Production process for low-calorific-value anthracite stepwise utilization and comprehensive conversion
By sorting and utilizing low-calorific-value anthracite in stages, high-value-added products are produced and waste is recycled, solving the problems of low utilization rate and high pollutant emissions of low-calorific-value anthracite resources, and forming a clean and efficient comprehensive utilization system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 张勇
- Filing Date
- 2026-05-26
- Publication Date
- 2026-06-30
Abstract
Description
Technical Field
[0001] This invention relates to the field of comprehensive energy utilization and clean production technology, and in particular to a production process and preparation method for the cascade utilization and comprehensive conversion of low-calorific-value anthracite. Background Technology
[0002] Low-calorific-value anthracite refers to anthracite with a calorific value below 16.7 MJ / kg (approximately 3990 kcal / kg). It is widely distributed in Shanxi, Guizhou, Ningxia Hui Autonomous Region, and Henan Province in my country, accounting for more than 30% of my country's total anthracite reserves. Traditionally, low-calorific-value anthracite, due to its low calorific value, high ash content, and large fluctuations in sulfur content, has been considered inferior coal and mainly used for direct combustion in power generation or heating. Its resource utilization rate is less than 40%, and the combustion process produces large amounts of SO2 and NO. x And particulate matter, environmental treatment costs are high. At the same time, the high-quality coal rock components contained in low-calorific-value anthracite are wasted by direct combustion and fail to be transformed into high-value-added products, resulting in low economic benefits.
[0003] Existing technologies for utilizing low-calorific-value coal have many limitations: direct combustion power generation has low thermal efficiency and serious resource waste; coal washing and upgrading produce a large amount of gangue, which is difficult to dispose of and easily causes secondary pollution; coal gasification and coal-to-chemicals require high-quality raw materials, making low-calorific-value anthracite unsuitable; the preparation of coal-based carbon materials mostly uses high-quality coal as raw material, and research and application of low-calorific-value anthracite are limited. In addition, existing technologies are mostly for single-purpose use and have not formed a tiered comprehensive utilization system. Wastewater, waste gas, and solid waste are treated independently, resulting in low resource utilization rates.
[0004] With increasingly scarce coal resources and ever-increasing environmental protection requirements in my country, the efficient and clean utilization of low-calorific-value coal resources has become a crucial issue urgently needing to be addressed in the energy industry. Currently, low-calorific-value coal is mainly utilized through direct combustion power generation, washing and upgrading, coal gasification and synthetic oil production, and coal-to-chemicals. However, these methods generally suffer from low resource utilization rates, low product added value, high pollutant emissions, stringent coal quality requirements, or high investment costs. Although the development of environmental protection and new energy industries has driven the growth in demand for coal-based carbon materials, providing new directions for their high-value utilization, existing technologies for the preparation of activated carbon, lithium battery anode materials, and carbon-based new materials mostly use high-quality coal as raw materials, with limited research and application of low-calorific-value anthracite. Furthermore, the large amount of gangue generated from the washing of low-calorific-value anthracite is mostly disposed of through landfill, easily causing land occupation and environmental pollution. Additionally, wastewater, waste gas, and solid waste generated during the preparation of coal-based materials are mostly treated independently, without forming a synergistic system, resulting in high treatment costs and low resource utilization rates.
[0005] Therefore, developing a clean production process that enables the tiered and graded utilization of low-calorific-value anthracite, multi-stage conversion into high-value-added products, and co-processing of waste is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0006] In view of this, the present invention proposes a production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite to solve the above problems.
[0007] The technical solution of this invention is implemented as follows: a production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal, comprising the following steps: S1 Separation: After crushing and screening, low-calorific-value anthracite raw materials are separated by density separation through a combination of heavy media separation and jigging separation. Then, industrial analysis is performed to classify the coal into three grades: Grade I coal, Grade II coal, and Grade III coal, while separating the washed gangue. S2 Multi-stage High-Value Conversion: Grade I coal is transported to the lithium battery anode material preparation unit to prepare coal-based hard carbon anode materials, Grade II coal is transported to the high-end activated carbon preparation unit to prepare high-performance activated carbon, and Grade III coal is transported to the carbon-based new material preparation unit to prepare carbon-based new materials. S3 Gangue Clean Power Generation: Washed gangue is transported to a circulating fluidized bed combustion power generation unit for combustion power generation. The generated steam drives a steam turbine to generate electricity. The flue gas generated by combustion is treated for desulfurization, denitrification and dust removal before being discharged in compliance with standards. The fly ash and bottom ash generated by combustion are used for building material production. S4 waste co-processing: Wastewater generated during the production process is treated and reused, process exhaust gas is purified and discharged in compliance with standards, waste catalysts generated during the production process are regenerated and reused in production, and valuable metals are recovered from waste acid liquid through neutralization and precipitation, realizing the resource utilization of solid waste and zero waste throughout the entire process.
[0008] Furthermore, the specific process for quality separation and sorting in step S1 is as follows: S11 Raw Material Crushing and Screening: Low-calorific-value anthracite is crushed to a particle size ≤50mm, and pulverized coal with a particle size ≤5mm and lump coal with a particle size >5mm are separated by vibrating screen. S12 Heavy Medium Separation: Lump coal is fed into a heavy medium hydrocyclone, where magnetite powder is used as a weighting agent to prepare a mixture with a density of 1.4~1.6 g / cm³. 3 The heavy medium suspension is sorted to separate clean coal, middlings and gangue; S13 Jigging Separation: Pulverized coal is fed into a jig and density separation is performed at a pulsating frequency of 30~50Hz and a bed thickness of 100~200mm to separate fine pulverized coal, medium pulverized coal and pulverized gangue. S14 graded conveying: The sorted clean coal and middlings are industrially analyzed and graded according to quality before being conveyed to the corresponding preparation units. The gangue is conveyed to the circulating fluidized bed combustion power generation unit.
[0009] Furthermore, in step S1, the fixed carbon content of Grade I coal is ≥85% and the ash content is ≤10%, the fixed carbon content of Grade II coal is 75%~85% and the ash content is 10%~20%, and the fixed carbon content of Grade III coal is ≤75% and the ash content is ≥20%.
[0010] Furthermore, the specific process of the high-end activated carbon preparation unit in step S2 is as follows: A1 Raw Material Pretreatment: Crush Grade II coal to a particle size ≤3mm, acid wash with 8~12wt% dilute hydrochloric acid solution at 70~90℃ for 1~3h, wash with water until neutral, and then dry; A2 carbonization: The pretreated coal is heated to 450-550℃ at a heating rate of 4-6℃ / min under nitrogen protection and held at the temperature for 1-3 hours to obtain carbonized material. A3 Composite Activation: The carbonized material and the composite activator are mixed and impregnated at a mass ratio of 1:(2~4) for 10-15 hours. The composite activator is a mixture of KOH and K2CO3 at a mass ratio of 1:(1~2). The impregnated material is then heated to 700~800℃ at a heating rate of 2~4℃ / min under nitrogen protection and kept at the temperature for 1~2 hours for chemical activation. A4 Post-processing: The activated product is washed until neutral and then dried. It is then granulated and sieved to obtain high-end activated carbon products of different specifications.
[0011] Furthermore, the specific process of the lithium battery anode material preparation unit in step S2 is as follows: B1 Deep Deashing: Crush Grade I coal to a particle size ≤2mm, acid wash with 15~25wt% hydrofluoric acid solution at 50~70℃ for 3~5h, wash with water until neutral, and then dry. B2 segmented heat treatment: The deashed coal is heated to 550-650℃ at a heating rate of 2-4℃ / min under nitrogen protection and held at the temperature for 3 hours to obtain pyrolytic carbon; then the pyrolytic carbon is heated to 1100-1300℃ at a heating rate of 1-3℃ / min under argon protection and held at the temperature for 1-3 hours to obtain carbonized material. B3 doping modification: The carbonized material and the phosphorus source are mixed at a mass ratio of 100:(3~7) and treated at 700~900℃ for 1~1.2h under an inert atmosphere. The phosphorus source is ammonium dihydrogen phosphate. B4 graphitization: The modified carbonized material is heated to 2400~2600℃ at a heating rate of 4~6℃ / min under argon protection and held at the temperature for 1~3h to obtain coal-based hard carbon. After crushing and sieving to a particle size ≤15μm, lithium battery anode material products are obtained.
[0012] Furthermore, the carbon-based new material preparation unit in step S2 is for preparing porous carbon electrode materials, and the specific process is as follows: C1 solvent extraction: Grade III coal is crushed to a particle size ≤1mm, and extracted with 99.0~99.9%wt% N-methylpyrrolidone solvent, with the mass ratio of solvent to coal controlled at (8~15):1, at 100~140℃ for 2~6h, and the extract and extraction residue are separated. C2 chemical modification: The extract is mixed with benzaldehyde at a molar ratio of 1:(1~3) and a condensation reaction is carried out at 160~200℃ for 2~4h to obtain the modified intermediate; C3 carbonization and activation: The modified intermediate was heated to 650-750℃ at a heating rate of 4-6℃ / min under nitrogen protection and held at the temperature for 2h to obtain the carbonized product; the carbonized product was mixed with ZnCl2 activator at a mass ratio of 1:(1.5-2.5) and activated at 550-650℃ for 1h. C4 post-treatment: The activated product is washed until neutral and then dried to obtain porous carbon electrode material product.
[0013] Furthermore, the specific process of the gangue washing and processing circulating fluidized bed combustion power generation unit described in step S3 is as follows: S31 gangue pretreatment: Crush the washed gangue to a particle size ≤10mm and screen to remove large particles of impurities; S32 fluidized bed combustion: Pretreated gangue is mixed with quartz sand and limestone bed material and fed into a circulating fluidized bed boiler for combustion at a combustion temperature of 850~900℃ and a fluidization velocity of 3~5m / s. S33 Steam Power Generation: The high-temperature flue gas generated by combustion heats the boiler feedwater, producing superheated steam at 3.5~4.1MPa and 430~470℃, which is then sent to the steam turbine to drive the generator to generate electricity; S34 Flue Gas Purification: Boiler flue gas is sequentially treated by selective catalytic reduction (SCR) for denitrification, semi-dry desulfurization, and bag filter dust removal before being discharged in compliance with standards.
[0014] Furthermore, the specific process for wastewater treatment and reuse in step S4 is as follows: the production wastewater is sequentially subjected to screen interception, equalization in the equalization tank, coagulation sedimentation, A / O biological treatment, and deep treatment by ultrafiltration-reverse osmosis dual membrane method. The produced water is reused in production, and the concentrated water is sent to evaporation and crystallization. The wastewater reuse rate is ≥80%, and the discharged wastewater has COD ≤50mg / L and ammonia nitrogen ≤5mg / L.
[0015] Furthermore, the specific process for treating the waste gas and solid waste in step S4 is as follows: S41 Process Waste Gas Treatment: VOCs-containing process waste gas generated by the lithium battery anode material preparation unit and the carbon-based new material preparation unit is treated by an activated carbon adsorption device and then discharged in compliance with standards. S42 Solid Waste Resource Utilization: Fly ash and bottom ash from circulating fluidized bed boilers, after passing heavy metal testing, are used to prepare cement admixtures, concrete aggregates, or aerated concrete blocks; waste catalysts generated during activated carbon preparation and negative electrode material preparation are recycled for production after regeneration; waste acid generated from pickling is neutralized and precipitated to recover valuable metals, and the neutralization residue is sent to a compliant solid waste landfill for disposal.
[0016] Furthermore, the waste gas treatment described in step S41 also includes a flue gas treatment process for combustion in a circulating fluidized bed boiler: selective catalytic reduction (SCR) is used for denitrification, with ammonia as the reducing agent, to remove NO from the flue gas under the action of a catalyst. X The process reduces SO2 to nitrogen (N2); a semi-dry desulfurization process is used, employing slaked lime as the desulfurizing agent, which reacts with SO2 in the flue gas within the reaction tower to produce calcium sulfite and calcium sulfate; a bag filter is used to remove particulate matter from the flue gas, achieving a dust emission concentration ≤10 mg / m³ after treatment. 3 .
[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. Resource utilization rate is significantly improved. Through sorting and tiered utilization, low-calorific-value anthracite is converted into high-end activated carbon, lithium battery anode materials, and carbon-based new materials, respectively. The comprehensive utilization rate of resources can reach over 80%, which is more than twice that of traditional direct combustion methods, fully tapping the potential value of coal resources. At the same time, it significantly increases the added value of products and greatly improves economic benefits.
[0018] 2. Environmentally friendly with significantly reduced pollutant emissions: The high-value conversion route does not produce combustion exhaust gas; the gangue power generation adopts circulating fluidized bed combustion and ultra-low emission technology, resulting in significantly reduced SO2 and NO emissions in the flue gas. X The emission concentration is lower than the national ultra-low emission standard; the wastewater reuse rate is ≥80%, and the consumption of fresh water is reduced by more than 50%; all solid waste is utilized as a resource, and the amount of landfill is reduced by more than 90%.
[0019] 3. Advanced technology and high process maturity: The technologies adopted in this invention, such as fractional sorting, carbonization activation, pyrolysis graphitization, circulating fluidized bed combustion, and waste treatment, are all mature technologies in the industry. Through system integration and optimized configuration, a complete technical route is formed, with low technical risk and high industrialization feasibility.
[0020] 4. Extending the industrial chain and driving regional economic development: Expanding low-calorific-value anthracite coal from a single energy sector to new materials, new energy, environmental protection and other fields, forming a new industrial chain of coal-carbon materials-new energy, providing new economic growth points for coal-rich areas and driving the development of related industries. Detailed Implementation
[0021] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.
[0022] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.
[0023] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available. Implementation conditions
[0024] This invention is applicable to low-calorific-value anthracite with a calorific value ≤16.7 MJ / kg (3990 kcal / kg), moisture content ≤10%, and total moisture content ≤15%. A typical implementation scale is as follows: a sorting and separation unit with a processing capacity of 1 million tons / year; a high-end activated carbon preparation unit with a processing capacity of 200,000 tons / year; a lithium battery anode material preparation unit with a processing capacity of 50,000 tons / year; a carbon-based new material preparation unit with a processing capacity of 50,000 tons / year; a circulating fluidized bed combustion power generation unit with a gangue processing capacity of 300,000 tons / year; a generator unit with an installed capacity of 30 MW; and a wastewater treatment capacity of 5000 m³ / h. 3 / day, flue gas treatment capacity 500,000 Nm³ 3 / Hour.
[0025] Environmental emission standards are met: SO2 emission concentration in flue gas ≤ 35 mg / m³ 3 NO x Emission concentration ≤50mg / m³ 3 Dust emission concentration ≤10mg / m³ 3 Wastewater COD concentration ≤50mg / L, ammonia nitrogen ≤5mg / L. I. Overall Process Flow
[0026] The overall process flow of this invention is as follows: Low-calorific-value anthracite is separated into four material streams—Grade I coal, Grade II coal, Grade III coal, and gangue—by a sorting and separation unit. Grade I coal is transported to a lithium-ion battery anode material preparation unit to prepare coal-based hard carbon anode materials; Grade II coal is transported to a high-end activated carbon preparation unit to prepare high-performance activated carbon; and Grade III coal is transported to a carbon-based new material preparation unit to prepare porous carbon electrode materials. Gangue is transported to a circulating fluidized bed combustion power generation unit for combustion power generation. The generated electricity and steam are used for production. The flue gas is treated for desulfurization, denitrification, and dust removal before being discharged in compliance with standards. Fly ash and bottom ash are used in building material production. Wastewater generated during the production process is treated and reused, process exhaust gas is purified before being discharged in compliance with standards, and all solid waste is utilized as a resource, forming a closed-loop system of tiered utilization of materials, tiered utilization of energy, and resource utilization of waste. II. Sorting and Grading Unit
[0027] The specific process flow of the quality sorting and separation unit is as follows: 1. Raw material crushing and screening: Low-calorific-value anthracite raw material is conveyed to the crusher via belt conveyor and crushed to a particle size ≤50mm. Then, the powdered coal with a particle size ≤5mm and the lump coal with a particle size >5mm are separated by vibrating screen.
[0028] 2. Heavy medium separation: The lump coal is fed into a heavy medium hydrocyclone, where magnetite powder is used as the weighting medium to prepare a solution with a density of 1.5 g / cm³. 3 The heavy medium suspension is separated by density separation under centrifugal force, separating clean coal, middlings and gangue.
[0029] 3. Jigging: Pulverized coal is fed into a jig, where the material is stratified by density through water pulsation. The separation is carried out at a pulsation frequency of 40Hz and a bed thickness of 150mm, separating fine pulverized coal, medium pulverized coal, and pulverized gangue.
[0030] 4. Quality Analysis and Grading: Industrial analysis is performed on the sorted clean coal and middlings to determine indicators such as fixed carbon, ash content, and sulfur content. The coal is divided into three grades: Grade I coal (fixed carbon ≥ 85%, ash content ≤ 10%), Grade II coal (fixed carbon 75%~85%, ash content 10%~20%), and Grade III coal (fixed carbon ≤ 75%, ash content ≥ 20%).
[0031] 5. Material conveying: Grade I coal is conveyed to the lithium battery anode material preparation unit, Grade II coal is conveyed to the high-end activated carbon preparation unit, Grade III coal is conveyed to the carbon-based new material preparation unit, and gangue is conveyed to the circulating fluidized bed combustion power generation unit. III. High-end Activated Carbon Preparation Unit
[0032] The specific process flow of the high-end activated carbon preparation unit is as follows: 1. Raw material pretreatment: Crush Grade II coal to a particle size ≤2mm, acid wash with 10% dilute hydrochloric acid solution at 80℃ for 2h to remove ash and some minerals, then wash with deionized water until neutral, and dry at 110℃ for 12h.
[0033] 2. Carbonization: The pretreated coal is placed in a rotary carbonization furnace and heated to 500°C at a heating rate of 5°C / min under nitrogen protection. The temperature is maintained for 2 hours to obtain carbonized material.
[0034] 3. Composite Activation: Mix the carbonized material with a composite activator (KOH and K2CO3 in a mass ratio of 1:1) at a mass ratio of 1:3, add an appropriate amount of deionized water and stir evenly, then let it stand and soak for 12 hours. Place the soaked material in an activation furnace and heat it to 750℃ at a heating rate of 3℃ / min under nitrogen protection, and hold it at this temperature for 1.5 hours for chemical activation.
[0035] 4. Washing and drying: Wash the activated product with dilute hydrochloric acid to remove residual activator, then wash with deionized water until neutral, and dry at 110℃ for 12h.
[0036] 5. Granulation and sieving: According to the application requirements, the activated carbon is granulated into columnar particles and then sieved to obtain products with different particle size specifications. IV. Lithium-ion Battery Anode Material Preparation Unit
[0037] The specific process flow for the lithium battery anode material preparation unit is as follows: 1. Deep ash removal: Crush Grade I coal to a particle size ≤1.5mm, acid wash with 20% hydrofluoric acid solution at 60℃ for 4h to deeply remove ash, then wash with deionized water until neutral, and dry at 110℃ for 12h.
[0038] 2. Pyrolysis: The deashed coal is placed in a pyrolysis furnace and heated to 600℃ at a heating rate of 3℃ / min under nitrogen protection, and held at the temperature for 3 hours to obtain pyrolytic carbon.
[0039] 3. Carbonization: The pyrolytic carbon is placed in a tubular carbonization furnace and heated to 1200℃ at a heating rate of 2℃ / min under argon protection. The temperature is maintained for 2 hours to obtain carbonized material.
[0040] 4. Doping modification: The carbonized material and ammonium dihydrogen phosphate are mixed evenly at a mass ratio of 100:5, placed in a tube furnace, and treated at 800℃ for 1 hour under argon protection to achieve phosphorus doping modification.
[0041] 5. Graphitization: The modified carbonized material is placed in a graphitization furnace and heated to 2500℃ at a heating rate of 5℃ / min under argon protection, and held at the temperature for 2 hours to obtain coal-based hard carbon.
[0042] 6. Crushing and sieving: The graphitized products are crushed to a particle size ≤15μm using an air jet mill and then sieved to obtain lithium battery anode material products. V. Carbon-based New Material Preparation Unit (Porous Carbon Electrode Materials)
[0043] The specific process flow of the carbon-based new material preparation unit is as follows: 1. Solvent extraction: Grade III coal is crushed to a particle size ≤1mm, and N-methylpyrrolidone solvent with a mass fraction of 99.5% is added. The mass ratio of solvent to coal is controlled at 10:1. The mixture is stirred and extracted at 120℃ for 4h. The extract and extraction residue are obtained by filtration.
[0044] 2. Chemical modification: The extract was mixed with benzaldehyde at a molar ratio of 1:2 and placed in a reaction vessel. The mixture was subjected to a condensation reaction at 180°C for 3 hours to obtain the modified intermediate.
[0045] 3. Carbonization: The modified intermediate is placed in a carbonization furnace and heated to 700℃ at a heating rate of 5℃ / min under nitrogen protection, and held at the temperature for 2 hours to obtain the carbonized product.
[0046] 4. Activation and pore formation: Mix the carbonization product with ZnCl2 activator at a mass ratio of 1:2, place in an activation furnace, and activate at 600℃ for 1 hour to obtain porous carbon material.
[0047] 5. Washing and drying: The activated product is washed with dilute hydrochloric acid to remove residual activator, then washed with deionized water until neutral, and dried at 110℃ for 12 hours to obtain porous carbon electrode material product. VI. Wastewater combustion power generation unit
[0048] The specific process flow of the gangue washing and combustion power generation unit is as follows: 1. Gangue pretreatment: Crush the washed gangue to a particle size ≤ 8mm and screen to remove large particles of impurities.
[0049] 2. Fluidized bed combustion: The pretreated gangue is mixed with quartz sand and limestone bed material at a mass ratio of 10:1:1 and fed into a circulating fluidized bed boiler. The bed material is fluidized by fluidizing air. The combustion temperature is controlled at 875℃ and the fluidization velocity is 4m / s.
[0050] 3. Steam power generation: The high-temperature flue gas generated by combustion heats the boiler feedwater, producing superheated steam at 3.82 MPa and 450°C, which is then sent to the steam turbine to drive the generator to generate electricity.
[0051] 4. Ash and ash separation: The fly ash and bottom ash generated by the boiler are separated by a cyclone separator. The fly ash is collected by a bag filter and the bottom ash is discharged after being cooled by a ash cooler.
[0052] 5. Flue gas purification: The boiler flue gas is successively treated by SCR denitrification (denitrification efficiency 95%), semi-dry desulfurization (desulfurization efficiency 99%), and bag filter dust collection (dust collection efficiency 99.95%) before being discharged in compliance with standards. VII. Waste Resource Utilization Unit
[0053] The specific technological process of the waste resource utilization unit is as follows: 1. Wastewater Treatment and Reuse: Large particulate impurities in production wastewater are removed by a screen and then enter an equalization tank to adjust the water volume and quality. Polyaluminum chloride (PAC) and polyacrylamide (PAM) are added for coagulation and sedimentation to remove suspended solids and colloids. Biological treatment using an A / O process is employed to remove COD and ammonia nitrogen. Finally, the wastewater undergoes deep treatment using an ultrafiltration-reverse osmosis dual-membrane method, and the treated water is reused in production (reuse rate 85%), while the concentrated water is sent to an evaporation and crystallization facility.
[0054] 2. Waste gas treatment and emission compliance: The VOCs-containing process waste gas generated by the lithium battery anode material preparation unit and the carbon-based new material preparation unit is treated by a honeycomb activated carbon adsorption device and then discharged in compliance with standards; the flue gas from the circulating fluidized bed boiler is treated by SCR denitrification, semi-dry desulfurization and bag filter dust removal and then discharged in compliance with standards.
[0055] 3. Solid waste resource utilization: Fly ash and bottom ash from circulating fluidized bed boilers, after passing heavy metal testing, are used to prepare cement admixtures, concrete aggregates, and aerated concrete blocks; waste catalysts generated during activated carbon preparation and negative electrode material preparation are sent to catalyst regeneration units for regeneration treatment, and the regenerated catalysts are reused in production; waste acid from pickling is neutralized and precipitated to recover valuable metals such as iron and aluminum, and the neutralization residue is sent to a compliant solid waste landfill for disposal. Example 1: Preparation of high-end activated carbon
[0056] Raw materials: Grade II low-calorific-value anthracite, with 82% fixed carbon, 15% ash, and 0.8% sulfur.
[0057] Process parameters: Raw material crushing particle size 2mm; 10wt% dilute hydrochloric acid, pickling at 80℃ for 2h; carbonization temperature 500℃, nitrogen protection, constant temperature for 2h; composite activator KOH:K2CO3=1:1, charcoal:activator=1:3; activation temperature 750℃, nitrogen protection, constant temperature for 1.5h.
[0058] Product performance: Specific surface area 1350m² 2 / g, iodine value 1100mg / g, methylene blue value 280mg / g, bulk density 0.45g / cm³ 3 , moisture 5%.
[0059] Application Results: This activated carbon is used in industrial wastewater treatment, achieving an adsorption capacity of 280 mg / g for COD and a removal rate of 95%; in air purification, it has an adsorption capacity of 150 mg / m³ for formaldehyde. 3 The removal rate reached 90%. Example 2: Preparation of lithium battery anode materials
[0060] Raw materials: Grade I low-calorific-value anthracite, with 88% fixed carbon, 8% ash, and 0.5% sulfur.
[0061] Process parameters: raw material crushing particle size 1.5mm; 20wt% hydrofluoric acid, pickling at 60℃ for 4h; pyrolysis temperature 600℃, nitrogen protection, constant temperature for 3h; carbonization temperature 1200℃, argon protection, constant temperature for 2h; phosphorus doping ratio 5%, treatment at 800℃ for 1h; graphitization temperature 2500℃, argon protection, constant temperature for 2h; crushed particle size ≤15μm.
[0062] Product performance: Specific capacity 380mAh / g (0.1C), initial coulombic efficiency 87%, capacity retention 82% after 1000 cycles, tap density 1.1g / cm³ 3 , moisture 0.1%.
[0063] Application results: This anode material is used in 18650 lithium-ion batteries, achieving an energy density of 260Wh / kg and a cycle life of over 1000 cycles, with performance approaching that of commercially available hard carbon anode materials. Example 3: Preparation of porous carbon electrode materials
[0064] Raw materials: Grade III low-calorific-value anthracite, with 70% fixed carbon, 25% ash, and 1.2% sulfur.
[0065] Process parameters: Raw material crushed particle size ≤1mm; 99.5wt% NMP, agent-to-coal ratio 10:1, extraction at 120℃ for 4h; extract to benzaldehyde molar ratio 1:2, condensation reaction at 180℃ for 3h; carbonization temperature 700℃, nitrogen protection, constant temperature for 2h; ZnCl2 activator, carbon material:activator = 1:2, activation at 600℃ for 1h.
[0066] Product performance: Specific surface area 1200m² 2 / g, mesopore volume ratio 65%, specific capacitance 220F / g (1A / g), capacitance retention 95% after 10,000 cycles.
[0067] Application results: This porous carbon material, when used as an electrode in a supercapacitor, exhibits excellent rate performance and cycle stability, making it suitable for high-power energy storage applications. Example 4: Co-processing of XuanShi Power Generation and Waste
[0068] Raw material: washed gangue, calorific value 3.5 MJ / kg, ash content 75%.
[0069] Process parameters: gangue particle size 8mm; combustion temperature 875℃, fluidization velocity 4m / s; superheated steam parameters 3.82MPa, 450℃; generator unit capacity 30MW.
[0070] Operational results: Combustion efficiency 92%, annual power generation 150 million kWh, annual steam production 200,000 tons (for production use); SO2 emission concentration in flue gas 20 mg / m³ 3 NO X Emission concentration 30mg / m³ 3 Dust emission concentration 8mg / m³ 3 Annual fly ash production: 50,000 tons, all used as cement admixtures; annual bottom slag production: 80,000 tons, all used as concrete aggregate; wastewater treatment capacity: 5,000 m³. 3 / day, reuse rate 87%, wastewater discharge COD 35mg / L, ammonia nitrogen 3mg / L.
[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite, characterized in that, Includes the following steps: S1 Separation: After crushing and screening, low-calorific-value anthracite raw materials are separated by density separation through a combination of heavy media separation and jigging separation. Then, industrial analysis is performed to classify the coal into three grades: Grade I coal, Grade II coal, and Grade III coal, while separating the washed gangue. S2 Multi-stage High-Value Conversion: Grade I coal is transported to the lithium battery anode material preparation unit to prepare coal-based hard carbon anode materials, Grade II coal is transported to the high-end activated carbon preparation unit to prepare high-performance activated carbon, and Grade III coal is transported to the carbon-based new material preparation unit to prepare carbon-based new materials. S3 Gangue Clean Power Generation: Washed gangue is transported to a circulating fluidized bed combustion power generation unit for combustion power generation. The generated steam drives a steam turbine to generate electricity. The flue gas generated by combustion is treated for desulfurization, denitrification and dust removal before being discharged in compliance with standards. The fly ash and bottom ash generated by combustion are used for building material production. S4 waste co-processing: Wastewater generated during the production process is treated and reused, process exhaust gas is purified and discharged in compliance with standards, waste catalysts generated during the production process are regenerated and reused in production, and valuable metals are recovered from waste acid liquid through neutralization and precipitation, realizing the resource utilization of solid waste and zero waste throughout the entire process.
2. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 1, characterized in that, The specific process for quality separation in step S1 is as follows: S11 Raw Material Crushing and Screening: Low-calorific-value anthracite is crushed to a particle size ≤50mm, and pulverized coal with a particle size ≤5mm and lump coal with a particle size >5mm are separated by vibrating screen. S12 heavy medium separation: the lump coal is sent into a heavy medium cyclone, magnetite powder is used as a weighting agent to prepare a heavy medium suspension with a density of 1.4-1.6 g / cm 3 , and the heavy medium suspension is separated to obtain clean coal, medium coal and gangue; S13 Jigging Separation: Pulverized coal is fed into a jig and density separation is performed at a pulsating frequency of 30~50Hz and a bed thickness of 100~200mm to separate fine pulverized coal, medium pulverized coal and pulverized gangue. S14 graded conveying: The sorted clean coal and middlings are industrially analyzed and graded according to quality before being conveyed to the corresponding preparation units. The gangue is conveyed to the circulating fluidized bed combustion power generation unit.
3. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 1, characterized in that, In step S1, the fixed carbon content of Grade I coal is ≥85% and the ash content is ≤10%, the fixed carbon content of Grade II coal is 75%~85% and the ash content is 10%~20%, and the fixed carbon content of Grade III coal is ≤75% and the ash content is ≥20%.
4. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 1, characterized in that, The specific process of the high-end activated carbon preparation unit in step S2 is as follows: A1 Raw Material Pretreatment: Crush Grade II coal to a particle size ≤3mm, acid wash with 8~12wt% dilute hydrochloric acid solution at 70~90℃ for 1~3h, wash with water until neutral, and then dry; A2 carbonization: The pretreated coal is heated to 450-550℃ at a heating rate of 4-6℃ / min under nitrogen protection and held at the temperature for 1-3 hours to obtain carbonized material. A3 Composite Activation: The carbonized material and the composite activator are mixed and impregnated at a mass ratio of 1:(2~4) for 10-15 hours. The composite activator is a mixture of KOH and K2CO3 at a mass ratio of 1:(1~2). The impregnated material is then heated to 700~800℃ at a heating rate of 2~4℃ / min under nitrogen protection and kept at the temperature for 1~2 hours for chemical activation. A4 Post-processing: The activated product is washed until neutral and then dried. It is then granulated and sieved to obtain high-end activated carbon products of different specifications.
5. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 1, characterized in that, The specific process of the lithium battery anode material preparation unit in step S2 is as follows: B1 Deep Deashing: Crush Grade I coal to a particle size ≤2mm, acid wash with 15~25wt% hydrofluoric acid solution at 50~70℃ for 3~5h, wash with water until neutral, and then dry. B2 segmented heat treatment: The deashed coal is heated to 550-650℃ at a heating rate of 2-4℃ / min under nitrogen protection and held at the temperature for 3 hours to obtain pyrolytic carbon; then the pyrolytic carbon is heated to 1100-1300℃ at a heating rate of 1-3℃ / min under argon protection and held at the temperature for 1-3 hours to obtain carbonized material. B3 doping modification: The carbonized material and the phosphorus source are mixed at a mass ratio of 100:(3~7) and treated at 700~900℃ for 1~1.2h under an inert atmosphere. The phosphorus source is ammonium dihydrogen phosphate. B4 graphitization: The modified carbonized material is heated to 2400~2600℃ at a heating rate of 4~6℃ / min under argon protection and held at the temperature for 1~3h to obtain coal-based hard carbon. After crushing and sieving to a particle size ≤15μm, lithium battery anode material products are obtained.
6. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 1, characterized in that, The carbon-based new material preparation unit mentioned in step S2 is for preparing porous carbon electrode materials, and the specific process is as follows: C1 solvent extraction: Grade III coal is crushed to a particle size ≤1mm, and extracted with 99.0~99.9%wt% N-methylpyrrolidone solvent, with the mass ratio of solvent to coal controlled at (8~15):1, at 100~140℃ for 2~6h, and the extract and extraction residue are separated. C2 chemical modification: The extract is mixed with benzaldehyde at a molar ratio of 1:(1~3) and a condensation reaction is carried out at 160~200℃ for 2~4h to obtain the modified intermediate; C3 carbonization and activation: The modified intermediate was heated to 650-750℃ under nitrogen protection at a heating rate of 4-6℃ / min and held at the temperature for 2 hours to obtain the carbonized product. The carbonization product was mixed with ZnCl2 activator at a mass ratio of 1:(1.5~2.5) and activated at 550~650℃ for 1h. C4 post-treatment: The activated product is washed until neutral and then dried to obtain porous carbon electrode material product.
7. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 1, characterized in that, The specific process of the gangue washing and recycling circulating fluidized bed combustion power generation unit described in step S3 is as follows: S31 gangue pretreatment: Crush the washed gangue to a particle size ≤10mm and screen to remove large particles of impurities; S32 fluidized bed combustion: Pretreated gangue is mixed with quartz sand and limestone bed material and fed into a circulating fluidized bed boiler for combustion at a combustion temperature of 850~900℃ and a fluidization velocity of 3~5m / s. S33 Steam Power Generation: The high-temperature flue gas generated by combustion heats the boiler feedwater, producing superheated steam at 3.5~4.1MPa and 430~470℃, which is then sent to the steam turbine to drive the generator to generate electricity; S34 Flue Gas Purification: Boiler flue gas is sequentially treated by selective catalytic reduction for denitrification, semi-dry desulfurization, and bag filter dust removal before being discharged in compliance with standards.
8. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 1, characterized in that, The specific process for wastewater treatment and reuse in step S4 is as follows: the production wastewater is sequentially intercepted by a screen, homogenized in an equalization tank, coagulated and settled, treated by A / O biological treatment, and deeply treated by ultrafiltration-reverse osmosis dual membrane method. The produced water is reused in production, and the concentrated water is sent to evaporation and crystallization.
9. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 1, characterized in that, The specific process for treating waste gas and solid waste in step S4 is as follows: S41 Process Waste Gas Treatment: VOCs-containing process waste gas generated by the lithium battery anode material preparation unit and the carbon-based new material preparation unit is treated by an activated carbon adsorption device and then discharged in compliance with standards. S42 Solid Waste Resource Utilization: Fly ash and bottom ash from circulating fluidized bed boilers, after passing heavy metal testing, are used to prepare cement admixtures, concrete aggregates, or aerated concrete blocks; waste catalysts generated during activated carbon preparation and negative electrode material preparation are recycled for production after regeneration; waste acid generated from pickling is neutralized and precipitated to recover valuable metals, and the neutralization residue is sent to a compliant solid waste landfill for disposal.
10. The production process for the cascade utilization and comprehensive conversion of low-calorific-value anthracite coal as described in claim 8, characterized in that, The exhaust gas treatment in step S41 also includes a flue gas treatment process generated by the circulating fluidized bed boiler: using selective catalytic reduction process for denitration, using ammonia as reducing agent, and under the action of catalyst, the NO X The process reduces SO2 to nitrogen (N2); a semi-dry desulfurization process is used, employing slaked lime as the desulfurizing agent, which reacts with SO2 in the flue gas within the reaction tower to produce calcium sulfite and calcium sulfate; a bag filter is used to remove particulate matter from the flue gas, achieving a dust emission concentration ≤10 mg / m³ after treatment. 3 .