Method for preparing catalyst from waste incineration fly ash and electrolytic manganese residues, product prepared by method and application of catalyst

Abstract

The invention discloses a method for preparing a catalyst from waste incineration fly ash and electrolytic manganese residues as well as a product and application thereof. The method comprises the following steps: mixing the reduced electrolytic manganese residues and the waste incineration fly ash to obtain a mixture, and drying the mixture in a drying oven to constant weight; transferring the dried mixture into a calcining furnace for calcining, generating waste gas containing flue gas dust in the calcining process, and recovering the dust in the waste gas to obtain dry-process enriched powder; uniformly mixing the desulfurization waste liquid, sugar alcohol and the dry-process enriched powder, and performing hydrothermal reaction to obtain a hydrothermal active material; and taking out the hydrothermal active material, drying to constant weight, and calcining to obtain the catalyst product. The preparation process is simple, efficient recycling of the hazardous solid waste incineration fly ash and the electrolytic manganese residues is achieved through the steps of pre-reduction, calcination, hydrothermal treatment, secondary calcination and the like, and the high-performance catalytic material is prepared. The prepared catalyst can effectively degrade COD (Chemical Oxygen Demand), ammonia nitrogen, total phosphorus and heavy metal pollutants in landfill leachate under illumination and stirring conditions.

Description

Technical Field

[0001] The present invention belongs to the field of resource utilization of hazardous waste, and particularly relates to a method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese slag, and products and applications thereof. Background Art

[0002] As a by-product of domestic waste incineration, waste incineration fly ash contains high concentrations of heavy metals (such as lead, cadmium, mercury) and persistent organic pollutants such as dioxins, and is classified as hazardous waste. Traditional treatment methods mainly focus on solidification and landfill, but there are problems such as limited landfill capacity, long-term stability risks, and heavy metal leaching pollution. Electrolytic manganese slag is an acidic waste residue generated during the production of electrolytic manganese, containing pollutants such as manganese, ammonia nitrogen, and heavy metals.

[0003] Existing fly ash resource utilization paths include building materials utilization, ceramic raw materials, and adsorption materials, etc., but are limited by unstable heavy metal solidification effects and low added values of products. When fly ash is used as a cement admixture, the chloride salt content needs to be strictly controlled to avoid steel corrosion; when used for preparing ceramsite, high-temperature sintering is required to decompose dioxins, resulting in high energy consumption. The resource utilization direction of manganese slag covers manganese recovery, fertilizer preparation, and building material utilization, but there are technical and economic contradictions. Although the microbial leaching method can achieve a manganese recovery rate of over 90%, the strain culture cycle is long and the process is complex; directly preparing fertilizers requires solving the problem of controlling ammonia nitrogen release, otherwise it is easy to cause soil acidification.

[0004] Industrial catalysts are mainly based on precious metals (such as platinum, palladium) and transition metal oxides, with high costs, easy deactivation, and environmental risks. The proportion of precious metals in automotive exhaust purification catalysts exceeds 80%, resulting in strong resource dependence. At the same time, the recycling and regeneration technology of waste catalysts is not yet mature, exacerbating resource waste. In recent years, using fly ash, steel slag, etc. to prepare catalysts has become a research hotspot. For example, the silicon and aluminum components in fly ash can be made into molecular sieve catalysts by acid leaching and loading active components for the degradation of volatile organic compounds. However, the utilization of single waste still faces problems such as poor dispersion of active components and low catalytic efficiency.

[0005] Fly ash is rich in silicon and aluminum elements, which can provide the framework structure required for the catalyst carrier; the manganese and iron oxides in manganese slag are ideal sources of active components. Through high-temperature melting or chemical stabilization treatment, the heavy metals in fly ash and ammonia nitrogen in manganese slag can be simultaneously solidified, reducing the risk of secondary pollution. The co-utilization of waste can reduce raw material costs. Replacing part of the manganese salt precursor with manganese slag can reduce the production cost of the catalyst by more than 30%. With the tightening of environmental protection standards, the market demand for industrial catalysts continues to grow. For example, after the implementation of the VI emission standard, the demand for high-performance exhaust purification catalysts has increased sharply. At the same time, the demand for low-cost and high-stability catalysts in the new energy field (such as fuel cells) provides an application scenario for industrial waste-based catalysts. Summary of the Invention

[0006] Objective of the Invention: The technical problem to be solved by the present invention is to provide a method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese residue.

[0007] Another technical problem to be solved by the present invention is to provide a catalyst product prepared by the above method.

[0008] The last technical problem to be solved by the present invention is to provide the application of the above-mentioned catalyst product in the treatment of landfill leachate.

[0009] Technical Solution: To solve the above technical problems, the present invention provides a method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese residue, comprising the following steps: (1) Weigh desulfurized waste liquid and electrolytic manganese residue, and place them in a stirring device to stir to obtain reduced electrolytic manganese residue; (2) Mix the reduced electrolytic manganese residue with waste incineration fly ash, stir in a high-speed mixer to obtain a mixture, and place the mixture in an oven to dry to constant weight to obtain a dried mixture; (3) Transfer the dried mixture to a calcination furnace for calcination. During the calcination process, waste gas containing flue gas dust is generated, and the dust therein is recovered to obtain dry-process enriched powder; (4) Mix desulfurized waste liquid, sugar alcohol and dry-process enriched powder, and after mixing them evenly, pour them into a hydrothermal reaction kettle for hydrothermal reaction. After the reaction, hydrothermally active material is obtained; (5) After the hydrothermal reaction is completed, take out the hydrothermally active material in the reaction kettle, dry it to constant weight, and then further calcine it to obtain a catalyst product.

[0010] Among them, in step (1), the mass ratio of the desulfurized waste liquid to the electrolytic manganese residue is 20-50:100.

[0011] Among them, in step (1), the stirring speed is 250-750 rpm, and the stirring time is 1.5-4.5 hours.

[0012] Among them, in step (2), the mass ratio of the reduced electrolytic manganese residue to the waste incineration fly ash is 10-30:100.

[0013] Among them, in step (2), the stirring speed is 800-1200 rpm, the stirring time is 10-20 minutes, and the temperature of the oven is 80-120 °C.

[0014] Among them, in step (3), the calcination temperature is 500-800 °C, and the calcination time is 1-3 hours.

[0015] Among them, the mass ratio of the mixed desulfurized waste liquid, sugar alcohol and dry enrichment powder in step (4) is 20-60:0.5-2.5:100. The time of the hydrothermal reaction is 4-12 hours, and the temperature of the hydrothermal reaction is 160-240 °C.

[0016] Among them, the drying temperature in step (5) is 60-120 °C, the calcination temperature is 400-800 °C, and the calcination time is 1.5-4.5 hours.

[0017] The present invention also includes the catalyst product prepared by the described method.

[0018] The present invention also includes the application of the described catalyst product in the treatment of landfill leachate.

[0019] Reaction mechanism of the present invention: When the desulfurized waste liquid is mixed with electrolytic manganese residue in a certain mass ratio and stirred, the reducing substances in the desulfurized waste liquid react with the high-valent manganese ions in the electrolytic manganese residue in a key reduction reaction, reducing the valence state of the manganese ions, changing their surface charge and chemical activity, transforming the surface property of the electrolytic manganese residue from hydrophilic to hydrophobic, enhancing its interaction ability with other raw materials, and providing more active sites for subsequent reactions. After the reduced electrolytic manganese residue is mixed with the municipal solid waste incineration fly ash, the minerals such as silicon, aluminum and calcium in the municipal solid waste incineration fly ash interact with the active groups on the surface of the reduced electrolytic manganese residue to form a primary composite mineral phase. In the calcination stage, the mixture undergoes complex physical and chemical changes. High temperature causes the organic matter to undergo thermal decomposition reactions, generating small molecule hydrocarbons and gases such as CO2 to escape. At the same time, redox reactions occur to metal ions. Some low-valent manganese ions are oxidized to high-valent states, and the valence states of heavy metal ions in the municipal solid waste incineration fly ash change, thus changing their existence form and stability in the material. After mixing the dry enrichment powder, desulfurized waste liquid and sugar alcohol and carrying out a hydrothermal reaction, the reactants in the system undergo complex chemical reactions in a high-temperature and high-pressure aqueous solution. The hydrothermal reaction promotes the dissolution-recrystallization process of the substances in the system. The metal oxides in the dry enrichment powder react with the sulfide ions in the desulfurized waste liquid to form more insoluble and more stable sulfide precipitates. The sugar alcohol undergoes decomposition reactions under high temperature and high pressure to generate intermediate products such as reducing sugars and polyols. These intermediate products react with metal ions to form stable coordination compounds, further regulating the crystal structure and surface properties of the material. Calcining the hydrothermally active material, some of the coordination compounds in the hydrothermally active material decompose or reconstruct, releasing more active metal centers, optimizing the electronic structure and the distribution of catalytic active sites of the material. Some manganese coordination compounds decompose at high temperature to generate highly active manganese oxides and are evenly dispersed in other composite material matrices, forming efficient catalytic active sites, thus significantly improving the catalytic performance of the catalyst.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following advantages: The preparation process of the present invention is simple. Through steps such as pre-reduction, calcination, hydrothermal treatment, and secondary calcination, the efficient resource utilization of hazardous solid waste incineration fly ash and electrolytic manganese slag is realized, and a high-performance catalytic material is prepared. The prepared catalyst can effectively degrade COD, ammonia nitrogen, total phosphorus, and heavy metal pollutants in landfill leachate under light and stirring conditions. Description of the Drawings

[0021] Figure 1 It is a flow chart of the treatment method of the present invention. Detailed Embodiments

[0022] The present invention will be further described below in conjunction with the drawings and embodiments.

[0023] Preparation of landfill leachate and landfill leachate containing mercury: The landfill leachate used in the experiment was taken from Zhuji Sanfeng Environmental Energy Co., Ltd. The COD mass concentration of this batch of landfill leachate was 4152 mg / L, the total phosphorus concentration was 305 mg / L, and the ammonia nitrogen concentration was 1075 mg / L. 500 mg of mercury was added to 1 L of landfill leachate and stirred evenly to prepare landfill leachate containing mercury; Municipal solid waste incineration fly ash: Municipal solid waste incineration fly ash was provided by the Second Municipal Solid Waste Incineration Power Plant in Changshu, Jiangsu Province, and mainly included 38.14% CaO, 24.05% Cl, 10.21% SO3, 12.15% Na2O, 6.21% K2O, 3.17% SiO2, 1.41% Fe2O3, 1.19% Al2O3 and other components (loss on ignition and other inevitable impurities); Desulfurization waste liquid: The desulfurization waste liquid came from Fujian Longking Co., Ltd., in which ammonium sulfate accounted for 44.56%, ammonium thiosulfate 12.75%, ammonium sulfite 23.84%, 2.42% metal sulfides and other components (inevitable impurities and loss on ignition); Electrolytic manganese slag: The electrolytic manganese slag was taken from Guizhou Nengkuang Manganese Industry Group Co., Ltd., and mainly included 23.52% SO3, 13.17% SiO2, 15.21% CaO, 13.09% Fe2O3, 6.82% Al2O3, 10.21% MnO, 2.96% K2O, 1.55% MgO, 0.86% TiO2 and other components (inevitable impurities and loss on ignition).

[0024] Example 1 Influence of the mass ratio of desulfurization waste liquid and electrolytic manganese slag on the performance of the prepared catalyst product Weigh the desulfurized waste liquid and electrolytic manganese slag according to the mass ratios of 5:100, 10:100, 15:100, 20:100, 35:100, 50:100, 55:100, 60:100, and 65:100 respectively, place them in a stirring device, and stir for 1.5 hours under the condition of a rotation speed of 250 rpm to obtain 9 portions of reduced electrolytic manganese slag. Mix the 9 portions of reduced electrolytic manganese slag with 9 portions of fly ash from waste incineration according to the mass ratio of 10:100, stir in a high-speed mixer at a rotation speed of 800 rpm for 10 minutes, place the mixture in an oven, and dry it to a constant weight at a temperature of 80 °C to obtain 9 portions of dried mixture. Transfer the 9 portions of dried mixture to a calcination furnace, and calcine at a temperature of 500 °C for 1 hour. During the calcination process, waste gas containing flue gas dust is generated, and the dust therein is recovered to obtain 9 portions of dry enrichment powder. Mix the desulfurized waste liquid, sugar alcohol, and dry enrichment powder according to the mass ratio of 20:0.5:100. After mixing the three evenly, pour them into a hydrothermal reaction kettle for hydrothermal reaction. After the reaction ends, hydrothermally activated material is obtained. The sugar alcohol is maltitol, the hydrothermal time is 4 hours, and the hydrothermal temperature is 160 °C. After the hydrothermal reaction ends, take out the hydrothermally activated material in the reaction kettle, dry it to a constant weight, and then further calcine to obtain 9 portions of catalyst products. The drying temperature is 60 °C, the calcination temperature is 400 °C, and the calcination time is 1.5 hours.

[0025] Photocatalytic removal test: Put 9 portions of 1 g of catalyst products into 1 L of mercury-containing landfill leachate respectively, stir at a rotation speed of 120 rpm while irradiating with an ultraviolet lamp for 120 min, and then centrifuge at a rotation speed of 5000 rpm for solid-liquid separation. Detect the concentrations of different pollutants in the separated liquid and calculate the removal rate. The specific detection and calculation are as follows: Detection of COD concentration and calculation of COD removal capacity: The chemical oxygen demand (COD) concentration of the leachate is determined according to the standard "Water Quality - Determination of Chemical Oxygen Demand - Dichromate Method" (HJ 828-2017). The COD removal capacity is calculated according to formula (1), where is the COD removal capacity (mg / g), and are the COD concentrations (mg / L) of the mercury-containing landfill leachate before and after disposal respectively, m is the mass (1 g) of the catalyst product prepared in this example, and V is the volume (1 L) of the mercury-containing landfill leachate.

[0026] (1) Detection of total phosphorus concentration and calculation of total phosphorus removal capacity: The total phosphorus concentration of the leachate is determined according to the standard "Water Quality - Determination of Phosphate and Total Phosphorus - Continuous Flow - Ammonium Molybdate Spectrophotometry" (HJ 670-2013). The total phosphorus removal rate is calculated according to formula (2), where is the total phosphorus removal capacity (mg / g), and are the total phosphorus concentrations (mg / L) of the mercury-containing landfill leachate before and after treatment, m is the mass of the catalyst prepared in this example (1 g), and V is the volume of the mercury-containing landfill leachate (1 L).

[0027] (2)

[0028] The concentration of ammonia nitrogen in the leachate is determined according to the "Water Quality - Determination of Ammonia Nitrogen - Spectrophotometric Method with Salicylic Acid" (HJ 536 - 2009). The ammonia nitrogen removal capacity is calculated according to formula (3), where is the ammonia nitrogen removal capacity (mg / g), is the initial concentration of ammonia nitrogen in the mercury-containing landfill leachate before treatment (mg / L), is the remaining concentration of ammonia nitrogen in the mercury-containing landfill leachate after treatment (mg / L). m is the mass of the catalyst prepared in this example (1 g), and V is the volume of the mercury-containing landfill leachate (1 L).

[0029] (3) Detection of mercury ion concentration and calculation of removal capacity: The concentration of mercury ions in the leachate is determined according to the "Water Quality - Determination of Mercury, Arsenic, Selenium, Bismuth and Antimony - Atomic Fluorescence Spectrometry" (HJ 694 - 2014). The mercury ion removal capacity is calculated according to formula (4), where is the mercury ion removal capacity (mg / g), is the initial concentration of mercury ions in the mercury-containing landfill leachate before treatment (mg / L), is the concentration of mercury ions in the leachate after treatment (mg / L), V is the volume of the mercury-containing landfill leachate (LL), m is the mass of the catalyst product prepared in this example (1 g).

[0030] (4) The test results of this example are shown in Table 1.

[0031] Table 1 Influence of the mass ratio of desulfurization waste liquid to electrolytic manganese slag on the performance of the prepared catalyst product

[0032] As can be seen from Table 1, when the mass ratio of desulfurized waste liquid to electrolytic manganese slag is less than 20:100 (as shown in Table 1, when the mass ratio of desulfurized waste liquid to electrolytic manganese slag = 15:100, 10:100, 5:100 and lower ratios not listed in Table 1), less desulfurized waste liquid is added, and the reaction between the desulfurized waste liquid and the electrolytic manganese slag is insufficient, resulting in a significant decrease in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacities of the prepared catalyst product as the mass ratio of desulfurized waste liquid to electrolytic manganese slag decreases. When the mass ratio of desulfurized waste liquid to electrolytic manganese slag is equal to 20 - 50:100 (as shown in Table 1, when the mass ratio of desulfurized waste liquid to electrolytic manganese slag = 20:100, 35:100, 50:100), when the desulfurized waste liquid and the electrolytic manganese slag are mixed and stirred in a certain mass ratio, the reducing substances in the desulfurized waste liquid react with the high-valent manganese ions in the electrolytic manganese slag in a key reduction reaction, reducing the valence state of the manganese ions, changing their surface charge and chemical activity, and transforming the surface properties of the electrolytic manganese slag from hydrophilic to hydrophobic, enhancing its interaction ability with other raw materials, and providing more active sites for subsequent reactions. Finally, the COD removal capacity of the prepared catalyst product is higher than 2765 mg / g, the total phosphorus removal capacity is higher than 188 mg / g, the ammonia nitrogen removal capacity is higher than 679 mg / g, and the mercury removal capacity is higher than 254 mg / g. When the mass ratio of desulfurized waste liquid to electrolytic manganese slag is greater than 50:100 (as shown in Table 1, when the mass ratio of desulfurized waste liquid to electrolytic manganese slag = 55:100, 60:100, 65:100 and higher ratios not listed in Table 1), excessive desulfurized waste liquid is added, and the reaction between the desulfurized waste liquid and the electrolytic manganese slag is unbalanced, resulting in a significant decrease in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacities of the prepared catalyst product as the mass ratio of desulfurized waste liquid to electrolytic manganese slag further increases. Generally speaking, considering the benefits and costs, when the mass ratio of desulfurized waste liquid to electrolytic manganese slag is equal to 20 - 50:100, it is most beneficial to improve the performance of the prepared catalyst product.

[0033] Example No. 2 Influence of the mass ratio of reduced electrolytic manganese slag to municipal solid waste incineration fly ash on the performance of the prepared catalyst product Weigh the desulfurized waste liquid and electrolytic manganese slag according to a mass ratio of 50:100, place them in a stirring device, and stir for 3 hours under the condition of a rotation speed of 500 rpm to obtain reduced electrolytic manganese slag. Mix the reduced electrolytic manganese slag with municipal solid waste incineration fly ash according to mass ratios of 2.5:100, 5:100, 7.5:100, 10:100, 20:100, 30:100, 35:100, 40:100, and 45:100. Stir the mixture in a high-speed mixer at a rotation speed of 1000 rpm for 15 minutes. Place the mixture in an oven and dry it to a constant weight at a temperature of 100 °C to obtain nine portions of dried mixture. Transfer the nine portions of dried mixture to a calcination furnace and calcine at a temperature of 650 °C for 2 hours. During the calcination process, waste gas containing flue gas dust is generated, and the dust therein is recovered to obtain nine portions of dry enrichment powder. Mix the desulfurized waste liquid, sugar alcohol, and dry enrichment powder according to a mass ratio of 40:1.5:100 respectively. After mixing them evenly, pour them into a hydrothermal reaction kettle for hydrothermal reaction. After the reaction, nine portions of hydrothermally active materials are obtained, where the sugar alcohol is xylitol, the hydrothermal time is 8 hours, and the hydrothermal temperature is 200 °C. After the hydrothermal reaction is completed, take out the hydrothermally active materials in the reaction kettle, dry them to a constant weight, and then further calcine to obtain nine portions of catalyst products, where the drying temperature is 80 °C, the calcination temperature is 600 °C, and the calcination time is 3 hours.

[0034] The photocatalytic removal test, the detection of COD concentration and the calculation of COD removal capacity, the detection of total phosphorus concentration and the calculation of total phosphorus removal capacity, the detection of ammonia nitrogen concentration and the calculation of ammonia nitrogen removal capacity, and the detection of mercury ion concentration and the calculation of removal capacity are the same as in Example 1. The test results of this example are shown in Table 2.

[0035] Table 2 Influence of the mass ratio of reduced electrolytic manganese slag to municipal solid waste incineration fly ash on the performance of the prepared catalyst products

[0036] As can be seen from Table 2, when the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash is less than 10:100 (as in Table 2, the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash = 7.5:100, 5:100, 2.5:100 and lower ratios not listed in Table 2), the addition of reduced electrolytic manganese residue is less, and the reaction between reduced electrolytic manganese residue and municipal solid waste incineration fly ash is insufficient, resulting in a significant decrease in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacities of the prepared catalyst product as the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash decreases. When the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash is equal to 10 - 30:100 (as in Table 2, the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash = 10:100, 20:100, 30:100), after the reduced electrolytic manganese residue and municipal solid waste incineration fly ash are mixed, minerals such as silicon, aluminum, and calcium in the municipal solid waste incineration fly ash interact with the active groups on the surface of the reduced electrolytic manganese residue to form a primary composite mineral phase. During the calcination stage, the mixture undergoes complex physical and chemical changes. High temperature causes the organic matter to undergo thermal decomposition reactions, generating small molecule hydrocarbons and gases such as CO2 to escape. At the same time, redox reactions occur for metal ions, with some low-valent manganese ions being oxidized to high-valent states, and the valence states of heavy metal ions in the municipal solid waste incineration fly ash change, thus changing their existence form and stability in the material. After mixing the dry enrichment powder, desulfurized waste liquid, and sugar alcohol for hydrothermal reaction, the reactants in the system undergo complex chemical reactions in a high-temperature and high-pressure aqueous solution. Finally, the prepared catalyst product has a COD removal capacity higher than 3016 mg / g, a total phosphorus removal capacity higher than 204 mg / g, an ammonia nitrogen removal capacity higher than 738 mg / g, and a mercury removal capacity higher than 275 mg / g. When the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash is greater than 30:100 (as in Table 2, the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash = 35:100, 40:100, 45:100 and higher ratios not listed in Table 2), the addition of reduced electrolytic manganese residue is excessive, and the reaction between reduced electrolytic manganese residue and municipal solid waste incineration fly ash is unbalanced, resulting in a significant decrease in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacities of the prepared catalyst product as the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash further increases. Generally speaking, considering the benefits and costs, when the mass ratio of reduced electrolytic manganese residue to municipal solid waste incineration fly ash is equal to 10 - 30:100, it is most beneficial to improve the performance of the prepared catalyst product.

[0037] Example 3 Influence of the mass ratio of desulfurized waste liquid, sugar alcohol, and dry enrichment powder on the performance of the prepared catalyst product Weigh the desulfurized waste liquid and electrolytic manganese slag according to a mass ratio of 50:100, place them in a stirring device, and stir for 4.5 hours under the condition of a rotation speed of 750 rpm to obtain reduced electrolytic manganese slag. Mix the reduced electrolytic manganese slag and municipal solid waste incineration fly ash according to a mass ratio of 30:100, stir in a high-speed mixer at a rotation speed of 1200 rpm for 20 minutes, place the mixture in an oven, and dry it to a constant weight at a temperature of 120 °C to obtain a dried mixture. Transfer the dried mixture to a calcination furnace and calcine it at a temperature of 800 °C for 3 hours. During the calcination process, waste gas containing flue gas dust is generated, and the dust is recovered to obtain dry enrichment powder. Mix the desulfurized waste liquid, sugar alcohol, and dry enrichment powder according to mass ratios of 12.5:0.5:100, 15:0.5:100, 17.5:0.5:100, 20:0.35:100, 20:0.4:100, 20:0.45:100, 20:0.5:100, 40:0.5:100, 60:0.5:100, 20:1.5:100, 40:1.5:100, 60:1.5:100, 20:2.5:100, 40:2.5:100, 60:2.5:100, 60:2.75:100, 60:3:100, 60:3.25:100, 65:2.5:100, 70:2.5:100, 75:2.5:100 respectively. After mixing the three evenly, pour them into a hydrothermal reaction kettle for hydrothermal reaction. After the reaction, 21 portions of hydrothermally active materials are obtained. The sugar alcohol is sorbitol, the hydrothermal time is 12 hours, and the hydrothermal temperature is 240 °C. After the hydrothermal reaction, take out the hydrothermally active materials in the reaction kettle, dry them to a constant weight, and then further calcine them to obtain 21 portions of catalyst products. The drying temperature is 120 °C, the calcination temperature is 800 °C, and the calcination time is 4.5 hours.

[0038] The photocatalytic removal test, COD concentration detection and COD removal capacity calculation, total phosphorus concentration detection and total phosphorus removal capacity calculation, ammonia nitrogen concentration detection and ammonia nitrogen removal capacity calculation, and mercury ion concentration detection and removal capacity calculation are the same as those in Example 1. The test results of this example are shown in Table 3.

[0039] Table 3 Influence of mass ratios of desulfurized waste liquid, sugar alcohol, and dry enrichment powder on the performance of the prepared catalyst products

[0040] As can be seen from Table 3, when the mass ratio of desulfurized waste liquid, sugar alcohol and dry enrichment powder is less than 20:0.5:100 (as shown in Table 3, when the mass ratio of desulfurized waste liquid, sugar alcohol and dry enrichment powder = 20:0.45:100, 20:0.4:100, 20:0.35:100, 17.5:0.5:100, 15:0.5:100, 12.5:0.5:100 and lower ratios not listed in Table 3), the addition of desulfurized waste liquid and sugar alcohol is less, and the reaction of desulfurized waste liquid, sugar alcohol and dry enrichment powder is insufficient during the hydrothermal reaction, resulting in a significant decrease in the COD, total phosphorus, ammonia nitrogen and mercury removal capacities of the prepared catalyst products as the mass ratio of desulfurized waste liquid, sugar alcohol and dry enrichment powder decreases. When the mass ratio of desulfurized waste liquid, sugar alcohol and dry enrichment powder is equal to 20 - 60:0.5 - 2.5:100 (as shown in Table 3, when the mass ratio of desulfurized waste liquid, sugar alcohol and dry enrichment powder = 20:0.5:100, 40:0.5:100, 60:0.5:100, 20:1.5:100, 40:1.5:100, 60:1.5:100, 20:2.5:100, 40:2.5:100, 60:2.5:100), after mixing dry enrichment powder, desulfurized waste liquid and sugar alcohol and carrying out hydrothermal reaction, the reactants in the system undergo complex chemical reactions in a high-temperature and high-pressure aqueous solution. The hydrothermal reaction promotes the dissolution-recrystallization process of the substances in the system. The metal oxides in the dry enrichment powder react with the sulfide ions in the desulfurized waste liquid to form more insoluble and stable sulfide precipitates. The sugar alcohol undergoes a decomposition reaction under high temperature and high pressure to generate intermediate products such as reducing sugars and polyols. These intermediate products undergo a coordination reaction with metal ions to form stable coordination compounds, further regulating the crystal structure and surface properties of the material. By calcining the hydrothermal active material, some of the coordination compounds in the hydrothermal active material decompose or reconstruct, releasing more active metal centers, optimizing the electronic structure and the distribution of catalytic active sites of the material. Some of the manganese coordination compounds decompose at high temperature to generate highly active manganese oxides and are uniformly dispersed in other composite material matrices, forming efficient catalytic active sites, thus significantly improving the catalytic performance of the catalyst products. Finally, the prepared catalyst products have a COD removal capacity higher than 3325 mg / g, a total phosphorus removal capacity higher than 221 mg / g, an ammonia nitrogen removal capacity higher than 773 mg / g, and a mercury removal capacity higher than 288 mg / g.When the mass ratio of desulfurized waste liquid, sugar alcohol, and dry enrichment powder is greater than 60:2.5:100 (as shown in Table 3, when the mass ratio of desulfurized waste liquid, sugar alcohol, and dry enrichment powder = 60:2.75:100, 60:3:100, 60:3.25:100, 65:2.5:100, 70:2.5:100, 75:2.5:100, and higher ratios not listed in Table 3), the addition of desulfurized waste liquid and sugar alcohol is excessive, and the reaction between desulfurized waste liquid, sugar alcohol, and dry enrichment powder is unbalanced during the hydrothermal reaction, resulting in a significant decrease in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacity of the prepared catalyst product as the mass ratio of desulfurized waste liquid, sugar alcohol, and dry enrichment powder further increases. Generally speaking, considering the benefits and costs, when the mass ratio of desulfurized waste liquid, sugar alcohol, and dry enrichment powder is equal to 20 - 60:0.5 - 2.5:100, it is most beneficial to improve the performance of the prepared catalyst product.

[0041] Comparative Example Influence of Different Comparative Processes on the Performance of the Prepared Catalyst Product Process of the present invention: Weigh desulfurized waste liquid and electrolytic manganese slag according to a mass ratio of 50:100, place them in a stirring device, and stir for 4.5 hours under the condition of a rotation speed of 750 rpm to obtain reduced electrolytic manganese slag. Mix the reduced electrolytic manganese slag and municipal solid waste incineration fly ash according to a mass ratio of 30:100, stir in a high-speed mixer at a rotation speed of 1200 rpm for 20 minutes, place the mixture in an oven, and dry it to a constant weight at a temperature of 120°C to obtain a dried mixture. Transfer the dried mixture to a calcination furnace and calcine it at a temperature of 800°C for 3 hours. During the calcination process, waste gas containing flue gas dust is generated, and the dust is recovered to obtain dry enrichment powder. Mix desulfurized waste liquid, sugar alcohol, and dry enrichment powder according to a mass ratio of 60:2.5:100, mix the three evenly and pour them into a hydrothermal reaction kettle for hydrothermal reaction. After the reaction, hydrothermally active material is obtained. Among them, the sugar alcohol is sorbitol, the hydrothermal time is 12 hours, and the hydrothermal temperature is 240°C. After the hydrothermal reaction is completed, take out the hydrothermally active material in the reaction kettle, dry it to a constant weight, and then further calcine it to obtain a catalyst product. Among them, the drying temperature is 120°C, the calcination temperature is 800°C, and the calcination time is 4.5 hours.

[0042] Comparative Process 1: Mix electrolytic manganese residue and municipal solid waste incineration fly ash in a mass ratio of 30:100, stir in a high-speed mixer at a rotation speed of 1200 rpm for 20 minutes, place the mixture in an oven, and dry it to a constant weight at a temperature of 120 °C to obtain a dried mixture. Transfer the dried mixture to a calcination furnace and calcine it at a temperature of 800 °C for 3 hours. During the calcination process, waste gas containing flue gas dust is generated, and the dust is recovered to obtain a dry enrichment powder. Mix desulfurization waste liquid, sugar alcohol, and dry enrichment powder in a mass ratio of 60:2.5:100. After mixing the three evenly, pour them into a hydrothermal reaction kettle for hydrothermal reaction. After the reaction, a hydrothermally activated material is obtained. The sugar alcohol is sorbitol, the hydrothermal time is 12 hours, and the hydrothermal temperature is 240 °C. After the hydrothermal reaction, take out the hydrothermally activated material in the reaction kettle, dry it to a constant weight, and then further calcine it to obtain a catalyst product. The drying temperature is 120 °C, the calcination temperature is 800 °C, and the calcination time is 4.5 hours.

[0043] Comparative Process 2: Weigh desulfurization waste liquid and electrolytic manganese residue in a mass ratio of 50:100, place them in a stirring device, and stir at a rotation speed of 750 rpm for 4.5 hours to obtain reduced electrolytic manganese residue. Mix the reduced electrolytic manganese residue and municipal solid waste incineration fly ash in a mass ratio of 30:100, stir in a high-speed mixer at a rotation speed of 1200 rpm for 20 minutes, place the mixture in an oven, and dry it to a constant weight at a temperature of 120 °C to obtain a dried mixture. Transfer the dried mixture to a calcination furnace and calcine it at a temperature of 800 °C for 3 hours. During the calcination process, waste gas containing flue gas dust is generated, and the dust is recovered to obtain a dry enrichment powder. Mix desulfurization waste liquid and dry enrichment powder in a mass ratio of 60:100. After mixing the two evenly, pour them into a hydrothermal reaction kettle for hydrothermal reaction. After the reaction, a hydrothermally activated material is obtained. The hydrothermal time is 12 hours, and the hydrothermal temperature is 240 °C. After the hydrothermal reaction, take out the hydrothermally activated material in the reaction kettle, dry it to a constant weight, and then further calcine it to obtain a catalyst product. The drying temperature is 120 °C, the calcination temperature is 800 °C, and the calcination time is 4.5 hours.

[0044] The photocatalytic removal test, COD concentration detection and COD removal capacity calculation, total phosphorus concentration detection and total phosphorus removal capacity calculation, ammonia nitrogen concentration detection and ammonia nitrogen removal capacity calculation, mercury ion concentration detection and removal capacity calculation are the same as those in Example 1. The test results of this comparative example are shown in Table 4.

[0045] Table 4 Influence of Different Comparative Processes on the Performance of the Prepared Catalyst Products

[0046] As can be seen from Table 4, the performance of the catalyst material prepared by the process of the present invention is significantly superior to that of Comparative Process 1 and Comparative Process 2.

Claims

1. A method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese residue, characterized in that, It includes the following steps: (1) Weigh the desulfurized waste liquid and electrolytic manganese slag, place them in a stirring device and stir to obtain reduced electrolytic manganese slag; (2) Mix the reduced electrolytic manganese slag with fly ash from waste incineration, stir in a high-speed mixer to obtain a mixture, place the mixture in an oven and dry it to constant weight to obtain a dried mixture; (3) Transfer the dried mixture to a calcination furnace for calcination. During the calcination process, waste gas containing flue gas dust is generated, and the dust therein is recovered to obtain dry enrichment powder; (4) Mix the desulfurized waste liquid, sugar alcohol and dry enrichment powder, pour the three after mixing evenly into a hydrothermal reaction kettle for hydrothermal reaction, and obtain hydrothermally activated material after the reaction ends; (5) After the hydrothermal reaction ends, take out the hydrothermally activated material in the reaction kettle, dry it to constant weight, and then further calcine it to obtain a catalyst product.

2. The method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese slag according to claim 1, characterized in that, In step (1), the mass ratio of the desulfurized waste liquid to the electrolytic manganese slag is 20-50:

100.

3. The method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese slag according to claim 1, wherein In step (1), the stirring speed is 250-750 rpm, and the stirring time is 1.5-4.5 hours.

4. The method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese slag according to claim 1, characterized in that, In step (2), the mass ratio of the reduced electrolytic manganese slag to the fly ash from waste incineration is 10-30:

100.

5. The method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese residue according to claim 1, wherein In step (2), the stirring speed is 800-1200 rpm, the stirring time is 10-20 minutes, and the temperature of the oven is 80-120 °C.

6. The method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese residue according to claim 1, characterized in that, In step (3), the calcination temperature is 500-800 °C, and the calcination time is 1-3 hours.

7. The method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese slag according to claim 1, characterized in that, In step (4), the mass ratio of the mixed desulfurized waste liquid, sugar alcohol and dry enrichment powder is 20-60:0.5-2.5:100, the time of the hydrothermal reaction is 4-12 hours, and the temperature of the hydrothermal reaction is 160-240 °C.

8. The method for preparing a catalyst by using waste incineration fly ash and electrolytic manganese residue according to claim 1, characterized in that, In step (5), the drying temperature is 60-120 °C, the calcination temperature is 400-800 °C, and the calcination time is 1.5-4.5 hours.

9. A catalyst product prepared by the method according to any one of claims 1-8.

10. Use of the catalyst product according to claim 9 in the treatment of landfill leachate.

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