Method for synthesizing carbon-hybridized multi-metal center mesoporous material by using coal gangue

Abstract

The invention relates to the technical field of coal gangue utilization, and provides a method for synthesizing a carbon-hybridized multi-metal center mesoporous material by using coal gangue, which comprises the following steps: (1) adding coal gangue into a solution containing potassium permanganate, hydrochloric acid and phosphoric acid, and magnetically stirring to obtain a suspension; hydrogen peroxide is added into the solution before the suspension treatment time is over; (2) adding soluble silicate and / or soluble silicic acid into the obtained suspension to obtain a suspension A; (3) adding a solution B containing an alkaline metal compound and metal salt into the suspension A, and magnetically stirring to obtain a precursor solution; (4) transferring the obtained precursor solution into a closed reactor, and applying a magnetic field to react to obtain a mixed product containing solid and liquid; and (5) carrying out solid-liquid separation on the obtained mixed product to obtain the solid carbon-hybridized multi-metal center mesoporous material. The carbon-hybridized multi-metal center is uniformly dispersed, analcime and the like are generated in the mesoporous material so as to be beneficial to adsorption of crystal forms, and mesopores are stable.

Description

Technical Field

[0001] This application relates to the technical field of coal gangue utilization, and particularly relates to a method for synthesizing carbon hybrid multi-metal center mesoporous materials using coal gangue. Background Art

[0002] After multiple coal washing processes, a large amount of solid waste such as coal gangue is generated. Coal gangue is a black-gray rock with a low carbon content (10%-30%) and harder than coal, usually accounting for about 10-20% of coal production.

[0003] Coal gangue mainly consists of kaolinite, quartz, calcite, pyrite, and illite, and contains a certain amount of organic matter and a small amount of mica. Its main elements include Si, Al, C, Ca, Fe, Mg, K, etc. In the past few decades, extensive research has been conducted on the utilization of coal gangue, mainly focusing on landfilling, building materials production, the energy industry, and agriculture. Nevertheless, achieving high-value utilization of coal gangue remains a challenge.

[0004] The results of mineral composition analysis show that the components of coal gangue vary with its geographical location. However, most coal gangue is mainly composed of a hydrated aluminosilicate clay mineral, kaolinite (Al2O3·2SiO2·2H2O), in which SiO2 and Al2O3 usually account for more than 80% of the overall composition. Clay minerals such as kaolinite are 1:1 or 1:2 type nanolayered silicate minerals composed of silicon-oxygen tetrahedra and metal-oxygen octahedra. The silicon-oxygen tetrahedra and metal-oxygen octahedra are connected by Si-O-Si and Si-O-M (M: Al, Fe, Mg) bonds to form a nanosheet structure. For example, Chinese Patent CN115196640A discloses a method for preparing a mesoporous silica material using coal gangue. The coal gangue-based silicon source, organic carboxylic acid, anhydrous organic alcohol, and surfactant are mixed and reacted. Through a series of steps such as self-assembly treatment, centrifugation, drying, activation with an inorganic strong acid solution, and calcination, a mesoporous material is prepared. However, this method uses the silicon species extract obtained after the coal gangue, as a solid waste, is successively treated with acid washing for dealumination under stirring reflux, activation treatment under high temperature and high pressure (subcritical) conditions with an inorganic strong base solution, and dissolution treatment with an inorganic strong acid solution as the silicon source. That is, the coal gangue needs to be treated with processes such as acid washing and alkali treatment and then used as a raw material. With the selective and appropriate introduction of organic alcohol and organic carboxylic acid, combined with solvothermal self-assembly, the hydrolysis-polymerization degree of silicon species and the content of surface hydroxyl groups are regulated, promoting its synergistic self-assembly with a block copolymer non-ionic surfactant, and through high-temperature hydrothermal polymerization treatment under the condition that the pH value in the strong acid solution is close to the isoelectric point of silica, a mesoporous silica material with a highly uniform mesoporous channel structure and high hydrothermal stability is prepared; it is modified with strong acids, strong bases, and other additives repeatedly, the process is complex, the cross-use of acids and bases leads to a significant increase in consumption, and it is only utilized from the perspective of the raw material composition substances, without being utilized from the perspectives of the composition of coal gangue such as carbon-containing substances and layered crystal structures.

[0005] Chinese Patent CN115057458A discloses a method for preparing nano-aluminum oxide from coal gangue. The coal gangue loaded with inorganic salts of alkali metal K, inorganic salts of Na or biomass is gasified or burned at high temperature to achieve the activation of coal gangue at high temperature. The obtained aluminum hydroxide precursor is subjected to high-temperature roasting, water washing, acid washing, and filtration to obtain flaky aluminum oxide. The temperature of gasification or combustion is 600-1000 °C. The alkali metal is used as an activator. Using inorganic salts or biomass containing alkali metal as an activator can improve the aluminum extraction efficiency and effectively reduce the temperature of thermal activation. According to the characteristics of the solution after acid dissolution, combined with the traditional molten salt method (MSS) for preparing flaky aluminum oxide, adding a mixed solution of KOH and NaOH to the acidic crude liquid can achieve the purpose of adjusting the pH and form molten salts K2SO4 and Na2SO4. The recycled molten salt can be used again as an activator for coal gangue. The coal gangue loaded with inorganic salts of alkali metal K, inorganic salts of Na or biomass is gasified or burned at high temperature to achieve the activation of coal gangue, and this process can also consume the carbon element in the coal gangue. However, in this method, the carbon element in the coal gangue is mainly consumed by combustion, and carbon is only used for combustion. Flaky aluminum oxide is obtained through acid leaching and alkali solution coordination, with low utilization rate of the components in coal gangue, only one component, aluminum oxide, can be effectively used, and complex processes such as impurity removal are required.

[0006] Chinese Patent discloses a method in which sulfuric acid reacts fully with carbonate impurities in coal gangue; the obtained powder is ground by a stone mill and then calcined at 200-600 °C for 1-6 h to obtain activated coal gangue powder. Then the activated coal gangue powder is dispersed into an aqueous solution of soluble silicate, and then a magnesium salt and nitrilotriacetic acid are added successively. Adding nitrilotriacetic acid promotes the mineral transformation and reconstruction into flower-shaped zeolite. A pure-phase zeolite product with a flower-shaped morphology is obtained through hydrothermal reaction. However, in this method, after the reaction of acid with the components in coal gangue and then calcination, substances such as organic carbon in coal gangue seriously affect the progress of the reaction. At the same time, converting crystals through special acids such as nitrilotriacetic acid increases the cost and cannot be applied on a large scale, and the use of nitrilotriacetic acid has limited effect on the zeolite structure, etc.

[0007] Chinese Patent CN110921677A discloses a method for preparing 4A zeolite from kaolin. After the kaolin is calcined at low temperature, the alkali fusion activator is aged under an external magnetic field. The action of the magnetic field can increase the number of 4A zeolite crystal nuclei and reduce the crystal aggregation particle size, so that the volume of the formed colloid and the stability of the colloid are relatively high, improving the quantity and quality of the synthesized 4A zeolite after crystallization, reducing the particle size, and enhancing the quality of 4A zeolite. Crystallization is carried out without an external magnetic field. Without an external magnetic field, the water molecules are demagnetized, which can reduce the solubility and form a supersaturated solution. A large amount of supersaturated solute precipitates out, forming a large number of crystal nuclei with small sizes. Crystallization occurs on these small crystal nuclei, reducing the particle size of 4A zeolite, increasing the calcium exchange capacity and whiteness, and improving the yield and quality of 4A zeolite. This method requires mixing saturated sodium hydroxide aqueous solution with kaolin and then calcining, consuming a large amount of soda ash. The magnetic field is used to increase dissolution. After that, without an external magnetic field during crystallization, the crystallization process is slow, making it difficult to more effectively promote the crystallization transformation of zeolite and further improve the adsorption efficiency. In addition, this method fails to effectively utilize components such as carbon in coal gangue, and carbon is lost during the soda ash calcination process, making it difficult to play the role of carbon components.

[0008] In addition, in the prior art, during the utilization of coal gangue, soluble silicate is added to supplement metal salts to prepare mesoporous materials. In order to facilitate the dispersion and reasonable distribution of metal salts, substances such as template agents and surfactants need to be added to improve the adsorption performance. However, the addition of template agents and surfactants undoubtedly increases the cost and the complexity of the process.

[0009] As can be seen from the above, the preparation process using the existing method is relatively complex, with a large amount of acid-base cooperation, external additives for pore formation, and the need to add substances such as template agents and surfactants. The utilization of coal gangue components is single, and processes such as impurity removal further complicate the process, and components such as carbon in coal gangue are difficult to effectively utilize. Therefore, the present invention provides a new technology for synthesizing carbon hybrid multi-metal center mesoporous materials using coal gangue. There is currently no literature report and technical application precedent for this technology. Summary of the Invention

[0010] Overcoming the deficiencies of the prior art, the present application provides a method for synthesizing carbon hybrid multi-metal center mesoporous materials using coal gangue, achieving the obtainment of carbon hybrid multi-metal center mesoporous materials without external additives such as concentrated alkali, template agents, surfactants, and complexing agents and with less acid. The carbon hybrid multi-metal centers are evenly dispersed, and zeolite and other crystal forms beneficial for adsorption are generated inside the mesoporous materials. The mesopores are stable, and organic dyes, heavy metals, antibiotics, phosphorus and other pollutants can be efficiently removed. The mineral components in coal gangue are transformed into multi-metal-carbon composite materials, effectively utilizing metal elements, carbon and other components, largely avoiding the waste of valuable metals and carbon, and being suitable for industrial production.

[0011] Embodiments of the present application are implemented as follows: The present application example provides a method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue, including: (1) Crushing 10 - 60 g of coal gangue into powder and adding it to a solution containing 0.09 - 0.15 mol / L of potassium permanganate, 2 - 5 mol / L of hydrochloric acid, and 0.5 - 1 mol / L of phosphoric acid; dispersing it in deionized water according to a solid-liquid ratio of 10:1 - 100:1 (g / L) under the action of magnetic stirring to obtain a uniform suspension; the treatment temperature is 45 - 73 °C, and the treatment time is 30 - 130 min; 5 - 10 min before the end of the suspension treatment time, adding 0.01 - 0.02 mol / L of hydrogen peroxide to the solution; (2) Adding soluble silicate and / or soluble silicic acid to the suspension obtained above, stirring evenly, then ultrasonically treating with a cell crusher for 1 - 10 min, and continuing magnetic stirring to obtain a uniform suspension A; (3) Adding an alkaline metal compound and a metal salt to 30 - 100 ml of deionized water, and magnetic stirring to dissolve the metal compound and the metal salt to obtain a clear solution B; slowly adding the solution B dissolved with the alkaline metal compound and the metal salt to the suspension A, and continuing magnetic stirring for 10 - 60 min to obtain a uniform precursor solution; During the magnetic stirring process, the magnetic field intensity is 0.15 - 0.3 T; (4) Transferring the precursor solution obtained above into a closed reactor, applying a magnetic field under the conditions of a temperature of 60 - 300 °C and a pressure of 1 - 20 MPa for reaction for 2 - 36 h to obtain a mixed product containing solid and liquid, and the magnetic field intensity is 0.45 - 0.65 T; (5) Separating the solid and liquid of the mixed product obtained above to obtain a solid carbon hybrid multi-metal center mesoporous material.

[0012] Optionally, in step (1), after crushing the coal gangue into powder, it is calcined at 125 - 160 °C. During the calcination process, an aqueous solution of potassium permanganate with a mass fraction of 0.7 - 1.1 wt% is sprayed through a nozzle, the spraying mass accounts for 0.05 - 0.08 wt% of the mass of the coal gangue, and the spraying time is 0.5 - 1 h.

[0013] Optionally, in step (2), the soluble silicate is one or any combination of lithium silicate, sodium silicate, ammonium silicate, and potassium silicate, the soluble silicic acid is orthosilicic acid, and the addition amount of the soluble silicate and / or soluble silicic acid is 10 - 50% of the total mass of the suspension.

[0014] Optionally, the soluble silicate in step (2) is lithium silicate, sodium silicate and potassium silicate, and based on the total mass of the soluble silicate, the ratio of lithium silicate:sodium silicate:potassium silicate is (1.5-1.7):(14-15):(17-18).

[0015] Optionally, the metal salt in step (3) is one or any combination of magnesium carbonate, magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium trisilicate, zinc chloride, zinc sulfate, zinc nitrate, zinc dihydrogen phosphate, calcium halide, calcium carbonate, calcium nitrate, calcium chlorate, calcium perchlorate, calcium bicarbonate, calcium dihydrogen phosphate, and the addition amount is 5-50% of the mass of the soluble silicate and / or soluble silicic acid.

[0016] Optionally, one of magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium acetate, and magnesium trisilicate in the metal salt in step (3) accounts for 55-85% of the total mass of the metal salt.

[0017] Optionally, the alkaline metal compound in step (3) is one or any combination of magnesium hydroxide, magnesium oxide, basic magnesium carbonate, zinc oxide, zinc hydroxide, calcium oxide, calcium hydroxide, and dolomite, and the addition amount is 10-60% of the mass of the soluble silicate and / or soluble silicic acid.

[0018] Optionally, the particle size of the powder of the coal gangue after crushing in step (1) is 62-100 μm.

[0019] Optionally, the treatment temperature in step (1) is 45-53 °C.

[0020] Optionally, the addition amount of the soluble silicate and / or soluble silicic acid in step (2) is 33-41% of the total mass of the suspension.

[0021] The beneficial effects include: The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue provided by the present invention dissolves part of Al in the coal gangue through hydrochloric acid to increase the porosity and simultaneously form an Si-C skeleton; by adding phosphoric acid, since it can passivate some active sites and simultaneously inhibit Fe 3+Metal impurities such as [metal name] catalyze the deep oxidation of carbon, reduce the breakage of the carbon structure, inhibit the over-oxidation of the Si-C skeleton by potassium permanganate, and reduce the carbon loss rate; in the sulfuric acid-phosphoric acid mixed acid, KMnO4 shows strong oxidation ability, which is beneficial to oxidize the active sites (such as edge carbon, defect sites) of the carbon components in coal gangue. Carbon is partially oxidized to oxygen-containing functional groups such as carboxyl and carbonyl groups. The increased oxygen-containing groups are beneficial to adsorb metal ions and become the subsequent nucleation sites, providing the conditions for the transformation, growth, and crystal nucleus of the formation of carbon hybrid metal multi-metal centers; the generation of more nucleation sites utilizes the carbon component in coal gangue, can avoid agglomeration during the metal loading process, and at the same time greatly reduces the demand for templating agents (especially alkyl imidazole organic templating agents) and organic surfactants during metal hybridization. Then, the above components are omitted, reducing the process complexity, reducing costs, and also avoiding the deterioration risk caused by inappropriate amounts of templating agents, surfactants, etc. At the same time, KMnO4 shows strong oxidation ability, which is beneficial to the partial graphitization of the carbon components in coal gangue under strong oxidation, increasing the porosity, and facilitating the realization of a stable mesoporous structure. By adding an appropriate proportion and reasonably controlling the oxidation ability, some have a tendency to graphene, that is, the carbon component lamellarization and flattening, which is beneficial to increasing the nucleation sites and the formation of carbon hybrid metal multi-metal centers, thereby increasing the adsorption performance. After adding hydrogen peroxide (H2O2), it reacts with residual potassium permanganate, etc. to generate soluble Mn 2+ ions, which can terminate the oxidation reaction, moderately control the oxidation intensity, block the further reaction of carbon, prevent excessive oxidation loss of carbon, facilitate the stability of graphene-like carbon, increase the hydroxyl groups, increase the metal ion loading sites, facilitate the increase of nucleation sites, and facilitate the formation of carbon hybrid metal multi-metal centers, thereby increasing the adsorption performance. During the stirring process, a higher magnetic field intensity is adopted, which has a solubilization effect and is beneficial to promoting the uniform dispersion of metal ions. Hydrothermal reaction generates solid carbon hybrid multi-metal center mesoporous materials in the solution. The oxygen-containing groups generated in the early stage, the Si-O, Si-O-C, Si-O-C-Al and other skeletons formed by reacting with soluble silicate substances, and a large number of nucleation sites provide extremely favorable conditions for the adsorption, nucleation, and crystallization of metal ions in the solution. By applying a high-intensity magnetic field, at this time, the magnetic field not only has a solubilization effect, but also is beneficial to the uniform dispersion and diffusion of metal ions, is beneficial to the formation of a large number of small-sized crystal nuclei, and crystallizes on the small crystal nuclei, which has a greater promoting effect on the crystallization process and is more beneficial to the generation of crystallization structures such as analcime, improving the catalytic ability. Description of the Drawings

[0022] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0023] Figure 1 SEM image of the carbon hybrid multi-metal center mesoporous material of Example 1; Figure 2 N2 adsorption-desorption isotherm of the carbon hybrid multi-metal center mesoporous material of Example 1; Figure 3 Pore size distribution curve of the carbon hybrid multi-metal center mesoporous material of Example 1; Figure 4 XRD curve of the carbon hybrid multi-metal center mesoporous material of Example 1.

[0024] Explanation of the attached tables: Table 1 shows the pore structure parameters of the carbon hybrid multi-metal center mesoporous material; Table 2 shows the saturated adsorption capacities of the carbon hybrid multi-metal center mesoporous material for phosphate, tetracycline, Cd(II), and Pb(II). Detailed implementation manners

[0025] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0026] Those skilled in the art of the present technology can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those of ordinary skill in the technical field to which the present invention belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as here.

[0027] Those skilled in the art can understand that, unless specifically stated otherwise, the singular forms "a", "an", "the" and "said" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention means the presence of the recited features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items. The raw materials used hereinafter, unless otherwise specified, are all commercially available products. For performance testing, refer to national standards or industry standards.

[0028] Aiming at the problems that the preparation process using the existing method is relatively complex, a large amount of acid-base cooperation is used, pore formation is carried out with the addition of auxiliary agents, substances such as templating agents and surfactants need to be added, the utilization of coal gangue components is single, impurity removal, etc. lead to further complexity of the process, and components such as carbon in coal gangue are difficult to be effectively utilized, etc. Therefore, the embodiment of the present invention provides a method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue.

[0029] The features and performance of the present application will be further described in detail in combination with the following embodiments: The embodiment of the present invention provides a method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue, comprising: (1)Crush the coal gangue into powder with a mass of 10 - 60 g, and add it to a solution containing 0.09 - 0.15 mol / L of potassium permanganate (which can be 0.09 mol / L, 0.1 mol / L, 0.11 mol / L, 0.12 mol / L, 0.13 mol / L, 0.14 mol / L, 0.15 mol / L, etc.), 2 - 5 mol / L of hydrochloric acid (which can be 2 mol / L, 2.3 mol / L, 2.6 mol / L, 2.7 mol / L, 2.8 mol / L, 3.3 mol / L, 3.5 mol / L, 3.6 mol / L, 3.8 mol / L, 3.9 mol / L, 4.1 mol / L, 4.4 mol / L, 4.6 mol / L, 4.7 mol / L, 4.8 mol / L, 4.9 mol / L, 5 mol / L, etc.), and 0.5 - 1 mol / L of phosphoric acid (which can be 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, etc.) for 30 - 130 min; disperse it in deionized water under magnetic stirring according to a solid-liquid ratio of 10:1 - 100:1 (g / L) (10:1 g / L, 13:1 g / L, 17:1 g / L, 22:1 g / L, 25:1 g / L, 29:1 g / L, 33:1 g / L, 36:1 g / L, 39:1 g / L, 42:1 g / L, 45:1 g / L, 47:1 g / L, 56:1 g / L, 59:1 g / L, 63:1 g / L, 68:1 g / L, 72:1 g / L, 77:1 g / L, 88:1 g / L, 91:1 g / L, 93:1 g / L, 97:1 g / L, 100:1 g / L, etc.) to obtain a homogeneous suspension; the treatment temperature is 45 - 73 °C, preferably 45 - 53 °C (which can be 45 °C, 47 °C, 48 °C, 49 °C, 52 °C, 54 °C, 55 °C, 58 °C, 61 °C, 64 °C, 66 °C, 68 °C, 71 °C, 72 °C, 73 °C, etc.).

[0030] Dissolve part of the Al in the coal gangue through hydrochloric acid to increase the porosity and simultaneously form an Si-C skeleton; by adding phosphoric acid, since it can passivate some active sites and simultaneously inhibit Fe 3+Metal impurities such as [metal name] catalyze the deep oxidation of carbon, reduce the breakage of the carbon structure, inhibit the over-oxidation of the Si-C framework by potassium permanganate (over-oxidizing C to generate gases such as CO2, and C will be over-oxidized into gases and lost, which is not conducive to carbon retention and hybridization), and reduce the carbon loss rate. If the proportion of phosphoric acid is less than the above range, C will be over-oxidized into gases, and the generated oxygen-containing functional groups will decrease, which is not conducive to the formation of multi-metal centers for carbon hybridization with metals and reduces the adsorption performance; if the phosphoric acid is higher than the above range, the reaction activity is low, which is not conducive to leaching out part of Al in the coal gangue, forming the Si-C framework, and the product may block pores, etc., which is not conducive to increasing the porosity and reduces the adsorption performance.

[0031] In the sulfuric acid-phosphoric acid mixed acid, KMnO4 shows strong oxidation ability, which is conducive to oxidizing the active sites (such as edge carbon, defect sites) of the carbon components in the coal gangue. Carbon is partially oxidized into oxygen-containing functional groups such as carboxyl and carbonyl. The increased oxygen-containing groups are conducive to adsorbing metal ions and becoming the subsequent nucleation sites, providing the conditions for the transformation, growth, and crystal nucleus of the formation of multi-metal centers for carbon hybridization; the generation of more nucleation sites utilizes the carbon components in the coal gangue, which can avoid agglomeration during the metal loading process and greatly reduce the demand for template agents (especially alkyl imidazole organic template agents) and organic surfactants during metal hybridization. Furthermore, eliminating the above components reduces the process complexity, cost, and also avoids the deterioration risk caused by inappropriate amounts of template agents and surfactants. At the same time, KMnO4 shows strong oxidation ability, which is conducive to the partial graphitization of the carbon components in the coal gangue under strong oxidation, increasing the porosity and facilitating the formation of a stable mesoporous structure. By adding an appropriate proportion and reasonably controlling the oxidation ability, some have a tendency to graphene, that is, the carbon component sheets become laminated and flattened, which is conducive to increasing the nucleation sites and the formation of multi-metal centers for carbon hybridization, thereby increasing the adsorption performance. If the potassium permanganate is lower than the above range, the oxidation ability is insufficient; if it is higher than the above range, the oxidation ability is too high, both of which are not conducive to increasing the proportion of nucleation site formation and thus affect the improvement of the adsorption performance.

[0032] The above treatment temperature is relatively low, avoiding the adverse effects caused by the too-high activity and too-strong oxidation ability of potassium permanganate at high temperature, and the oxidation of carbon components into gases.

[0033] 5 - 10 minutes before the end of the above homogeneous suspension treatment time, add hydrogen peroxide with a concentration of 0.01 - 0.02 mol / L to the solution. After adding hydrogen peroxide (H2O2), it reacts with the residual potassium permanganate, etc. to generate soluble Mn 2+Ions can terminate the oxidation reaction, moderately control the oxidation intensity, block the further reaction of carbon, prevent excessive oxidation loss of carbon, facilitate the stability of graphene-like carbon, increase hydroxyl groups, increase metal ion loading sites, facilitate the increase of nucleation sites, and facilitate the formation of carbon hybridized multi-metal centers, thereby increasing the adsorption performance. The addition time should not be too early. If it is too early, it will hinder the reaction of potassium permanganate. If it is too late, it is not conducive to adjusting the oxidation intensity and blocking the excessive reaction of carbon.

[0034] Optionally: After crushing the coal gangue into powder, calcine it at 125 - 160 °C (which can be 125 °C, 129 °C, 132 °C, 136 °C, 138 °C, 146 °C, 149 °C, 155 °C, 156 °C, 158 °C, 160 °C, etc.) for 0.7 - 2 h; during the calcination process, spray an aqueous solution of potassium permanganate with a concentration of 0.7 - 1.1 wt% (i.e., the mass of potassium permanganate accounts for 0.7 - 1.1 wt%) through a nozzle, and the spraying mass accounts for 0.05 - 0.08 wt% of the mass of the coal gangue, and the spraying time is 0.5 - 1 h; Through relatively low-temperature calcination, crystalline aluminous minerals such as kaolinite, the main minerals in coal gangue, are transformed into semi-crystalline or even amorphous metakaolinite and other minerals. Their structures are in a thermodynamically metastable state. They mainly remove the hydroxyl groups (-OH) in the structure, resulting in the breakage of interlayer hydrogen bonds in layered silicates, the loosening of the layered structure, and the exposure of more surface active sites (a large number of broken Si-O and Al-O bonds, forming surface hydroxyl groups (Si-OH, Al-OH) and defect sites, etc., which are conducive to the reaction and combination with potassium permanganate, hydrochloric acid, phosphoric acid, hydrogen peroxide, soluble silicate and / or soluble silicic acid, alkaline metal compounds, metal salts, etc.); more amorphous phases (such as amorphous silica) are produced, which is conducive to subsequent mixing and reaction with potassium permanganate, hydrochloric acid, soluble silicate and / or soluble silicic acid, alkaline metal compounds, metal salts and water. The low-temperature calcination overcomes the deficiency that the layered structure of the original high-temperature direct sintering cannot be fully changed into a loose structure and the reaction activity cannot be greatly improved. The low-temperature calcination does not completely destroy its layered aluminosilicate skeleton, avoids the melting and collapse of internal pores caused by high-temperature calcination, and still maintains a two-dimensional sheet structure with an enlarged interlayer spacing, providing an insertion channel for soluble silicate and metal ions. The low-temperature calcination greatly reduces the energy consumption. The main purpose of the previous calcination was to remove carbon and activate it. The low-temperature calcination of this application has a different purpose. Through low-temperature calcination, while activating, the combustion loss of carbon is reduced, which will be beneficial to the retention of carbon and the generation of active reaction sites, improve the porosity, and make the layered silicate minerals become a fine nano-scale pore structure with rich porous silica and porous carbon composite (i.e., the pore structure of the silica-C composite structure), which is conducive to the formation of a more abundant Si-O-Al skeleton, increases the loading capacity and loading stability, and thus is conducive to improving the adsorption property and the ability to load metals. The value of carbon combustion is obviously lower than the value of being a component of the adsorption material, which also greatly improves the application value of coal gangue and reduces carbon emissions. Using a shorter heat treatment time is more conducive to less carbon loss and increasing the carbon hybridization ratio.

[0035] Potassium permanganate can release oxygen, MnO2, etc. above 120 °C, especially above 150 °C. Due to its unique redox activity, high specific surface area, porous structure and rich hydroxyl functional groups on the surface, MnO2 shows significant advantages in removing pollutants such as organic dyes, heavy metals, antibiotics and phosphorus. The hydroxyl groups (-OH) and oxygen vacancies on the surface of MnO2 can adsorb heavy metal ions (such as Pb 2+ 、Cd 2+), MnO2 can reduce Cr(VI) to less toxic and easily precipitated Cr(III), oxidize more toxic As(III) to As(V), which is more easily adsorbed or co-precipitated. The carboxylic acid group of antibiotic molecules (such as ofloxacin) forms hydrogen bonds or coordination bonds with the hydroxyl groups on the surface of MnO2. However, directly soaking coal gangue in potassium permanganate solution and decomposing to produce MnO2 easily clogs the pores of coal gangue and affects the improvement of adsorption performance. During the low-temperature calcination of coal gangue, the reaction between oxygen and carbon is slow, which affects the formation of carbonaceous micropores. By spraying an aqueous solution of potassium permanganate with a low content of 0.7-1.1 wt% during the low-temperature calcination of coal gangue powder, water reacts with carbon in coal gangue through the water-gas reaction to generate hydrogen, CO, and accompanying water vapor, which can effectively improve the gas circulation within the layered structure of coal gangue, facilitate the formation of mesopores with moderate pores, improve the generation of carbonaceous pores, and the generated oxygen reacts with carbon, and the water reacts with carbon in coal gangue through the water-gas reaction. Thus, while partially consuming the carbon in coal gangue (meeting the need to control the appropriate carbon content), the generated gas promotes the formation of pores and is conducive to improving the adsorption performance. The concentration and dosage of the potassium permanganate aqueous solution should not be too large, as this will lead to excessive reaction of carbon, even complete reaction, unable to form carbonaceous micropores, and problems such as too large pores and the risk of explosion due to excessive generation of oxygen; the concentration and dosage of the potassium permanganate aqueous solution should not be too low, as this cannot effectively create pores quickly and improve the porosity and specific surface area. It can be understood that spraying a lower content of potassium permanganate without acid is conducive to pore formation and the activation of coal gangue under low-temperature calcination; combined with the addition of potassium permanganate and hydrogen peroxide in an acid system, by regulating the oxidation ability, oxygen-containing groups of carbon are obtained, and the nucleation cores of metal ions are increased to facilitate the formation of more carbon hybrid multi-metal centers.

[0036] (2) Add soluble silicate and / or soluble silicic acid to the above-obtained suspension, stir well, then ultrasonicate with a cell disruptor for 1-10 min, and continue magnetic stirring to obtain a homogeneous suspension A.

[0037] Soluble silicate (such as sodium silicate, etc.) and / or orthosilicic acid hydrolyze to generate silicate anions (SiO4 4-)(or oligomeric silicic acid), by connecting with active sites in the suspension and Al ions in the solution, for example, connecting with the Si-O framework and Al ions in the suspension through a polycondensation reaction to form cross-linked Si-O-Al. The layered open structure of the layered silicate can effectively block, separate and insert soluble silicate and / or orthosilicic acid. The silicate ion penetrates into the interlayer, fills the interlayer voids, forms a three-dimensional interpenetrating network, enhances the mechanical strength of the material. The silicate gel shrinks during the pressure drying process, generating mesopores (2-30 nm) (which is beneficial to the diffusion of macromolecular pollutants), and mesopores and macropores (>30 nm) in the layered silicate mineral structure (reduce the mass transfer resistance and provide a stable channel for material migration), forming a hierarchical pore system, greatly enriching the pore type and pore density, significantly increasing the specific surface area of the material, and improving the adsorption capacity.

[0038] Optionally, the soluble silicate is one or any combination of lithium silicate, sodium silicate, ammonium silicate, and potassium silicate, and the soluble silicic acid is orthosilicic acid. The addition amount of the soluble silicate and / or soluble silicic acid is 10-50% of the total mass of the suspension, preferably 33-41% (optionally 10%, 16%, 21%, 27%, 33%, 38%, 42%, 47%, 50%, etc.). Controlling the addition amount of the soluble silicate and acid is beneficial to forming pores of appropriate size through a polycondensation reaction; too much will intercalate the layered silicate and form a coating at the same time, affecting the formation of the hierarchical pore system; too little will result in less filling of voids, being unfavorable for forming a three-dimensional interpenetrating network and enhancing the mechanical strength of the material, and at the same time the pores will become larger. Both too high and too low are not conducive to improving the adsorption performance. Preferably, in the case of controlling the appropriate pore diameter, a lower range is selected.

[0039] Optionally: the soluble silicate is lithium silicate, sodium silicate, and potassium silicate. Based on the total mass of the soluble silicate, the ratio of lithium silicate:sodium silicate:potassium silicate is (1.5-1.7):(14-15):(17-18); sodium silicate hydrolyzes to generate silicate ions, and its gelation process has strong controllability and is easy to control the formation of a mesoporous structure; the ionic radius of potassium ions is relatively large, which is beneficial to delaying the polycondensation rate and is conducive to expanding the pore size distribution (coexistence of mesopores and macropores). By appropriately increasing potassium ions, the pore size distribution is expanded, which is beneficial to the penetration and loading of metal ions and more uniform distribution; the strong polarization effect of lithium ions promotes the densification of the silicic acid gel structure, thus being beneficial to improving the pore strength and maintaining the pore stability; the ternary cation system of sodium, potassium, and lithium can balance the gelation rate, structural stability, and pore-forming radius, thereby improving the adsorption performance.

[0040] (3) Add an alkaline metal compound and a metal salt to 30 - 100 ml (preferably 30 - 40 ml) of deionized water, and stir magnetically to dissolve the metal compound and the metal salt to obtain a clear solution B; slowly add the solution B in which the alkaline metal compound and the metal salt are dissolved to the suspension A, and continue magnetic stirring for 10 - 60 min to obtain a homogeneous precursor solution. During the above magnetic stirring process, the magnetic field strength is 0.15 - 0.3 T (which can be optionally 0.15 T, 0.18 T, 0.19 T, 0.21 T, 0.23 T, 0.27 T, 0.3 T, etc.). Using a higher magnetic field strength during the stirring process has a solubilizing effect and is conducive to promoting the uniform dispersion of metal ions.

[0041] Optionally, the metal salt is one or any combination of magnesium carbonate, magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium trisilicate, zinc chloride, zinc sulfate, zinc nitrate, zinc dihydrogen phosphate, calcium halide, calcium carbonate, calcium nitrate, calcium chlorate, calcium perchlorate, calcium bicarbonate, calcium dihydrogen phosphate, and the addition amount is 5 - 50% of the mass of soluble silicate and / or soluble silicic acid, preferably 15 - 25% (which can be optionally 5%, 9%, 10%, 13%, 17%, 21%, 27%, 34%, 37%, 41%, 45%, 48%, 50%, etc.). The appropriate addition amount of the metal salt replenishes and regulates the metal ion composition in the solution, which is conducive to the formation of a multi-metal carbon hybrid crystallization structure, especially a high catalytic structure such as a reasonable structure close to analcime and promoting the formation of the analcime crystallization structure. Too high or too low is not conducive to the formation of a suitable crystallization structure. Preferably, one of magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium trisilicate accounts for 55 - 85% of the total mass of the metal salt; using a larger proportion of magnesium salts such as magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium trisilicate is conducive to promoting the formation of the analcime crystallization structure and improving the catalytic ability.

[0042] Optionally, the alkaline metal compound is one or any combination of magnesium hydroxide, magnesium oxide, basic magnesium carbonate, zinc oxide, zinc hydroxide, calcium oxide, calcium hydroxide, dolomite, and the addition amount is 10 - 60% of the mass of soluble silicate and / or soluble silicic acid, preferably 21 - 34% (which can be optionally 10%, 13%, 17%, 21%, 27%, 34%, 37%, 41%, 45%, 48%, 51%, 53%, 57%, 60%, etc.). The alkaline metal compound can promote the formation of a multi-metal composite by multi-metal hybridization; at the same time, it has the effect of enhancing the pore structure strength, etc.

[0043] (4) Transfer the precursor solution obtained above into a closed reactor, and carry out a reaction for 2 - 36 h under the conditions of a temperature of 60 - 300 °C (which can be 60 °C, 61 °C, 62 °C, 64 °C, 69 °C, 74 °C, 75 °C, 78 °C, 86 °C, 89 °C, 93 °C, 96 °C, 98 °C, 107 °C, 115 °C, 143 °C, 152 °C, 161 °C, 178 °C, 183 °C, 194 °C, 204 °C, 235 °C, 252 °C, 264 °C, 284 °C, 295 °C, 300 °C, etc.) and a pressure of 1 - 20 MPa (which can be 1 MPa, 5 MPa, 7 MPa, 9 MPa, 11 MPa, 14 MPa, 16 MPa, 18 MPa, 20 MPa, etc.) while applying a magnetic field, to obtain a mixed product containing solids and liquids, with a magnetic field intensity of 0.45 - 0.65 T (which can be 0.45 T, 0.48 T, 0.51 T, 0.54 T, 0.58 T, 0.62 T, 0.65 T, etc.). At the same time, in the above hydrothermal reaction, a solid carbon hybrid multi-metal center mesoporous material is formed in the solution. The oxygen-containing groups generated in the early stage react with soluble silicate substances to form skeletons such as Si - O, Si - O - C, Si - O - C - Al, etc., and a large number of nucleation sites, which provide extremely favorable conditions for the adsorption, nucleation, and crystallization of metal ions in the solution. By applying a high-intensity magnetic field, at this time, the magnetic field not only has a solubilizing effect, but also is conducive to the uniform dispersion and diffusion of metal ions, conducive to the formation of a large number of small-sized crystal nuclei, and crystallization on the small crystal nuclei, which has a greater promoting effect on the crystallization process and is more conducive to the generation of crystallization structures such as analcime, thereby improving the catalytic ability.

[0044] (5) Carry out solid-liquid separation on the mixed product obtained above to obtain a solid carbon hybrid multi-metal center mesoporous material. The obtained material has characteristics such as a high specific surface area and a porous structure, the adsorption performance can be increased to dozens of times that of the original raw coal gangue, the removal efficiency of pollutants in wastewater is more efficient, and at the same time, it effectively repairs soil severely polluted by heavy metals.

[0045] Optionally, the particle size of the powder of the coal gangue after crushing is 62 - 100 μm (which can be 62 μm, 64 μm, 69 μm, 78 μm, 82 μm, 91 μm, 97 μm, 100 μm, etc.). Preferably: 68 - 81 μm. Shortening the internal mass transfer distance of fine particles is conducive to the reaction of organic volatile components (such as tar, hydrocarbons) with potassium permanganate and HCl, and the dehydroxylation of layered silicates such as kaolinite in fine particles is more thorough, converting into an active structure of metakaolinite, which is conducive to the formation of uniformly distributed micropores and mesopores.

[0046] Example 1 A method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue, comprising: (1) Crush the coal gangue into powder. The particle size (average) of the powder after crushing the coal gangue is 69 μm. Then, calcine it at 134 °C for 0.8 h. During the calcination process, spray an aqueous solution of potassium permanganate with a concentration of 0.8 wt% through a nozzle, and the spraying mass accounts for 0.06 wt% of the mass of the coal gangue, and the spraying time is 0.5; Crush 30 g of the coal gangue into powder and add it to a solution containing 0.13 mol / L of potassium permanganate, 3.2 mol / L of hydrochloric acid, and 0.6 mol / L of phosphoric acid for treatment for 40 min; Disperse it in deionized water according to a solid-liquid ratio of 18:1 under magnetic stirring to obtain a homogeneous suspension; The treatment temperature is 49 °C. 6 min before the end of the treatment time of the above homogeneous suspension, add hydrogen peroxide with a concentration of 0.01 mol / L to the solution.

[0047] (2) Add soluble silicate to the suspension obtained above, stir well, and then ultrasonicate it with a cell crusher for 5 min, and continue magnetic stirring to obtain a homogeneous suspension A. The addition amount is 36% of the total mass of the suspension. The soluble silicate is lithium silicate, sodium silicate, and potassium silicate. Based on the total mass of the soluble silicate, the ratio of lithium silicate: sodium silicate: potassium silicate is 1.6:14:18.

[0048] (3) Add the alkaline metal compound and the metal salt to 40 ml of deionized water, and stir magnetically to dissolve the metal compound and the metal salt to obtain a clear solution B; Slowly add the solution B dissolved with the alkaline metal compound and the metal salt to the suspension A, and continue magnetic stirring for 20 min to obtain a homogeneous precursor solution. The magnetic field intensity during the above magnetic stirring process is 0.2 T.

[0049] The addition amount of the metal salt is 16% of the mass of the soluble silicate. The metal salt is magnesium chloride, accounting for 75% of the total mass of the metal salt. The alkaline metal compound is magnesium hydroxide, and the addition amount is 22% of the mass of the soluble silicate.

[0050] (4) Transfer the precursor solution obtained above into a closed reactor, and carry out a reaction for 8 h under the conditions of a temperature of 89 °C and a pressure of 13 MPa while applying a magnetic field. The magnetic field intensity is 0.55 T, and a mixed product containing solid and liquid is obtained.

[0051] (5) Carry out solid-liquid separation on the mixed product obtained above to obtain a solid carbon hybrid multi-metal center mesoporous material.

[0052] Combining Figures 1-4 and Table 1-2 shows that the carbon hybrid multi-metal center mesoporous material prepared in Example 1 was subjected to SEM testing, and the results are as Figure 1 shown. It can be seen from the figure that the carbon hybrid multi-metal center mesoporous material prepared by the present invention is in the shape of flocs and clusters and has a porous structure. Carry out nitrogen adsorption-desorption testing and pore size testing, and the results are as Figure 2 、Figure 3 As shown, it can be seen from the figure that the carbon hybrid multi-metal center mesoporous material is a mesoporous material with a pore size distribution range between 2 nm and 50 nm, and the pore size is mainly concentrated between 2 nm and 20 nm. The pore structure parameters are shown in Table 1. X-ray powder diffraction test shows that Figure 4 it can be seen that the carbon hybrid multi-metal center mesoporous material prepared by the present invention is basically consistent with the crystal structure of analcime. As can be seen from Table 2, compared with the raw coal gangue and the coal gangue calcined at 300 °C directly used as an adsorbent, the saturated adsorption capacities for phosphate, tetracycline, Cd(II) and Pb(II) are all very small. The saturated adsorption capacities of the carbon hybrid multi-metal center mesoporous material of Example 1 for phosphate, tetracycline, Cd(II) and Pb(II) are increased by dozens of times, and it has good ability to remove the above components. Among them Figure 3 is the pore size distribution curve of the carbon hybrid multi-metal center mesoporous material of Example 1. The ordinate is dV / dlogD, which represents the change in pore volume (dV) within a unit logarithmic pore size interval (dlogD), unit: cm³ / g; the abscissa is the pore diameter, unit: nm.

[0053] Table 1 Pore structure parameters of the carbon hybrid multi-metal center mesoporous material

[0054] Table 2 Saturated adsorption capacities (mg / g) of the carbon hybrid multi-metal center mesoporous material for phosphate, tetracycline, Cd(II) and Pb(II)

[0055] Example 2 It is basically the same as the method of Example 1, except that: in step (1), after the coal gangue is crushed into powder, it is not calcined and potassium permanganate is not sprayed. Compared with Example 1, the uncalcined porosity is not high, which is not conducive to improving the adsorption performance.

[0056] Example 3 It is basically the same as the method of Example 1, except that: during the calcination process, potassium permanganate solution is not sprayed.

[0057] Example 4 It is basically the same as the method of Example 1, except that: 0.3 wt% aqueous potassium permanganate solution is sprayed.

[0058] Example 5 It is basically the same as the method of Example 1, except that: 2.1 wt% aqueous potassium permanganate solution is sprayed.

[0059] Example 6 It is basically the same as the method of Example 1, except that: the ratio of lithium silicate: sodium silicate: potassium silicate is 1.6:14:7.

[0060] Example 7 It is basically the same as the method of Example 1, except that: the metal salt is zinc sulfate.

[0061] Comparative Example 1 It is basically the same as the method of Example 1, except that: it is added to a solution containing 0.04 mol / L of potassium permanganate.

[0062] Comparative Example 2 It is basically the same as the method of Example 1, except that: it is added to a solution containing 0.4 mol / L of potassium permanganate.

[0063] Comparative Example 3 It is basically the same as the method of Example 1, except that: phosphoric acid is not added.

[0064] Comparative Example 4 It is basically the same as the method of Example 1, except that: hydrogen peroxide is not added.

[0065] Comparative Example 5 It is basically the same as the method of Example 1, except that: the magnetic field strength is 0.1 T.

[0066] Comparative Example 6 It is basically the same as the method of Example 1, except that: the magnetic field strength is 0.1 T during magnetic stirring.

[0067] Comparative Example 7 It is basically the same as the method of Example 2, except that: hydrogen peroxide is not added, and it is added to a solution containing 0.5 mol / L of potassium permanganate.

[0068] Comparative Example 8 It is basically the same as the method of Example 7, except that: no magnetic field is applied.

[0069] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for synthesizing carbon hybrid multi-metal center mesoporous materials using coal gangue, characterized in that, Comprising: (1) Crushing gangue into powder with a particle size of 10 - 60 g, and adding it into a solution containing 0.09 - 0.15 mol / L of potassium permanganate, 2 - 5 mol / L of hydrochloric acid, and 0.5 - 1 mol / L of phosphoric acid; dispersing it in deionized water according to a solid-liquid ratio of 10:1 - 100:1 (g / L) under the action of magnetic stirring to obtain a homogeneous suspension; the treatment temperature is 45 - 73 °C, and the treatment time is 30 - 130 min; 5 - 10 min before the end of the suspension treatment time, adding 0.01 - 0.02 mol / L of hydrogen peroxide to the solution; (2) Adding soluble silicate and / or soluble silicic acid to the suspension obtained above, stirring well, and then ultrasonically treating it with a cell crusher for 1 - 10 min, and continuing magnetic stirring to obtain a homogeneous suspension A; (3) Adding an alkaline metal compound and a metal salt to 30 - 100 ml of deionized water, and dissolving the metal compound and the metal salt by magnetic stirring to obtain a clear solution B; Slowly adding the solution B in which the alkaline metal compound and the metal salt are dissolved to the suspension A, and continuing magnetic stirring for 10 - 60 min to obtain a homogeneous precursor solution; During the magnetic stirring process, the magnetic field intensity is 0.15 - 0.3 T; (4) Transferring the precursor solution obtained above into a closed reactor, and reacting it under the conditions of a temperature of 60 - 300 °C and a pressure of 1 - 20 MPa while applying a magnetic field for 2 - 36 h to obtain a mixed product containing solids and liquids, and the magnetic field intensity is 0.45 - 0.65 T; (5) Separating the solid-liquid of the mixed product obtained above to obtain a solid carbon hybrid multi-metal center mesoporous material.

2. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 1, wherein In step (1), after crushing the gangue into powder, it is calcined at 125 - 160 °C. During the calcination process, an aqueous solution of potassium permanganate with a mass fraction of 0.7 - 1.1 wt% is sprayed in through a nozzle, and the spraying mass accounts for 0.05 - 0.08 wt% of the mass of the gangue, and the spraying time is 0.5 - 1 h.

3. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 1, wherein In step (2), the soluble silicate is one or any combination of lithium silicate, sodium silicate, ammonium silicate, and potassium silicate, the soluble silicic acid is orthosilicic acid, and the addition amount of the soluble silicate and / or soluble silicic acid is 10 - 50% of the total mass of the suspension.

4. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 3, characterized in that, In step (2), the soluble silicate is lithium silicate, sodium silicate, and potassium silicate, and based on the total mass of the soluble silicate, the ratio of lithium silicate:sodium silicate:potassium silicate is (1.5 - 1.7):(14 - 15):(17 - 18).

5. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 1, characterized in that, In step (3), the metal salt is one or any combination of magnesium carbonate, magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium trisilicate, zinc chloride, zinc sulfate, zinc nitrate, zinc dihydrogen phosphate, calcium halide, calcium carbonate, calcium nitrate, calcium chlorate, calcium perchlorate, calcium bicarbonate, and calcium dihydrogen phosphate, and the addition amount is 5 - 50% of the mass of the soluble silicate and / or soluble silicic acid.

6. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 5, characterized in that, In step (3), one of magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium acetate, and magnesium trisilicate accounts for 55 - 85% of the total mass of the metal salt.

7. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 1, characterized in that, In step (3), the alkaline metal compound is one or any combination of magnesium hydroxide, magnesium oxide, basic magnesium carbonate, zinc oxide, zinc hydroxide, calcium oxide, calcium hydroxide, and dolomite, and the addition amount is 10-60% of the mass of soluble silicate and / or soluble silicic acid.

8. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 1, wherein In step (1), the particle size of the powder of the coal gangue after crushing is 62-100 μm.

9. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 1, wherein In step (1), the treatment temperature is 45-53 °C.

10. The method for synthesizing a carbon hybrid multi-metal center mesoporous material using coal gangue according to claim 3, characterized in that, In step (2), the addition amount of soluble silicate and / or soluble silicic acid is 33-41% of the total mass of the suspension.

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