Method for preparing catalytic material by synergistically utilizing red mud and electrolytic manganese residues as well as product and application thereof

Abstract

The invention discloses a method for preparing a catalytic material by synergistically utilizing red mud and electrolytic manganese residues as well as a product and application thereof. The method comprises the following steps: mixing electrolytic manganese residues and red mud, uniformly stirring, adding ammonium chloride, stirring, adding a hydrochloric acid solution, stirring, roasting and grinding. And adding an auxiliary agent, uniformly stirring, adding water, granulating, standing, carrying out hydrothermal reaction, and roasting to obtain the catalytic material. The preparation process is simple, the technological process is brief, the needed core raw materials are only the red mud and the electrolytic manganese residues, and resource utilization of the red mud and the electrolytic manganese residues is efficiently achieved. The prepared catalytic material can quickly adsorb pollutants in waste liquid under the condition of no photocatalysis, and the removal effect on COD (Chemical Oxygen Demand), ammonia nitrogen, total phosphorus and heavy metal mercury can be further remarkably improved under the photocatalysis condition.

Description

Technical Field

[0001] The invention relates to a method for preparing a catalytic material by collaboratively utilizing red mud and electrolytic manganese slag, and a product and application thereof, and belongs to the field of resource utilization of industrial solid waste. Background Art

[0002] Red mud and electrolytic manganese slag have significant acid-base complementary properties. In the process of preparing catalytic materials, the strong alkalinity of red mud can neutralize the free sulfate and ammonia nitrogen pollutants in the electrolytic manganese slag, and achieve stable solidification of heavy metals. At the same time, the alkaline environment of red mud can promote the hydrolysis of aluminosilicates in silicoaluminous solid waste, accelerate the hydration reaction rate, and improve the solidification effect of heavy metals, providing new ideas for industrial solid waste treatment.

[0003] The alkaline environment of red mud can also promote the hydrolysis of aluminosilicates in silicoaluminate solid wastes, accelerate the hydration reaction rate, and thus improve the solidification effect of heavy metals. This synergistic treatment method not only solves the pollution problem of red mud and electrolytic manganese slag, but also provides a reference for the treatment of other industrial solid wastes. Red mud and electrolytic manganese slag are rich in a variety of metal oxides and have a catalytically active material basis. 2 O 3 、Al 2 O 3 and TiO 2 , which can provide redox active sites; the electrolytic manganese slag contains MnO 2 and sulfate, and has the ability to transfer electrons. Through processes such as thermal activation and acid leaching purification, supported multi-metal composite catalysts can be prepared for wastewater treatment (such as Fenton catalysis) or VOCs degradation. The synergistic system of steel slag-red mud-manganese slag can significantly improve the hydration activity of cementitious materials, and the increase in the amount of red mud can significantly improve the mechanical properties and cementitious activity of the material.

[0004] At present, there are certain limitations in the preparation of catalytic materials using red mud and electrolytic manganese slag. On the one hand, traditional methods do not fully explore the synergistic effect of the two, and most of them do not fully utilize their acid-base complementary properties, resulting in poor performance of catalytic materials. On the other hand, the existing processes are complex and costly, or there are problems such as poor adaptability to raw materials and difficulty in large-scale production. For example, some methods require the addition of a large amount of chemical reagents or the use of special equipment, which increases production costs and process complexity; some methods have strict requirements on the composition and properties of red mud and electrolytic manganese slag, which limits their wide application. Summary of the invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for preparing catalytic materials by synergistically utilizing red mud and electrolytic manganese slag, and its products and applications.

[0006] Technical solution: To solve the above technical problems, the present invention provides a method for preparing a catalytic material by synergistically utilizing red mud and electrolytic manganese slag, comprising the following steps: (1) mixing electrolytic manganese slag and red mud, stirring evenly to obtain red slag mud; mixing ammonium chloride and red slag mud, stirring evenly to obtain ammonium-loaded slag mud; mixing hydrochloric acid solution and ammonium-loaded slag mud, stirring evenly to obtain acid leaching slag mud, roasting, grinding and obtaining de-ironizing powder; (2) mixing an auxiliary agent and the de-ironized powder in step (1), stirring evenly, and obtaining a hydrothermal raw material; the auxiliary agent comprises any one of tetraethylammonium hydroxide, isopropylamine, triethylamine or diethylamine; (3) Mixing water and the hydrothermal raw material in step (2), granulating, standing, hydrothermally reacting, and calcining to obtain a catalytic material.

[0007] Wherein, the mass ratio of the electrolytic manganese slag to the red mud in step (1) is 40-120:100.

[0008] Wherein, the mass ratio of ammonium chloride to red slag mud in step (1) is 2.5~17.5:100.

[0009] Wherein, the liquid-to-solid ratio of the hydrochloric acid solution and the ammonium-loaded sludge in step (1) is 0.2-0.6:1 mL / g.

[0010] Wherein, the concentration of the hydrochloric acid solution in step (1) is 2~6M.

[0011] The calcination temperature in step (1) is 450-750°C and the calcination time is 0.5-4.5 hours.

[0012] The grinding time in step (1) is 5 to 35 minutes.

[0013] Wherein, the mass ratio of the auxiliary agent to the deironing powder in step (2) is 0.25~2.75:100.

[0014] Wherein, the liquid-to-solid ratio of water to hydrothermal raw material in step (3) is 0.35-0.65:1 mL / g.

[0015] The hydrothermal reaction in step (3) is carried out for 0.5 to 4.5 hours at a temperature of 120 to 280°C.

[0016] The calcination temperature in step (3) is 650-950°C and the calcination time is 0.5-4.5 hours.

[0017] The standing time in step (3) is 1 to 3 days.

[0018] The invention also provides a catalytic material prepared by the method.

[0019] The invention also provides application of the catalytic material in removing pollutants.

[0020] The method comprises the following steps: putting the catalytic material into the sample to be processed, stirring and irradiating with ultraviolet light, centrifuging, and separating the solid and the liquid to obtain the sample after the pollutants are removed.

[0021] Reaction mechanism: The acid leaching sludge is roasted. Under high temperature, the ammonium chloride and chlorine in hydrochloric acid combine with iron and aluminum in red mud and electrolytic manganese slag to form ferric chloride and aluminum chloride and volatilize into the flue gas, while the ammonium ions react with nitrogen oxides formed in the air to generate nitrogen. At the same time, during the roasting process, the hydrogen ions in the hydrochloric acid promote the release of titanium, manganese and other small metal elements in red mud and electrolytic manganese slag. High-temperature roasting improves the activity of regular acid salts and gypsum materials in red mud and electrolytic manganese slag through thermal activation, removing free water and crystal water. Mix water and hydrothermal raw materials, and the additives dissolve into the hydrothermal raw material particles during stirring and standing, and promote the reaction of aluminosilicates, iron-aluminum salts and gypsum calcium-based materials in the activated red mud and electrolytic manganese slag to form a solidified colloid through structural guidance, and induce titanium, manganese and other small heavy metal elements to hydrolyze to form co-precipitates and cement on the solidified body. The roasted raw material is placed in a hydrothermal kettle for hydrothermal reaction of the roasted raw particles, the structural guiding effect of the additive is strengthened, the aluminosilicate undergoes hydrolysis and polymerization, the self-excitation and self-gelling effect between the aluminosilicate and the iron-aluminum salt and gypsum calcium-based materials becomes more obvious, and titanium, manganese and other small amounts of heavy metal elements are fully hydrolyzed and mixed with each other.

[0022] The hydrated material is roasted, and the additive is oxidized in a high temperature environment to form carbon dioxide and water vapor and diffuse out from the gelled solid material. The co-precipitated mixture of titanium, manganese and heavy metals is dehydrated to form mixed metal oxides and cemented on the surface of the solid particles.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the preparation process is simple, the process flow is brief, the core raw materials required are only red mud and electrolytic manganese slag, and the resource utilization of red mud and electrolytic manganese slag is efficiently realized. The prepared catalytic material can quickly adsorb pollutants in waste liquid without photocatalysis, and can further significantly improve the removal effect of COD, ammonia nitrogen, total phosphorus, and heavy metal mercury under photocatalytic conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a flow chart of the processing method of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0026] Preparation of landfill leachate and mercury-containing landfill leachate: The landfill leachate used in the experiment was taken from Zhuji Sanfeng Environmental Protection 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 mercury-containing landfill leachate.

[0027] Red mud: provided by Shandong Zibo Zhengheng Aluminum Co., Ltd., the main test components include: 38.52%Fe 2 O 3 、27.83%Al 2 O 3 、12.49%SiO 2 、11.36%Na 2 O, 5.61% TiO 2 , 0.57%CaO, 0.34%SO 3 and other components (inevitable impurities and loss on ignition); Electrolytic manganese slag: Electrolytic manganese slag is taken from Guizhou Energy Mining Manganese Industry Group Co., Ltd., mainly including 23.52% SO 3 、13.17% SiO 2 、15.21% CaO、13.09% Fe 2 O 3 、6.82% Al 2 O 3 、10.21% MnO、2.96% K 2 O, 1.55% MgO, 0.86% TiO 2 and other ingredients (inevitable impurities and loss on ignition).

[0028] Example 1 Effect of the mass ratio of electrolytic manganese slag and red mud on the performance of the prepared catalyst Electrolytic manganese slag and red mud are mixed in a mass ratio of 25:100, 30:100, 35:100, 40:100, 80:100, 120:100, 130:100, 140:100, and 150:100, and stirred evenly to obtain red slag mud. Ammonium chloride and red slag mud are mixed in a mass ratio of 2.5:100, and stirred evenly to obtain ammonium-loaded slag mud. Hydrochloric acid solution and ammonium-loaded slag mud are mixed in a liquid-solid ratio of 0.2:1mL / g, and stirred evenly to obtain acid leaching slag mud, wherein the concentration of the hydrochloric acid solution is 2M. The acid leaching slag mud is roasted, and the roasted slag is ground to obtain deiron powder, wherein the roasting temperature is 450°C, the roasting time is 0.5 hours, and the grinding time is 5 minutes. The auxiliary agent and the deiron powder are mixed in a mass ratio of 0.25:100, and stirred evenly to obtain a hydrothermal raw material, wherein the auxiliary agent is tetraethylammonium hydroxide. Water and hydrothermal raw materials were mixed at a liquid-solid ratio of 0.35:1 mL / g, granulated, and allowed to stand for 1 day to obtain roasted raw materials. The roasted raw materials were placed in a hydrothermal kettle to perform a hydrothermal reaction on the roasted raw materials to obtain hydrated materials, wherein the hydrothermal time was 0.5 hours and the hydrothermal temperature was 120°C. The hydrated materials were roasted to obtain catalytic materials, wherein the roasting temperature was 650°C and the roasting time was 0.5 hours.

[0029] Adsorption test: 1g of catalytic material was added to 1L of landfill leachate, stirred at 120rpm for 120min, and then centrifuged at 5000rpm to separate the solid and liquid. The concentrations of different pollutants in the separated liquid were tested and the removal rate was calculated. The specific test and calculation are as follows.

[0030] COD concentration detection and calculation of COD removal capacity: The COD concentration of the leachate was measured in accordance with the national standard "Determination of Chemical Oxygen Demand of Water Quality - Dichromate Method" (HJ 828-2017). The COD removal capacity was calculated according to formula (1), where R COD is COD removal capacity (mg / g), C COD0 and C CODt are the COD concentrations of domestic waste leachate before and after treatment (mg / L), m is the mass of the catalyst (1 g), and V is the volume of the leachate (1 L).

[0031]

[0032] Total phosphorus concentration detection and total phosphorus removal capacity calculation: The total phosphorus concentration of the leachate was determined according to the standard "Determination of phosphate and total phosphorus in water - continuous flow - ammonium molybdate spectrophotometry" (HJ 670-2013). The total phosphorus removal rate was calculated according to formula (2), where R TP is the total phosphorus removal capacity (mg / g), c TP0 and c TPtare the total phosphorus concentrations of domestic waste leachate before and after treatment (mg / L), m is the mass of the catalyst (1 g), and V is the volume of the leachate (1 L).

[0033]

[0034] Ammonia nitrogen concentration detection and ammonia nitrogen removal capacity calculation: The ammonia nitrogen concentration of the leachate is determined according to the "Determination of Ammonia Nitrogen in Water Quality - Salicylic Acid Spectrophotometry" (HJ536-2009). The ammonia nitrogen removal capacity is calculated according to formula (3), where R N is the ammonia nitrogen removal capacity (mg / g), c N0 is the initial concentration of ammonia nitrogen in the leachate before treatment (mg / L), c Nt is the residual concentration of ammonia nitrogen in the treated leachate (mg / L), m is the mass of the catalyst (1g), and V is the volume of the leachate (1L).

[0035]

[0036] Mercury ion concentration detection and removal capacity calculation: The mercury ion concentration in the leachate was determined according to the "Determination of Mercury, Arsenic, Selenium, Bismuth and Antimony in Water by Atomic Fluorescence Method" (HJ 694-2014). The mercury ion removal capacity was calculated according to formula (4), where R Hg is the mercury ion removal capacity (mg / g), c Hg0 is the initial concentration of mercury ions in the leachate before treatment (mg / L), c Hgt is the mercury ion concentration in the treated leachate (mg / L), m is the mass of the catalyst (1 g), and V is the volume of the leachate (1 L).

[0037]

[0038] The test results of this embodiment are shown in Table 1.

[0039] Table 1 Effect of mass ratio of electrolytic manganese slag and red mud on the performance of the prepared catalyst

[0040] It can be seen from Table 1 that when the mass ratio of electrolytic manganese slag to red mud is less than 40:100 (such as in Table 1, the mass ratio of electrolytic manganese slag to red mud = 35:100, 30:100, 25:100 and lower ratios not listed in Table 1), less electrolytic manganese slag is added, and the electrolytic manganese slag and red mud react insufficiently, resulting in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacity of the prepared catalyst significantly reduced with the decrease of the mass ratio of electrolytic manganese slag to red mud. When the mass ratio of electrolytic manganese slag to red mud is equal to 40~120:100 (such as in Table 1, the mass ratio of electrolytic manganese slag to red mud = 40:100, 80:100, 120:100), the acid leaching sludge is roasted, and the ammonium chloride and chlorine in the hydrochloric acid combine with the iron and aluminum in the red mud and electrolytic manganese slag in a high temperature environment to form ferric chloride and aluminum chloride and volatilize into the flue gas, while the ammonium ions react with the nitrogen oxides formed in the air to generate nitrogen. At the same time, during the roasting process, the hydrogen ions in the hydrochloric acid promote the release of titanium, manganese and other small amounts of metal elements in red mud and electrolytic manganese slag. High-temperature roasting enhances the activity of regular acid salts and gypsum materials in red mud and electrolytic manganese slag through thermal activation, removing free water and crystal water. Finally, the COD removal capacity of the prepared catalysts is higher than 478 mg / g, the total phosphorus removal capacity is higher than 32 mg / g, the ammonia nitrogen removal capacity is higher than 69 mg / g, and the mercury removal capacity is higher than 21 mg / g. When the mass ratio of electrolytic manganese slag to red mud is greater than 120:100 (such as in Table 1, the mass ratio of electrolytic manganese slag to red mud = 130:100, 140:100, 150:100 and higher ratios not listed in Table 1), the electrolytic manganese slag is added excessively, and the reaction between the electrolytic manganese slag and red mud is unbalanced, resulting in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacity of the prepared catalysts significantly decreasing with the further increase of the mass ratio of electrolytic manganese slag to red mud. In summary, considering benefits and costs, when the mass ratio of electrolytic manganese slag to red mud is equal to 40~120:100, it is most conducive to improving the performance of the prepared catalyst.

[0041] Example 2 Effect of the mass ratio of ammonium chloride to red slag mud on the performance of the prepared catalyst Electrolytic manganese slag and red mud are mixed in a mass ratio of 120:100, and stirred evenly to obtain red slag mud. Ammonium chloride and red slag mud are mixed in a mass ratio of 1:100, 1.5:100, 2:100, 2.5:100, 10:100, 17.5:100, 20:100, 22.5:100, and 25:100, and stirred evenly to obtain ammonium-loaded slag mud. Hydrochloric acid solution and ammonium-loaded slag mud are mixed in a liquid-solid ratio of 0.4:1mL / g, and stirred evenly to obtain acid leaching slag mud, wherein the concentration of the hydrochloric acid solution is 4M. The acid leaching slag mud is roasted, and the roasted slag is ground to obtain deironized powder, wherein the roasting temperature is 600°C, the roasting time is 2.5 hours, and the grinding time is 20 minutes. The auxiliary agent and the deironized powder are mixed in a mass ratio of 1.5:100, and stirred evenly to obtain a hydrothermal raw material, wherein the auxiliary agent is isopropylamine. Water and hydrothermal raw materials were mixed at a liquid-solid ratio of 0.5:1 mL / g, granulated, and allowed to stand for 2 days to obtain roasted raw materials. The roasted raw materials were placed in a hydrothermal kettle to perform a hydrothermal reaction on the roasted raw materials to obtain hydrated materials, wherein the hydrothermal time was 2.5 hours and the hydrothermal temperature was 200°C. The hydrated materials were roasted to obtain catalytic materials, wherein the roasting temperature was 800°C and the roasting time was 2.5 hours.

[0042] The adsorption test, COD concentration detection and calculation of COD removal capacity, total phosphorus concentration detection and calculation of total phosphorus removal capacity, ammonia nitrogen concentration detection and calculation of ammonia nitrogen removal capacity, and mercury ion concentration detection and removal capacity calculation are all the same as in Example 1. The test results of this example are shown in Table 2.

[0043] Table 2 Effect of the mass ratio of ammonium chloride and red slag mud on the performance of the prepared catalyst

[0044] It can be seen from Table 2 that when the mass ratio of ammonium chloride to red slag mud is less than 2.5:100 (such as in Table 2, the mass ratio of ammonium chloride to red slag mud = 2:100, 1.5:100, 1:100 and lower ratios not listed in Table 2), less ammonium chloride is added, and the reaction of ammonium chloride and red slag mud is insufficient under the high-temperature roasting environment, resulting in the COD, total phosphorus, ammonia nitrogen and mercury removal capacity of the prepared catalyst to decrease significantly with the decrease of the mass ratio of ammonium chloride to red slag mud. When the mass ratio of ammonium chloride to red slag mud is equal to 2.5~17.5:100 (as shown in Table 2, the mass ratio of ammonium chloride to red slag mud = 2.5:100, 10:100, 17.5:100), the acid leaching slag mud is roasted. Under high temperature environment, the chlorine in ammonium chloride and hydrochloric acid combines with the iron and aluminum in red mud and electrolytic manganese slag to form iron chloride and aluminum chloride and volatilize into the flue gas, while the ammonium ions react with the nitrogen oxides formed in the air to generate nitrogen. At the same time, during the roasting process, the hydrogen ions in the hydrochloric acid promote the release of titanium, manganese and other small amounts of metal elements in red mud and electrolytic manganese slag. High-temperature roasting improves the activity of regular acid salts and gypsum materials in red mud and electrolytic manganese slag through thermal activation, so that free water and crystal water are removed. Finally, the prepared COD removal capacity is higher than 512 mg / g, the total phosphorus removal capacity is higher than 38 mg / g, the ammonia nitrogen removal capacity is higher than 77 mg / g, and the mercury removal capacity is higher than 26 mg / g. When the mass ratio of ammonium chloride to red slag mud is greater than 17.5:100 (such as in Table 2, the mass ratio of ammonium chloride to red slag mud = 20:100, 22.5:100, 25:100 and higher ratios not listed in Table 2), excessive addition of ammonium chloride will cause an imbalance in the reaction between ammonium chloride and red slag mud under high-temperature roasting conditions, resulting in a significant decrease in the removal capacity of COD, total phosphorus, ammonia nitrogen and mercury of the prepared catalyst as the mass ratio of ammonium chloride to red slag mud further increases. In general, considering benefits and costs, when the mass ratio of ammonium chloride to red slag mud is equal to 2.5~17.5:100, it is most conducive to improving the performance of the prepared catalyst.

[0045] Example 3 Effect of the mass ratio of additive and de-iron powder on the performance of the prepared catalyst Electrolytic manganese slag and red mud are mixed in a mass ratio of 120:100, stirred evenly, and red slag mud is obtained. Ammonium chloride and red slag mud are mixed in a mass ratio of 17.5:100, stirred evenly, and ammonium-loaded slag mud is obtained. Hydrochloric acid solution and ammonium-loaded slag mud are mixed in a liquid-solid ratio of 0.6:1mL / g, stirred evenly, and acid leaching slag mud is obtained, wherein the concentration of the hydrochloric acid solution is 6M. The acid leaching slag mud is roasted, and the roasted slag is ground to obtain deiron powder, wherein the roasting temperature is 750°C, the roasting time is 4.5 hours, and the grinding time is 35 minutes. The auxiliary agent and deiron powder are mixed in a mass ratio of 0.1:100, 0.15:100, 0.2:100, 0.25:100, 1.5:100, 2.75:100, 3:100, 3.25:100, and 3.5:100, stirred evenly, and a hydrothermal raw material is obtained, wherein the auxiliary agent is triethylamine. Water and hydrothermal raw materials were mixed at a liquid-solid ratio of 0.65:1 mL / g, granulated, and allowed to stand for 3 days to obtain roasted raw materials. The roasted raw materials were placed in a hydrothermal kettle to perform a hydrothermal reaction on the roasted raw materials to obtain hydrated materials, wherein the hydrothermal time was 4.5 hours and the hydrothermal temperature was 280°C. The hydrated materials were roasted to obtain catalytic materials, wherein the roasting temperature was 950°C and the roasting time was 4.5 hours.

[0046] The adsorption test, COD concentration detection and calculation of COD removal capacity, total phosphorus concentration detection and calculation of total phosphorus removal capacity, ammonia nitrogen concentration detection and calculation of ammonia nitrogen removal capacity, and mercury ion concentration detection and removal capacity calculation are all the same as in Example 1. The test results of this example are shown in Table 3.

[0047] Table 3 Effect of the mass ratio of additives and de-ironized powder on the performance of the prepared catalyst

[0048] It can be seen from Table 3 that when the mass ratio of the additive to the deironing powder is less than 0.25:100 (such as in Table 3, the mass ratio of the additive to the deironing powder = 0.2:100, 0.15:100, 0.1:100 and lower ratios not listed in Table 3), less additive is added, and the additive and the deironing powder do not react fully, resulting in the COD, total phosphorus, ammonia nitrogen and mercury removal capacity of the prepared catalyst all significantly reduced with the decrease of the mass ratio of the additive to the deironing powder. When the mass ratio of the additive to the deironing powder is equal to 0.25~2.75:100 (as in Table 3, the mass ratio of the additive to the deironing powder = 0.25:100, 1.5:100, 2.75:100), water and hydrothermal raw materials are mixed, and the additive dissolves into the hydrothermal raw material particles during stirring and standing, and promotes the reaction of the activated red mud and electrolytic manganese slag with the aluminosilicate, iron aluminum salt and gypsum calcium-based materials to form a solidified body colloid through the structural guidance effect, and induces titanium, manganese and other small amounts of heavy metal elements to hydrolyze to form a coprecipitate and cement on the solidified body. The roasted raw material is placed in a hydrothermal kettle to perform a hydrothermal reaction on the roasted raw particles, the structural guidance effect of the additive is strengthened, the aluminosilicate undergoes hydrolysis and polymerization, and the self-excitation and self-gelling effect between it and the iron aluminum salt and gypsum calcium-based materials is more obvious, and titanium, manganese and other small amounts of heavy metal elements are fully hydrolyzed and mixed with each other. The hydrated material is roasted, and the additive is oxidized to form carbon dioxide and water vapor under high temperature environment and diffused from the gelled solidified material. The co-precipitated mixture of titanium, manganese and heavy metals is dehydrated to form mixed metal oxides and cemented on the surface of the solidified particles. Finally, the COD removal capacity of the prepared catalyst is higher than 538 mg / g, the total phosphorus removal capacity is higher than 46 mg / g, the ammonia nitrogen removal capacity is higher than 85 mg / g, and the mercury removal capacity is higher than 32 mg / g. When the mass ratio of the additive to the de-iron powder is greater than 2.75:100 (such as in Table 3, the mass ratio of the additive to the de-iron powder = 3:100, 3.25:100, 3.5:100 and higher ratios not listed in Table 3), the additive is added excessively, and the reaction between the additive and the de-iron powder is unbalanced, resulting in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacity of the prepared catalyst significantly decreasing with the further increase of the mass ratio of the additive to the de-iron powder.

[0049] In summary, considering benefits and costs, when the mass ratio of additive to de-ironing powder is equal to 0.25~2.75:100, it is most conducive to improving the performance of the prepared catalyst.

[0050] Example 4 Comparison of catalyst performance under light irradiation conditions Electrolytic manganese slag and red mud are mixed in a mass ratio of 80:100, stirred evenly, and red slag mud is obtained. Ammonium chloride and red slag mud are mixed in a mass ratio of 2.5:100, stirred evenly, and ammonium-loaded slag mud is obtained. Hydrochloric acid solution and ammonium-loaded slag mud are mixed in a liquid-solid ratio of 0.6:1mL / g, stirred evenly, and acid leaching slag mud is obtained, wherein the concentration of the hydrochloric acid solution is 6M. The acid leaching slag mud is roasted, and the roasted slag is ground to obtain deiron powder, wherein the roasting temperature is 450°C, the roasting time is 2.5 hours, and the grinding time is 35 minutes. The auxiliary agent and the deiron powder are mixed in a mass ratio of 2.75:100, stirred evenly, and a hydrothermal raw material is obtained, wherein the auxiliary agent is diethylamine. Water and hydrothermal raw material are mixed in a liquid-solid ratio of 0.65:1mL / g, granulated, and left to stand for 3 days to obtain roasted raw granules. The calcined raw material was placed in a hydrothermal kettle to perform hydrothermal reaction on the calcined raw particles to obtain a hydrated material, wherein the hydrothermal time was 4.5 hours and the hydrothermal temperature was 120° C. The hydrated material was calcined to obtain a catalytic material, wherein the calcination temperature was 950° C. and the calcination time was 2.5 hours.

[0051] Photocatalytic removal test: 1g of catalytic material was put into 1L of landfill leachate, stirred at 120 rpm and irradiated with UV light for 120 min, then centrifuged at 5000 rpm for solid-liquid separation. The concentration of different pollutants in the separated liquid was tested and the removal rate was calculated. The specific test and calculation were the same as in Example 1.

[0052] The adsorption test, COD concentration detection and calculation of COD removal capacity, total phosphorus concentration detection and calculation of total phosphorus removal capacity, ammonia nitrogen concentration detection and calculation of ammonia nitrogen removal capacity, and mercury ion concentration detection and calculation of removal capacity are all the same as in Example 1.

[0053] The test results of this embodiment are shown in Table 4.

[0054] Table 4 Comparison of catalyst performance under light irradiation conditions

[0055] It can be seen from Table 4 that under photocatalytic conditions, the removal effect of the catalyst on COD, ammonia nitrogen, total phosphorus and heavy metal mercury can be further significantly improved.

[0056] Comparative Example Effects of Different Processes on the Performance of the Prepared Catalysts The process of the present invention is as follows: electrolytic manganese slag and red mud are mixed in a mass ratio of 40:100, and stirred evenly to obtain red slag mud. Ammonium chloride and red slag mud are mixed in a mass ratio of 10:100, and stirred evenly to obtain ammonium-loaded slag mud. Hydrochloric acid solution and ammonium-loaded slag mud are mixed in a liquid-solid ratio of 0.6:1mL / g, and stirred evenly to obtain acid leaching slag mud, wherein the concentration of the hydrochloric acid solution is 2M. The acid leaching slag mud is roasted, and then the roasted slag is ground to obtain deironing powder, wherein the roasting temperature is 750°C, the roasting time is 4.5 hours, and the grinding time is 35 minutes. The auxiliary agent and the deironing powder are mixed in a mass ratio of 2.75:100, and stirred evenly to obtain hydrothermal raw material, wherein the auxiliary agent is diethylamine. Water and hydrothermal raw material are mixed in a liquid-solid ratio of 0.35:1mL / g, granulated, and left to stand for 3 days to obtain roasted raw granules. The calcined raw material was placed in a hydrothermal kettle to perform hydrothermal reaction on the calcined raw particles to obtain a hydrated material, wherein the hydrothermal time was 4.5 hours and the hydrothermal temperature was 280° C. The hydrated material was calcined to obtain a catalytic material, wherein the calcination temperature was 950° C. and the calcination time was 4.5 hours.

[0057] Comparative process 1: Ammonium chloride and red mud are mixed in a mass ratio of 10:100, stirred evenly, and ammonium-loaded mud is obtained. Hydrochloric acid solution and ammonium-loaded mud are mixed in a liquid-solid ratio of 0.6:1mL / g, stirred evenly, and acid leaching mud is obtained, wherein the concentration of the hydrochloric acid solution is 2M. The acid leaching mud is roasted, and the roasted slag is ground to obtain deiron powder, wherein the roasting temperature is 750°C, the roasting time is 4.5 hours, and the grinding time is 35 minutes. The auxiliary agent and deiron powder are mixed in a mass ratio of 2.75:100, stirred evenly, and hydrothermal raw material is obtained, wherein the auxiliary agent is diethylamine. Water and hydrothermal raw material are mixed in a liquid-solid ratio of 0.35:1mL / g, granulated, and left to stand for 3 days to obtain roasted raw granules. The roasted raw material is placed in a hydrothermal kettle for hydrothermal reaction of the roasted raw granules to obtain hydrated material, wherein the hydrothermal time is 4.5 hours and the hydrothermal temperature is 280°C. The hydrated material is calcined to obtain a catalytic material, wherein the calcination temperature is 950° C. and the calcination time is 4.5 hours.

[0058] Comparative process 2: Electrolytic manganese slag and red mud are mixed in a mass ratio of 40:100, stirred evenly, and red slag mud is obtained. Ammonium chloride and red slag mud are mixed in a mass ratio of 10:100, stirred evenly, and ammonium-loaded slag mud is obtained. Hydrochloric acid solution and ammonium-loaded slag mud are mixed in a liquid-solid ratio of 0.6:1mL / g, stirred evenly, and acid leaching slag mud is obtained, wherein the concentration of the hydrochloric acid solution is 2M. The acid leaching slag mud is roasted, and then the roasted slag is ground to obtain deiron powder, wherein the roasting temperature is 750℃, the roasting time is 4.5 hours, and the grinding time is 35 minutes. Water and deiron powder are mixed in a liquid-solid ratio of 0.35:1mL / g, granulated, and left to stand for 3 days to obtain roasted raw granules. The roasted raw material is placed in a hydrothermal kettle for hydrothermal reaction of the roasted raw granules to obtain hydrated material, wherein the hydrothermal time is 4.5 hours and the hydrothermal temperature is 280℃. The hydrated material is calcined to obtain a catalytic material, wherein the calcination temperature is 950° C. and the calcination time is 4.5 hours.

[0059] The photocatalytic removal test is the same as in Example 3, and the specific detection and calculation are the same as in Example 1.

[0060] The test results of this comparative example are shown in Table 5.

[0061] Table 5 Effects of different processes on the performance of the prepared catalysts

[0062] It can be seen from Table 5 that the catalyst prepared by the process of the present invention has significantly higher removal effects on COD, ammonia nitrogen, total phosphorus and heavy metal mercury than comparative process 1 and comparative process 2.

Claims

1. A method for preparing catalytic materials by synergistically utilizing red mud and electrolytic manganese slag, characterized in that: The following steps are involved: (1) mixing electrolytic manganese slag and red mud, stirring evenly to obtain red slag mud; mixing ammonium chloride and red slag mud, stirring evenly to obtain ammonium-loaded slag mud; mixing hydrochloric acid solution and ammonium-loaded slag mud, stirring evenly to obtain acid leaching slag mud, roasting, grinding to obtain deironing powder; the mass ratio of the electrolytic manganese slag to the red mud is 40-120:100; the mass ratio of the ammonium chloride to the red slag mud is 2.5-17.5:100; (2) mixing an auxiliary agent and the deironing powder in step (1), stirring evenly, and obtaining a hydrothermal raw material; the auxiliary agent comprises any one of tetraethylammonium hydroxide, isopropylamine, triethylamine or diethylamine; and the mass ratio of the auxiliary agent to the deironing powder is 0.25-2.75:100; (3) Mixing water and the hydrothermal raw material in step (2), granulating, standing, hydrothermally reacting, and calcining to obtain a catalytic material.

2. The method according to claim 1, characterized in that: The liquid-to-solid ratio of the hydrochloric acid solution and the ammonium-loaded sludge in step (1) is 0.2-0.6:1 mL / g.

3. The method according to claim 1, characterized in that: The concentration of the hydrochloric acid solution in step (1) is 2-6 M.

4. The method according to claim 1, characterized in that: The calcination temperature in step (1) is 450-750° C. and the calcination time is 0.5-4.5 hours.

5. The method according to claim 1, characterized in that: The grinding time in step (1) is 5 to 35 minutes.

6. The method according to claim 1, characterized in that: The liquid-to-solid ratio of water to hydrothermal raw material in step (3) is 0.35-0.65:1 mL / g.

7. The method according to claim 1, characterized in that: The hydrothermal reaction time in step (3) is 0.5 to 4.5 hours, and the temperature is 120 to 280°C.

8. The method according to claim 1, characterized in that: The calcination temperature in step (3) is 650-950° C. and the calcination time is 0.5-4.5 hours.

9. A catalytic material prepared by the method according to any one of claims 1 to 8.

10. Use of the catalytic material according to claim 9 in removing pollutants.

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