Device for preparing cementing material by pyrolyzing and activating coal gangue at low temperature and use method of device

Abstract

The invention discloses a device for preparing a cementing material by pyrolyzing and activating coal gangue at low temperature and a using method thereof, and belongs to the field of coal gangue resource utilization and cementing material production equipment and processes. Comprising a pretreatment device, a pyrolysis activation device and a belt type sintering maintenance machine, the pretreatment device is communicated with the pyrolysis activation device, and the pyrolysis activation device is communicated with the belt type sintering maintenance machine. According to the technical scheme, the coal gangue is used as solid waste generated in the coal mining and washing process, and the annual discharge amount exceeds 0.5 billion tons. Long-term stockpiling not only occupies a large amount of land resources, but also easily causes environmental problems such as dust raising and leaching pollution. At present, coal gangue recycling ways mainly comprise preparation of building aggregate, use of the coal gangue as power generation fuel, preparation of a cementing material admixture through low-temperature pyrolysis activation and the like. Wherein although the added value can be increased by low-temperature pyrolysis activation preparation of the cementing material admixture, the existing equipment has a key technical bottleneck problem.

Description

Technical Field

[0001] This invention relates to an apparatus and method for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue, belonging to the field of coal gangue resource utilization and cementitious material production equipment and processes. Background Technology

[0002] Coal gangue, a solid waste generated during coal mining and washing, has an annual emission exceeding 500 million tons. Long-term stockpiling not only occupies significant land resources but also easily leads to environmental problems such as dust and leaching pollution. Currently, the main resource utilization pathways for coal gangue include preparing building aggregates, using it as fuel for power generation, and preparing cementitious material admixtures through low-temperature pyrolysis activation. While the preparation of cementitious material admixtures through low-temperature pyrolysis activation can increase added value, existing equipment faces key technological bottlenecks.

[0003] The curing process for cementitious materials (such as cement and lime-based cementitious materials) requires a stable temperature and humidity environment. In existing processes, the pyrolysis of coal gangue and the curing process of cementitious materials operate independently. The high-temperature exhaust gas generated by pyrolysis is directly emitted, wasting more than 50% of the waste heat, while curing requires additional fuel consumption for heating, creating an energy waste contradiction of "pyrolysis releasing heat - curing absorbing heat". At the same time, traditional rotary kiln pyrolysis of coal gangue requires periodic shutdowns to clean the materials adhering to the walls. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides an apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue and its usage method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an apparatus and method for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue, comprising: a pretreatment device, a pyrolysis activation device, and a belt sintering and curing machine, wherein the pretreatment device is connected to the pyrolysis activation device, and the pyrolysis activation device is connected to the belt sintering and curing machine.

[0006] The pretreatment device includes a jaw crusher, a screening unit, and a screw feeder. The jaw crusher is provided with a feed inlet and a discharge outlet. The discharge outlet is fixedly connected to the screening unit, and the screening unit is fixedly connected to the screw feeder.

[0007] The screening unit includes: a box body, a conical screening screen, a rotating shaft, a deflector plate, a drive motor, a baffle, round holes, a discharge port, and a discharge port. The conical screening screen is fixed inside the box body. The discharge port is fixedly connected to the box body. One end of the rotating shaft is rotatably connected to the conical screening screen through a shaft bracket. The other end of the rotating shaft rotatably passes through the box body. Multiple deflector plates are symmetrically fixed on the rotating shaft. The drive motor is fixed on the side of the box body. The output shaft of the drive motor is fixedly connected to the other end of the rotating shaft. The baffle is fixed on the rotating shaft. Multiple round holes are evenly distributed on the baffle. The discharge port is located on the side of the box body. The size of the discharge port matches the round holes. The discharge port is located at the lower end of the box body.

[0008] The spiral feeding unit includes: a feeding hopper, a second drive motor, a second rotating shaft, and spiral blades. The outer wall of the jaw crusher is fixedly connected to the feeding hopper. The second drive motor is fixedly mounted on the top surface of the feeding hopper. One end of the second rotating shaft is rotatably connected to the bottom surface of the inner wall of the feeding hopper. The other end of the second rotating shaft rotatably passes through the top surface of the feeding hopper and is fixedly connected to the output shaft of the second drive motor. Spiral blades are fixedly mounted on the second rotating shaft. The second discharge port is fixedly connected to the lower end of the feeding hopper. The upper end of the feeding hopper is provided with a fourth discharge port, which is located above the first inlet.

[0009] The pyrolysis activation device includes: a support plate, a support platform unit, a third drive motor, gears, a conveying unit, a heating unit, a circulation unit, a cleaning unit, and a rotary unit. Multiple support platform units are fixed to the upper end of the support plate. Each support platform unit includes a base and guide wheels, with the guide wheels symmetrically rotatably connected to the base. The base is fixed to the upper end of the support plate. A third drive motor is fixed to the upper end of the support plate, and gears are fixed to the output shaft of the third drive motor. A conveying unit is fixed to the support plate. The conveying unit includes: a conveying cover, an annular groove, a conveying pipe, and a limiting pin. An opening is provided on one side of the conveying cover, and an annular groove is provided on one side end face of the conveying cover. A conveying pipe is provided inside the conveying cover. The third discharge port is fixedly connected to one end of the conveying pipe. The limiting pin slides through the conveying cover and is positioned within the annular groove. The heating unit is fixed... The heating unit, which passes through the conveying hood and is located inside the conveying pipe, includes a fixed pipe, a fuel pipe, and a ventilation pipe. The fixed pipe passes through the conveying hood and is located inside the conveying pipe. The fixed pipe contains the fuel pipe and the ventilation pipe. The circulation unit includes a circulation hood, a collection pipe, and an exhaust pipe. The circulation hood is fixed on the support plate. The circulation hood is sized to match the conveying hood and is symmetrically arranged. The exhaust pipe is located inside the circulation hood. One side of the circulation hood has an opening, and one side end of the circulation hood has an annular groove. One end of the exhaust pipe passes through the other side of the circulation hood. The upper end of the circulation hood has an exhaust pipe, and the exhaust pipe passes through the circulation hood. The cleaning unit passes through the exhaust pipe and is located inside the rotary unit. The rotary unit is slidably and sealingly connected to the conveying hood and the circulation hood. The exhaust pipe is fixedly connected to the air inlet pipe of the belt sintering curing machine.

[0010] The cleaning unit includes: a drive motor four, a rotating shaft three, a scraper, a support plate and sliding beads. The drive motor four is fixed to the outer wall of the collection tube. One end of the rotating shaft three is fixedly connected to the output shaft of the drive motor four. A scraper is fixed on the rotating shaft three. The scraper is inclined and spirally arranged. A support plate is fixed to the other end of the rotating shaft three. Multiple sliding beads are evenly distributed and rotatably connected to the periphery of the support plate.

[0011] The rotating unit includes a rotating tube, a gear ring, an insulation layer, an inner tube, and a raised edge. The gear ring is fixed to the outer wall of the rotating tube and meshes with a gear. An insulation layer is fixed between the rotating tube and the inner tube. Raised edges are provided on both end faces of the rotating tube. Limiting annular grooves are provided on the outer surfaces of the raised edges. The two raised edges slide in the annular grooves of the conveying cover and the circulation cover, respectively. Limiting pins are provided in the limiting annular grooves. The rotating tube rests against the guide wheel. One end of the inner tube slides against the conveying tube, and the other end of the inner tube rests against the collecting tube. A sliding bead slides against the inner wall of the inner tube.

[0012] The insulation layer is made of aluminum plate with a honeycomb structure.

[0013] A method for using an apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue, the method comprising the following steps:

[0014] S1: The coal gangue is fed into the jaw crusher through the feed inlet for crushing.

[0015] S2: Powering on the drive motor allows for the screening of the crushed coal gangue;

[0016] S3: Ignite the fuel gas sprayed from the fuel pipe to perform low-temperature pyrolysis activation on the coal gangue, and energize the drive motor to drive the rotary tube to rotate, causing the coal gangue inside to rotate and disperse.

[0017] S4: Power on the belt sintering and curing machine to carry out subsequent calcination operations.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention addresses the background problem: coal gangue, a solid waste generated during coal mining and washing, has an annual emission exceeding 500 million tons. Long-term stockpiling not only occupies significant land resources but also easily leads to environmental problems such as dust and leaching pollution. Currently, the main resource utilization methods for coal gangue include preparing building aggregates, using it as fuel for power generation, and preparing cementitious material admixtures through low-temperature pyrolysis activation. While low-temperature pyrolysis activation for preparing cementitious material admixtures can increase added value, existing equipment faces key technological bottlenecks.

[0020] Furthermore, the curing process for cementitious materials (such as cement and lime-based cementitious materials) requires a stable temperature and humidity environment. In the existing process, the pyrolysis of coal gangue and the curing process of cementitious materials operate independently. The high-temperature exhaust gas generated by pyrolysis is directly emitted, wasting more than 50% of the waste heat, while curing requires additional fuel consumption for heating, creating an energy waste contradiction of "heat release during pyrolysis and heat absorption during curing". At the same time, traditional rotary kiln pyrolysis of coal gangue requires periodic shutdowns to clean the materials adhering to the walls. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the screening unit structure;

[0023] Figure 3 This is a front view of the baffle;

[0024] Figure 4 This is a schematic diagram of the pyrolysis activation device;

[0025] Figure 5 This is the front view of the support platform unit;

[0026] Figure 6 This is a schematic diagram of the conveying unit and heating unit.

[0027] Figure 7 This is a schematic diagram of the limit pin structure;

[0028] Figure 8 This is a front view of the conveyor unit;

[0029] Figure 9 This is a schematic diagram of a cyclic unit structure;

[0030] Figure 10 This is a schematic diagram of the cleaning unit structure;

[0031] Figure 11 This is a top view of the cleanup unit;

[0032] Figure 12 This is a schematic diagram of the rotary unit structure;

[0033] Figure 13 This is a schematic diagram of the convex edge structure. Detailed Implementation

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

[0035] A device for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue and its usage method are disclosed, comprising: a pretreatment device 1, a pyrolysis activation device 2, and a belt sintering and curing machine 3, wherein the pretreatment device 1 is connected to the pyrolysis activation device 2, and the pyrolysis activation device 2 is connected to the belt sintering and curing machine 3.

[0036] The pretreatment device 1 includes: a jaw crusher 1-1, a screening unit 1-2 and a screw feeder 1-3. The jaw crusher 1-1 is provided with a feed inlet and a discharge outlet. The discharge outlet is fixedly connected to the screening unit 1-2. The screening unit 1-2 is fixedly connected to the screw feeder 1-3.

[0037] The screening unit 1-2 includes: a housing 1-2-1, a conical screening screen 1-2-2, a rotating shaft 1-2-3, a toggle plate 1-2-4, a drive motor 1-2-5, a baffle plate 1-2-6, a round hole 1-2-7, a discharge port 1-2-8, and a discharge port 1-2-9. The conical screening screen 1-2-2 is fixed inside the housing 1-2-1. The discharge port 1-2-8 is fixedly connected to the housing 1-2-1. One end of the rotating shaft 1-2-3 is rotatably connected to the conical screening screen 1-2-2 via a shaft bracket. The other end of the rotating shaft 1-2-3 rotatably extends out of the housing 1-2-1. Multiple actuating plates 1-2-4 are symmetrically fixed on 2-3. A drive motor 1-2-5 is fixed on one side of the housing 1-2-1. The output shaft of the drive motor 1-2-5 is fixedly connected to the other end of the rotating shaft 1-2-3. A baffle 1-2-6 is fixed on the rotating shaft 1-2-3. Multiple round holes 1-2-7 are evenly distributed on the baffle 1-2-6. A discharge port 2 1-2-8 is provided on one side of the housing 1-2-1. The size of the discharge port 2 1-2-8 matches that of the round holes 1-2-7. A discharge port 3 1-2-9 is provided at the lower end of the housing 1-2-1.

[0038] The spiral feeding unit 1-3 includes: a feeding hopper 1-3-1, a second drive motor 1-3-2, a second rotating shaft 1-3-3, and spiral blades 1-3-4. The outer wall of the jaw crusher 1-1 is fixedly connected to the feeding hopper 1-3-1. The second drive motor 1-3-2 is fixedly mounted on the top surface of the feeding hopper 1-3-1. One end of the second rotating shaft 1-3-3 is rotatably connected to the inner bottom surface of the feeding hopper 1-3-1. The other end of the second rotating shaft 1-3-3 rotatably passes through the top surface of the feeding hopper 1-3-1 and is fixedly connected to the output shaft of the second drive motor 1-3-2. Spiral blades 1-3-4 are fixedly mounted on the second rotating shaft 1-3-3. The second discharge port 1-2-8 is fixedly connected to the lower end of the feeding hopper 1-3-1. The upper end of the feeding hopper 1-3-1 is provided with a fourth discharge port, which is located above the first inlet.

[0039] The pyrolysis activation device 2 includes: a support plate 2-1, a support platform unit 2-2, a drive motor 2-3, a gear 2-4, a conveying unit 2-5, a heating unit 2-6, a circulation unit 2-7, a cleaning unit 2-8, and a rotation unit 2-9. Multiple support platform units 2-2 are fixed to the upper end of the support plate 2-1. Each support platform unit 2-2 includes: a base 2-2-1 and guide wheels 2-2-2. The guide wheels 2-2-2 are symmetrically rotatably connected to the base 2-2-1. The base 2-2-1 is fixed to the upper end of the support plate 2-1, and the drive motor 2-3 is fixed to the upper end of the support plate 2-1. A gear 2-4 is fixed to the output shaft of the drive motor 2-3. Gear 2-4; a conveying unit 2-5 is fixed on the support plate 2-1; the conveying unit 2-5 includes: a conveying cover 2-5-1, an annular groove 2-5-2, a conveying pipe 2-5-3, and a limiting pin 2-5-4; the conveying cover 2-5-1 has an opening on one side; the annular groove 2-5-2 is provided on one side end face of the conveying cover 2-5-1; the conveying pipe 2-5-3 is arranged inside the conveying cover 2-5-1; the discharge port 1-2-9 is fixedly connected to one end of the conveying pipe 2-5-3; the limiting pin 2-5-4 slides through the conveying cover 2-5-1 and is arranged in the annular groove 2-5-2; the heating unit 2-6 is fixedly passed through the conveying cover 2-5-1. The heating unit 2-6 includes a fixed pipe 2-6-1, a fuel pipe 2-6-2, and a ventilation pipe 2-6-3, and is installed inside the conveying hood 2-5-1. The fixed pipe 2-6-1 passes through the conveying hood 2-5-1 and is installed inside the conveying pipe 2-5-3. The fuel pipe 2-6-2 and the ventilation pipe 2-6-3 are installed inside the fixed pipe 2-6-1. The circulation unit 2-7 includes a circulation hood 2-7-1, a collection pipe 2-7-2, and an exhaust pipe 2-7-3. The circulation hood 2-7-1 is fixed on the support plate 2-1. The circulation hood 2-7-1 is sized to match the conveying hood 2-5-1 and is symmetrically arranged. The circulation hood 2-7-1 is equipped with... The exhaust pipe 2-7-3 has an opening on one side of the circulation cover 2-7-1, and an annular groove 2-5-2 on one side end face of the circulation cover 2-7-1. One end of the exhaust pipe 2-7-3 is fixedly passed through the other side of the circulation cover 2-7-1. The exhaust pipe 2-7-3 is provided at the upper end of the circulation cover 2-7-1 and is fixedly extended out of the circulation cover 2-7-1. The cleaning unit 2-8 is fixedly passed through the exhaust pipe 2-7-3 and is set inside the rotary unit 2-9. The rotary unit 2-9 is slidably and sealingly connected to the conveyor cover 2-5-1 and the circulation cover 2-7-1. The exhaust pipe 2-7-3 is fixedly connected to the air inlet pipe of the belt sintering curing machine 3.

[0040] The limiting pins 2-5-4 are equipped with ball bearings on all sides to reduce friction.

[0041] The cleaning unit 2-8 includes: a drive motor 2-8-1, a rotating shaft 2-8-2, a scraper 2-8-3, a support plate 2-8-4, and sliding beads 2-8-5. The drive motor 2-8-1 is fixed to the outer wall of the collection tube 2-7-2. One end of the rotating shaft 2-8-2 is fixedly connected to the output shaft of the drive motor 2-8-1. The scraper 2-8-3 is fixed on the rotating shaft 2-8-2 and is arranged in an inclined spiral. The other end of the rotating shaft 2-8-2 is fixed to the support plate 2-8-4. Multiple sliding beads 2-8-5 are evenly distributed and rotatably connected to the periphery of the support plate 2-8-4.

[0042] The rotating unit 2-9 includes: a rotating tube 2-9-1, a gear ring 2-9-2, a heat insulation layer 2-9-3, an inner tube 2-9-4, and a flange 2-9-5. The gear ring 2-9-2 is fixed to the outer wall of the rotating tube 2-9-1, and the gear ring 2-9-2 meshes with the gear 2-4. The heat insulation layer 2-9-3 is fixed between the rotating tube 2-9-1 and the inner tube 2-9-4. A flange 2-9-5 is provided on both end faces of the rotating tube 2-9-1, and a limiting annular groove is provided on the outer side of the flange 2-9-5. The two protruding edges 2-9-5 slide in the annular groove 2-5-2 of the conveying cover 2-5-1 and the annular groove 2-5-2 of the circulation cover 2-7-1, respectively. The limiting pin 2-5-4 is set in the limiting annular groove. The rotary tube 2-9-1 abuts against the guide wheel 2-2-2. One end of the inner tube 2-9-4 slides against the conveying tube 2-5-3, and the other end of the inner tube 2-9-4 abuts against the collecting tube 2-7-2. The sliding ball 2-8-5 slides against the inner wall of the inner tube 2-9-4.

[0043] The insulation layer 2-9-3 is a honeycomb structure made of aluminum plate.

[0044] A method for using an apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue, the method comprising the following steps:

[0045] S1: Coal gangue is fed into jaw crusher 1-1 through the feed inlet for crushing.

[0046] S2: Power on drive motor 1-2-5 to screen the crushed coal gangue;

[0047] S3: Ignite the fuel gas ejected from fuel pipe 2-6-2 to perform low-temperature pyrolysis activation on the coal gangue, and energize drive motor 2-3 to drive the rotary tube 2-9-1 to rotate, causing the coal gangue inside to rotate and disperse.

[0048] S4: Power on the belt sintering and curing machine 3 to carry out subsequent calcination operations.

[0049] The working principle is as follows:

[0050] Jaw crusher 1-1 and belt sintering curing machine 3 are both existing technologies and are purchased externally, so they will not be discussed further.

[0051] During operation, coal gangue is fed into the jaw crusher 1-1 through the feed inlet. The jaw crusher 1-1 is connected to an external power source. Powering on the jaw crusher 1-1 crushes the coal gangue. The crushed coal gangue then enters the conical screen 1-2-2 through the discharge outlet. Powering on the drive motor 1-2-5 drives the actuating plate 1-2-4 to rotate via the rotating shaft 1-2-3. The rotating actuating plate 1-2-4 actuates the coal gangue within the conical screen 1-2-2, causing coal gangue of the correct particle size to fall through the screen into the housing 1-2-1 and slide out through the discharge outlet 1-2-9. Simultaneously, coal gangue that does not meet the required size slides out through the discharge outlet 1-2-8 into the feeding bucket 1-3-1. The baffle 1-2-6 serves to block the flow of coal gangue. The function is to increase the retention time of coal gangue in the conical screen 1-2-2, and to prevent coal gangue of the correct size from being directly discharged through the discharge port 1-2-8. When the rotating shaft 1-2-3 drives the baffle 1-2-6 to rotate so that the round hole 1-2-7 coincides with the discharge port 1-2-8, the coal gangue of the incorrect size slides out. When the round hole 1-2-7 is misaligned with the discharge port 1-2-8, the coal gangue no longer slides out. The speed of the drive motor 1-2-5 is controlled to be 0.1 rpm, and the drive motor 2-3-2 is powered on. Through the rotating shaft 2-3-3, the spiral blade 1-3-4 is driven to rotate, which drives the coal gangue of the incorrect size in the feeding bucket 1-3-1 to move upward and slide out through the discharge port 4 and fall into the feed port 1 to re-enter the jaw crusher 1-1 for crushing.

[0052] The coal gangue sliding out of outlet 1-2-9 enters the conveying pipe 2-5-3, and then from the conveying pipe 2-5-3 into the inner pipe 2-9-4. Fuel gas is fixedly connected to fuel pipe 2-6-2 via a pipeline, and ventilation pipe 2-6-3 is connected to a blower. The fuel gas ejected from fuel pipe 2-6-2 is ignited to preheat and perform low-temperature pyrolysis activation on the coal gangue in inner pipe 2-9-4, removing moisture and decomposing organic matter and activating active components. Ventilation pipe 2-6-3 ventilates inner pipe 2-9-4, ensuring more complete combustion. Base 2-2-1 and guide wheel 2-2-2 support rotating pipe 2-9-1. Meanwhile, the guide wheel 2-2-2 reduces the friction when the rotary tube 2-9-1 rotates. The rotary tube 2-9-1 is tilted at 10°, energizing the drive motor 2-3, which in turn drives the gear ring 2-9-2 to rotate via gear 2-4. This, in turn, drives the rotary tube 2-9-1 to rotate. The rotation of the rotary tube 2-9-1 causes the coal gangue inside to rotate, allowing the coal gangue in the inner tube 2-9-4 to be dispersed and fully heated. Simultaneously, the coal gangue slides along the tilted rotary tube 2-9-1, is collected by the collection pipe 2-7-2, and then slides out. The convex edge 2-9-5 slides within the annular groove 2-5-2 and is limited by the limiting pin 2-5-4, thus achieving rotation. Pipe 2-9-1 rotates independently. When maintenance is required on the rotating pipe 2-9-1, the limit pin 2-5-4 is removed. This allows the rotating pipe 2-9-1 to be separated from the conveyor hood 2-5-1 and the circulation hood 2-7-1 for easy maintenance. The high-temperature exhaust gas inside the inner pipe 2-9-4 is discharged through the exhaust pipe 2-7-3 and enters the inlet pipe of the belt sintering curing machine 3, achieving energy recycling. The insulation layer 2-9-3 is made of aluminum plate with a honeycomb structure, which can insulate the inner pipe 2-9-4 and prevent heat loss from increasing fuel consumption. The drive motor 2-8-1 drives the scraper 2-8-3 to rotate through the rotating shaft 2-8-2. When plate 2-8-3 rotates, it can clean the inner wall of inner tube 2-9-4, preventing material from sticking to the wall; when rotating shaft 3 2-8-2 rotates, it drives the support plate 2-8-4 to rotate, and the sliding ball 2-8-5 reduces the friction between the support plate 2-8-4 and inner tube 2-9-4. The support plate 2-8-4 and the sliding ball 2-8-5 are set to support the rotating shaft 3 2-8-2. At the same time, the sliding ball 2-8-5 is set to create a gap between the support plate 2-8-4 and inner tube 2-9-4 to facilitate the movement of coal gangue; the inclined spiral of scraper 2-8-3 can push the coal gangue to move while cleaning the inner tube 2-9-4, preventing coal gangue from accumulating.

[0053] The coal gangue that slides out of the collection pipe 2-7-2 is collected and mixed with the purchased cement clinker, gypsum and water. The mixture is then poured into test blocks, placed on the conveyor belt of the belt sintering and curing machine 3, and the belt sintering and curing machine 3 is powered on for subsequent calcination operations.

[0054] Jaw crusher 1-1 has a processing capacity of 50t / h, with a crushing particle size ≤20mm. Conical screen 1-2-2 has a screen aperture of 5-20mm and a screening efficiency ≥95%. Screw feeder unit 1-3 has a conveying capacity of 10-20t / h, adjustable via frequency conversion. Rotary unit 2-9 has a length of 15-20m, a diameter of 1.2-1.5m, and a rotation speed of 1-3r / min. Inner tube 2-9-4 has a 50mm thick alumina wear-resistant coating on its inner wall. The internal temperature gradient of rotary unit 2-9 is as follows: preheating section temperature 200-300℃, equipped with an electromagnetic induction heating module (50-80kW); pyrolysis section temperature 400-500℃, using a gas heating module (100-150kW heat load); cooling section temperature 200-250℃; and heat exchange tube assembly with a heat exchange area of ​​20-30㎡.

[0055] The belt sintering and curing machine has a belt width of 1.5-2m and a length of 25-30m. The conveyor belt is made of 316 stainless steel mesh with a mesh diameter of 5mm. Along its length, it is divided into three sections: a heating section (80-100℃, equipped with an infrared heating plate, power 30-50kW), a constant temperature curing section (100-120℃, using a steam heating chamber, humidity 80-90%), and a cooling section (50-60℃, equipped with an air-cooling module). The entire machine is sealed under negative pressure with a negative pressure value of -20 to -50Pa. A material recovery trough with a 10° inclination angle is located below the mesh belt, and it features a screw conveyor function.

[0056] The overall control system of the device adopts a PLC controller model S7-1200, equipped with a temperature sensor with a temperature measurement range of 0-600℃ and an accuracy of ±2℃, a pressure sensor with a range of -100 to 100Pa, and a flow sensor with a measurement range of 0-500m³ / h, so as to realize the linkage control of parameters of each unit.

[0057] Production process:

[0058] Coal gangue with a particle size ≤50mm is fed into jaw crusher 1-1 and crushed to ≤20mm. After being screened by conical screen 1-2-2, 5-20mm particles are removed. The coal gangue then enters the inner tube 2-9-4. The rotary tube 2-9-1 rotates at a speed of 1-3r / min. In the preheating section at 200-300℃ for 20-30min, the coal gangue removes moisture. In the pyrolysis section at 400-500℃ for 40-60min, the organic matter is decomposed and the active components are activated, resulting in activated coal gangue powder with a particle size ≤5mm and an activity index ≥85%. Mix 30-50 parts of activated coal gangue, 40-60 parts of cement clinker, and 5-10 parts of gypsum evenly, add water at a water-cement ratio of 0.4-0.45 and stir to form a slurry. Pour the slurry into test blocks of 100×100×100mm and send them to the conveyor belt of belt sintering and curing machine 3. The test blocks are conveyed at a speed of 0.5-1m / min through the heating section at 80-100℃ for 30-40min at a heating rate of 5℃ / min, the constant temperature curing section at 100-120℃ for 80-120min at a humidity of 80-90%, and the cooling section at 50-60℃ for 20-30min. The resulting cementitious material test block has a 28-day compressive strength ≥42.5MPa. The tail gas generated by the pyrolysis of the inner tube 2-9-4 has a temperature of 300-400℃ and a flow rate of 200-300m³ / h, which supplements the heat source of the heating section 3 of the belt sintering curing machine.

[0059] Example 1:

[0060] A production process for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue includes the following steps:

[0061] S1: Equipment parameters: Rotary tube 2-9-1: length 18m, diameter 1.4m, rotation speed 2r / min; Belt sintering and curing machine 3: width 1.8m, length 28m, mesh belt speed 0.8m / min; Fluidized bed: diameter 0.9m, height 3.5m.

[0062] S2: Process parameters: Coal gangue preheated to 120℃; Inner tube 2-9-4 preheating section 250℃ / 25min, pyrolysis section 450℃ / 50min, cooling section 220℃ / 18min; 40 parts activated coal gangue powder, 50 parts cement clinker, 10 parts gypsum, water-cement ratio 0.42; Belt sintering curing machine 3 heating section 90℃ / 35min, constant temperature section 110℃ / 100min, cooling section 55℃ / 25min.

[0063] S3: Results: Activated coal gangue activity index 88%, cementitious material compressive strength 45.2 MPa after 28 days, unit energy consumption 420 kWh / t, treatment efficiency 90 t / d, and exhaust gas temperature 75℃.

[0064] Example 2:

[0065] S1: Equipment parameters: Rotary tube 2-9-1: length 15m, diameter 1.2m, rotation speed 1.5r / min; Belt sintering and curing machine 3: width 1.5m, length 25m, mesh belt speed 0.6m / min; Fluidized bed: diameter 0.8m, height 3m.

[0066] S2: Process parameters: Coal gangue preheated to 100℃; inner tube 2-9-4 preheating section 200℃ / 20min, pyrolysis section 400℃ / 40min, cooling section 200℃ / 15min; activated coal gangue powder 30 parts, cement clinker 60 parts, gypsum 10 parts, water-cement ratio 0.4.

[0067] S3: Results: Activated coal gangue activity index 85%, cementitious material compressive strength 43.8 MPa after 28 days, unit energy consumption 400 kWh / t, treatment efficiency 80 t / d, and exhaust gas temperature 70℃.

[0068] Example 3:

[0069] S1: Equipment parameters: Rotary tube 2-9-1: length 20m, diameter 1.5m, rotation speed 3r / min; Belt sintering and curing machine 3: width 2m, length 30m, mesh belt speed 1m / min; Fluidized bed: diameter 1m, height 4m.

[0070] S2: Process parameters: Coal gangue preheated to 150℃; inner tube 2-9-4 preheating section 300℃ / 30min, pyrolysis section 500℃ / 60min, cooling section 250℃ / 20min; 50 parts activated coal gangue powder, 40 parts cement clinker, 10 parts gypsum, water-cement ratio 0.45.

[0071] S3: Results: Activated coal gangue activity index 90%, cementitious material 28d compressive strength 46.5MPa, unit energy consumption 480kWh / t, treatment efficiency 100t / d, tail gas emission temperature 80℃.

[0072] Comparative Example 1:

[0073] S1. Equipment: Ordinary rotary kiln (no segmented heating, thermal efficiency 50%) + static curing kiln (intermittent, curing 100 test blocks each time).

[0074] S2. Process: Direct pyrolysis of coal gangue (450℃ / 60min, no preheating), static curing of cementitious materials (110℃ / 120min, heated separately by natural gas).

[0075] S3. Results: The activation index of activated coal gangue was 80%, the compressive strength of cementitious material after 28 days was 40.2 MPa, the unit energy consumption was 920 kWh / t, the treatment efficiency was 35 t / d, and the exhaust gas temperature was 350℃.

[0076] Comparative Example 2:

[0077] S1. Device: Same as in Example 1, but exhaust gas is emitted directly.

[0078] S2. Process: Same as Example 1, but the coal gangue is not preheated, and the heating section of the belt conveyor is heated separately by electricity.

[0079] S3. Results: The activation index of activated coal gangue was 88%, the compressive strength of cementitious material after 28 days was 45.0 MPa, the unit energy consumption was 680 kWh / t, the treatment efficiency was 90 t / d, and the exhaust gas temperature was 380℃.

[0080] The experimental results show that:

[0081] The embodiments of this invention, through integrated device and exhaust gas recirculation, reduce unit energy consumption by 54%-56% compared to the traditional process (Comparative Example 1), increase processing efficiency by 1.3-1.9 times, and reduce carbon emissions by 35%-40%. Compared to the scheme without exhaust gas utilization (Comparative Example 2), the energy consumption of this invention is reduced by 38%-41%, proving that exhaust gas recirculation is the core energy-saving point. The activation index of activated coal gangue and the strength of cementitious materials are both better than those of the traditional process, indicating that continuous temperature control does not affect product performance, but rather improves performance indicators due to process stability.

[0082] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0083] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue, characterized in that: include: The pretreatment device (1), the pyrolysis activation device (2), and the belt sintering curing machine (3) are connected together. The pretreatment device (1) is connected to the pyrolysis activation device (2), and the pyrolysis activation device (2) is connected to the belt sintering curing machine (3).

2. The apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue according to claim 1, characterized in that: The pretreatment device (1) includes: a jaw crusher (1-1), a screening unit (1-2) and a screw feeder (1-3). The jaw crusher (1-1) is provided with a feed inlet and a discharge outlet. The discharge outlet is fixedly connected to the screening unit (1-2), and the screening unit (1-2) is fixedly connected to the screw feeder (1-3).

3. The apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue according to claim 2, characterized in that: The screening unit (1-2) includes: a box body (1-2-1), a conical screening screen (1-2-2), a rotating shaft (1-2-3), a toggle plate (1-2-4), a drive motor (1-2-5), a baffle (1-2-6), a round hole (1-2-7), a discharge port (1-2-8), and a discharge port (1-2-9). The conical screening screen (1-2-2) is fixed inside the box body (1-2-1). The discharge port is fixedly connected to the box body (1-2-1). One end of the rotating shaft (1-2-3) is rotatably connected to the conical screening screen (1-2-2) through a shaft bracket. The other end of the rotating shaft (1-2-3) rotatably passes through the box body (1-2-1). Multiple actuating plates (1-2-4) are symmetrically fixed on the box body (1-2-1). A drive motor (1-2-5) is fixed on one side of the box body (1-2-1). The output shaft of the drive motor (1-2-5) is fixedly connected to the other end of the rotating shaft (1-2-3). A baffle (1-2-6) is fixed on the rotating shaft (1-2-3). Multiple round holes (1-2-7) are evenly distributed on the baffle (1-2-6). A discharge port (1-2-8) is provided on one side of the box body (1-2-1). The size of the discharge port (1-2-8) matches that of the round holes (1-2-7). A discharge port (1-2-9) is provided at the lower end of the box body (1-2-1).

4. The apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue according to claim 3, characterized in that: The spiral feeding unit (1-3) includes: a feeding hopper (1-3-1), a second drive motor (1-3-2), a second rotating shaft (1-3-3), and spiral blades (1-3-4). The outer wall of the jaw crusher (1-1) is fixedly connected to the feeding hopper (1-3-1). The second drive motor (1-3-2) is fixed on the top surface of the feeding hopper (1-3-1). One end of the second rotating shaft (1-3-3) is connected to the inner bottom surface of the feeding hopper (1-3-1). The rotating shaft (1-3-3) is connected to the top surface of the feeding barrel (1-3-1) at the other end, and is fixedly connected to the output shaft of the drive motor (1-3-2). A spiral blade (1-3-4) is fixed on the rotating shaft (1-3-3). The discharge port (1-2-8) is fixedly connected to the lower end of the feeding barrel (1-3-1). The upper end of the feeding barrel (1-3-1) is provided with a discharge port (4), which is located above the inlet port (1).

5. The apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue according to claim 3, characterized in that: The pyrolysis activation device (2) includes: a support plate (2-1), a support platform unit (2-2), a drive motor (2-3), a gear (2-4), a conveying unit (2-5), a heating unit (2-6), a circulation unit (2-7), a cleaning unit (2-8), and a rotation unit (2-9). Multiple support platform units (2-2) are fixed to the upper end of the support plate (2-1). Each support platform unit (2-2) includes: a base (2-2-1) and guide wheels (2-2-2). The guide wheels (2-2-2) are symmetrically rotatably connected to the base (2-2-1). The base (2-2-1) is fixed to the upper end of the support plate (2-1), and the drive motor (2-3) is fixed to the upper end of the support plate (2-1). The drive motor (2-3) has a gear (2-4) fixed on its output shaft. A conveying unit (2-5) is fixed on the support plate (2-1). The conveying unit (2-5) includes a conveying cover (2-5-1), an annular groove (2-5-2), a conveying pipe (2-5-3), and a limiting pin (2-5-4). The conveying cover (2-5-1) has an opening on one side, and an annular groove (2-5-2) is provided on one side end face of the conveying cover (2-5-1). The conveying pipe (2-5-3) is installed inside the conveying cover (2-5-1). The discharge port (1-2-9) is fixedly connected to one end of the conveying pipe (2-5-3). The limiting pin (2-5-4) slides through the conveying cover (2-5-1) and is provided with... The heating unit (2-6) is fixedly placed inside the annular groove (2-5-2), passing through the conveying cover (2-5-1) and located inside the conveying pipe (2-5-3). The heating unit (2-6) includes a fixed pipe (2-6-1), a fuel pipe (2-6-2), and a ventilation pipe (2-6-3). The fixed pipe (2-6-1) passes through the conveying cover (2-5-1) and is located inside the conveying pipe (2-5-3). The fuel pipe (2-6-2) and the ventilation pipe (2-6-3) are arranged inside the fixed pipe (2-6-1). The circulation unit (2-7) includes a circulation cover (2-7-1), a collection pipe (2-7-2), and an exhaust pipe (2-7-3). The circulation cover is fixed on the support plate (2-1). (2-7-1) The circulation hood (2-7-1) and the conveying hood (2-5-1) are matched in size and arranged symmetrically. An exhaust pipe (2-7-3) is provided inside the circulation hood (2-7-1). An opening is provided on one side of the circulation hood (2-7-1). An annular groove (2-5-2) is provided on one end face of the circulation hood (2-7-1). One end of the exhaust pipe (2-7-3) is fixedly passed through the other side of the circulation hood (2-7-1). An exhaust pipe (2-7-3) is provided at the upper end of the circulation hood (2-7-1). The exhaust pipe (2-7-3) is fixedly passed out of the circulation hood (2-7-1). The cleaning unit (2-8) is fixedly passed through the exhaust pipe (2-7-3) and is set inside the rotary unit (2-9).The rotary unit (2-9) is slidably and sealedly connected to the conveyor hood (2-5-1) and the circulation hood (2-7-1), and the exhaust pipe (2-7-3) is fixedly connected to the air inlet pipe of the belt sintering curing machine (3).

6. The apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue according to claim 5, characterized in that: The cleaning unit (2-8) includes: a drive motor (2-8-1), a rotating shaft (2-8-2), a scraper (2-8-3), a support plate (2-8-4), and sliding beads (2-8-5). The drive motor (2-8-1) is fixed to the outer wall of the collection tube (2-7-2). One end of the rotating shaft (2-8-2) is fixedly connected to the output shaft of the drive motor (2-8-1). The scraper (2-8-3) is fixed on the rotating shaft (2-8-2). The scraper (2-8-3) is arranged in an inclined spiral. The other end of the rotating shaft (2-8-2) is fixed to the support plate (2-8-4). Multiple sliding beads (2-8-5) are evenly distributed and rotatably connected to the periphery of the support plate (2-8-4).

7. The apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue according to claim 6, characterized in that: The rotating unit (2-9) includes: a rotating tube (2-9-1), a gear ring (2-9-2), a heat insulation layer (2-9-3), an inner tube (2-9-4), and a flange (2-9-5). The gear ring (2-9-2) is fixed to the outer wall of the rotating tube (2-9-1), and the gear ring (2-9-2) meshes with the gear (2-4). The heat insulation layer (2-9-3) is fixed between the rotating tube (2-9-1) and the inner tube (2-9-4). A flange (2-9-5) is provided on both end faces of the rotating tube (2-9-1), and a limit is provided on the outer side of the flange (2-9-5). The two protruding edges (2-9-5) slide in the annular groove (2-5-2) of the conveying cover (2-5-1) and the annular groove (2-5-2) of the circulation cover (2-7-1). The limiting pin (2-5-4) is set in the limiting annular groove. The rotary tube (2-9-1) abuts against the guide wheel (2-2-2). One end of the inner tube (2-9-4) slides against the conveying tube (2-5-3), and the other end of the inner tube (2-9-4) abuts against the collecting tube (2-7-2). The sliding ball (2-8-5) slides against the inner wall of the inner tube (2-9-4).

8. The apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue according to claim 7, characterized in that: The insulation layer (2-9-3) is a honeycomb structure made of aluminum plate.

9. The method of using the apparatus for preparing cementitious materials by low-temperature pyrolysis activation of coal gangue according to claim 8, characterized in that: The method includes the following steps: S1: The coal gangue is fed into the jaw crusher (1-1) through the feed inlet for crushing; S2: Power on drive motor one (1-2-5) to screen the crushed coal gangue; S3: Ignite the fuel gas ejected from the fuel pipe (2-6-2) to perform low-temperature pyrolysis activation on the coal gangue, and energize the drive motor three (2-3) to drive the rotary tube (2-9-1) to rotate, causing the coal gangue inside to rotate and disperse. S4: Power on the belt sintering curing machine (3) to carry out subsequent calcination operations.

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