum ore tailings and then ball milling them to obtain aluminum ore tailings powder;

[0008] (2) ultrasonically mixing the aluminum ore tailings powder with the precursor solution, followed by stirring, and then solid-liquid separation, and calcining the obtained solid phase;

[0009] The precursors are copper salt and manganese salt.

[0010] Preferably, the aluminum ore tailings contain 18-24 wt% of Al2O3, 3-5 wt% of CaO, 4-7 wt% of MgO and 1-3 wt% of Fe2O3.

[0011] Preferably, the particle size of the aluminum ore tailings powder is 40-80 mesh.

[0012] Preferably, the weight ratio of the aluminum ore tailings powder, copper salt and manganese salt is 17-31:1.2-3.5:1;

[0013] Preferably, the copper salt is selected from copper nitrate, copper chloride or copper sulfate; and the manganese salt is manganese nitrate or manganese chloride.

[0014] Preferably, in step (2), the calcination conditions include: temperature of 450-550° C. and time of 5-8 h.

[0015] A second aspect of the present invention provides a catalyst prepared by the above method for preparing a catalyst using aluminum ore tailings.

[0016] A third aspect of the present invention provides a use of the above catalyst in treating tail gas containing CO and NO.

[0017] A fourth aspect of the present invention provides a method for treating tail gas containing CO and NO, the method comprising: mixing the tail gas containing CO and NO, oxygen and ammonia to react in the presence of the above-mentioned catalyst;

[0018] Preferably, the reaction temperature is 100-320°C, preferably 150-300°C.

[0019] Preferably, in the tail gas containing CO and NO, the concentration of CO is 80-150 ppm, and the concentration of NO is 400-600 ppm.

[0020] Beneficial effects of the present invention:

[0021] (1) In the method described in the present invention, aluminum ore tailings are creatively used to prepare a catalyst. The prepared catalyst can simultaneously catalytically remove NO and CO from exhaust gas, which not only broadens the preparation method of the SCR catalyst, but also further expands the application range of the SCR catalyst. Compared with the conventional SCR denitrification catalyst in the prior art that can only remove NOx, it has a broader application prospect;

[0022] (2) The method of the present invention uses aluminum ore tailings as raw materials for preparing catalysts, fully utilizing the excellent properties of aluminum ore tailings such as large specific surface area, rich pore structure and strong stability, using aluminum ore tailings as carriers of catalysts, and combining various components such as aluminum oxide, calcium oxide, iron oxide and magnesium oxide contained in the aluminum ore tailings with copper oxide and manganese oxide to give the catalyst excellent performance, making overall use of the aluminum ore tailings, utilizing components such as CaO, MgO, Al2O3 and Fe2O3 in the aluminum ore tailings, and not generating additional residues, and using all components of the aluminum ore tailings for preparing catalysts; and the pretreatment of the aluminum ore tailings in the present invention is simple, requiring only crushing, ball milling and screening of the aluminum ore tailings, without the need for acid hydrolysis treatment, without generating a large amount of waste liquid, and avoiding secondary pollution, thereby greatly improving the utilization rate of the aluminum ore tailings and truly realizing the resource recovery and reuse of all the aluminum ore tailings;

[0023] (3) The catalyst prepared by the method described in the present invention has a wider active temperature window, and the prepared catalyst has a large specific surface area and excellent catalytic activity. It can simultaneously catalyze the synergistic removal of NO and CO in the exhaust gas. The catalyst described in the present invention has excellent catalytic performance at a temperature of 100-350°C, with an NO conversion rate of 95.2% and a CO conversion rate of 94.6%, and has great application prospects. DETAILED DESCRIPTION

[0024] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0025] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0026] The present invention provides a method for preparing a catalyst using aluminum ore tailings, the method comprising the following steps:

[0027] (1) crushing the aluminum ore tailings and then ball milling them to obtain aluminum ore tailings powder;

[0028] (2) ultrasonically mixing the aluminum ore tailings powder with the precursor solution, followed by stirring, and then solid-liquid separation, and calcining the obtained solid phase;

[0029] The precursors are copper salt and manganese salt.

[0030] In the method of the present invention, the aluminum ore tailings are a byproduct of titanium ore mining and utilization, and contain various metal oxides such as K2O, CaO, MgO, Al2O3, and Fe2O3. In the present invention, the selected aluminum tailings are limited to contain 18-24wt% Al2O3, 3-5wt% CaO, 4-7wt% MgO, and 1-3wt% Fe2O3.

[0031] In the method described in the present invention, Al2O3, CaO and MgO in the aluminum ore tailings are used as carriers of the active components of the catalyst. The doping of CaO and MgO in the aluminum ore tailings may make the active components more evenly dispersed on the surface of the catalyst carrier, which is conducive to increasing the specific surface area of ​​the catalyst. The doping of Fe2O3 can further enhance the catalytic activity of the catalyst, thereby making the catalytic activity of the prepared catalyst more excellent. In addition, since the surface acidity of the catalyst prepared by using aluminum ore tailings as a carrier of the active components of the catalyst is stronger, the activity window of the obtained catalyst is further widened. Furthermore, in the prior art, nitric acid is usually used to leach Al2O3 in the aluminum ore tailings, and then the active components are loaded to prepare NH3-SCR catalysts. This only utilizes a part of the components in the aluminum ore tailings, and there is still a large waste of resources. In the method described in the present invention, when the aluminum ore tailings are recycled and reused as resources, the aluminum ore tailings can be crushed and ball-milled and then all used to prepare the catalyst. All components of the aluminum ore tailings can be used without generating additional residue, thus truly realizing the resource recycling of the entire aluminum ore tailings and opening up a new direction for the overall resource utilization of aluminum ore tailings.

[0032] In a preferred embodiment, in step (1), the ball milling time is 15-75 min, preferably 30-50 min. Specifically, the ball milling time can be 15 min, 30 min, 40 min, 50 min, 60 min, 70 min or 75 min.

[0033] In a preferred embodiment, in order to further improve the activity of the prepared catalyst, the particle size of the aluminum ore tailings powder is controlled to be 40-80 mesh, preferably 40-60 mesh.

[0034] In a specific embodiment, aluminum ore tailings powder with a particle size of 40-80 mesh can be collected by screening, and the specific method is: the ball-milled material is passed through a 40-mesh sieve to collect the undersize material, and then the undersize material is passed through an 80-mesh sieve to collect the oversize material to obtain aluminum ore tailings powder with a particle size of 40-80 mesh.

[0035] In a specific embodiment, the precursors are a copper salt and a manganese salt. More specifically, the copper salt is selected from copper nitrate, copper chloride, or copper sulfate; and the manganese salt is manganese nitrate or manganese chloride. Preferably, the copper salt is copper nitrate, and the manganese salt is manganese nitrate.

[0036] In the method described herein, the copper salt in the precursor is subsequently calcined to form copper oxide, which serves as the active component of the catalyst. The manganese salt in the precursor is then calcined to form manganese oxide, which serves as a catalyst additive. Both the active component and the additive are loaded onto aluminum ore tailings. The synergistic effect between the copper oxide, manganese oxide, and the aluminum oxide, iron oxide, calcium oxide, and magnesium oxide contained in the aluminum ore tailings enables the prepared catalyst to simultaneously remove NO and CO from exhaust gas, further expanding the catalyst's application range.

[0037] In the method of the present invention, the precursor solution is prepared by uniformly mixing copper salt and manganese salt with water to obtain the precursor solution.

[0038] In a specific embodiment, in step (2), the aluminum ore tailings powder is ultrasonically mixed with the precursor solution, and the aluminum ore tailings powder is better dispersed in the precursor solution by ultrasound, which is conducive to the full mixing of the aluminum ore tailings and the precursor solution, and at the same time, it can also enhance the activity of the prepared catalyst.

[0039] In a preferred embodiment, in step (2), the ultrasonic mixing time is 20-40 minutes. Specifically, the ultrasonic mixing time can be 20 minutes, 30 minutes or 40 minutes.

[0040] In a preferred embodiment, in step (2), the ultrasonically mixed material is stirred so that the precursor is attached to the aluminum ore tailings powder as much as possible, so that it is loaded with more active substances. The stirring time is 6-10 hours, preferably 7-9 hours, and the stirring speed is 2000-2500 r / min. Specifically, the stirring time can be 6 hours, 7 hours, 8 hours, 9 hours or 10 hours; the stirring speed can be 2000 r / min, 2100 r / min, 2200 r / min, 2300 r / min, 2400 r / min or 2500 r / min.

[0041] In a specific embodiment, the stirring method is mechanical stirring or magnetic stirring.

[0042] In a preferred embodiment, to further enhance the activity of the prepared catalyst, the weight ratio of the aluminum ore tailings powder, copper salt, and manganese salt is controlled to be 17-31:1.2-3.5:1, more preferably 17-31:1.5-2.5:1, and even more preferably 17-27:2-2.8:1. When the amounts of aluminum ore tailings powder, copper salt, and manganese salt are outside the range defined by the present invention, the catalytic efficiency of the prepared catalyst will be adversely affected, resulting in a decrease in the removal efficiency of NO and CO in the exhaust gas.

[0043] In the method of the present invention, in step (2), the solid phase obtained by solid-liquid separation needs to be dried before calcining. The drying conditions include: a temperature of 100-150°C and a time of 40-55 hours. Specifically, the drying temperature can be 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C; and the drying time can be 40 hours, 45 hours, 48 ​​hours, 50 hours, 53 hours, or 55 hours.

[0044] In a preferred embodiment, in step (2), the calcination conditions include: a temperature of 450-550°C, preferably 480-520°C; and a time of 5-8 hours, preferably 5.5-7 hours. Specifically, the calcination temperature can be 450°C, 480°C, 500°C, 520°C, 540°C, or 550°C; and the calcination time can be 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, or 8 hours.

[0045] In a preferred embodiment, in step (2), the atmosphere during calcination is air, the heating rate during calcination is 5-10°C / min, the heating rate refers to the rate at which the room temperature is raised to the calcination temperature, and the calcination time refers to the holding time during calcination.

[0046] In a specific embodiment, the heating rate during calcination can be 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min.

[0047] The present invention further provides a catalyst prepared by the above-mentioned method for preparing a catalyst using aluminum ore tailings. In the catalyst of the present invention, the active ingredient is copper oxide, the catalyst promoter is manganese oxide, and the catalyst carrier is the oxides obtained from calcined aluminum ore tailings. The synergistic effect between the copper oxide, manganese oxide, and the aluminum oxide, iron oxide, calcium oxide, and magnesium oxide contained in the calcined aluminum ore tailings enables the catalyst to simultaneously remove both NO and CO from exhaust gas, eliminating its limitation to removing only a single harmful gas. Compared to SCR denitrification catalysts prepared using existing technologies, its application range is broader.

[0048] The present invention also provides an application of the catalyst prepared by the above method in treating tail gas containing CO and NO.

[0049] The present invention further provides a method for treating tail gas containing CO and NO, the method comprising: mixing the tail gas containing CO and NO with oxygen and ammonia to react in the presence of the above catalyst.

[0050] In the method described in the present invention, the method for treating tail gas containing CO and NO is to use ammonia as a reducing gas. With the assistance of oxygen, in the presence of the catalyst described in the present invention, NO in the tail gas is mixed with ammonia and oxygen and then undergoes an oxidation-reduction reaction to convert it into nitrogen and water, thereby removing NO gas from the tail gas. In addition, CO in the tail gas also reacts with oxygen or NO2, an intermediate product of the NO redox reaction, in the presence of the catalyst prepared by the present invention, to convert it into CO2, thereby converting CO to CO2 and reducing the CO content in the tail gas emissions. In addition, during the CO removal process, the reaction of CO with oxygen can also release a large amount of heat energy, further promoting the NO redox reaction, increasing the rate of the NO redox reaction, prompting more NO to be converted into N2, and further improving the NO conversion rate, thereby achieving the purpose of synergistic removal of NO and CO, while reducing the emissions of CO and NO in the tail gas.

[0051] In a preferred embodiment, the reaction temperature is 100-320° C., preferably 150-300° C., more preferably 200-300° C. Specifically, the reaction temperature can be 100° C., 150° C., 200° C., 250° C., 300° C. or 320° C.

[0052] In a preferred embodiment, in the tail gas containing CO and NO, the concentration of CO is 80-150 ppm, preferably 90-120 ppm; the concentration of NO is 400-600 ppm, preferably 450-550 ppm. Specifically, the concentration of CO is 80 ppm, 90 ppm, 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140 ppm, or 150 ppm; and the concentration of NO is 400 ppm, 450 ppm, 500 ppm, 550 ppm, or 600 ppm.

[0053] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0054] The aluminum ore tailings used in the following examples and comparative examples are tailings produced when Gansu Zhangye Silicon Products Development Co., Ltd. mines aluminum ore.

[0055] The aluminum ore tailings used in Examples 1 to 3 contained 21.37 wt% of Al2O3, 4.2 wt% of CaO, 5.37 wt% of MgO and 1.56 wt% of Fe2O3, which were determined by X-ray fluorescence spectroscopy.

[0056] The calculation formula for the NO conversion rate is: (NO concentration in the gas before reaction - NO concentration in the gas after reaction) / NO concentration in the gas before reaction; the calculation formula for the CO conversion rate is: (CO concentration in the gas before reaction - CO concentration in the gas after reaction) / CO concentration in the gas before reaction.

[0057] Example 1

[0058] (1) crushing the aluminum ore tailings and ball milling for 30 min, then passing the ball-milled material through a 40-mesh sieve, taking the undersize material and passing it through a 60-mesh sieve, and taking the oversize material to obtain aluminum ore tailings powder with a particle size of 40-60 mesh;

[0059] (2) 6 g of Cu(NO3)2 and 2.5 g of Mn(NO3)2 were mixed and dissolved in 100 mL of deionized water to obtain a precursor solution. Then, 55 g of aluminum ore tailings powder was ultrasonically mixed with the precursor solution for 30 min, followed by stirring for 8 h at a stirring speed of 2200 r / min. The solid and liquid were then separated, and the obtained solid phase was dried at 120 °C for 48 h, then heated to 500 °C at 8 °C / min in an air atmosphere and calcined for 6 h. The catalyst was obtained after natural cooling.

[0060] Example 2

[0061] (1) crushing the aluminum ore tailings and ball milling for 30 min, then passing the ball-milled material through a 40-mesh sieve, taking the undersize material and passing it through a 60-mesh sieve, and taking the oversize material to obtain aluminum ore tailings powder with a particle size of 40-60 mesh;

[0062] (2) 7 g of Cu(NO3)2 and 2.5 g of Mn(NO3)2 were mixed and dissolved in 100 mL of deionized water to obtain a precursor solution. Then, 57.5 g of aluminum ore tailings powder was ultrasonically mixed with the precursor solution for 35 min, and then stirred for 8.5 h at a stirring speed of 2300 r / min. The solid and liquid were then separated, and the obtained solid phase was dried at 120 ° C for 50 h, and then heated to 520 ° C at 7 ° C / min in an air atmosphere and calcined for 7 h. The catalyst was obtained after natural cooling.

[0063] Example 3

[0064] (1) crushing the aluminum ore tailings and ball milling for 30 min, then passing the ball-milled material through a 40-mesh sieve, taking the undersize material and passing it through a 60-mesh sieve, and taking the oversize material to obtain aluminum ore tailings powder with a particle size of 40-60 mesh;

[0065] (2) 6.3 g of Cu(NO3)2 and 2.5 g of Mn(NO3)2 were mixed and dissolved in 100 mL of deionized water to obtain a precursor solution. Then, 62.5 g of aluminum ore tailings powder was ultrasonically mixed with the precursor solution for 30 min, followed by stirring for 8 h at a stirring speed of 2200 r / min. The solid-liquid separation was then carried out, and the obtained solid phase was dried at 140 °C for 45 h, heated to 480 °C at 6 °C / min in an air atmosphere, and calcined for 7 h. The catalyst was obtained after natural cooling.

[0066] Application Example 1

[0067] A small piece of the catalyst prepared in Example 1 was placed in a catalyst evaluation device (provided by Tianjin Xianquan Industry and Trade Development Co., Ltd., model WFS-3015), and a simulated gas was introduced to carry out the reaction at a temperature of 300° C. After the reaction, the concentrations of NO and CO in the product were detected online using a flue gas analyzer (provided by MRU, Germany, model MGA-5). The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0068] The composition of the simulated gas is: 500ppm NO, 500ppm NH3, 7.5vol% O2, 100ppm CO, and N2 as the balance gas; the simulated air flow rate is 1000ml / min, and the space velocity is 36000h -1 .

[0069] Application Example 2

[0070] A small piece of the catalyst prepared in Example 2 was placed in a catalyst evaluation device (provided by Tianjin Xianquan Industry and Trade Development Co., Ltd., model WFS-3015), and a simulated gas was introduced to carry out the reaction at a temperature of 300°C. After the reaction, the concentrations of NO and CO in the product were detected online using a flue gas analyzer (provided by MRU, Germany, model MGA-5). The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0071] The composition of the simulated gas is: 500ppm NO, 500ppm NH3, 7.5vol% O2, 100ppm CO, and N2 as the balance gas; the simulated air flow rate is 1000ml / min, and the space velocity is 36000h -1 .

[0072] Application Example 3

[0073] A small piece of the catalyst prepared in Example 3 was placed in a catalyst evaluation device (provided by Tianjin Xianquan Industry and Trade Development Co., Ltd., model WFS-3015), and a simulated gas was introduced to carry out the reaction at a temperature of 300°C. After the reaction, the concentrations of NO and CO in the product were detected online using a flue gas analyzer (provided by MRU, Germany, model MGA-5). The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0074] The composition of the simulated gas is: 500ppm NO, 500ppm NH3, 7.5vol% O2, 100ppm CO, and N2 as the balance gas; the simulated air flow rate is 1000ml / min, and the space velocity is 36000h -1 .

[0075] Application Example 4

[0076] The method of Application Example 1 was followed, except that the reaction temperature in Application Example 1 was changed to 100° C. The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0077] Application Example 5

[0078] The method of Application Example 1 was followed, except that the reaction temperature in Application Example 1 was changed to 150° C. The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0079] Application Example 6

[0080] The method of Application Example 1 was followed, except that the reaction temperature in Application Example 1 was changed to 200° C. The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0081] Application Example 7

[0082] The method of Application Example 1 was followed, except that the reaction temperature in Application Example 1 was changed to 250° C. The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0083] Application Example 8

[0084] The method of Application Example 1 was followed, except that the reaction temperature in Application Example 1 was changed to 320° C. The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0085] Comparative Example 1

[0086] The method described in Example 1 was carried out, except that the aluminum ore tailings were replaced with gold-copper tailings of equal weight, and the gold-copper tailings used contained 32.12 wt% SiO2, 26.08 wt% CaO and 21.13 wt% Fe2O3 (this content was obtained by X-ray fluorescence spectroscopy).

[0087] Comparative Example 2

[0088] The method described in Example 1 was used, except that Cu(NO3)2 was replaced by ammonium metatungstate of equal weight for preparation.

[0089] Comparative Example 3

[0090] The method described in Example 1 was used, except that Mn(NO3)2 was replaced by an equal weight of zinc nitrate for preparation.

[0091] Comparative Example 4

[0092] A small piece of the catalyst prepared in Comparative Example 1 was placed in a catalyst evaluation device (provided by Tianjin Xianquan Industry and Trade Development Co., Ltd., model WFS-3015), and a simulated gas was introduced to react at a temperature of 300°C. After the reaction, the concentrations of NO and CO in the product were detected online by a flue gas analyzer (provided by MRU, Germany, model MGA-5). The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0093] The composition of the simulated gas is: 500ppm NO, 500ppm NH3, 7.5vol% O2, 100ppm CO, and N2 as the balance gas; the simulated air flow rate is 1000ml / min, and the space velocity is 36000h -1 .

[0094] Comparative Example 5

[0095] A small piece of the catalyst prepared in Comparative Example 2 was placed in a catalyst evaluation device (provided by Tianjin Xianquan Industry and Trade Development Co., Ltd., model WFS-3015), and a simulated gas was introduced to react at a temperature of 300°C. After the reaction, the concentrations of NO and CO in the product were detected online by a flue gas analyzer (provided by MRU, Germany, model MGA-5). The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0096] The composition of the simulated gas is: 500ppm NO, 500ppm NH3, 7.5vol% O2, 100ppm CO, and N2 as the balance gas; the simulated air flow rate is 1000ml / min, and the space velocity is 36000h -1 .

[0097] Comparative Example 6

[0098] A small piece of the catalyst prepared in Comparative Example 3 was placed in a catalyst evaluation device (provided by Tianjin Xianquan Industry and Trade Development Co., Ltd., model WFS-3015), and a simulated gas was introduced to react at a temperature of 300°C. After the reaction, the concentrations of NO and CO in the product were detected online by a flue gas analyzer (provided by MRU, Germany, model MGA-5). The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0099] The composition of the simulated gas is: 500ppm NO, 500ppm NH3, 7.5vol% O2, 100ppm CO, and N2 as the balance gas; the simulated air flow rate is 1000ml / min, and the space velocity is 36000h -1 .

[0100] Comparative Example 7

[0101] The method of Application Example 1 was followed, except that the reaction temperature in Application Example 1 was changed to 50° C. The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0102] Comparative Example 8

[0103] The method of Application Example 1 was followed, except that the reaction temperature in Application Example 1 was changed to 350° C. The NO conversion rate and CO conversion rate were calculated, and the results are shown in Table 1.

[0104] Table 1

[0105] Example No. Reaction temperature NO conversion rate CO conversion rate Application Example 1 300℃ 95.6％ 94.6％ Application Example 2 300℃ 96.2％ 92.2％ Application Example 3 300℃ 95.4％ 91.5％ Application Example 4 100℃ 92.3％ 80％ Application Example 5 150℃ 92.4％ 84.1％ Application Example 6 200℃ 95.1％ 91.8％ Application Example 7 250℃ 95.2％ 93.1％ Application Example 8 320℃ 90.8％ 90.4％ Comparative Example 4 300℃ 82.3％ 70.1％ Comparative Example 5 300℃ 78.2％ 68.3％ Comparative Example 6 300℃ 69.2％ 59.2％ Comparative Example 7 50℃ 57.2％ 44.8％ Comparative Example 8 350℃ 78.5％ 78.6％

[0106] The results in Table 1 indicate that the catalyst prepared using the method described herein can simultaneously and synergistically remove NO and CO, and achieves high conversion rates for both NO and CO in tail gas. Furthermore, the present invention utilizes aluminum ore tailings to prepare a catalyst capable of simultaneous and synergistic removal of NO and CO, further realizing resource utilization of aluminum ore tailings and possessing promising industrial application prospects.

[0107] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for preparing a catalyst using aluminum ore tailings, characterized in that: The method comprises the following steps: (1) crushing the aluminum ore tailings and then ball milling them to obtain aluminum ore tailings powder; (2) Ultrasonic mixing of aluminum ore tailings powder and precursor solution, followed by stirring, followed by solid-liquid separation, and calcination of the obtained solid phase; The precursors are copper salt and manganese salt; The aluminum ore tailings contain 18-24wt% Al2O3, 3-5wt% CaO, 4-7wt% MgO and 1-3wt% Fe2O3; The weight ratio of the aluminum ore tailings powder, copper salt and manganese salt is (17-31): (1.2-3.5):

1.

2. The method for preparing a catalyst using aluminum ore tailings according to claim 1, wherein: The particle size of the aluminum ore tailings powder is 40-80 meshes.

3. The method for preparing a catalyst using aluminum ore tailings according to claim 1, wherein: The copper salt is selected from copper nitrate, copper chloride or copper sulfate; the manganese salt is manganese nitrate or manganese chloride.

4. The method for preparing a catalyst using aluminum ore tailings according to claim 1, wherein: In step (2), the calcination conditions include: temperature of 450-550°C and time of 5-8h.

5. A catalyst prepared by the method for preparing a catalyst using aluminum ore tailings according to claim 1.

6. Use of the catalyst according to claim 5 in treating tail gas containing CO and NO.

7. A method for treating tail gas containing CO and NO, characterized in that: The method comprises: mixing tail gas containing CO and NO, oxygen and ammonia to react in the presence of the catalyst according to claim 5; The reaction temperature is 100-320°C.

8. The method for treating tail gas containing CO and NO according to claim 7, characterized in that: In the exhaust gas containing CO and NO, the concentration of CO is 80-150 ppm, and the concentration of NO is 400-600 ppm.

9. The method for treating tail gas containing CO and NO according to claim 7, characterized in that: The reaction temperature is 150-300°C.