Quality-divided separation and high-valued utilization method for coal gasification slag, generated product and application

Abstract

The invention discloses a quality-divided separation and high-valued utilization method of coal gasification slag, a generated product and application, and belongs to the technical field of high-valued recycling of coal gasification slag. According to the method, the coal gasification slag is classified by adopting an alkali fusion-acid leaching two-step method, components in the coal gasification slag are classified into pure carbon components and a metal-containing acid leaching salt solution, a high-valued utilization method is provided for the classified components, and the carbon components are activated into an active carbon electrode material with a high specific surface area and applied to the field of energy storage. The metal-containing acid leaching salt solution is prepared into the metal cross-linked hydrogel, and the metal cross-linked hydrogel is applied to the field of coal flame retardance. The method can effectively solve the technical problem that the overall utilization is restricted by carbon ash caused by multi-metal component mixing and high carbon content of the coal gasification slag in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of high-value reuse technology of coal gasification waste residue, specifically involving a method for high-value utilization of coal gasification waste residue through graded separation, as well as the resulting products and applications. Background Technology

[0002] Coal gasification slag, due to its low cost and abundant aluminum, silicon, and carbon resources, possesses broad potential for raw material substitution. Its composition is similar to traditional building material raw materials, thus it can effectively replace some traditional mineral raw materials in the production of building materials, particularly in the preparation of cement concrete and road filler materials. Furthermore, the high carbon content and large specific surface area of ​​coal gasification slag also give it great application potential in industrial recycling and adsorbent preparation. However, the recycling of coal gasification slag still faces significant technical challenges. Coal gasification slag contains a large amount of incompletely gasified carbon (approximately 30%-40%), making it difficult to recycle as a building filler. Simultaneously, the aluminosilicates and other minerals that encapsulate residual carbon particles significantly reduce the combustion efficiency of coal gasification slag. In addition, research on the recycling of coal gasification slag has largely focused on extracting single components such as carbon or metallic aluminum, failing to achieve large-scale utilization of coal gasification slag. Porous activated carbon (AC) materials are the most researched and widely used materials for supercapacitors due to their tunable pore structure, large specific surface area (SSA), good conductivity, and low-cost raw materials. The residual carbon in coal gasification slag has a high degree of graphitization, making it an ideal precursor for preparing porous activated carbon materials. If it can be separated and purified to prepare porous activated carbon materials, its application in energy storage technology can be expanded to achieve high-value resource utilization. However, the inorganic components also present in coal gasification slag increase the resistance and voltage drop of porous activated carbon materials, reducing their power density. Therefore, it is necessary to separate the metallic components to meet the inorganic standards for capacitive carbon-based electrodes (ash content less than 0.5%).

[0003] In recent years, the application of metal cross-linked hydrogels in flame retardancy and fire extinguishing has gradually attracted attention. Compared with traditional coal flame retardants, it can form a stable protective film on the coal surface. Under high-temperature conditions, it can effectively reduce the coal combustion rate and improve flame retardant performance through multiple mechanisms such as heat absorption, carbonization, and gas release. In addition, its high water content and good adhesion enable it to inhibit flame spread, reduce smoke emissions, and delay coal oxidation reactions, providing a new solution for safety protection during coal storage and transportation. If the carbon components of coal gasification slag can be purified and separated, and the separated metal components can be rationally utilized to prepare metal cross-linked hydrogels, the overall fractional utilization of coal gasification slag can be achieved.

[0004] It is evident that existing technologies cannot achieve the overall fractional utilization of coal gasification slag. Therefore, the key to current research is how to effectively solve the problem of carbon ash restricting the overall utilization of coal gasification slag due to the mixing of multiple metal components and high carbon content, and how to develop a simple, adaptable, and practically applicable process technology for fractional separation and high-value utilization. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for separating coal gasification slag into different grades, as well as the resulting products and applications. Using coal gasification slag as raw material, the method employs a two-step process of alkali melting and acid leaching to separate the coal gasification slag into different grades, effectively solving the technical problems that the prior art cannot solve, such as the mixing of multiple metal components and the carbon ash content that restricts the overall utilization of coal gasification slag.

[0006] To achieve the above objectives, the present invention employs the following technical solution: The first aspect of this invention is to provide a method for the high-value utilization of coal gasification slag through fractional separation. Using coal gasification slag as raw material, a two-step method of alkali melting and acid leaching is adopted to achieve the fractional separation of coal gasification slag, providing a complete and innovative solution for the high-value utilization of its components.

[0007] Specifically, including: Using coal gasification slag as raw material, it is first mixed with alkali, then heat-treated under a protective atmosphere, and then washed until neutral to obtain the first solid, which is a mixture of metal oxides and carbon. The first solid is mixed with an acid solution, subjected to hydrothermal treatment, filtered, and the filtrate and the second solid are collected; the filtrate is an acid leaching salt solution containing metal, and the second solid is a pure carbon component; The pure carbon component was washed until neutral and then activated to obtain a porous activated carbon material with a high specific surface area. A long-chain polymer compound is added to a metal-containing acid leaching salt solution, and the mixture is stirred until polymerization is obtained to obtain a hydrogel.

[0008] Preferably, the coal gasification slag described in the method of the present invention is applicable to all coal gasification slags, including coarse coal gasification slag and fine coal gasification slag, or a mixture of coarse coal gasification slag and fine coal gasification slag.

[0009] Preferably, the mass ratio of coal gasification slag to alkali is 1:2-1:4, and the heat treatment temperature is 450-500 ℃.

[0010] More preferably, the alkali can be sodium hydroxide, potassium hydroxide, or other alkalis.

[0011] Preferably, the protective atmosphere is an argon atmosphere, a nitrogen atmosphere, or a mixture of argon and nitrogen.

[0012] Preferably, the volume ratio of the first solid to the acid solution is 1:20-1:30, and the hydrothermal treatment is 100-120 °C.

[0013] More preferably, the acid solution is an HCl solution with a mass concentration of 20-30 wt%.

[0014] The main components of the prepared metal-containing acid leaching salt solution are AlCl3, FeCl3, CaCl2, etc.

[0015] Preferably, the activation treatment involves mixing a pure carbon component washed to neutral with KOH and KCl, then heating it under a protective atmosphere to obtain a third solid. The third solid is then washed with water until neutral to obtain a high specific surface area porous activated carbon material.

[0016] More preferably, the mass ratio of pure carbon component, KOH and KCl is 1:3:(1-3), the heat treatment temperature is 700-750 ℃, and the heat treatment time is 0.5-1 h.

[0017] More preferably, the mass ratio of pure carbon component, KOH and KCl is selected as 1:3:1, 1:3:2, or 1:3:3.

[0018] More preferably, the protective atmosphere is an argon atmosphere, a nitrogen atmosphere, or a mixture of argon and nitrogen.

[0019] Preferably, the long-chain polymer compound is a combination of sodium carboxymethyl cellulose and sodium alginate.

[0020] In preparation, a long-chain polymer compound is added to a metal-containing acid leaching salt solution and stirred slowly until a hydrogel is formed. This invention transforms a metal salt solution into a hydrogel through polymer polymerization, expanding the application scenarios of metal components.

[0021] The second aspect of the present invention is that the above-mentioned method for the high-value utilization of coal gasification slag through fractional separation can simultaneously prepare two high-value products in one process flow: high specific surface area porous activated carbon material and hydrogel.

[0022] Electrochemical tests were conducted on the high specific surface area porous activated carbon material. Its charge-discharge curves exhibited good linearity and symmetry, indicating excellent charge-discharge reversibility. At 1 A·g -1 At the given current density, the optimal sample exhibits a specific capacitance as high as 346.9 F·g. -1 It has good electrochemical energy storage performance.

[0023] The coal flame retardant properties of the hydrogel were tested. The release of CO during the coal combustion process was detected by temperature programmed oxidation (TPO) experiment. It was found that the hydrogel can significantly reduce the release of CO during the spontaneous combustion stage of coal, indicating that it has a good inhibitory effect on low-temperature oxidation and spontaneous combustion of coal.

[0024] A third aspect of the present invention also discloses the application of the above-mentioned high specific surface area porous activated carbon material and hydrogel.

[0025] Among them, the application of high specific surface area porous activated carbon materials in the preparation of activated carbon electrode sheets is disclosed; High specific surface area porous activated carbon material and polytetrafluoroethylene emulsion are thoroughly ground to obtain a mixed slurry. The mixed slurry is then uniformly coated on the surface of nickel foam, and after thorough drying, it is pressed into a sheet to obtain an activated carbon electrode sheet.

[0026] Furthermore, with a mass ratio of high specific surface area porous activated carbon material to polytetrafluoroethylene emulsion of 9:1, the effective coating amount of activated carbon is approximately 3.0 mg·cm³. -1 The drying temperature was 80 ºC, the drying time was 1 h, the tableting pressure was 10 MPa, and the tableting time was 1 min.

[0027] Among them, the application of hydrogels in the preparation of coal flame retardant materials was disclosed, and hydrogel materials were used for coal flame retardancy.

[0028] Compared with the prior art, the present invention has the following beneficial effects: This invention uses coal gasification slag as raw material and achieves complete separation of metal oxides and carbon components in the slag through a two-step separation process of "alkali treatment-acid leaching," converting both into high-value products with no waste discharge, effectively improving resource utilization. It fully solves the problem that existing technologies often focus on the recovery of single components from coal gasification slag, and the secondary solid waste problem caused by incomplete extraction and separation. In this method, during the hydrothermal leaching process with hydrochloric acid, the metal oxides in the coal gasification slag are fully dissolved, generating Al-rich... 3+ Ca 2+ Fe 3+ Acid leaching salt solutions containing metals, such as Ca. 2+ And Al 3+It is a common and highly efficient crosslinking agent that can crosslink with linear polymers, causing their molecular chains to intertwine and form a stable three-dimensional network framework structure, thereby encapsulating water and other metal ions, ultimately forming a high-strength metal-crosslinked hydrogel. The high-value utilization of this invention is reflected in: using widely available and extremely low-cost industrial solid waste coal gasification slag as raw material, through a two-step separation process, it simultaneously produces "high specific surface area porous activated carbon" (which can be used for adsorption, electrochemistry, and energy storage) and "metal-based hydrogel" (which can be used in coal flame retardant materials). Both are high-value-added products with high market demand, thus demonstrating significant economic advantages. Therefore, the solution of this invention, based on the idea of ​​high-value utilization of all components of coal gasification slag, solves the pain points of traditional technologies such as "low utilization rate and single product," and has good industrialization potential. Attached Figure Description

[0029] Figure 1 Cyclic voltammetry curves for embodiments 1, 2, 3, 4, and 5 of the present invention are shown.

[0030] Figure 2 The DC charge-discharge curves of embodiments 1, 2, 3, 4, and 5 of the present invention are shown. Figure 3 The N2 adsorption-desorption curves of embodiments 1, 2, 3, 4, and 5 of the present invention are shown.

[0031] Figure 4 A scanning electron microscope image of Embodiment 6 of the present invention is shown.

[0032] Figure 5 The diagram shows the CO release during programmed heating in Embodiment 6 and Comparative Example 1 of the present invention.

[0033] Figure 6 A diagram of the programmed heating device of the present invention is shown; in the diagram, 1 is a programmed heating stage; 2 is a chromatographic analyzer; and 3 is a coal sample. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] The present invention will now be described in further detail with reference to the accompanying drawings: In the first part, to obtain the pure carbon component in the coal gasification slag, the following experimental procedures were performed to achieve the complete separation of the components of the coal gasification slag: 1) First, mix coal gasification slag and sodium hydroxide at a mass ratio of 1:3 and place them in a SiC boat.

[0037] Using a tube furnace, in an argon atmosphere, at 10 °C·min -1 The mixture was heated to 450 °C and maintained for 2 hours. After cooling to room temperature, the mixture was washed with deionized water and centrifuged. The supernatant was a mixture of sodium silicate and residual sodium hydroxide. The resulting solid was a mixture of carbon and metal oxides.

[0038] 2) Then, the lower precipitate mixture was mixed with 20% HCl solution and placed in a hydrothermal reactor. The mixture was hydrothermally heated at 110°C for 4 hours, with a solid-liquid volume ratio of 1:20. After acid treatment, the solid was separated by filtration and thoroughly washed with deionized water until the pH was neutral. The resulting acid filtration solution, containing metal-containing acid leaching salts, was used for subsequent flame-retardant hydrogel preparation.

[0039] 3) Finally, the sample was dried in an oven at 110 °C for 2 hours. The resulting solid is the pure carbon component in the coal gasification slag.

[0040] The second part involves further activating the pure carbon component separated from the coal gasification slag into high specific surface area active carbon. The operation steps are as follows: First, 1 g of carbon component, 3 g of KOH, and 1-3 g of KCl were mixed thoroughly and placed in a nickel boat. The mixture was heated to 700 °C in an Ar atmosphere in a tube furnace. After maintaining this temperature for 60 min, the sample was cooled to room temperature. Then, the sample was washed with deionized water until the pH reached 7. Finally, it was dried in a vacuum drying oven at 60 °C for 12 hours. The resulting solid is high specific surface area activated carbon.

[0041] The third part involves the high-specific-surface-area active carbon prepared to be used as an electrode sheet. First, AC and polytetrafluoroethylene (PTFE) emulsion were placed in a mortar at a mass ratio of 9:1, and an appropriate amount of anhydrous ethanol was added to wet the system. The mixture was then thoroughly ground to obtain a slurry. Using nickel foam with a pore size of 50 ppi as the current collector, the nickel foam was cut into 10 mm × 10 mm pieces. The slurry was then uniformly coated onto the surface of the nickel foam, ensuring that the effective coating mass of activated carbon on each working electrode was approximately 3.0 mg·cm³. -1 The electrode was then dried thoroughly at 80 ºC for 1 h, and finally compressed at 10 MPa for 1 min on a tablet press to obtain the electrode sheet.

[0042] Part Four involves the high-value preparation of the metal acid leaching solution generated during the fractionation process into a hydrogel. Sodium carboxymethyl cellulose and sodium alginate were added to the obtained metal-containing acid leaching salt solution and stirred slowly until they polymerized into a gel.

[0043] Example 1: Preparation of AC: 1 g of the fractionated pure carbon component, 3 g of KOH, and 0 g of KCl were mixed thoroughly and placed in a nickel boat. The mixture was heated to 700 °C in an Ar atmosphere in a tube furnace. After maintaining the temperature for 60 min, the sample was cooled to room temperature. The sample was then washed with deionized water until the pH reached 7. Finally, it was dried in a vacuum drying oven at 60 °C for 12 hours. The prepared sample is designated AC.

[0044] Example 2 Preparation of AC-0.5 1 g of the fractionated pure carbon component, 3 g of KOH, and 0.5 g of KCl were mixed thoroughly and placed in a nickel boat. The mixture was heated to 700 °C in an Ar atmosphere in a tube furnace. After maintaining this temperature for 60 min, the sample was cooled to room temperature. The sample was then washed with deionized water until the pH reached 7. Finally, it was dried in a vacuum drying oven at 60 °C for 12 hours. The prepared sample was designated AC-0.5.

[0045] Example 3 Preparation of AC-1 1 g of the fractionated pure carbon component, 3 g of KOH, and 1 g of KCl were mixed thoroughly and placed in a nickel boat. The mixture was heated to 750 °C in an Ar atmosphere in a tube furnace. After maintaining this temperature for 60 min, the sample was cooled to room temperature. The sample was then washed with deionized water until the pH reached 7. Finally, it was dried in a vacuum drying oven at 60 °C for 12 hours. The prepared sample is designated AC-1.

[0046] Example 4 Preparation of AC-2 1 g of the fractionated pure carbon component, 3 g of KOH, and 2 g of KCl were mixed thoroughly and placed in a nickel boat. The mixture was heated to 700 °C in a tube furnace under a N2 atmosphere. After maintaining this temperature for 60 min, the sample was cooled to room temperature. The sample was then washed with deionized water until the pH reached 7. Finally, it was dried in a vacuum drying oven at 60 °C for 12 hours. The prepared sample is designated AC-2.

[0047] Example 5 Preparation of AC-3 1 g of the fractionated carbon component, 3 g of KOH, and 3 g of KCl were mixed thoroughly and placed in a nickel boat. The mixture was heated to 700 °C in a tube furnace under a N2 atmosphere. After maintaining this temperature for 60 min, the sample was cooled to room temperature. The sample was then washed with deionized water until the pH reached 7. Finally, it was dried in a vacuum drying oven at 60 °C for 12 hours. The prepared sample is designated AC-3.

[0048] Performance testing: The AC, AC-0.5, AC-1, AC-2, and AC-3 prepared in Examples 1 to 5, respectively, were used to prepare electrode sheets, and electrochemical tests were performed. The results are as follows: Cyclic voltammetry test results are as follows Figure 1 As shown, the electrochemical performance of samples AC, AC-0.5, AC-1, AC-2, and AC-3 was tested in a three-electrode system. The CV curves of the electrode materials at a scan rate of 25 mV·s⁻¹ are presented. Figure 1 As can be seen, the cyclic voltammetry curves of all samples are nearly rectangular, which indicates that the energy storage mechanism of the AC electrode mainly relies on the double-layer capacitance (EDLC) behavior and does not involve the redox changes of the substance. The positive and negative ions of the electrolyte migrate to the corresponding electrodes through the electric field, and the charge is stored in the electrochemical double layer. The electrode material mainly stores and releases electrical energy by adsorbing and desorbing ions.

[0049] DC charge and discharge test results are as follows Figure 2 As shown, all GCD curves exhibit a good linear and symmetrical triangular structure, indicating that the material has excellent charge-discharge efficiency. At a current density of 1 A·g⁻¹, the AC⁻² sample shows the maximum discharge time, with a specific capacitance reaching 346.9 F·g⁻¹. -1 .

[0050] Adsorption-desorption test results are as follows Figure 3 As shown, all samples exhibited type IV adsorption isotherms with hysteresis loops, indicating that the pore structure of the samples is mainly micropores and mesopores. After activation with KOH, the specific surface area of ​​the samples increased significantly, and the calculated specific surface area results are shown in Table 1. Table 1 shows that the specific surface area of ​​the samples increased from 648.85 m² before activation.2 ·g -1 Rising to 2112.93m 2 ·g -1 Pore ​​size distribution analysis showed that KOH mainly activated the pore structure of the carbon components obtained by fractionation into mesopores, and the addition of KCl was beneficial to the formation of microporous structures in the samples. As the amount of KCl added increased, the microporous structure also increased further.

[0051] Table 1. Specific surface area test results of different activated carbons

[0052] Example 6 Preparation of hydrogel materials Prepare an aqueous solution of sodium carboxymethyl cellulose. Weigh 5g of sodium carboxymethyl cellulose powder and add it to 100ml of deionized water. Stir slowly for 0.5h in a 40℃ water bath until the solution becomes clear. Name this solution Reagent A. Prepare an aqueous solution of sodium alginate using a similar method. Add 5g of sodium alginate powder to 100ml of deionized water. Stir slowly for 0.5h in a 40℃ water bath until the solution becomes clear. Name this solution Reagent B. Name the resulting acid-leached salt solution containing the metal Reagent C.

[0053] Equal volumes of solutions A, B, and C were mixed at different temperatures and slowly stirred until a gel formed. The mixture was then allowed to stand for 2 hours until fully formed. The prepared gel was named CGS-gel. SEM images of the gel surface morphology are shown below. Figure 4 As shown, the prepared hydrogel forms a good three-dimensional network framework, in which a large number of pores are conducive to water storage and retention.

[0054] Flame retardant effect tests were conducted on CGS-gel using a programmed temperature-propelled oxidation method to simulate spontaneous combustion of coal. The reaction apparatus for the entire experiment was as follows: Figure 6 As shown in the figure. This experiment uses a fixed-bed reactor and a programmed temperature rise control system to simulate the spontaneous combustion process of coal in order to study the effect of hydrogels on the combustion characteristics of coal. The specific operating steps of the experiment are as follows: First, the coal powder used in the experiment was sieved through a 40-60 mesh sieve to ensure uniform particle size. Then, 3 g of coal powder sample was accurately weighed and mixed thoroughly with CGS-gel and an equal volume of deionized water as a control. The treated coal sample was then packed into a quartz tube with an inner diameter of 6 mm and secured at both ends with quartz wool to prevent sample loss or movement with the airflow that could affect experimental accuracy.

[0055] Next, the filled quartz tube is placed on the programmed heating platform, ensuring stable contact with the heat source. Combustion air is connected via pipelines to both the flow meter and the inlet of the quartz reactor to control the stability of the gas flow rate during the experiment. An M60x flue gas analyzer is connected to the reactor outlet to monitor the composition and concentration changes of the gases produced during coal combustion in real time.

[0056] Typical indicative gases of coal spontaneous combustion include carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ethylene (C2H4), and ethane (C2H6). In this experiment, CO outlet concentration was selected as the key characterization indicator for coal spontaneous combustion to evaluate the impact of different treatment methods on coal combustion behavior. During the experiment, air was introduced at a flow rate of 100 mL / min. -1 A constant flow rate is introduced into the quartz tube, and the heating system adopts a programmed temperature control mode, at a rate of 1 °C·min. -1 The sample temperature was gradually increased from 30 °C to 300 °C using a controlled heating rate. During the heating process, the CO concentration was detected and recorded every 10 °C increase in sample temperature.

[0057] See the graph showing CO emission as a function of temperature. Figure 5 ,Depend on Figure 5 It can be seen that the CO concentration trends with increasing temperature are generally consistent among the three samples: raw coal, coal + CGS-gel, and coal + ungelled coal gasification slag acid leaching solution. However, the specific release amounts differ significantly. Between 20-150 °C, the CO release of the three coal samples shows a relatively gradual trend with increasing temperature, with low CO release amounts and no significant differences among the three samples. When the temperature exceeds 150 °C, the CO concentration increases significantly with increasing temperature, exhibiting a clear exponential growth trend, indicating that the coal enters a stage of intense oxidation. The raw coal sample produces a large amount of CO gas after 150 °C; however, the addition of both CGS-gel and coal gasification slag acid leaching solution as flame retardants shows a significant inhibitory effect on the oxygen combustion of coal, delaying the rapid increase point of CO release to approximately 175 °C. The inhibitory effect of CGS-gel is more pronounced, with CO release consistently lower than that of the coal samples treated with coal gasification slag acid leaching solution and the raw coal sample throughout the entire heating stage. When the temperature reached 220 °C, compared with the raw coal sample, the coal sample with added CGS-gel showed the most significant reduction in CO release, with a decrease of 9582 ppm, a year-on-year decrease of 54%. The inhibitory effect of adding coal gasification slag acid dewatering liquid was the second largest, with a decrease in CO release of 2027 ppm.

[0058] In summary, this invention provides a technical solution for the fractional utilization of all components in coal gasification slag. The components in the coal gasification slag are separated into pure carbon components and a metal-containing acid leaching salt solution, providing a high-value utilization method for the separated components. The carbon components are activated into high-specific-surface-area active carbon electrode materials, which are then applied in the energy storage field. The metal-containing acid leaching salt solution is prepared into a metal cross-linked hydrogel and applied in the field of coal flame retardancy.

[0059] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for separating and utilizing coal gasification slag by quality, characterized in that, The application relates to a coal gasification slag separation and high-value utilization method. The coal gasification slag is mixed with alkali, heat-treated under a protective atmosphere, washed to neutral, and a first solid, i.e. a mixture of metal oxides and carbon, is obtained; The first solid is mixed with an acid solution, hydrothermally treated, filtered, and a filtrate and a second solid are collected; the filtrate is a metal-containing acid leaching salt solution, and the second solid is a pure carbon component; The pure carbon component is washed to neutral, and then activated to prepare a high specific surface area porous active carbon material; A long-chain polymer compound is added to the metal-containing acid leaching salt solution, and stirring treatment is carried out until a hydrogel is obtained.

2. The method according to claim 1, wherein The mass ratio of the coal gasification slag to the alkali is 1:2-1:4, and the heat treatment temperature is 450-500 DEG C.

3. The method according to claim 1, wherein the method is characterized by, The volume ratio of the first solid to the acid solution is 1:20-1:30, and the hydrothermal treatment temperature is 100-120 DEG C.

4. The method according to claim 1, wherein the method is characterized by, The activation treatment is that the pure carbon component washed to neutral is mixed with KOH and KCl, and then heated and treated under a protective atmosphere to obtain a third solid, and the third solid is washed to neutral to prepare the high specific surface area porous active carbon material.

5. The method according to claim 4, wherein The mass ratio of the pure carbon component, KOH and KCl is 1:3:(1-3), the heat treatment temperature is 700-750 DEG C, and the heat treatment time is 0.5-1 h.

6. The method according to claim 1, wherein the method is characterized by, The long-chain polymer compound is a combination of carboxymethyl cellulose sodium and sodium alginate.

7. The method according to claim 6, wherein the method is characterized by, The mass ratio of the carboxymethyl cellulose sodium and the sodium alginate is 1:

1.

8. The high specific surface area porous active carbon material and the hydrogel are separated by the coal gasification slag separation and high-value utilization method.

9. The high specific surface area porous active carbon material is applied to preparation of an active carbon electrode sheet.

10. The hydrogel is applied to preparation of a coal fire-retardant material.

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