Ecological nutrient soil preparation process based on coal-based solid waste

Abstract

The invention belongs to the field of coal gangue ecological soil preparation, and particularly relates to an ecological nutrient soil preparation technology based on coal-based solid waste. A cover body arranged outside a first air outlet pipe in a sleeving mode is fixedly arranged on the inner wall of a discharging opening; a connecting pipe facing the end part of the first air outlet pipe is fixedly arranged on the inner wall of the cover body; a plurality of pairs of arc-shaped baffles are symmetrically and fixedly arranged on the inner wall of the connecting pipe; the cover body can seal and protect the part of the first air outlet pipe in the rotary kiln so as to reduce damage caused by collision of internal large materials and the first air outlet pipe in the coal gangue conveying process, the connecting pipe and the first air outlet pipe can be connected in a sealed mode through a flange or a hoop, and the baffle can be connected with the first air outlet pipe through the arc-shaped outer wall of the connecting pipe. On one hand, airflow can flow out of the cover body from the first air outlet pipe, on the other hand, falling coal gangue materials are difficult to flow backwards into the first air outlet pipe through the cover body, and the materials are further difficult to intrude into the first air outlet pipe by controlling the power of the fan.

Description

Technical Field

[0001] This invention relates to the field of coal gangue ecological soil preparation, specifically a process for preparing ecological nutrient soil based on coal-based solid waste. Background Technology

[0002] Coal gangue, a major solid waste generated during coal mining and washing, poses significant environmental risks due to its large-scale stockpiling. This includes land occupation, spontaneous combustion, dust generation, and heavy metal leaching. In recent years, the resource utilization of coal gangue to prepare ecological nutrient soil has become an important disposal method. This not only effectively treats solid waste but also transforms its minerals, trace elements, and organic matter into carriers that improve soil structure and provide plant nutrients, achieving the dual value of ecological restoration and agricultural utilization.

[0003] According to the system described in patent document CN222090390U, the specific workflow for preparing ecological nutrient soil from coal gangue is as follows: First, after the coal gangue is crushed by a crusher, it is screened by a sorting feeder to obtain particles that meet the particle size requirements; then, the particles are fed into an activation mixer, while microbial agents are prepared into a solution and evenly sprayed onto it through atomizing nozzles to complete the mixing; the mixture then enters a modified reaction chamber, where microbial fermentation and activation are carried out under controlled temperature, pH, and ventilation conditions to release nutrients and passivate heavy metals; the activated coal gangue is then evenly mixed with sand and fertilizer in a mixing mixer in proportion; finally, the mixture is further matured in the fermentation reaction chamber to form ecological nutrient soil with good water retention, air permeability, and plant-available nutrients.

[0004] The aforementioned prior art has the following defects: the preparation starting point described in the patent document is the "direct crushing" of coal gangue; however, in actual production, whether it is newly produced wet gangue after coal washing or old gangue that has been piled up for a long time and absorbed moisture, it often contains high moisture content. If it is directly crushed, the wet and sticky material is very easy to adhere to the inner wall of the crushing chamber, the screen and the conveying equipment, resulting in serious blockage, grinding and efficiency reduction problems, and may even cause equipment overload failure.

[0005] Therefore, a process for preparing ecological nutrient soil based on coal-based solid waste is proposed to address the above problems. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0007] The technical solution adopted by this invention to solve its technical problem is: a process for preparing ecological nutrient soil based on coal-based solid waste, comprising the following steps:

[0008] S1. Raw material crushing: First, the coal gangue is dried by the drying equipment to remove the moisture accumulated in the coal gangue. Then, the dehydrated coal gangue is fed into the crusher for crushing. The crushed material is sent to the sorting feeder by the first conveyor. Particles that meet the target particle size requirements are sent to the next station, while those that do not meet the requirements are sent back to the crusher for secondary crushing by the second conveyor.

[0009] S2. Bio-activation: The microbial agent solution and the qualified coal gangue particles from the previous step are fed into the activation mixer. The microbial agent solution is sprayed onto the coal gangue particles through an atomizing nozzle and fully mixed by the stirring blades.

[0010] S3, Bio-modification: The mixed materials are sent to the modification reaction chamber by the third conveyor, where the materials are continuously stirred and air is introduced, while the materials are heated to create conditions for microbial fermentation.

[0011] S4. Fermentation and maturation: The improved coal gangue, stored sand and fertilizer are all sent to the mixing mixer by independent conveyors and physically mixed. The mixed materials are then transported to the fermentation reaction chamber by the fourth conveyor. Through stirring, gas injection and heating, the mixture is further fermented and matured, and finally coal gangue ecological nutrient soil is formed.

[0012] Preferably, the drying equipment in S1 includes a rotary kiln, a feeding port, and a first housing, wherein the feeding port is located at the discharge end of the rotary kiln, and the first housing is fixedly installed on the top of the feeding port; the outer wall of the first housing is sequentially connected to a first air inlet pipe, a first air outlet pipe, a second air inlet pipe, and a second air outlet pipe, and the interior is equipped with a rotor for dehumidifying the air, a first power source for driving the rotor to rotate, and a pair of fans for generating negative pressure; a heating plate is provided on the top of the rotor; the end of the first air outlet pipe extends into the interior of the rotary kiln; through the combined action of the rotor and the pair of fans, room temperature dry air can remove moisture from the coal gangue. Compared with the traditional high-temperature drying of coal gangue, which requires additional cooling measures to avoid adhesion during high-temperature material crushing, this dehumidification method is simpler and faster, and does not consume too much heat energy.

[0013] Preferably, the inner wall of the discharge port is fixedly provided with a cover sleeved outside the first air outlet pipe; the inner wall of the cover is fixedly provided with a connecting pipe facing the end of the first air outlet pipe; the inner wall of the connecting pipe is symmetrically provided with multiple pairs of arc-shaped baffles; the cover can provide a sealed protection for part of the first air outlet pipe in the rotary kiln, so as to reduce the damage caused by the collision between large pieces of material inside and the first air outlet pipe during the transportation of coal gangue. The connecting pipe and the first air outlet pipe can be sealed and connected by flanges or clamps. The baffles, through their arc-shaped outer walls, allow airflow to easily flow from the first air outlet pipe to the outside of the cover, and make it difficult for falling coal gangue material to backflow into the first air outlet pipe through the cover. Furthermore, the power of the fan can be controlled to make it even more difficult for material to invade the inside of the first air outlet pipe.

[0014] Preferably, the inner wall of the connecting pipe is provided with a plurality of first cavities; the inner wall of the first cavity is provided with a plurality of second cavities with ends facing the outer wall of the baffle; when the airflow flows through the first air outlet pipe toward the cover, part of the airflow can enter the interior of the first cavity and flow out from the second cavity. This part of the airflow can be blown to the side of the baffle facing the coal gangue material, thereby blowing away the particulate material attached to the surface of the baffle, further reducing the material entering the first air outlet pipe, and reducing the blockage caused by particle accumulation at the connecting pipe.

[0015] Preferably, the first cavity has a step at the end near the first air outlet pipe; the outer wall of the step is inclined; the outer wall of the step has a notch facing the first air outlet pipe. When the main airflow flows from the first air outlet pipe along the connecting pipe, the airflow can flow directly into the interior of the first cavity through the step. According to Bernoulli's principle, when a fluid flows through a protrusion or opening, its velocity will increase at the edge of the opening. The increased velocity will cause the static pressure at that point to decrease. Therefore, the first cavity here is a local low-pressure area compared to other first cavities. This allows the airflow to be stably ejected from the first cavity facing the outer wall of the baffle along the intended trajectory without backflow.

[0016] Preferably, a second housing is fixedly mounted on the top of the first housing; the outer wall of the second housing is connected to a third air inlet pipe, and is also connected to the first air inlet pipe and the second air inlet pipe respectively through pipes, and a filter element for air filtration is fixedly mounted on the inner wall; since the environment in which the device is located is a dusty environment of mineral processing, the air contains a large amount of dust impurities. Therefore, when the fan is started to blow air into the first housing, the outdoor airflow can enter the interior of the second housing through the third air inlet pipe, be filtered by the filter element, and then enter the first air inlet pipe or the second air inlet pipe respectively through pipes. It is worth mentioning that the pipes connected to the first air inlet pipe and the second air inlet pipe should be equipped with control valves. Since this is a mature technology, it will not be elaborated here.

[0017] Preferably, the inner wall of the second housing is provided with a rotatable shaft; the top of the shaft is fixed with a scraper via a connecting plate; the end of the shaft can be connected to the output end of a first power source, i.e., the first power source is preferably a dual-axis motor. This arrangement allows the shaft to drive the top scraper to rotate together, and the scraper can scrape off the filter cake formed on the outer wall of the filter element due to long-term air filtration, thereby extending the service life of the filter element and reducing its replacement frequency. It is worth mentioning that the outer shell of the second housing should be equipped with a maintenance plate to periodically replace the filter element and remove the scraped filter cake residue.

[0018] Preferably, a vibrator is fixedly provided on the outer wall of the scraper for shaking off impurities adhering to the outer wall of the scraper; the vibrator can be battery-driven and wirelessly controlled to avoid the need for an additional power cord as in the past. When the scraper cleans the surface of the filter element, the vibrator can be activated by remote control to generate vibration, thereby shaking off impurities adhering to the surface of the scraper and ensuring the cleaning effect of the scraper.

[0019] The advantages of this invention are:

[0020] 1. The present invention describes a process for preparing ecological nutrient soil based on coal-based solid waste. By setting up a drying device, the coal gangue can be dehumidified before crushing, thereby reducing the clogging problem caused by adhesion and other factors during crushing and improving the flowability of the material.

[0021] 2. The ecological nutrient soil preparation process based on coal-based solid waste described in this invention uses the combined action of a rotary wheel and a pair of fans to remove moisture from coal gangue with room temperature dry air. Compared with the traditional high-temperature drying of coal gangue, which requires additional cooling measures to prevent adhesion during high-temperature material crushing, this dehumidification method is simpler and faster, and does not consume too much heat energy. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the main body of the present invention;

[0024] Figure 2 This is a schematic diagram of the rotary kiln structure in this invention;

[0025] Figure 3 This is a schematic diagram of the structure of the first box in this invention;

[0026] Figure 4This is a schematic diagram of the baffle structure in this invention;

[0027] Figure 5 This is a schematic diagram of the heating plate in this invention;

[0028] Figure 6 This is a schematic diagram of the structure of the second box in this invention.

[0029] In the diagram: 1. Rotary kiln; 12. Feed port; 13. First housing; 141. First air inlet pipe; 142. First air outlet pipe; 151. Second air inlet pipe; 152. Second air outlet pipe; 16. Rotary wheel; 17. Heating plate; 2. Cover; 22. Connecting pipe; 23. Baffle; 3. First cavity; 32. Second cavity; 4. Step; 5. Second housing; 52. Filter element; 53. Third air inlet pipe; 6. Rotary shaft; 62. Scraper; 7. Vibrator. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Specific implementation examples are given below.

[0032] The present invention provides a process for preparing ecological nutrient soil based on coal-based solid waste, comprising the following steps:

[0033] S1. Raw material crushing: First, the coal gangue is dried by the drying equipment to remove the moisture accumulated in the coal gangue. Then, the dehydrated coal gangue is fed into the crusher for crushing. The crushed material is sent to the sorting feeder by the first conveyor. Particles that meet the target particle size requirements are sent to the next station, while those that do not meet the requirements are sent back to the crusher for secondary crushing by the second conveyor.

[0034] S2. Bio-activation: The microbial agent solution and the qualified coal gangue particles from the previous step are fed into the activation mixer. The microbial agent solution is sprayed onto the coal gangue particles through an atomizing nozzle and fully mixed by the stirring blades.

[0035] S3, Bio-modification: The mixed materials are sent to the modification reaction chamber by the third conveyor, where the materials are continuously stirred and air is introduced, while the materials are heated to create conditions for microbial fermentation.

[0036] S4. Fermentation and maturation: The improved coal gangue, stored sand and fertilizer are all sent to the mixing mixer by independent conveyors and physically mixed. The mixed materials are then transported to the fermentation reaction chamber by the fourth conveyor. Through stirring, gas injection and heating, the mixture is further fermented and matured, and finally coal gangue ecological nutrient soil is formed.

[0037] Please see Figures 1 to 6 As shown, the drying equipment in S1 includes a rotary kiln 1, a discharge port 12, and a first housing 13. The discharge port 12 is located at the discharge end of the rotary kiln 1, and the first housing 13 is fixedly installed on the top of the discharge port 12. The outer wall of the first housing 13 is sequentially connected to a first air inlet pipe 141, a first air outlet pipe 142, a second air inlet pipe 151, and a second air outlet pipe 152. Inside, there is a rotating wheel 16 for dehumidifying the air, a first power source for driving the rotating wheel 16 to rotate, and a pair of fans for generating negative pressure. The top of the rotating wheel 16 is provided with a heating plate 17. The end of the first air outlet pipe 142 extends into the interior of the rotary kiln 1.

[0038] Coal gangue is fed into the feed inlet at a high position in rotary kiln 1 via a conveyor. Rotary kiln 1 rotates via a gear and rack transmission structure. The coal gangue is continuously lifted and scattered within rotary kiln 1 by lifting plates (not shown in the figure, representing mature technology), forming a uniform material curtain. Simultaneously, a pair of fans inside the first housing 13 can also be started. Figure 3 and Figure 5 For example, when the right fan starts, it generates negative pressure, causing outdoor airflow to enter the first chamber 13 through the first air inlet pipe 141 and pass through the rotor 16. The rotor 16 is equipped with an adsorbent (specifically, activated silica gel, molecular sieve, etc.) to absorb moisture in the air, producing room temperature and extremely dry airflow. The airflow can be sent into the rotary kiln 1 through the first chamber 13 via the first air outlet pipe 142. The airflow can penetrate the aforementioned coal gangue material curtain. Since the water vapor partial pressure in this airflow is much lower than the water vapor partial pressure inside the coal gangue, the moisture inside the coal gangue will spontaneously "migrate" into the dry air and be continuously carried away, thereby achieving room temperature dehumidification of the coal gangue.

[0039] The left fan is controlled separately. The drying effect is monitored by a humidity sensor (mature technology, not shown in the figure) installed at the first air outlet duct 142. When the humidity exceeds the preset value, the left fan can be driven to start through the control system. Its start-up will also generate negative pressure, so that outdoor air enters the first box 13 through the second air inlet duct 151 and first reaches the heating plate 17. The heating plate 17 can be energized and heats this part of the airflow, so that the high temperature hot air (about 120-180℃) passes through the rotor 16. Here, the heating plate 17 covers one-quarter of the rotor 16. With the help of the first power source (such as a motor) to drive the rotor 16 to keep rotating, the saturated adsorbent on the rotor 16 can be blown off, thereby restoring its adsorption capacity. The high temperature and high humidity air is discharged to the outside through the second air outlet duct 152.

[0040] Through the combined action of the rotor 16 and a pair of fans, room temperature dry air can remove moisture from the coal gangue. Compared with the traditional high temperature drying of coal gangue, which requires additional cooling measures to prevent sticking during high temperature material crushing, this dehumidification method is simpler and faster, and does not consume too much heat energy.

[0041] Please see Figure 2 and Figure 4 As shown, a cover 2 is fixedly provided on the inner wall of the discharge port 12 and sleeved outside the first air outlet pipe 142; a connecting pipe 22 facing the end of the first air outlet pipe 142 is fixedly provided on the inner wall of the cover 2; and multiple pairs of arc-shaped baffles 23 are symmetrically fixed on the inner wall of the connecting pipe 22.

[0042] The enclosure 2 can seal and protect the first air outlet pipe 142 inside the rotary kiln 1, so as to reduce the damage caused by the collision between the large pieces of material inside and the first air outlet pipe 142 during the coal gangue transportation process. The connecting pipe 22 and the first air outlet pipe 142 can be sealed and connected by flange or clamp. The baffle 23, through its arc-shaped outer wall, allows the airflow to flow from the first air outlet pipe 142 to the outside of the enclosure 2, and makes it difficult for the falling coal gangue material to backflow into the first air outlet pipe 142 through the enclosure 2. Furthermore, the power of the blower can be controlled here to make it even more difficult for the material to invade the interior of the first air outlet pipe 142.

[0043] Please see Figure 4 As shown, the inner wall of the connecting pipe 22 is provided with a plurality of first cavities 3; the inner wall of the first cavity 3 is provided with a plurality of second cavities 32 with their ends facing the outer wall of the baffle 23;

[0044] When the airflow flows through the first air outlet duct 142 toward the cover 2, some of the airflow can enter the interior of the first cavity 3 and flow out from the second cavity 32. This part of the airflow can be blown to the side of the baffle 23 facing the coal gangue material, thereby blowing away the particulate material attached to the surface of the baffle 23, further reducing the material entering the first air outlet duct 142, and reducing the blockage caused by particle accumulation at the connecting pipe 22.

[0045] Please see Figure 4 As shown, a step 4 is provided at the end of the first cavity 3 near the first air outlet pipe 142; the outer wall of the step 4 is inclined.

[0046] The outer wall of step 4 has an opening facing the first air outlet 142. When the main airflow flows from the first air outlet 142 along the connecting pipe 22, the airflow can flow directly into the interior of the first cavity 3 through step 4. According to Bernoulli's principle, when a fluid flows through a protrusion or opening, its velocity will increase at the edge of the opening. The increased velocity will cause the static pressure at that point to decrease. Therefore, the first cavity 3 here is a local low-pressure area compared to other first cavities 3. This allows the airflow to be stably ejected from the first cavity 3 facing the outer wall of the baffle 23 along the intended trajectory without backflow.

[0047] Please see Figure 5 and Figure 6 As shown, a second box 5 is fixedly installed on the top of the first box 13; the outer wall of the second box 5 is connected to a third air inlet pipe 53, and is also connected to the first air inlet pipe 141 and the second air inlet pipe 151 respectively through pipes, and a filter element 52 for air filtration is fixedly installed on the inner wall.

[0048] Since the environment in which the device is located is a dusty environment of mineral processing, the air contains a large amount of dust and impurities. Therefore, when the fan is started to blow air into the first chamber 13, the outdoor airflow can enter the interior of the second chamber 5 through the third air inlet pipe 53, be filtered by the filter element 52, and then enter the first air inlet pipe 141 or the second air inlet pipe 151 through the pipes respectively. It is worth mentioning that the pipes connected to the first air inlet pipe 141 and the second air inlet pipe 151 should be equipped with control valves. Since this is a mature technology, it will not be elaborated here.

[0049] Please see Figure 3 and Figure 6 As shown, a rotatable shaft 6 is provided through the inner wall of the second housing 5; a scraper 62 is fixed to the top of the shaft 6 by a connecting plate.

[0050] The end of the rotating shaft 6 can be connected to the output end of the first power source, i.e., the first power source is preferably a dual-shaft motor. This arrangement allows the rotating shaft 6 to drive the top scraper 62 to rotate together. The scraper 62 can scrape off the filter cake formed on the outer wall of the filter element 52 due to long-term air filtration, thereby extending the service life of the filter element 52 and reducing its replacement frequency. It is worth mentioning that the outer shell of the second housing 5 should be equipped with a maintenance plate to regularly replace the filter element 52 and remove the scraped filter cake residue.

[0051] Please see Figure 6 As shown, a vibrator 7 is fixedly provided on the outer wall of the scraper 62 to shake off impurities adhering to the outer wall of the scraper 62;

[0052] The vibrator 7 can be battery-powered and wirelessly controlled to avoid the need for an additional power cord as in the past. When the scraper 62 is cleaning the surface of the filter element 52, the vibrator 7 can be activated by remote control to generate vibration, thereby shaking off the impurities attached to the surface of the scraper 62 and ensuring the cleaning effect of the scraper 62.

[0053] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A process for preparing ecological nutrient soil based on coal-based solid waste, characterized in that: Includes the following steps: S1. Raw material crushing: First, the coal gangue is dried by the drying equipment to remove the moisture accumulated in the coal gangue. Then, the dehydrated coal gangue is fed into the crusher for crushing. The crushed material is sent to the sorting feeder by the first conveyor. Particles that meet the target particle size requirements are sent to the next station, while those that do not meet the requirements are sent back to the crusher for secondary crushing by the second conveyor. S2. Bio-activation: The microbial agent solution and the qualified coal gangue particles from the previous step are fed into the activation mixer. The microbial agent solution is sprayed onto the coal gangue particles through an atomizing nozzle and fully mixed by the stirring blades. S3, Bio-modification: The mixed materials are sent to the modification reaction chamber by the third conveyor, where the materials are continuously stirred and air is introduced, while the materials are heated to create conditions for microbial fermentation. S4. Fermentation and maturation: The improved coal gangue, stored sand and fertilizer are all sent to the mixing mixer by independent conveyors and physically mixed. The mixed materials are then transported to the fermentation reaction chamber by the fourth conveyor. Through stirring, gas injection and heating, the mixture is further fermented and matured, and finally coal gangue ecological nutrient soil is formed.

2. The process for preparing ecological nutrient soil based on coal-based solid waste according to claim 1, characterized in that: The drying equipment in S1 includes a rotary kiln (1), a discharge port (12), and a first box (13), wherein the discharge port (12) is located at the discharge end of the rotary kiln (1), and the first box (13) is fixedly installed on the top of the discharge port (12); The outer wall of the first housing (13) is connected in sequence to the first air inlet pipe (141), the first air outlet pipe (142), the second air inlet pipe (151), and the second air outlet pipe (152). Inside, there is a rotating wheel (16) for dehumidifying the air and a first power source for driving the rotating wheel (16) to rotate, and a pair of fans for generating negative pressure. The top of the rotating wheel (16) is provided with a heating plate (17). The end of the first air outlet pipe (142) extends into the interior of the rotary kiln (1).

3. The process for preparing ecological nutrient soil based on coal-based solid waste according to claim 2, characterized in that: The inner wall of the discharge port (12) is fixedly provided with a cover (2) sleeved outside the first air outlet pipe (142); the inner wall of the cover (2) is fixedly provided with a connecting pipe (22) facing the end of the first air outlet pipe (142); the inner wall of the connecting pipe (22) is symmetrically provided with multiple pairs of arc-shaped baffles (23).

4. The process for preparing ecological nutrient soil based on coal-based solid waste according to claim 3, characterized in that: The inner wall of the connecting pipe (22) is provided with a plurality of first cavities (3); the inner wall of the first cavity (3) is provided with a plurality of second cavities (32) with their ends facing the outer wall of the baffle (23).

5. The process for preparing ecological nutrient soil based on coal-based solid waste according to claim 4, characterized in that: The first cavity (3) has a step (4) at the end near the first air outlet pipe (142); the outer wall of the step (4) is inclined.

6. The process for preparing ecological nutrient soil based on coal-based solid waste according to claim 2, characterized in that: The top of the first box (13) is fixedly provided with a second box (5); the outer wall of the second box (5) is connected to a third air inlet pipe (53), and is also connected to the first air inlet pipe (141) and the second air inlet pipe (151) respectively through pipes, and a filter element (52) for air filtration is fixedly provided on the inner wall.

7. The process for preparing ecological nutrient soil based on coal-based solid waste according to claim 6, characterized in that: The inner wall of the second box (5) is provided with a rotatable shaft (6); the top of the shaft (6) is fixed with a scraper (62) by a connecting plate.

8. The process for preparing ecological nutrient soil based on coal-based solid waste according to claim 7, characterized in that: The outer wall of the scraper (62) is fixedly equipped with a vibrator (7) for shaking off impurities adhering to the outer wall of the scraper (62).

Images