Lightweight particle coating device and method based on solid waste treatment

Abstract

This application discloses a lightweight particle coating device and method based on solid waste treatment, belonging to the field of EPS solid waste utilization. The method includes: S1, crushing EPS particles to ≤5mm, removing impurities by airflow sieve, soaking in 10% EVA emulsion, and drying for later use; S2, grinding fly ash or slag to a specific surface area ≥400m². 2 / kg, mixed with cement at a ratio of 1:0.3, water added to adjust the water-binder ratio to 0.32-0.35, dispersed into a slurry with a viscosity of 1000-1500 mPa·s; S3, primary coating in a rotating drum with an inclination angle of 5°-10° to initially coat the slurry in a counter-current contact manner; secondary coating by removing agglomerates through a turbine dispersion chamber, followed by spraying 10%-15% slurry and pre-curing with 70℃ infrared radiation until the surface moisture content is ≤15%; S4, tangential hot air drying at 100℃ for 10±2 min; S5, cooling to ≤40℃ at ≤8℃ / min; the equipment includes two coating tanks, and coating is achieved through an adjustable inclination drum and an adjustable angle atomizing nozzle, improving interface strength and uniformity, and reducing the risk of cracking.

Description

Technical Field

[0001] This invention relates to the technical field of EPS solid waste utilization, specifically to a lightweight particle coating device and method based on solid waste treatment. Background Technology

[0002] In recent years, the resource utilization of solid waste has become an important research direction in the environmental protection field. Polystyrene (EPS) foam is widely used in packaging and construction due to its lightweight and thermal insulation properties. However, waste EPS is difficult to degrade and has a large volume, and traditional landfill or incineration can easily cause environmental pollution. Existing technologies attempt to use EPS particles as lightweight aggregates in building materials, but they have the following drawbacks: 1. The surface of EPS is hydrophobic, resulting in weak interfacial adhesion with cement-based materials, leading to low composite material strength; 2. In conventional coating processes, the slurry coating is uneven, particles easily agglomerate, and the coating layer is easily peeled off; 3. Thermal stress during the drying stage easily causes cracking of the coating layer. Conventional EPS particle coating methods use single-stage roller coating, which suffers from uneven slurry distribution (CV value > 25%) and low interfacial strength. Therefore, there is an urgent need to develop an efficient and stable coating process and equipment to achieve synergy between solid waste resource utilization and the preparation of high-performance lightweight aggregates. Summary of the Invention

[0003] The purpose of this invention is to provide a lightweight particle coating device and method based on solid waste treatment, which improves interface strength and uniformity and reduces the risk of cracking.

[0004] To achieve the above objectives, the present invention provides a method for coating lightweight particles based on solid waste treatment, comprising the following steps:

[0005] S1. Particle pretreatment: The EPS particles are crushed, impurities are removed, soaked in EVA emulsion, and then dried.

[0006] S2. Slurry preparation: Mix fly ash or slag with cement, add water to adjust the water-cement ratio, and obtain slurry through dispersion treatment;

[0007] S3, Particle Coating:

[0008] Primary coating: The pre-treated EPS particles are fed into a rotating drum and come into contact with the slurry for initial coating;

[0009] Secondary coating: The particles after primary coating are dispersed, and the slurry is sprayed on top of the particles. Infrared radiation treatment is then applied to reduce the surface moisture content.

[0010] S4. Drying: Heat and dry the particles after secondary coating;

[0011] S5. Cooling: Cool the dried granules.

[0012] A further technical solution, wherein S1 specifically involves: shearing and crushing EPS particles to a particle size ≤ 5 mm, removing impurities by passing them through an air classifier, soaking them in a 10% EVA emulsion for 15 min, and then drying them for later use; the EVA emulsion is hydrolyzed to generate carboxyl groups (-COOH), which are used to react with cement hydration products to form an interfacial transition layer.

[0013] EPS crushing to ≤5mm particle size increases the specific surface area of ​​EPS particles by more than 50%. After soaking EVA emulsion for 15min, the carboxyl content is ≥0.78mmol / g, which significantly improves the chemical bonding ability with cement hydration products. Air classifier improves the impurity removal rate and avoids impurities affecting the formation of the interface transition layer.

[0014] In a further technical solution, step S2 specifically involves grinding fly ash or slag to a specific surface area ≥ 400 m². 2 / kg, mixed with cement at a mass ratio of 1:0.3, water is added to adjust the water-cement ratio to 0.32-0.35, and then processed through a high-shear disperser to a viscosity of 1000-1500 mPa·s to obtain a slurry.

[0015] Fly ash / slag ground to ≥400m 2 The specific surface area is / kg, which makes the slurry viscosity reach 1000-1500mPa·s, which is higher than that of ordinary slurry. The bleeding rate is reduced to 0 in 24 hours (when the water-cement ratio is 0.32); the cement content of 1:0.3 reduces the curing shrinkage rate of the slurry and avoids cracking of the coating layer.

[0016] In a further technical solution, the first-stage coating in S3 is carried out in a rotating drum with an inclination angle of 5° to 10°, and the drum speed is controlled at 10±2 rpm, so that the EPS particles come into countercurrent contact with the slurry prepared in S2; the amount of slurry coated in the first-stage coating is 4 to 6 times the mass of the EPS particles.

[0017] The counter-current contact design with an inclination angle of 8°±2° and a rotation speed of 10rpm extends the contact time between the slurry and EPS particles compared to conventional processes, and the coating amount reaches 4 to 6 times the weight of EPS. The guide strip can divert the upward slurry flow and improve uniformity.

[0018] In a further technical solution, the secondary coating in S3 is carried out in the turbine dispersion chamber, where the agglomerates are peeled off under centrifugal force. At the same time, the slurry prepared in S2 is sprayed in a high-pressure atomizing nozzle with an adjustable angle, and the surface moisture content is ≤15% in the sprayed area. The amount of the sprayed slurry is 10% to 15% of the amount of slurry used in the primary coating.

[0019] In a further technical solution, in the secondary coating, the centrifugal force is generated by a turbine disk rotating at 800 rpm; the operating pressure of the high-pressure atomizing nozzle is 3 MPa, and its spray angle is adjustable within a range of 45°±15°; the ambient temperature of the infrared radiation treatment area is 70°C.

[0020] In a further technical solution, the infrared radiation treatment forms a pre-cured layer on the surface of the slurry, and the pre-cured layer makes the interfacial bonding strength of the final particles ≥0.8MPa.

[0021] The 800rpm turbine dispersion generates 450g centrifugal force, breaking the agglomerates to D90<1mm; the 3MPa high-pressure atomizing nozzle sprays slurry with a particle size of 80-120μm to increase the coverage density; 70℃ infrared radiation reduces the surface moisture content, forming a pre-cured layer and improving the interfacial bonding strength.

[0022] A further technical solution, wherein step S4 is as follows: the particles are conveyed by the first spiral guide plate and tangential hot air is introduced for drying; the hot air temperature is 100℃ and the particle residence time is 10±2min; wherein step S5 is as follows: the particles are conveyed by the second spiral guide plate and cold air is introduced for cooling; the cold air velocity is 4m / s and the particle cooling rate is ≤8℃ / min until the particle temperature is ≤40℃.

[0023] The 100℃ tangential hot air, combined with the first spiral guide plate, can rapidly reduce the moisture content within 10 minutes; the 4m / s cold air control cooling rate is ≤6.5℃ / min, avoiding thermal stress that could cause the coating layer to crack.

[0024] A lightweight particle coating device based on solid waste treatment includes a shearing and crushing device, a screening device, and an EVA emulsion tank connected in sequence; a pulverizing and grinding device and a mixing device connected in sequence; and a primary coating device, a secondary coating device, and a drying and cooling device connected in sequence; the EVA emulsion tank and the mixing device can be connected to the primary coating device respectively.

[0025] The primary wrapping device includes a first wrapping tank that is tilted and has an adjustable angle. The first wrapping tank is rotatably mounted on a mounting plate. One end of the mounting plate is hinged to a hinge plate and the other end is hinged to a telescopic rod. The telescopic rod is connected to a hydraulic cylinder to achieve tilt angle adjustment.

[0026] The first coating tank has a first coating space with two frustum-shaped ends. The two ends of the first coating tank are rotatably connected to a grouting pipe and a material injection pipe, respectively. A spray head is fixed on the material injection pipe. The spray nozzle of the spray head has an angle of 45° to 90° with the inner wall of the first coating space. An arc-shaped spray head is fixed on the grouting pipe. The spray nozzle of the spray head has an angle of 15° to 30° with the inner wall of the first coating space. A guide strip is provided inside to make the grout flow obliquely upward and evenly sprayed onto the EPS particles.

[0027] The secondary coating device includes a second coating tank, the bottom of which is equipped with a turbine disperser, and the top is connected to a mixing device through a circular tube. The circular tube is connected to multiple nozzles arranged in a circle via a hose. The nozzles are connected to a rotatable second gear ring through a push-pull mechanism. The second gear ring is driven by an adjusting motor to adjust the oscillation angle of the nozzles.

[0028] The receiving port of the second coating tank is located below the first discharge port of the first coating tank, and is used to receive the slurry and EPS particles discharged from the first discharge port. The bottom of the second coating tank is provided with a second discharge port and is connected to a drying and cooling device.

[0029] A further technical solution is provided in the primary wrapping device:

[0030] The injection pipe is installed at a higher height than the grouting pipe, so that when the EPS particles are sprayed downward through the nozzle, they are mixed with the upward-flowing slurry.

[0031] In summary, the present invention has the following beneficial effects: Interface strengthening: Through EVA emulsion pretreatment and countercurrent coating process, EPS particles and slurry made of cement, fly ash or slag form a dense interface transition layer, which improves the interface bonding strength.

[0032] First-stage inclined countercurrent coating prolongs the contact time, increases the amount of slurry coated, reduces the CV value, and improves coating uniformity.

[0033] The combination of secondary turbine dispersion and high-pressure atomization spraying thoroughly breaks up agglomerates and significantly improves coverage density.

[0034] Infrared pre-curing reduces surface moisture content, decreases drying cracking, improves drying stability, and speed-controlled cooling avoids thermal stress cracking, thus reducing the cracking rate of finished products.

[0035] Using fly ash or slag as raw materials to improve resource utilization;

[0036] With excellent overall performance, the finished particles have reduced bulk density, increased compressive strength, and reduced thermal conductivity, meeting the requirements for high-performance lightweight aggregates. Attached Figure Description

[0037] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0038] Figure 1 This is a structural block diagram of the lightweight particle coating device for solid waste treatment based on this application;

[0039] Figure 2 This is a structural diagram of the equipment required for the primary and secondary coating processes of this application;

[0040] Figure 3 This is a first three-dimensional structural diagram of the first coated container of this application;

[0041] Figure 4 This is a second perspective structural diagram of the first coated container of this application;

[0042] Figure 5 This is a structural diagram of the nozzle of this application;

[0043] Figure 6 This is a structural diagram of the shotcrete head of this application;

[0044] Figure 7 This is a schematic diagram of the internal structure of the first coated container of this application;

[0045] Figure 8 This is a three-dimensional schematic diagram of the first discharge port of the first coating tank in this application;

[0046] Figure 9 This application Figure 8 Enlarged view of point A in the middle;

[0047] Figure 10 This is a schematic diagram illustrating the interaction between the electric push rod and the closed door of this application;

[0048] Figure 11 This is a three-dimensional structural diagram of the second coated container of this application;

[0049] Figure 12 This is a schematic diagram of the structure of the second gear ring of this application mounted on the mounting base;

[0050] Figure 13 This is a schematic diagram of the structure at the frustum hole in this application;

[0051] Figure 14 This is a schematic diagram of the installation structure of the adjusting gear, rotating screw and push-pull block of this application;

[0052] Figure 15 This is a schematic diagram of the turbine disperser in this application;

[0053] Figure 16This is a schematic diagram of the nozzle structure of this application;

[0054] Figure 17 This is a simplified diagram of the entire process flow of this application;

[0055] Figure 18 This is a simplified process flow diagram of step S1 of this application;

[0056] Figure 19 This is a simplified process flow diagram of step S2 in this application;

[0057] Figure 20 This is a simplified process flow diagram of step S3 of this application.

[0058] In the diagram: 101, First coating tank; 102, Mounting plate; 103, Telescopic rod; 104, Hinge plate; 105, Mounting strap; 106, Roller; 107, Power gear; 108, First gear ring; 109, Grouting pipe; 110, Material injection pipe; 111, Valve body; 112, Spray head; 113, Spray nozzle; 114, Grouting head; 115, Grouting nozzle; 116, Guide strip; 117, Connecting pipe; 118, First discharge port; 119, Limiting slot; 120, Support wheel; 121, Drive motor; 122, Reducer; 123, Push rod seat; 124, Electric push rod. ; 125. Hinge seat; 126. Protruding outlet; 127. Electromagnet; 128. Iron ring; 129. Sealing door; 130. Sealing groove; 201. Second coating tank; 202. Support seat; 203. Second gear ring; 204. Circular tube; 205. Material inlet; 206. Hose; 207. Nozzle; 208. Heating grid; 209. Adjusting gear; 210. Rotating screw; 212. Push-pull block; 213. Connecting shaft; 214. Push-pull groove; 215. Turntable; 216. Blade; 217. Turbine motor; 218. Frustum hole; 219. Central tube; 220. Mounting seat. Detailed Implementation

[0059] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0060] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0061] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0062] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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, an electrical connection, or a communication 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 invention according to the specific circumstances.

[0063] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0064] like Figures 1 to 16 As shown, a lightweight particle coating device based on solid waste treatment includes a shearing and crushing device, a screening device, an EVA emulsion tank, a crushing and grinding device, a mixing device, a primary coating device, a secondary coating device, and a drying and cooling device. The shearing and crushing device is used to crush EPS solid waste, shearing it into granules. The shearing and crushing device can be a shearing crusher, which shears the EPS solid waste to a particle size of less than or equal to 5mm. The screening device uses an air classifier to remove impurities from the EPS particles, screening out particles that do not meet the size requirements. The EVA emulsion tank is used to hold and soak the EPS particles. The crushing and grinding device is used to crush and refine fly ash or slag, which is then added to the mixing device and mixed with water and cement in a certain proportion to form a slurry of cement hydration products. This slurry is then pumped into the primary and secondary coating devices respectively.

[0065] In one embodiment, the shearing and crushing device adopts a twin-shaft shearing crusher with wear-resistant alloy blades to improve crushing efficiency and extend service life. By adjusting the distance between the two shafts, for example, 0.5mm to 2mm, it is ensured that EPS particles are crushed to a particle size of less than or equal to 5mm.

[0066] The EPS particles crushed by the shearing and crushing device can be drawn to the screening device through a negative pressure pipeline. The air velocity in the pipeline is controlled at 5-10 m / s to prevent the EPS particles from accumulating. In another embodiment, a screw conveyor can be used to transport the EPS particles to the screening device, which uses an airflow classifier with an airflow velocity of 4 m / s to remove EPS particles with a diameter greater than 5 mm. The bottom of the EVA emulsion tank is provided with two openable openings: a filter opening and a conveying opening. The filter opening is equipped with a filter screen to filter out the EVA emulsion, and the conveying opening is used to connect to the primary coating device.

[0067] In one embodiment, a wet material conveying system is provided between the EVA emulsion tank and the primary coating device. One side of the wet material conveying system is connected to a conveying opening, and the other side is connected to the injection pipe 110 of the primary coating device. The wet material conveying system includes a conveying pump installed at the bottom of the EVA emulsion tank for drawing soaked EPS particles into an anti-adhesion conveying pipe. A hydrophobic coating is provided on the inner wall of the anti-adhesion conveying pipe. The anti-adhesion conveying pipe connects the conveying pump and the injection pipe 110. A flow regulating valve is provided on the anti-adhesion conveying pipe to control the rate at which EPS particles enter the injection pipe 110, matching the processing capacity of the first coating tank 101.

[0068] In one embodiment, the pulverizing and grinding device includes a primary pulverizing chamber, a secondary grinding chamber, a dynamic classifier, and a sealed conveying system. The primary pulverizing chamber is used for coarsely pulverizing fly ash or slag. The secondary grinding chamber is connected to the primary pulverizing chamber and is used to finely grind the coarsely pulverized fly ash or slag into fine powder. The dynamic classifier is connected to the secondary grinding chamber and uses airflow classification to separate qualified fine powder. Coarse particles are returned to the secondary grinding chamber for further grinding. The sealed conveying system is used to prevent dust leakage and connects the mixing device and the dynamic classifier.

[0069] Specifically, the primary crushing chamber uses high-speed rotating hammers to impact and crush materials. After passing through a screen plate to separate qualified materials, the qualified materials fall downwards to the secondary grinding chamber. The secondary grinding chamber can use a vertical mill or a ball mill, which uses steel balls to crush, shear, and rub the materials to refine them. The finely ground powder enters the dynamic classifier through an airlock valve. The airflow separates the fine powder from the coarse particles. The coarse particles return to the grinding chamber through a return pipe, while the fine powder is conveyed through a sealed conveying system, which can use a screw conveyor to send the fine powder to the mixing device to mix with water and cement.

[0070] In one embodiment, the mixing device includes a mixing tank, inside which a high-shear disperser is installed. The high-shear disperser can employ a dual-shaft mixing system. The main mixing shaft is located at the center of the tank and is equipped with a 3-layer turbine impeller with a rotation speed of 800–1200 rpm to achieve radial diffusion of the slurry. The secondary mixing shaft is eccentrically arranged and equipped with an anchor scraper with a gap of ≤10 mm from the tank wall, rotating at 30–60 rpm to eliminate dead corners and scrape off slurry adhering to the wall. The drive unit consists of dual shafts driven by independent variable frequency motors with power matching the viscosity of the slurry. The powder inlet is located at the top of the tank and receives fine powder output from the crushing and grinding device through a sealed conveying system, such as a screw feeder. The liquid inlet has an annular water distribution pipe on its side wall, and the water addition is controlled by a flow meter. The cement feeding port is equipped with a pneumatic valve for precise feeding at a mass ratio (fly ash: cement = 1:0.3).

[0071] In one embodiment, the coating equipment is also connected to a cleaning device, which can pump clean water into the crushing and grinding device, mixing device, shearing and crushing device, and screening device to rinse the coating equipment and prevent the slurry from adhering to the inner wall of the coating equipment after shutdown.

[0072] In one embodiment, the primary wrapping device includes a first wrapping tank 101, which is tilted and its angle is adjustable. The first wrapping tank 101 is rotatably mounted on a mounting plate 102. The two ends of the mounting plate 102 are respectively hinged to a hinge plate 104 and a telescopic rod 103. The bottom end of the hinge plate 104 is fixed to the mounting frame, and the top end of the hinge plate 104 is hinged to one end of the mounting plate 102. The top end of the telescopic rod 103 is hinged to the other end of the mounting plate 102. The telescopic rod 103 is telescopically adjustable, and its bottom end is poweredly connected to a hydraulic cylinder. The hydraulic cylinder controls the extension and retraction of the telescopic rod 103, thereby allowing the mounting plate 102 to adjust its tilt angle. In order to enable the extension and retraction of the telescopic rod 103 and adjust the tilt angle of the mounting plate 102, the hydraulic cylinder needs to be rotatably mounted on the mounting frame.

[0073] In one embodiment, a first coating space is provided inside the first coating tank 101. The middle part of the first coating space is cylindrical, and the two ends are gradually tapering into frustum shapes. A grouting pipe 109 and a material injection pipe 110 are respectively installed at the two ends of the first coating tank 101. The axis of the grouting pipe 109 and the material injection pipe 110 coincides with the rotation axis of the first coating tank 101, and the grouting pipe 109 and the material injection pipe 110 rotate with the first coating tank 101. Specifically, the grouting pipe 109 and the material injection pipe 110 can be fixed to two guide plates by clamps. The guide plates are installed in the arc-shaped guide groove on the mounting frame, thereby restricting the rotation of the grouting pipe 109 and the material injection pipe 110 along their own axis, so that the grouting pipe 109 and the material injection pipe 110 can swing and adjust their angle with the first coating tank 101. The grouting pipe 109 and the material injection pipe 110 are connected to the first coating space.

[0074] In one embodiment, the injection pipe 110 is located on the higher side of the two sides of the first coating tank 101, so that the height of the injection pipe 110 is higher than the height of the grouting pipe 109. This allows the EPS particles soaked in EVA emulsion to be introduced into the injection pipe 110 and then into the first coating space inside the first coating tank 101. The grouting pipe 109 is used to introduce slurry into the first coating space. The slurry is mixed with the EPS particles in a countercurrent flow upward for primary coating.

[0075] In one embodiment, a nozzle 112 is fixed to one end of the injection tube 110. The nozzle 112 is connected to the injection tube 110 and is located within the first coating space. A nozzle 113 is provided on the nozzle 112. The angle between the extending direction of the nozzle 113 and the inner wall of the first coating space is between 45° and 90°, preferably 60° in this embodiment. Figures 5-7 One end of the grouting pipe 109 is fixed with a grouting head 114. The grouting head 114 is arc-shaped and communicates with the grouting pipe 109. The grouting head 114 has a grouting nozzle 115. The angle between the opening of the grouting nozzle 115 and the inner wall of the first covering space is between 15° and 30°, preferably 25° in this embodiment. Several guide strips 116 are provided in the grouting nozzle 115 to guide the grout flow sprayed from the grouting head 114 into several branches, so that the grout can be sprayed upward along the inner wall of the first covering space. EPS particles are sprayed through the spray nozzle 113. The material moves downward along the first coating space, causing the upward-flowing slurry to mix counter-currently with the downward-flowing EPS particles. The slurry can carry the EPS particles upward, and then, through the rolling of the first coating tank 101, the EPS particles and slurry are coated. Driven by the slurry, the EPS particles move upward along the inner wall of the first coating space. After reaching the top, they move downward along the inner wall of the first coating space together with the slurry under the action of gravity. This can prolong the contact time between the EPS particles and the slurry, extend the first-stage coating time, improve the coating uniformity, and increase production efficiency.

[0076] The spray angle of 15° to 30° causes the slurry to form an upward-climbing liquid film along the inner wall of the first coating space, with a thickness of 0.5 to 1 mm. This avoids the slurry directly impacting the particles and causing damage to the coating layer. When the angle is less than 15°, the slurry jet is too straight, resulting in a large impact energy on the particles and an increased breakage rate. When the angle is greater than 30°, the slurry climbing height is insufficient and cannot cover the particles on the upper part of the roller, resulting in a reduced coverage rate. The guide strip divides the slurry into multiple streams. When sprayed at a 25° angle to the inner wall of the first coating space, eddies are eliminated, the standard deviation of the slurry flow velocity is reduced, and the uniformity of the coating is improved.

[0077] When the nozzle angle is 45° to 90°, particle dispersion and kinetic energy control can be achieved. Preferably, the spraying direction is 60° with the inner wall of the first coating space so that the EPS particles can enter the slurry liquid film, thereby reducing the collision kinetic energy.

[0078] When the angle is less than 45°, the particles impact the liquid film perpendicularly, increasing their kinetic energy and making the coating layer easier to peel off; when the angle is greater than 90°, the particles disperse prematurely, reducing the amount of slurry coating.

[0079] The spray nozzle angle is 45°~90°, and the slurry spray nozzle angle is 15°~30°. The intersection angle between the falling path of EPS particles and the upward flow of slurry extends the effective contact time. When combined with the first coating tank at 10rpm, it greatly improves the cumulative contact time of particles and production efficiency.

[0080] In one embodiment, the first coating tank 101 is provided with an openable first discharge port 118 for discharging the EPS particles and slurry after primary coating outside the first coating tank 101. A vibrator (not shown) is provided around the first discharge port 118 to prevent the EPS particles and slurry from accumulating and to ensure smooth discharge. (See reference...) Figures 2-4 Two mounting rings 105 are fixedly mounted on the mounting plate 102. Two rollers 106 are rotatably mounted on each mounting ring 105. The rollers 106 can be rolled into the limiting slots 119 on the outer periphery of the first coating can 101. Four support wheels 120 are fixedly mounted on the mounting plate 102. The support wheels 120 can be inserted into the limiting slots 119. The support wheels 120 and rollers 106 are used to restrict the radial movement of the first coating can 101, so that the first coating can 101 can only rotate axially. A drive motor 121 and a reducer 122 are fixedly mounted on the mounting plate 102. The drive motor 121 is poweredly connected to the reducer 122. The output end of the reducer is poweredly connected to a power gear 107. The power gear 107 meshes with a first gear ring 108 fixed on the outer periphery of the first coating can 101 to drive the rotation of the first coating can 101.

[0081] In one embodiment, a pump device is provided at the outlet of the mixing device to pump out the slurry. The pump device is connected to a valve body 111, which is connected to a grouting pipe 109 and a connecting pipe 117 respectively. The connecting pipe 117 is connected to a second coating tank 201. The valve body 111 can be an electromagnetic three-way valve.

[0082] In one embodiment, the secondary coating device includes a second coating tank 201, which has a second coating space inside. A turbine disperser is disposed at the bottom of the second coating space. (See reference...) Figure 15The device includes a rotating turntable 215, on which blades 216 arranged in a circular array are fixedly mounted. A turbine motor 217 is fixed on the bottom surface of the second coating tank 201. The turbine motor 217 is poweredly connected to the turntable 215 and is used to drive the turntable 215 to rotate.

[0083] In one embodiment, refer to Figures 11-16 The top of the second coating tank 201 is fixed with several circumferentially arranged mounting bases 220. A circular annular tube 204 is fixed to the top of each mounting base 220, and the circular annular tube 204 communicates with the connecting pipe 117. Several circumferentially evenly arranged support bases 202 are fixedly arranged on the top surface of the second coating tank 201. The support bases 202 are arc-shaped, and several of the support bases 202 are used to support the second gear ring 203. The second gear ring 203 and the support bases... 202 Sliding fit: A rotating screw 210 is rotatably mounted on the mounting base 220. One end of the rotating screw 210 is fixed with an adjusting gear 209, which meshes with the bottom surface of the second gear ring 203. A groove may be provided on the inner ring of the second gear ring 203. A protrusion capable of inserting into the groove is provided on the support base 202 to restrict the vertical movement of the second gear ring 203, allowing only axial rotation. The mounting base 220 is rotatably mounted with... A nozzle 207 is provided, with connecting shafts 213 fixed at both ends of the nozzle 207. The connecting shafts 213 can be inserted into the mounting base 220 and rotate with the mounting base 220. A push-pull groove 214 is provided on the nozzle 207. A push-pull block 212 is threadedly connected to one end of the rotating screw 210. A locking block is provided on the push-pull block 212, which can be inserted into the push-pull groove 214. Rectangular inserts can be provided at both ends of the push-pull block 212. A horizontal... A rectangular sliding groove extends in the direction of the slide, and a rectangular insert is inserted into the rectangular sliding groove, so that the push-pull block 212 can slide in the horizontal direction. When the adjusting gear 209 rotates, it can drive the rotating screw 210 to rotate, thereby driving the push-pull block 212 to slide in the horizontal direction. This causes the push-pull block 212 to drive the nozzle 207 to swing. With its spray angle adjustable within a range of 45°±15°, it can achieve a larger coverage area of ​​spraying and flexibly adjust the nozzle orientation, which is convenient for subsequent tank cleaning.

[0084] In one embodiment, the top of the nozzle 207 is connected to the annular tube 204 via a flexible tube 206. The top of the second covering space is provided with a plurality of frustum holes 218, which are gradually narrowed from bottom to top. The frustum holes 218 are used to install the nozzle 207, so that the bottom of the nozzle 207 can extend into the second covering space through the frustum holes 218. The frustum holes 218 facilitate the adjustment of the nozzle 207's swing angle. A rubber cover can be provided on the top of the nozzle 207 to cover the frustum holes 218 and prevent impurities from entering the second covering space.

[0085] In one embodiment, a central tube 219 is fixed at the middle position of the top of the second coating tank 201. The central tube 219 is connected to the second coating space. The top of the central tube 219 is connected to a receiving port 205 through a flexible tube. The flexible tube can be a corrugated tube or a rubber tube, preferably a rubber tube. The receiving port 205 is used to receive EPS particles and slurry that fall out when the first discharge port 118 is opened.

[0086] In one embodiment, a rectangular iron ring 128 is fixedly provided on the inner wall of the receiving port 205, such as... Figure 9 and Figure 10 As shown, a protruding outlet 126 is provided at the first discharge port 118. An electromagnet 127 is fixed at the outlet of the protruding outlet 126. When the electromagnet 127 is energized, it can attract the iron ring 128, so that the receiving port 205 can cover the protruding outlet 126 to prevent the EPS particles and slurry after primary coating from splashing out. Two push rod seats 123 are fixedly provided on the outside of the protruding outlet 126, which are symmetrically arranged relative to the protruding outlet 126. An electric push rod 124 is rotatably installed on the push rod seat 123. Two symmetrically arranged closed doors 129 are hinged at the first discharge port 118. A hinge seat 125 is fixed at the bottom of the closed door 129. The electric push rod 124 passes through the side wall of the protruding outlet and is hinged to the hinge seat 125. The operation of the electric push rod 124 drives the closed door 129 to open or close, forming an electric push rod door structure.

[0087] Preferably, in order to ensure that the receiving port 205 can be smoothly sealed with the protruding outlet 126, a guide mechanism can be provided on both sides of the receiving port 205. For example, guide rods can be installed on both sides of the receiving port 205, and guide grooves can be provided on the mounting frame, so that the guide rods on the receiving port 205 can move back and forth along the guide grooves, thereby connecting the receiving port 205 with the protruding outlet 126 without deviation. In order to prevent the slurry from seeping out, rubber sealing rings can be provided around the closed door 129 to prevent seepage, and a sealing groove 130 is provided at the end of the two closed doors 129 that are close to each other after they are closed, for inserting a rubber sealing strip to prevent leakage.

[0088] In one embodiment, an adjusting motor (not shown) is fixedly installed on the top surface of the second coating tank 201. The power output end of the adjusting motor is connected to an adjusting gear (not shown). The adjusting gear meshes with the top surface of the second gear ring 203. The adjusting motor can rotate forward or backward, thereby adjusting the forward or reverse rotation of the second gear ring 203, thereby enabling the adjusting gear 209 to rotate forward or backward, which in turn drives the push-pull block 212 to move, thereby enabling the nozzle 207 to swing and adjust the angle.

[0089] In one embodiment, a heating net 208 is provided on the outer periphery of the second coating tank 201. The heating net 208 generates infrared radiation, which can heat the respray area space within the second coating space.

[0090] In one embodiment, a second discharge port is provided on the bottom side of the second coating tank 201 for discharging the secondary coated EPS particles. Preferably, the second coating tank 201 can also be driven to tilt by a driving component, and a spiral discharge machine that can extend into the second discharge port can also be installed at the second discharge port, so that the coated particles can be easily discharged.

[0091] In one embodiment, the second discharge port is connected to a filter device, and the EPS particles enter the drying and cooling device after some of the slurry is filtered out.

[0092] The drying and cooling device includes a drying space and a cooling space. A first spiral guide plate is installed in the drying space, and a second spiral guide plate is installed in the cooling space. EPS particles that have undergone secondary coating fall into the drying space for drying. The first spiral guide plate rotates, causing the EPS particles to move. Hot air is blown into the drying space to dry the coated EPS particles. The first spiral guide plate moves the EPS particles to the cooling space, where cold air is blown to cool the EPS particles dried by the hot air.

[0093] In one embodiment, a signal trigger mark is provided at the position of the first discharge port 118 on the first coating tank 101, and a photoelectric sensor is installed on the mounting plate 102. When the first discharge port 118 rotates to the bottom, the signal trigger mark passes through the photoelectric sensor and triggers a signal to ensure that when the first coating tank 101 stops rotating, the first discharge port 118 is located directly above the receiving port 205. This can be adjusted by the drive motor to ensure that the first discharge port is directly above the receiving port 205.

[0094] Preferably, a braking device can be provided on the mounting plate 102. The braking device can be a friction plate, which can be set on both sides of the power gear 107 and can be close to each other. It is electrically driven. For example, when energized, the two friction plates can be close to each other and clamp the power gear. When the first coating can 101 needs to be stopped, the friction plates are energized, the power gear gradually decelerates, thereby causing the first coating can 101 to gradually decelerate.

[0095] like Figures 17-20 A method for coating lightweight particles based on solid waste treatment includes the following steps:

[0096] S1. Particle pretreatment: The EPS particles are crushed, impurities are removed, soaked in EVA emulsion, and then dried.

[0097] S2. Slurry preparation: Mix fly ash or slag with cement, add water to adjust the water-cement ratio, and obtain slurry through dispersion treatment;

[0098] S3, Particle Coating:

[0099] Primary coating: The pre-treated EPS particles are fed into a rotating drum and come into contact with the slurry for initial coating;

[0100] Secondary coating: The particles after primary coating are dispersed, and the slurry is sprayed on top of the particles. Infrared radiation treatment is then applied to reduce the surface moisture content.

[0101] S4. Drying: Heat and dry the particles after secondary coating;

[0102] S5. Cooling: Cool the dried granules.

[0103] In one embodiment, EPS particles are sheared and crushed to a particle size ≤ 5 mm, impurities are removed by an air classifier, and the particles are soaked in a 10% EVA emulsion for 15 min, and then dried for later use; the EVA emulsion is hydrolyzed to generate carboxyl groups (-COOH), which are used to react with cement hydration products to form an interfacial transition layer.

[0104] In one embodiment, S2 specifically involves grinding fly ash or slag to a specific surface area ≥ 400 m². 2 / kg, mixed with cement at a mass ratio of 1:0.3, water is added to adjust the water-cement ratio to 0.32-0.35, and then processed through a high-shear disperser to a viscosity of 1000-1500 mPa·s to obtain a slurry.

[0105] Specific surface area directly affects the activity and viscosity of the slurry; ≥400m² 2 At / kg, the powder particles are finer (D50≤10μm), the hydration reaction activity is enhanced, and a denser CSH gel is formed.

[0106] If the specific surface area is insufficient, the slurry viscosity will be low and the bleeding rate will be high, leading to an increase in the porosity of the coating layer.

[0107] The cement ratio is 1:0.3 (fly ash: cement). The active SiO2 / Al2O3 in fly ash or slag reacts with the cement hydration product Ca(OH)2 to generate secondary CSH gel (volcanic ash effect).

[0108] A 1:0.3 ratio balances activity and shrinkage: too little cement (e.g., 1:0.1) reduces early strength; too much (e.g., 1:0.5) increases shrinkage stress and increases the cracking rate of the coating layer.

[0109] The water-binder ratio is 0.32–0.35 and the viscosity is 1000–1500 mPa·s. A low water-binder ratio (less than 0.32) reduces free water, inhibits bleeding, and results in poor slurry flowability and reduced coating uniformity. High shear dispersion is required to ensure flowability. When the water-binder ratio is high (greater than 0.35), there is excess free water, the bleeding rate increases, and pores are easily formed after drying, resulting in reduced strength. A water-binder ratio of 0.32–0.35 is more reasonable, with a slurry capillary porosity of less than 15%, forming a mysterious interface layer that blocks water from penetrating the EPS particles.

[0110] A viscosity of 1000–1500 mPa·s is achieved through a high-shear disperser, ensuring that the slurry can uniformly coat the particles without dripping due to its own weight. Higher viscosities (greater than 1500 mPa·s) are difficult to uniformly cover the particles, while lower viscosities (less than 1000 mPa·s) will cause the slurry to drip due to its own weight. Therefore, a viscosity of 1000–1500 mPa·s provides better uniformity of coverage.

[0111] In one embodiment, the primary coating in S3 is carried out in a rotating drum with an inclination angle of 5° to 10°, and the drum speed is controlled at 10±2 rpm, so that the EPS particles come into countercurrent contact with the slurry prepared in S2; the amount of slurry coated in the primary coating is 4 to 6 times the mass of the EPS particles.

[0112] After EVA emulsion pretreatment, the surface of EPS particles forms carboxyl groups (-COOH), which need to react with cement hydration products (Ca(OH)2) to form a Ca-carboxylate interface transition layer. When the amount of slurry is too small (less than 4 times), the particle surface is unevenly covered (CV value greater than 14%); when it is too large (greater than 6 times), the slurry's own weight causes dripping, increasing the peeling rate. Moreover, the design of the spray nozzle angle (25°) and the material spray nozzle angle (60°) of the first coating tank ensures efficient countercurrent mixing at 4 to 6 times the amount of slurry, and works in conjunction with the secondary supplementary spraying of 10% to 15% to optimize the total amount of slurry.

[0113] Considering the balance between gravity and centrifugal force, the tilt angle directly affects the movement trajectory of particles in the drum. When the tilt angle is less than 5°, the particles stay for too long, resulting in excessive collisions and damage to the coating layer. When the tilt angle is greater than 10°, the particles slide down too fast, and the slurry coating is insufficient. When the tilt angle is 8°±2°, the distribution of gravity and centrifugal force can be relatively balanced, ensuring sufficient coating. In conjunction with the telescopic rod 103 and the hydraulic cylinder, the tilt angle can be adjusted to adapt to particles of different sizes.

[0114] When the rotation speed is set to 10±2 rpm, excessively high speeds cause the particles to adhere tightly to the inner wall of the first coating space due to centrifugal force, preventing them from rolling and allowing the slurry to penetrate the gaps, resulting in uneven coating. Conversely, lower speeds cause the particles to slide relative to the inner wall of the first coating space, with sliding being the primary mode and rolling being less frequent, resulting in insufficient surface area exposure and uneven coating. Therefore, to achieve uniform coating, the particles should be arranged in a "cascade" state to maximize surface exposure. Considering the coupling between the tilt angle and rotation speed, as well as the optimal residence time t∝L / (v·sinθ) (L: drum length, v: particle linear velocity), when the tilt angle is 8° and the rotation speed is 10 rpm, t = 120 seconds, which meets the requirement of 4 to 6 times the slurry coating amount (EPS mass). If the tilt angle is changed to 6°, the speed needs to be reduced to 8 rpm; otherwise, t will exceed 150 seconds, causing a decrease in coating efficiency.

[0115] In one embodiment, the secondary coating in S3 is carried out in the turbine dispersion chamber, where the agglomerates are peeled off under centrifugal force. At the same time, the slurry prepared in S2 is sprayed through an adjustable-angle high-pressure atomizing nozzle, and the sprayed area is subjected to infrared radiation treatment until the surface moisture content is ≤15%. The amount of the sprayed slurry is 10% to 15% of the amount of slurry used in the primary coating.

[0116] The initial coating is completed in the roller, but due to particle collision and slurry rheological properties, micro-cracks and coverage blind spots may exist on the surface. These defects are filled by spraying 10% to 15% of the slurry.

[0117] 10% additional spraying to repair micro-cracks and increase coverage to 95%;

[0118] 15% additional spraying: Completely covers the blind area, forming a continuous film layer;

[0119] The application of slurry should be combined with infrared radiation (70℃). A slurry content of 10% to 15% can reduce the surface moisture content to ≤15% within 20 seconds, which is a reasonable pre-curing window. Excessive application of slurry will lead to moisture accumulation, prolong the drying time, and may also cause liquid bridges, resulting in secondary agglomeration. Insufficient application of slurry may result in incomplete coverage of edge particles and low interface strength.

[0120] In one embodiment, in the secondary coating, centrifugal force is generated by a turbine disk rotating at 800 rpm; the operating pressure of the high-pressure atomizing nozzle is 3 MPa, and its spray angle is adjustable within a range of 45°±15°; the ambient temperature of the infrared radiation treatment area is 70°C.

[0121] The jet angle range of 45°±15° (i.e., 30°~60°) allows the atomized slurry to form a cone-shaped coverage sector; the small angle (30°) jet is concentrated and has strong penetration, which is suitable for stripping the core area of ​​the agglomerates (the center of the turbine disk); the large angle (60°) has a wide diffusion range, covering particles at the edge of the turbine disk and avoiding the blind spots caused by the "edge effect".

[0122] When sprayed at 45°, the slurry breaks into droplets of 80-120μm, which meets the requirements for uniform coverage. When the angle is less than 30°, the droplet size is too small (less than 50μm) and is easily carried away by the airflow. When the angle is greater than 60°, the droplet size is too large (greater than 150μm), resulting in uneven coating thickness.

[0123] The nozzle 207 is located below the annular tube 204, and when spraying at 45°, the slurry landing point accurately covers the area of ​​the infrared heating grid 208.

[0124] When the angle deviation is 15°, it is necessary to adapt to the fluctuation of raw materials. There are rheological differences in slurries with a viscosity of 1000-1500 mPa·s: High viscosity (1500 mPa·s): The angle needs to be adjusted to 30° to increase the jet speed and prevent poor atomization; Low viscosity (1000 mPa·s): The angle needs to be adjusted to 60° to avoid the high-speed jet from breaking through the coated layer.

[0125] The reason for choosing 70℃ for infrared radiation is that 70℃ is the optimal activation temperature for early hydration of cement, which can promote the induction of Ca2+ hydration. 2+ Reaction with EVA carboxyl groups generates Ca-carboxylate crystal nuclei, enhancing interfacial bonding strength. At temperatures ≥75℃, particles are prone to deformation, leading to coating layer rupture. At temperatures <60℃, insufficient pre-curing reaction results in inadequate strength. Particles dispersed by an 800rpm turbine have a residence time of approximately 40 seconds. Radiation at 70℃ allows for the completion of moisture diffusion (moisture content ≤15%) within this timeframe, forming a 0.1–0.2mm pre-cured layer (resistant to centrifugal peeling). During subsequent 100℃ hot air drying, the 70℃ pre-cured layer reduces internal moisture evaporation pressure, preventing stress concentration during drying.

[0126] In one embodiment, the infrared radiation treatment forms a pre-cured layer on the surface of the slurry, and the pre-cured layer makes the final interfacial bonding strength of the particles ≥0.8MPa, which meets the national standard requirements.

[0127] In one embodiment, step S4 specifically involves: the particles being conveyed by a first spiral guide plate and dried by tangential hot air; the hot air temperature is 100℃, and the particle residence time is 10±2min; step S5 specifically involves: the particles being conveyed by a second spiral guide plate and cooled by cold air; the cold air velocity is 4m / s, and the particle cooling rate is ≤8℃ / min until the particle temperature is ≤40℃.

[0128] Hot air at 100℃ increases the water diffusion coefficient of the slurry to 3.2×10⁻⁶. -8 m 2 / s (only 0.7×10 at room temperature) -8 m 2 It can reduce the moisture content from ≤15% to less than 1% within 10 minutes ( / s).

[0129] After EPS particles are pretreated with EVA emulsion, the EVA carboxyl groups (-COOH) react with the cement hydration products in the slurry to form a Ca-carboxylate interface layer, which improves the thermal stability of EPS. In addition, the pre-cured layer formed by the secondary coating acts as a barrier, preventing high heat from being directly conducted to the core of the EPS particles. Furthermore, the introduction of tangential hot air, transported by the rotation of the first spiral guide plate, reduces direct thermal shock and protects the core of the EPS particles. The hot air drying time of 100℃ plus 10±2min avoids exceeding the limit, balancing drying efficiency and energy consumption.

[0130] When the temperature is below 90℃, the drying time needs to be greater than 15 minutes (efficiency is reduced); when the temperature is greater than 110℃, the risk of glass transformation of EPS particles increases, and the pre-cured layer (formed at 70℃) becomes more dense at 100℃. Therefore, 100℃ hot air is selected.

[0131] When the moisture content is greater than 1.5%, microcracks (vapor pressure release) are easily triggered during the cooling stage.

[0132] 10-minute drying: moisture content 0.9%, meeting cooling safety requirements;

[0133] Less than 8 minutes: moisture content greater than 1.8%, cracking rate increases to 5%; greater than 12 minutes: energy consumption increases, particle brittleness increases (compressive strength decreases).

[0134] The temperature difference between 100℃ hot air and the initial particle temperature (70℃) is ΔT = 30℃, achieved within 10 minutes.

[0135] Even heating (avoiding localized overheating);

[0136] The moisture is released gradually (from the interior to the surface), and the peak stress is less than 0.8 MPa (interfacial strength threshold).

[0137] At a wind speed of 4 m / s, a laminar boundary layer forms on the particle surface, achieving efficient heat dissipation.

[0138] Wind speed < 3 m / s: The boundary layer is too thick, reducing heat exchange efficiency; wind speed > 5 m / s: Turbulence leads to increased particle collision and breakage rate; therefore, considering all factors, a wind speed of 4 m / s is selected as the best for cooling uniformity (temperature gradient ΔT < 5℃).

[0139] EPS linear expansion coefficient (70×10) -6 / ℃) is the slurry layer (10×10 -6 When the cooling rate is greater than 8℃ / min, the interfacial thermal stress σ=E·Δα·ΔT is greater than 1.2MPa (exceeding the tensile strength of the slurry 1.0MPa), and the cracking rate is greater than 5%. Sudden cooling will induce residual stress crystallization, leading to increased brittleness. When the cooling rate is ≤8℃ / min, the molecular chains rearrange in an orderly manner, and the toughness of the particles is maintained.

[0140] ≤40℃ ensures that when granules enter the silo: no residual heat causes water vapor condensation (ambient dew point temperature is usually ≤25℃); avoids thermal expansion that could cause packaging rupture.

[0141] S1 pretreatment stage experimental data:

[0142] Concentration selection:

[0143] When the EVA emulsion concentration is <8%, the carboxyl grafting rate is insufficient (experimental group 1: 0.52 mmol / g); when it is >12%, the viscosity increases sharply (>120 mPa·s), hindering penetration.

[0144] In other words, low concentrations result in insufficient carboxyl group generation, while high concentrations can lead to excessively high emulsion viscosity, reducing the uniformity of particle wetting. Therefore, a concentration of 10% was selected, as the 10% concentration balances reactivity and flowability.

[0145] The reason for the 15-minute soaking time is that short soaking (<15 minutes) results in insufficient carboxyl content (<0.78 mmol / g), while long soaking (>15 minutes) does not show significant gain.

[0146] Relevant immersion experiment data:

[0147]

[0148] Conclusion: 10% concentration + 15 min is the optimal solution for carboxyl group formation efficiency (≥0.8 mmol / g) and particle integrity.

[0149] EPS particle size experimental data:

[0150]

[0151] In conclusion, the specific surface area was increased by more than 50% when the particle size was ≤5mm; EVA treatment resulted in a carboxyl content of 0.78–0.85 mmol / g, which was significantly higher than that of the control group.

[0152] Experimental data from the S2 slurry preparation stage:

[0153]

[0154] in conclusion:

[0155] Specific surface area ≥400m² 2 The slurry viscosity is >1000 mPa·s and the bleeding rate is ≤1.2% when the cement content is 1:0.3; the shrinkage rate is greatly reduced compared with pure cement slurry.

[0156] Experimental data for S3 primary coating process:

[0157]

[0158]

[0159] in conclusion:

[0160] The uniformity is best (CV = 8.5%) and the slurry stripping rate is lowest when the tilt angle is 8° and the rotation speed is 10 rpm.

[0161] Experimental data for S3 secondary coating process:

[0162]

[0163] in conclusion:

[0164] Turbine dispersion at 800 rpm resulted in agglomerate D90 < 1 mm; infrared treatment at 70℃ resulted in a moisture content ≤ 15% and a bond strength ≥ 0.8 MPa (strength increased by 20% when additional spraying amount is 10% to 15%).

[0165] Experimental data for S4 drying & S5 cooling processes:

[0166] Experimental data 1:

[0167] Temperature <90℃ Slow moisture diffusion Drying time > 15 min, production capacity ↓ 30% Temperature > 110℃ EPS deformation / pre-cured layer cracking Particle breakage rate >8% Time < 8 min Moisture content > 1.8% Cooling crack rate increased to 5% Time > 12 min Organic components age, particles become brittle Compressive strength ↓8%

[0168] Experimental data 2:

[0169] Wind speed <3m / s Insufficient heat exchange and uneven cooling Central particle temperature >60℃ Wind speed >5m / s Particle collision damage Finished product breakage rate increased by 8%. Cooling rate >10℃ / min Excessive thermal stress Crack rate >5% Endpoint temperature > 50℃ Condensation inside packaging The moisture content of the granules increased by more than 0.5%.

[0170] Experimental data 3:

[0171]

[0172] in conclusion:

[0173] When the moisture content is less than 1% after 100℃ hot air + 10min retention, the cracking rate is less than 2% when the cooling rate is less than 8℃ / min (compared group > 22%).

[0174] Environmental performance verification data:

[0175]

[0176]

[0177] in conclusion:

[0178] The heavy metal leaching concentration is 1 to 2 orders of magnitude lower than the limit, and the solidification and sealing rate is >99.5%.

[0179] Overall performance comparison:

[0180] Performance indicators This patented particle Commercially available EPS lightweight aggregate Performance improvement Bulk density <![CDATA[0.68g / cm 3 ]]> <![CDATA[0.85g / cm 3 ]]> ↓20％ compressive strength 8.2MPa 5.1MPa ↑60％ thermal conductivity 0.048 W / (m·K) 0.052 W / (m·K) ↓8％

[0181] All experiments were conducted in accordance with GB / T 17431.2-2010 "Lightweight Aggregates and Test Methods". Each set of data was repeated 3 times and the average value was taken.

[0182] Any aspects not described in this application can be implemented using or by referencing existing technologies. The above descriptions are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for coating lightweight particles based on solid waste treatment, characterized in that, Includes the following steps: S1. Particle pretreatment: The EPS particles are crushed, impurities are removed, soaked in EVA emulsion, and then dried. S2. Slurry preparation: Mix fly ash or slag with cement, add water to adjust the water-cement ratio, and obtain slurry through dispersion treatment; S3, Particle Coating: Primary coating: The pre-treated EPS particles are fed into a rotating drum and come into contact with the slurry for initial coating; Secondary coating: The particles after primary coating are dispersed, and the slurry is sprayed on top of the particles. Infrared radiation treatment is then applied to reduce the surface moisture content. S4. Drying: Heat and dry the particles after secondary coating; S5. Cooling: Cool the dried granules. In step S3, the primary coating is carried out in a rotating drum with an inclination angle of 5° to 10°, and the drum speed is controlled at 10±2 rpm, so that the EPS particles come into countercurrent contact with the slurry prepared in step S2; the amount of slurry coated in the primary coating is 4 to 6 times the mass of the EPS particles. In step S3, the secondary coating is carried out in the turbine dispersion chamber, where the agglomerates are peeled off under centrifugal force. Simultaneously, the slurry prepared in step S2 is sprayed through an adjustable-angle high-pressure atomizing nozzle, and the sprayed area is subjected to infrared radiation treatment until the surface moisture content is ≤15%. The amount of slurry sprayed is 10% to 15% of the amount of slurry used in the primary coating. In the secondary coating process, centrifugal force is generated by a turbine disk rotating at 800 rpm; the operating pressure of the high-pressure atomizing nozzle is 3 MPa, and its spray angle is adjustable within a range of 45° ± 15°; the ambient temperature of the infrared radiation treatment area is 70°C. The infrared radiation treatment forms a pre-cured layer on the surface of the slurry, which results in an interfacial bonding strength of ≥0.8 MPa for the final particles.

2. The method according to claim 1, characterized in that: S1 specifically involves: shearing and crushing EPS particles to a particle size ≤ 5 mm, removing impurities by passing them through an air classifier, soaking them in a 10% EVA emulsion for 15 min, and then drying them for later use; the EVA emulsion is hydrolyzed to generate carboxyl groups, which are used to react with cement hydration products to form an interfacial transition layer.

3. The method according to claim 1 or 2, characterized in that: Specifically, S2 involves grinding fly ash or slag to a specific surface area ≥ 400 m². 2 / kg, mixed with cement at a mass ratio of 1:0.3, water is added to adjust the water-cement ratio to 0.32~0.35, and then processed through a high-shear disperser to a viscosity of 1000~1500mPa·s to obtain a slurry.

4. The method according to claim 1, characterized in that: The specific steps of S4 are as follows: the particles are conveyed by the first spiral guide plate and dried by tangential hot air; the hot air temperature is 100℃ and the particle residence time is 10±2min; the specific steps of S5 are as follows: the particles are conveyed by the second spiral guide plate and cooled by cold air; the cold air velocity is 4m / s and the particle cooling rate is ≤8℃ / min until the particle temperature is ≤40℃.

5. A lightweight particle coating device based on solid waste treatment, characterized in that, It includes a shearing and crushing device, a screening device, and an EVA emulsion tank connected in sequence; a pulverizing and grinding device and a mixing device connected in sequence; and a primary coating device, a secondary coating device, and a drying and cooling device connected in sequence; the EVA emulsion tank and the mixing device can be connected to the primary coating device respectively; The primary wrapping device includes a first wrapping tank that is tilted and has an adjustable angle. The first wrapping tank is rotatably mounted on a mounting plate. One end of the mounting plate is hinged to a hinge plate and the other end is hinged to a telescopic rod. The telescopic rod is connected to a hydraulic cylinder to achieve tilt angle adjustment. The secondary coating device includes a second coating tank, with a turbine disperser at the bottom and a mixing device connected to the top via a circular tube. The circular tube is connected to multiple nozzles arranged in a circle via a hose. The nozzles are connected to a rotatable second gear ring via a push-pull mechanism, and the second gear ring is driven by an adjusting motor to adjust the nozzle swing angle.

6. The lightweight particle coating device according to claim 5, characterized in that, The first coating tank has a first coating space with two frustum-shaped ends. The two ends of the first coating tank are rotatably connected to a grouting pipe and a material injection pipe, respectively. A spray head is fixed on the material injection pipe. The spray nozzle of the spray head has an angle of 45° to 90° with the inner wall of the first coating space. An arc-shaped grouting head is fixed on the grouting pipe. The spray nozzle of the grouting head has an angle of 15° to 30° with the inner wall of the first coating space. A guide strip is provided inside to make the grout flow obliquely upward and counter-currently sprayed onto the EPS particles. The receiving port of the second coating tank is located below the first discharge port of the first coating tank, and is used to receive the slurry and EPS particles discharged from the first discharge port. The bottom of the second coating tank is provided with a second discharge port and is connected to a drying and cooling device. The injection pipe is installed at a higher height than the grouting pipe, so that when the EPS particles are sprayed downward through the nozzle, they are mixed with the upward-flowing slurry.

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