Low-calorific-value coal gangue resource utilization system
Through steps such as crushing and screening, pyrolysis activation, and combustion decarbonization, desulfurization, and denitrification, low-calorific-value coal gangue is transformed into highly active semi-coke and building materials, solving the problem of the difficulty in utilizing low-calorific-value coal gangue, realizing resource utilization and harmless utilization, and improving environmental and economic benefits.
Patent Information
- Application Number
- CN202423263495.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-27
AI Technical Summary
Low-calorific-value coal gangue is difficult to utilize effectively, leading to environmental pollution and resource waste. Existing ecological backfilling methods cannot remove sulfides, posing potential pollution risks.
Through steps such as crushing and screening, pyrolysis activation, combustion decarbonization, desulfurization and denitrification, and flue gas treatment, low-calorific-value coal gangue is converted into highly active semi-coke and pyrolysis oil and gas. The combustion decarbonization, desulfurization and denitrification are carried out using a circulating fluidized bed boiler, and stable building materials are formed through waste heat utilization and product processing.
It realizes the resource utilization of low-calorific-value coal gangue, enhances stability and activity, reduces carbon impurities, and is suitable for various industrial production and environmentally friendly resource utilization, alleviating resource shortages and environmental pollution.
Smart Images
Figure CN223607230U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to coal gangue resource utilization technical field, concretely relates to a low calorific value coal gangue resource utilization system. BACKGROUND
[0002] Coal gangue is an industrial solid waste produced in the process of coal mining and washing, and is a black gray rock associated with the coal-forming process, which has low carbon content and high hardness. Because of its low calorific value, it is difficult to utilize, resulting in a large amount of coal gangue that can only be piled up on site, occupying land resources and causing environmental pollution risks.
[0003] During the natural accumulation of coal gangue, acid wastewater is produced under the combined action of rainwater leaching and oxidizing bacteria such as ferrous iron sulfur bacillus, and toxic and harmful substances such as heavy metals in coal gangue are dissolved to cause water and soil pollution. If the mass fraction of pyrite in coal gangue is high, oxidation will occur, causing spontaneous combustion, releasing SO2, H2S, CO, NO X , etc., which becomes the main source of regional air pollution.
[0004] For a long time, great importance has been attached to the utilization and disposal of large solid wastes such as coal gangue. The overall utilization trend is from resourceization to high value and back to large disposal, and the proportion is gradually increasing. The ecological backfilling mode of damaged land and non-utilizable land by ecological management of coal gangue is an important direction for large-scale utilization and consumption of coal gangue, but conventional ecological backfilling cannot remove sulfides in coal gangue, and there is still a potential risk of polluting the environment. Thermal activation decarburization and desulfurization treatment of coal gangue is an effective means to economically and conveniently treat coal gangue on a large scale. The treated coal gangue is stable and will not adversely affect the ecological environment.
[0005] The calorific value of coal gangue in China is generally below 1500kca l / kg, and coal gangue with a calorific value of more than 1500kca l / kg accounts for only 10% of the total. Coal gangue with a calorific value higher than 1500kca l / kg can be directly combusted, otherwise it needs to be mixed with a certain amount of high-calorific-value material for combustion, which will waste valuable fossil energy. Therefore, it is of great significance to study a combustion method for low-calorific-value coal gangue without adding other energy materials. UTILITY MODEL CONTENTS
[0006] The technical problem to be solved by the utility model is to provide a low-calorific-value coal gangue resource utilization system to overcome the deficiencies in the prior art.
[0007] The technical solution of the utility model to solve the above technical problem is as follows:
[0008] The application discloses a low-calorific-value coal gangue resource utilization system, which comprises a crushing and screening system, a pyrolysis and activation system, a combustion, decarburization, desulfurization and denitration system, a flue gas treatment system, a waste heat utilization system and a product processing system.
[0009] Based on the technical scheme, the utility model still can make improvement as follows.
[0010] Further, the discharge particle size of the crushing and screening system is less than or equal to 5 mm.
[0011] Further, the crushing and screening system comprises a toothed roll crusher, and the crushed coal gangue in the toothed roll crusher is sent into a screening machine, and the screened coal gangue in the screening machine is sent into the pyrolysis and activation system through a conveyor.
[0012] Further, the pyrolysis and activation temperature of the pyrolysis and activation system for the coal gangue is 180 DEG C to 200 DEG C.
[0013] Further, the pyrolysis and activation system adopts a pyrolysis and activation furnace.
[0014] Further, the combustion temperature of the combustion, decarburization, desulfurization and denitration system is 850 DEG C to 950 DEG C.
[0015] Further, the combustion, decarburization, desulfurization and denitration system adopts a circulating fluidized bed boiler, calcium injection is used for primary desulfurization in the circulating fluidized bed boiler, limestone powder is used as a desulfurization absorbent in the boiler, urea is used as a denitration reducing agent, and the particle size of the limestone powder is less than or equal to 1 mm.
[0016] Further, the flue gas treatment system comprises a bag-type dust collector, the outlet of the bag-type dust collector is communicated with the inlet of a high-efficiency dust and mist remover through a pipeline, the outlet of the high-efficiency dust and mist remover is communicated with a single-pipe sleeve chimney through a pipeline, and a centrifugal induced draft fan is arranged on the pipeline between the high-efficiency dust and mist remover and the single-pipe sleeve chimney.
[0017] Further, the waste heat utilization system adopts a waste heat boiler.
[0018] Further, the product processing system comprises a weighing type feeder, and the discharge of the weighing type feeder is sent into a vertical shaft planetary mixer through a belt conveyor.
[0019] The utility model discloses the beneficial effects are:
[0020] 1) Pyrolysis activation decarbonization, desulfurization, and denitrification treatment of low-calorific-value coal gangue not only utilizes the heat energy in the coal gangue and removes sulfides, thus stabilizing its physicochemical properties, but also enhances its activity. Specifically, the thermal activation process can change the crystal structure of the coal gangue from an ordered structure to a disordered active structure, thereby increasing the activity of components such as aluminosilicates. Therefore, it can be processed into relevant products according to different application scenarios for resource utilization such as land reclamation and backfilling, underground filling, roadbed filling, and building materials. For example, by adding corresponding solidifying agents, it can improve and formulate building materials and land backfill materials, realizing large-scale disposal and resource utilization of coal gangue. This resource utilization of low-calorific-value coal gangue is in line with policy direction and can bring better environmental and economic benefits.
[0021] 2) The carbon content in coal gangue can have an adverse effect on its application in many scenarios. Pyrolysis activation decarburization can reduce carbon impurities and make the color of coal gangue lighter, which can be used in industrial production such as ceramics where the color of raw materials is important. Moreover, decarburization can improve the thermal stability and other properties of coal gangue products.
[0022] 3) It transforms coal gangue, which originally occupied large amounts of land and polluted the environment, into a useful resource, realizes the comprehensive utilization of coal gangue resources in a harmless manner, improves the utilization rate of resources, alleviates the pressure of resource shortage to a certain extent, and brings good environmental and economic benefits. It has important reference and promotional effects on the resource utilization of coal gangue in other regions of my country, and can open up a new situation for the comprehensive utilization of bulk solid wastes such as coal gangue. Attached Figure Description
[0023] Figure 1 This is a structural diagram of the low-calorific-value coal gangue resource utilization system of this utility model.
[0024] The attached diagram lists the components represented by each number as follows:
[0025] 1. Crushing and screening system; 2. Pyrolysis activation system; 3. Combustion decarbonization, desulfurization and denitrification system; 4. Flue gas treatment system; 5. Waste heat utilization system; 6. Product processing system. Detailed Implementation
[0026] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.
[0027] Example 1
[0028] like Figure 1 As shown, a low-calorific-value coal gangue resource utilization system includes:
[0029] The gangue is sent into the crushing and screening system 1, the gangue is crushed and screened in the crushing and screening system 1, the gangue obtained by crushing and screening in the crushing and screening system 1 is sent into the pyrolysis and activation system 2, the gangue is pyrolyzed and activated in the pyrolysis and activation system 2, the gangue after pyrolysis and activation in the pyrolysis and activation system 2 is sent into the combustion and decarburization, desulfurization and denitrification system 3, the high-temperature gas-solid mixed fuel containing pyrolysis oil gas and high-activity semi-coke generated in the pyrolysis and activation system 2 during the pyrolysis and activation process of the gangue is also sent into the combustion and decarburization, desulfurization and denitrification system 3, the fly ash-containing flue gas in the combustion and decarburization, desulfurization and denitrification system 3 is sent into the flue gas treatment system 4, the flue gas is treated in the flue gas treatment system 4 to be discharged after reaching the standard, and part of the high-temperature flue gas in the combustion and decarburization, desulfurization and denitrification system 3 is sent into the pyrolysis and activation system 2 to assist in heating the gangue, and part of the high-temperature flue gas in the combustion and decarburization, desulfurization and denitrification system 3 is sent into the waste heat utilization system 5 to realize waste heat recovery and utilization;
[0030] The gangue after decarburization, desulfurization and denitrification in the combustion and decarburization, desulfurization and denitrification system 3 is discharged into the product processing system 6;
[0031] The pyrolysis and activation, decarburization, desulfurization and denitrification treatment of low-calorific-value gangue not only can utilize the heat energy in the gangue and remove sulfide substances in the gangue to make the physicochemical properties of the gangue tend to be stable, but also can enhance the activity of the gangue, specifically: the thermal activation process can change the crystal structure of the gangue, making it change from the original ordered structure to the disordered active structure, and the activity of silicate and other components in the gangue is enhanced, so the gangue can be configured and processed into related products according to different application scenarios, for example, the gangue can be used for land reclamation backfilling, underground filling, roadbed filling, building raw materials and other resource utilization, such as: by adding corresponding solidifying agents to improve and prepare building raw materials and land backfilling materials, realizing large-scale disposal and resource utilization of the gangue, and the resource utilization of the low-calorific-value gangue conforms to the policy direction and can bring better environmental and economic benefits;
[0032] The carbon component in the gangue will have adverse effects on the gangue in many application scenarios, and the pyrolysis and activation decarburization can reduce carbon impurities and make the color of the gangue lighter, which can be used in industrial production of ceramics and other materials with high requirements for color and luster, and the decarburized gangue can improve the thermal stability and other properties of the gangue products;
[0033] The gangue that originally occupied a large amount of land and polluted the environment becomes a useful resource, realizing comprehensive utilization of the gangue resources, improving the utilization rate of resources, alleviating the pressure of resource shortage to a certain extent, bringing good environmental and economic benefits, and having an important reference and promotion effect on the resource utilization of the gangue in other regions of China, which can open up a new situation for the comprehensive utilization of the gangue and other bulk solid wastes.
[0034] Example 2
[0035] AsFigure 1 As shown in the figure, the embodiment is a further improvement on the basis of example 1, as follows:
[0036] The discharge particle size of the crushing and screening system 1 is less than or equal to 5mm to meet the subsequent combustion requirements.
[0037] Further, in this embodiment, the crushing and screening system 1 includes a toothed roll crusher for crushing coal gangue, the crushed coal gangue in the toothed roll crusher is sent into a screening machine, and the screened coal gangue in the screening machine is sent into the pyrolysis activation system 2 via a conveyor.
[0038] Example 3
[0039] As shown in the figure, the embodiment is a further improvement on the basis of example 1 or 2, as follows: Figure 1
[0040] The pyrolysis activation temperature of the pyrolysis activation system 2 for coal gangue is 180-200℃.
[0041] Further, in this embodiment, the pyrolysis activation system 2 uses a pyrolysis activation furnace, and in actual application, a device similar to a rotary kiln is used to pyrolyze and activate the coal gangue. The crushed and screened coal gangue in the crushing and screening system 1 is sent into the pyrolysis activation cylinder of the pyrolysis activation furnace, and the coal gangue rotates and rolls in the pyrolysis activation cylinder of the pyrolysis activation furnace. The high-temperature gas-solid mixed fuel containing pyrolysis oil gas and high-activity semi-coke generated by pyrolysis and activation is sent into the combustion decarburization desulfurization denitrification system 3 and burned in the combustion decarburization desulfurization denitrification system 3. The coal gangue after pyrolysis and activation in the pyrolysis activation furnace is also sent into the combustion decarburization desulfurization denitrification system 3.
[0042] Example 4
[0043] As shown in the figure, the embodiment is a further improvement on the basis of example 1 or 2 or 3, as follows: Figure 1
[0044] The combustion temperature in the combustion decarburization desulfurization denitrification system 3 is 850-950℃, and the coal gangue after pyrolysis and activation is burned in the combustion decarburization desulfurization denitrification system 3 for decarburization, desulfurization and denitrification treatment.
[0045] Further, in this embodiment, the combustion decarburization desulfurization denitrification system 3 uses a circulating fluidized bed boiler, calcium injection is used for primary desulfurization in the circulating fluidized bed boiler, and limestone powder is used as the desulfurization absorbent, with a particle size less than or equal to 1mm. The selective non-catalytic reduction method (SNCR) is used for denitrification, and urea is used as the denitrification reducing agent. The coal gangue after combustion decarburization desulfurization denitrification is discharged from the bottom of the circulating fluidized bed boiler to enter the combustion decarburization desulfurization denitrification system 3, with a yield rate of 75%.
[0046] Embodiment 5
[0047] As Figure 1 shown, the embodiment is further improved on the basis of any one of embodiments 1-4, and specifically as follows:
[0048] The flue gas treatment system 4 adopts a bag filter + desulfurization tower top high-efficiency dust removal and mist removal device process, and the flue gas treatment system 4 comprises: a bag filter, an outlet of the bag filter is communicated with an inlet of a high-efficiency dust removal and mist removal device through a pipeline, an outlet of the high-efficiency dust removal and mist removal device is communicated with a single pipe sleeve chimney through a pipeline, and a centrifugal induced draft fan is arranged on the pipeline between the high-efficiency dust removal and mist removal device and the single pipe sleeve chimney. In the embodiment, each circulating fluidized bed boiler is configured with one bag filter + one high-efficiency dust removal and mist removal device + two 50% capacity centrifugal induced draft fans, and the two circulating fluidized bed boilers share one single pipe sleeve chimney.
[0049] Embodiment 6
[0050] As Figure 1 shown, the embodiment is further improved on the basis of any one of embodiments 1-5, and specifically as follows:
[0051] The waste heat utilization system 5 preferably adopts a waste heat boiler, and the waste heat boiler is used to produce steam and generate electricity.
[0052] Embodiment 7
[0053] As Figure 1 shown, the embodiment is further improved on the basis of any one of embodiments 1-6, and specifically as follows:
[0054] The product processing system 6 comprises: a weighing feeder, an outlet of the weighing feeder is sent into a vertical shaft planetary mixer through a belt conveyor, low-calorific-value coal gangue is sent into the vertical shaft planetary mixer after pyrolysis, activation, decarburization, desulfurization and denitration treatment, and is mixed with corresponding additives in the vertical shaft planetary mixer, and the finished product in the vertical shaft planetary mixer is finally sent into a product storage warehouse for storage.
[0055] Application example
[0056] A low calorific value coal gangue pyrolysis activation decarburization test project, the project design scale is 100 tons of coal gangue per day, the coal gangue with the calorific value of 500-700kcal / kg is selected, the crushed coal gangue is sent into the pyrolysis activation furnace, the high-temperature flue gas (950℃) circulating in the circulating fluidized bed boiler is used to heat the coal gangue to 200℃, the coal gangue forms pyrolysis oil gas and high-temperature gas-solid mixed fuel with high activity semi-coke, and then enters the circulating fluidized bed boiler for combustion, the coal gangue after pyrolysis activation in the pyrolysis activation furnace also enters the combustion decarburization desulfurization denitrification system 3, and the combustion temperature of the circulating fluidized bed boiler is controlled at 850℃-950℃, the high-temperature flue gas generated by combustion is partially used to heat the coal gangue in the pyrolysis activation furnace, and the other part is used to generate steam and electric power in the waste heat utilization system 5;
[0057] The product after the coal gangue is pyrolysis activated decarburization desulfurization denitrification contains less than 1% carbon and less than or equal to 1.0mg / L sulfide, and can be used as a land reclamation backfill material without environmental risk;
[0058] The product after pyrolysis activation decarburization desulfurization denitrification is mixed with the HAS curing agent in a laboratory at a sand ratio of 1:8 to form a paste material, the paste material has a slump of 224mm, a 3-day compressive strength of 2.29Mpa, a 7-day compressive strength of 3.4Mpa, and a 28-day compressive strength of 4.5Mpa, which can meet the requirements of underground filling pumping and strength;
[0059] After 5% of the product is mixed with the curing agent, the seven-day unconfined compressive strength is 0.9MPa, which can meet the requirements of roadbed filling;
[0060] The test project successfully demonstrates the feasibility of the resource utilization technology path of 500-700kcal / kg low calorific value coal gangue, the energy in the coal gangue is fully utilized by producing building material products through pyrolysis decarburization of the coal gangue, and the coal gangue product after decarburization can meet the resource utilization requirements, and realizes the resource utilization, harmless and large-scale comprehensive utilization of the coal gangue.
[0061] Although the embodiments of the utility model have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the utility model, and the ordinary skilled in the art can change, modify, replace and transform the above-mentioned embodiments within the scope of the utility model.
Claims
1. A low-calorific-value coal gangue resource utilization system, characterized in that, The application relates to a coal gangue pyrolysis and activation system. The particle size of the crushed and screened coal gangue is less than or equal to 5mm.
2. The low-calorific-value coal gangue resource utilization system according to claim 1, characterized in that, The crushed and screened coal gangue is sent into a pyrolysis and activation system (2) through a conveyor.
3. The low-calorific-value coal gangue resource utilization system according to claim 1, characterized in that, The pyrolysis and activation temperature of the coal gangue in the pyrolysis and activation system (2) is 180-200 DEG C.
4. The low-calorific-value coal gangue resource utilization system according to claim 1, characterized in that, The pyrolysis and activation system (2) adopts a pyrolysis and activation furnace.
5. The low-calorific-value coal gangue resource utilization system according to claim 1 or 4, characterized in that, The combustion temperature in the combustion, decarburization, desulfurization and denitration system (3) is 850-950 DEG C. 6.The low-calorific-value coal gangue resource utilization system according to claim 1, characterized in that, The combustion, decarburization, desulfurization and denitration system (3) adopts a circulating fluidized bed boiler.
7. The low-calorific-value coal gangue resource utilization system according to claim 1 or 6, characterized in that, The desulfurization in the circulating fluidized bed boiler adopts a calcium injection primary desulfurization, the desulfurization absorbent in the furnace is limestone powder, the particle size of the limestone powder is less than or equal to 1mm, and the denitration reducing agent is urea. 8.The low-calorific-value coal gangue resource utilization system according to claim 1, characterized in that, The flue gas treatment system (4) comprises a bag-type dust collector, the outlet of the bag-type dust collector is communicated with the inlet of a high-efficiency dust and mist remover through a pipeline, the outlet of the high-efficiency dust and mist remover is communicated with a single-pipe sleeve chimney through a pipeline, and a centrifugal induced draft fan is arranged on the pipeline between the high-efficiency dust and mist remover and the single-pipe sleeve chimney. 9.The low-calorific-value coal gangue resource utilization system according to claim 1, characterized in that, The waste heat utilization system (5) adopts a waste heat boiler. 10.The low-calorific-value coal gangue resource utilization system according to claim 1, characterized in that, The product processing system (6) comprises a weighing type feeder, and the discharge of the weighing type feeder is sent into a vertical shaft planetary mixer through a belt conveyor.