Preparation system of coal gangue sandy soil modifier

Abstract

The utility model discloses a preparation system of a coal gangue sandy soil modifier, which comprises a crusher, a discharge port of the crusher is connected with a screening machine, a feed port of the screening machine is connected with the discharge port of the crusher, a fine material outlet of the screening machine is connected with a preheater, a top end outlet and a bottom end outlet of the preheater are connected with a high-temperature combustion furnace, and the top end outlet and the bottom end outlet of the preheater are connected with an air inlet of the high-temperature combustion furnace. A discharge port of the high-temperature combustion furnace is connected with a cooler, a discharge port of the cooler is connected with a pulverizer, and an outlet of the pulverizer is a coal gangue-based sandy soil modifier product; a smoke outlet of the high-temperature combustion furnace is connected with a heat exchanger, and a tube pass inlet of the heat exchanger is connected with a smoke outlet of the high-temperature combustion furnace; a tube pass outlet of the heat exchanger is connected with a dust remover, the exhaust end of the dust remover is connected with a desulfurization device, and the exhaust end of the desulfurization device is connected with a denitration device. Heavy metal in the coal gangue is removed through heat treatment, and meanwhile the filtering risk of residual heavy metal is reduced.

Description

Technical Field

[0001] This utility model relates to the field of sand and soil amendment preparation technology, specifically a preparation system for a coal gangue sand and soil amendment. Background Technology

[0002] Coal gangue, a solid waste generated during coal mining and washing, not only occupies land resources when piled up in large quantities, but also causes numerous environmental hazards, such as air pollution from spontaneous combustion and soil and water pollution from leaching. Meanwhile, many areas have sandy soils with low fertility and poor water and fertilizer retention capacity, severely restricting agricultural production and vegetation restoration. Traditional methods of coal gangue disposal often involve simple stockpiling or landfilling, failing to fully exploit its potential value. For sandy soil improvement, methods such as applying organic fertilizers and topsoil are commonly used, but these methods suffer from high costs and short-lived effects.

[0003] In the prior art, Chinese patent application CN118904156A discloses a high-content coal gangue soil matrix preparation device, including a mounting frame and a bucket, with the bucket connected to the front of the mounting frame. This invention uses the bucket to scoop up the original soil, allowing the original soil and coal gangue to converge at the auger. Then, a first motor is started, and the auger rotates through a transmission assembly to mix the original soil and coal gangue. The mixed original soil and coal gangue are then discharged from the discharge pipe onto the soil surface. This achieves the effect of directly mixing coal gangue matrix with original soil at the location requiring soil improvement, improving soil improvement efficiency and saving costs.

[0004] The aforementioned patent essentially provides a method for mixing coal gangue matrix with native soil to improve soil amendment efficiency. However, in addition to SiO2, Al2O3, and macroelements such as Fe and Mn, coal gangue also contains harmful trace heavy metals such as Pb, Cd, Hg, As, and Cr, as well as organic carbon. These trace heavy metals and organic carbon can cause sandy soil to be polluted by heavy metals and organic matter. Therefore, when preparing sand amendments using coal gangue, it is necessary to remove the heavy metals and organic matter inside the coal gangue. However, existing devices for preparing sand amendments from coal gangue cannot effectively remove the heavy metals and organic matter from the coal gangue. Utility Model Content

[0005] The purpose of this invention is to provide a system for preparing a coal gangue soil conditioner, which aims to improve the existing equipment for preparing soil conditioners from coal gangue, which cannot effectively remove heavy metals and organic matter from the coal gangue.

[0006] This utility model is implemented as follows:

[0007] A system for preparing a coal gangue-based soil conditioner includes a crusher, a screening machine connected to the discharge port of the crusher, a preheater connected to the fine material outlet of the screening machine, a high-temperature combustion furnace connected to the top and bottom outlets of the preheater, a cooler connected to the discharge port of the high-temperature combustion furnace, a grinding mill connected to the discharge port of the cooler, and a coal gangue-based soil conditioner product being discharged from the grinding mill. A heat exchanger is connected to the exhaust port of the high-temperature combustion furnace, with the tube-side inlet of the heat exchanger connected to the exhaust port of the high-temperature combustion furnace. A dust collector is connected to the tube-side outlet of the heat exchanger, a desulfurization device is connected to the exhaust end of the dust collector, and a denitrification device is connected to the exhaust end of the desulfurization device.

[0008] Preferably, the crusher is a jaw crusher, and the coarse material outlet of the screening machine is connected to the feed inlet of the crusher.

[0009] Preferably, the preheater discharges air containing coal ash from the top exhaust port and discharges crushed coal ash powder from the bottom discharge port. The preheater inlet is located on the side and is connected to the discharge port of the screening machine. A hot air inlet is provided on the side of the preheater below its inlet.

[0010] Preferably, the feed inlet of the high-temperature combustion furnace is connected to the discharge outlet at the bottom of the preheater, and the air inlet of the high-temperature combustion furnace is connected to the exhaust outlet at the top of the preheater and the exhaust outlet at the top of the cooler.

[0011] Preferably, the cooler has an exhaust port at the top and a discharge port at the bottom, a feed port on the side of the cooler, the feed port being connected to the discharge port of the high-temperature combustion furnace, and a cold air inlet on the side of the cooler below the feed port.

[0012] Preferably, the heat exchanger has a cold air inlet and a hot air outlet on its side, and the hot air outlet of the heat exchanger is connected to the hot air inlet of the waste heat exchanger.

[0013] Preferably, the high-temperature combustion furnace is a tubular rotary high-temperature furnace, the dust collector is a cyclone separator, and the grinding mill is a ball mill.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This utility model removes heavy metals from coal gangue through heat treatment, while reducing the risk of residual heavy metal leaching and minimizing the secondary risks to the soil caused by coal gangue soil conditioner during the soil improvement process.

[0016] 2. This utility model increases the formation of nanoscale pores in coal gangue powder by controlling the combustion temperature of the high-temperature combustion furnace, thereby improving its water and fertilizer retention capacity. When applied to sandy soil, it can correspondingly improve the water and fertilizer retention capacity of the sandy soil, thus achieving the purpose of improving the sandy soil.

[0017] 3. This utility model preheats the coal gangue powder with the cold air after heat exchange in the heat exchanger before sending it into the high-temperature combustion furnace to aid combustion. At the same time, the hot air after heat exchange in the cooler is also sent into the high-temperature combustion furnace to aid combustion, which reduces the energy consumption of the high-temperature combustion furnace and achieves the purpose of energy saving. Attached Figure Description

[0018] Figure 1 This is a structural flowchart of the preparation system of this utility model.

[0019] In the diagram: 1. Crusher; 2. Screening machine; 3. Preheater; 4. High-temperature combustion furnace; 5. Cooler; 6. Grinding mill; 7. Heat exchanger; 8. Dust collector; 9. Desulfurization device; 10. Denitrification device. Detailed Implementation

[0020] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] The following description, in conjunction with the accompanying drawings and specific embodiments, provides further details:

[0022] Example 1

[0023] like Figure 1As shown, a coal gangue sand amendment preparation system includes a crusher 1, which is used to crush raw coal gangue. The raw coal gangue particle size is ≤100mm, and the outlet material particle size is ≤4mm. The discharge port of the crusher 1 is connected to a screening machine 2, and the inlet of the screening machine 2 is connected to the discharge port of the crusher 1. This structure facilitates the coal gangue crushed by the crusher 1 to enter the screening machine 2 for screening, separating the fine and coarse particles of the crushed coal gangue. The fine material outlet of the screening machine 2 is connected to a preheater 3, which facilitates the preheating of the screened fine coal gangue particles. The top and bottom outlets of the preheater 3 are connected to a high-temperature combustion furnace 4, which facilitates the injection of the preheated coal gangue particles into the high-temperature combustion furnace 4, and also facilitates the smooth entry of particles containing coal dust into the high-temperature combustion furnace 4. A cooler 5 is connected to the outlet of the high-temperature combustion furnace 4, which is used to cool the heated coal gangue particles. A grinding mill 6 is connected to the outlet of the cooler 5, which is used to grind the coal gangue particles. The outlet of the grinding mill 6 is a coal gangue-based sand and soil conditioner product. A heat exchanger 7 is connected to the flue gas outlet of the high-temperature combustion furnace 4, and the tube-side inlet of the heat exchanger 7 is connected to the flue gas outlet of the high-temperature combustion furnace 4. The heat exchanger 7 is used to recover and utilize the heat from the high-temperature flue gas generated by the high-temperature combustion furnace 4. A dust collector 8 is connected to the tube-side outlet of the heat exchanger 7, which is used to remove dust from the flue gas. A desulfurization device 9 is connected to the exhaust end of the dust collector 8, and a denitrification device 10 is connected to the exhaust end of the desulfurization device 9. The desulfurization device 9 and the denitrification device 10 are used for desulfurization and denitrification treatment of the dust.

[0024] Example 2

[0025] like Figure 1As shown, a coal gangue sand amendment preparation system includes a crusher 1, which is used to crush raw coal gangue. The raw coal gangue particle size is ≤100mm, and the outlet material particle size is ≤4mm. The discharge port of the crusher 1 is connected to a screening machine 2, and the inlet of the screening machine 2 is connected to the discharge port of the crusher 1. This structure facilitates the coal gangue crushed by the crusher 1 to enter the screening machine 2 for screening, separating the fine and coarse particles of the crushed coal gangue. The fine material outlet of the screening machine 2 is connected to a preheater 3, which facilitates the preheating of the screened fine coal gangue particles. The top and bottom outlets of the preheater 3 are connected to a high-temperature combustion furnace 4, which facilitates the injection of the preheated coal gangue particles into the high-temperature combustion furnace 4, and also facilitates the smooth entry of particles containing coal dust into the high-temperature combustion furnace 4. A cooler 5 is connected to the outlet of the high-temperature combustion furnace 4, which is used to cool the heated coal gangue particles. A grinding mill 6 is connected to the outlet of the cooler 5, which is used to grind the coal gangue particles. The outlet of the grinding mill 6 is a coal gangue-based sand and soil conditioner product. A heat exchanger 7 is connected to the flue gas outlet of the high-temperature combustion furnace 4, and the tube-side inlet of the heat exchanger 7 is connected to the flue gas outlet of the high-temperature combustion furnace 4. The heat exchanger 7 is used to recover and utilize the heat from the high-temperature flue gas generated by the high-temperature combustion furnace 4. A dust collector 8 is connected to the tube-side outlet of the heat exchanger 7, which is used to remove dust from the flue gas. A desulfurization device 9 is connected to the exhaust end of the dust collector 8, and a denitrification device 10 is connected to the exhaust end of the desulfurization device 9. The desulfurization device 9 and the denitrification device 10 are used for desulfurization and denitrification treatment of the dust.

[0026] like Figure 1 As shown, crusher 1 is a jaw crusher 1, used for effective crushing of coal gangue. The coarse material outlet of screening machine 2 is connected to the feed inlet of crusher 1, facilitating the return of the coarse material screened by screening machine 2 to the jaw crusher 1 for further crushing. The preheater 3 has an exhaust port at the top discharging air containing coal ash and a bottom discharge port discharging pulverized coal ash powder. The feed inlet of preheater 3 is located on the side and connected to the discharge port of screening machine 2. A hot air inlet is located on the side of preheater 3 below its feed inlet. This structure facilitates the upward blowing of hot air onto the coal gangue particles, preheating them. The preheated gas from the coal gangue particles is then discharged through the exhaust port at the top of preheater 3.

[0027] like Figure 1As shown, the feed inlet of the high-temperature combustion furnace 4 is connected to the discharge outlet at the bottom of the preheater 3, and the air inlet of the high-temperature combustion furnace 4 is connected to the exhaust outlet at the top of the preheater 3 and the exhaust outlet at the top of the cooler 5. This structure facilitates the smooth entry of preheated coal gangue particles into the high-temperature combustion furnace 4, and the injection of gas into the high-temperature combustion furnace 4 effectively ensures complete combustion of the fuel. The cooler 5 has an exhaust outlet at its top, which facilitates the discharge of hot air generated from cooling the coal gangue particles into the high-temperature combustion furnace 4. The bottom of the cooler 5 has a discharge outlet, facilitating the discharge of cooled coal gangue particles into the grinding mill. The cooler 5 has a feed inlet on its side, which is connected to the discharge outlet of the high-temperature combustion furnace 4, facilitating the smooth entry of material discharged from the high-temperature combustion furnace 4 into the cooler 5. The cooler 5 has a cold air inlet located below the feed inlet on its side. This inlet effectively blows cold air onto the high-temperature coal gangue particles, thereby cooling them down. The heat exchanger 7 has a cold air inlet and a hot air outlet on its side, and the hot air outlet of the heat exchanger 7 is connected to the hot air inlet of the preheater 3, facilitating the recovery and utilization of heat from the flue gas of the high-temperature combustion furnace, thus achieving energy saving. The high-temperature combustion furnace 4 is a tubular rotary high-temperature furnace with a temperature control range of 500-900℃ and a calcination residence time of 2 hours. The dust collector 8 is a cyclone separator with a dust removal efficiency >85% and an outlet particulate matter emission concentration ≤20mg / m3. The grinding mill 6 is a ball mill with a feed particle size ≤15mm and an output particle size ≤1mm.

[0028] like Figure 1 As shown, the desulfurization unit 9 preferably uses wet flue gas desulfurization with a desulfurization efficiency of ≥90% and an outlet SO2 concentration controlled at 150mg / m3. The desulfurizing agent is lime water, NaOH solution, and ammonia water, etc. The denitrification unit 10 has a denitrification efficiency of ≥80% and an outlet nitrogen oxide concentration controlled at 150mg / m3.

[0029] Working principle: The original coal gangue is fed into crusher 1 for crushing, and then into screening machine 2 for screening. The coarse particles after screening are sent back to crusher 1 for further crushing. Then, the coal gangue powder with a uniform particle size distribution of ≤4mm after screening by screening machine 2 is sent into preheater 3 for preheating. The preheated coal gangue powder is sent into high-temperature combustion furnace 4 for high-temperature calcination. After calcination, the coal gangue powder is sent into cooler 5, and cold air is simultaneously introduced to contact the coal gangue powder in a countercurrent flow for cooling. The cooled solid powder is sent into grinder for further grinding to obtain a loose-textured active coal gangue-based sand soil conditioner. The cold air is converted into hot air after heat exchange with the calcined coal gangue powder through cooler 5, and then sent into high-temperature combustion furnace 4 for combustion assistance. The flue gas emitted after high-temperature calcination in the high-temperature combustion furnace 4 is sent into the tube side of the heat exchanger 7, while cold air is sent into the shell side of the heat exchanger 7 to exchange heat with the flue gas in a countercurrent flow. After heat exchange, the cold air is first sent into the preheater 3 to preheat the coal gangue powder, and then sent into the high-temperature combustion furnace 4 for combustion assistance. The cooled flue gas is first sent into the dust collector 8 to remove particulate matter, then sent into the desulfurization device 9 for desulfurization treatment, then sent into the denitrification device 10 for denitrification treatment, and finally the treated flue gas that meets the standards is discharged into the air.

[0030] In summary, compared with existing technologies, this application removes heavy metals from coal gangue through heat treatment, while reducing the risk of residual heavy metal leaching and minimizing secondary risks to the soil caused by the coal gangue soil conditioner during soil improvement. By controlling the combustion temperature of the high-temperature combustion furnace 4, the formation of nanoscale pores in the coal gangue powder is increased, enhancing its water and fertilizer retention capacity. When applied to sandy soil, this can correspondingly improve the soil's water and fertilizer retention capacity, achieving the purpose of soil improvement. Preheating the coal gangue powder with the cold air from the heat exchanger 7 before sending it into the high-temperature combustion furnace 4 for combustion, while simultaneously sending the hot air from the cooler 5 into the high-temperature combustion furnace 4 for combustion, reduces the energy consumption of the high-temperature combustion furnace 4, achieving energy saving.

[0031] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A preparation system for a coal gangue sand amendment, comprising a crusher (1), characterized in that, The discharge port of the crusher (1) is connected to a screening machine (2), the inlet of the screening machine (2) is connected to the discharge port of the crusher (1), and the fine material outlet of the screening machine (2) is connected to a preheater (3). The top and bottom outlets of the preheater (3) are connected to a high-temperature combustion furnace (4). The discharge port of the high-temperature combustion furnace (4) is connected to a cooler (5). The discharge port of the cooler (5) is connected to a grinding mill (6). The outlet of the grinding mill (6) is a coal gangue-based sand soil conditioner product. The exhaust port of the high-temperature combustion furnace (4) is connected to a heat exchanger (7). The tube inlet of the heat exchanger (7) is connected to the exhaust port of the high-temperature combustion furnace (4). The tube outlet of the heat exchanger (7) is connected to a dust collector (8). The exhaust end of the dust collector (8) is connected to a desulfurization device (9). The exhaust end of the desulfurization device (9) is connected to a denitrification device (10).

2. The preparation system for a coal gangue and sand amendment according to claim 1, characterized in that, The crusher (1) is a jaw crusher (1), and the coarse material outlet of the screening machine (2) is connected to the feed inlet of the crusher (1).

3. The preparation system for a coal gangue and sand amendment according to claim 1, characterized in that, The preheater (3) has an exhaust port at the top that discharges air containing coal ash and a discharge port at the bottom that discharges crushed coal ash powder. The feed port of the preheater (3) is located on the side and is connected to the discharge port of the screening machine (2). The side of the preheater (3) has a hot air inlet below its feed port.

4. The preparation system for a coal gangue and sand amendment according to claim 3, characterized in that, The feed inlet of the high-temperature combustion furnace (4) is connected to the discharge outlet at the bottom of the preheater (3), and the air inlet of the high-temperature combustion furnace (4) is connected to the exhaust outlet at the top of the preheater (3) and the exhaust outlet at the top of the cooler (5).

5. The preparation system for a coal gangue and sand amendment according to claim 1, characterized in that, The cooler (5) has an exhaust port at the top and a discharge port at the bottom. The cooler (5) has a feed port on its side and the feed port is connected to the discharge port of the high-temperature combustion furnace (4). The cooler (5) has a cold air inlet below the feed port on its side.

6. The preparation system for a coal gangue and sand amendment according to claim 3, characterized in that, The heat exchanger (7) has a cold air inlet and a hot air outlet on its side, and the hot air outlet of the heat exchanger (7) is connected to the hot air inlet of the preheater (3).

7. A preparation system for a coal gangue and sand amendment according to any one of claims 1-6, characterized in that, The high-temperature combustion furnace (4) is a tubular rotary high-temperature furnace, the dust collector (8) is a cyclone separator, and the grinding mill (6) is a ball mill.

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