A dry method for removing clay by using a high frequency screen and a cyclone separator

Abstract

The application provides a dry method for removing mud by using high-frequency screening and cyclone separation, which comprises the following steps: providing wet sandstone aggregate with a water content of more than 15%; heating the wet sandstone aggregate to more than 60 DEG C and reducing the water content of the wet sandstone aggregate to less than 10%, then introducing the wet sandstone aggregate into the feeding end of a vibrating screen, and controlling the vibration frequency of the vibrating screen to be more than 45 Hz to perform high-frequency vibration treatment on the wet sandstone aggregate, so as to form on-screen aggregate located above the vibrating screen and under-screen material falling through the vibrating screen; and sending the under-screen material into a first-stage cyclone separator to perform first-stage separation treatment, so as to form cyclone separation aggregate. The dry method for removing mud by using high-frequency screening and cyclone separation can effectively strip the fine mud powder adhered to the surface of the sandstone aggregate, improve the cleanliness of the produced sandstone aggregate, and also can produce sandstone aggregate with different particle size distributions.

Description

Technical Field

[0001] This application relates to the field of sand and gravel aggregate technology, specifically to a dry desliming method utilizing high-frequency screening and cyclone separation. Background Technology

[0002] Sand and gravel aggregates are indispensable raw materials in the construction of infrastructure such as buildings, roads, and bridges. They are mainly processed from natural rocks, pebbles, or mine waste rock through crushing and screening. These sand and gravel aggregates typically have a large amount of mud and dust adhering to their surfaces, with a wide particle size distribution and strong adhesion, severely affecting their quality and subsequent utilization value. Therefore, efficient mud removal is a key pre-processing step in sand and gravel aggregate treatment.

[0003] In some related technologies, desliming methods for such sand and gravel aggregates are mainly divided into wet desliming and dry desliming. Wet desliming refers to washing the sand and gravel aggregates with a large amount of water to remove the mud adhering to the surface of the aggregates. Wet desliming has a good desliming effect, but it generates a large amount of difficult-to-treat mud and wastewater, resulting in problems such as high environmental pressure, high water consumption, and high energy consumption for subsequent dewatering and drying. Its application is limited, especially in water-scarce areas or situations with strict environmental requirements. Dry desliming mainly relies on air separation. Air separation is effective in separating coarse aggregates from fine dust, but it generally has the following problems: 1. Low efficiency in peeling and separating finely adhered mud and dust; 2. Equipment is prone to clogging, resulting in poor stability during continuous operation; 3. The overall process is crude, making it difficult to simultaneously meet the requirements of high aggregate cleanliness and high powder recovery rate. Summary of the Invention

[0004] Therefore, it is necessary to provide a dry desliming method that utilizes high-frequency screening and cyclone separation. This dry desliming method can effectively remove the fine mud powder adhering to the surface of sand and gravel aggregates, improve the cleanliness of the produced sand and gravel aggregates, and also produce sand and gravel aggregates with different particle size distributions.

[0005] According to some embodiments of this application, a dry desliming method utilizing high-frequency screening and cyclone separation is provided, comprising the following steps:

[0006] Provide wet sand and gravel aggregates with a moisture content of 15% or higher;

[0007] The wet sand and gravel aggregate is heated to above 60°C and its moisture content is reduced to below 10%. The wet sand and gravel aggregate is then introduced into the feed end of a vibrating screen, and the vibration frequency of the vibrating screen is controlled to be above 45Hz to perform high-frequency vibration treatment on the wet sand and gravel aggregate, forming oversize aggregate located above the vibrating screen and undersize material falling through the vibrating screen. The undersize material is then sent to a primary cyclone separator for primary separation treatment to form cyclone separated aggregate.

[0008] In some embodiments of this application, the moisture content of the wet sand and gravel aggregate is 6% to 10% before it is introduced into the feed end of the vibrating screen.

[0009] In some embodiments of this application, during the high-frequency vibration treatment of the wet sand and gravel aggregate, hot air at a temperature above 100°C is used to blow the wet sand and gravel aggregate to remove moisture from it.

[0010] In some embodiments of this application, during the high-frequency vibration treatment of the wet sand and gravel aggregate, the vibration frequency of the vibrating screen is controlled to be 45Hz~60Hz, and the amplitude of the vibrating screen is controlled to be 2mm~4mm.

[0011] In some embodiments of this application, the mesh size at the feed end of the vibrating screen is larger than the mesh size at the discharge end of the vibrating screen.

[0012] In some embodiments of this application, during the high-frequency vibration treatment of the wet sand and gravel aggregate, the moisture content of the wet sand and gravel aggregate is monitored at or before the feed end, and the vibration frequency and / or amplitude of the vibrating screen is adjusted according to the monitored moisture content; wherein, when adjusting the vibration frequency of the vibrating screen, the vibration frequency of the vibrating screen decreases as the moisture content increases; and when adjusting the amplitude of the vibrating screen, the amplitude of the vibrating screen increases as the moisture content increases.

[0013] In some embodiments of this application, the screen aperture at the feed end is 4mm to 8mm, and the screen aperture at the discharge end is 2.5mm to 4mm.

[0014] In some embodiments of this application, the process of performing high-frequency vibration treatment on the wet sand and gravel aggregate further includes the following steps: during the falling process of the undersize material, at least a portion of the undersize material is carried by carrier gas, and the carrier gas and the undersize material it carries are transported to the primary cyclone separator.

[0015] In some embodiments of this application, the D50 particle size of the cyclone-separated aggregate is 0.15 mm to 0.6 mm.

[0016] In some embodiments of this application, during the process of feeding the undersize material into a primary cyclone separator for primary separation, cyclone-separated aggregate and primary gas-solid mixture are separated. After the primary separation, the process further includes the following step: feeding the primary gas-solid mixture into a secondary cyclone separator for secondary separation to separate at least a portion of the mud powder in the primary gas-solid mixture, wherein the D50 particle size of the separated mud powder is smaller than the D50 particle size of the cyclone-separated aggregate; wherein the cylinder diameter of the secondary cyclone separator is smaller than the cylinder diameter of the primary cyclone separator.

[0017] In some embodiments of this application, the step of providing wet sand and gravel aggregate with a moisture content of more than 15% includes: providing raw sand and gravel aggregate, detecting the moisture content of the raw sand and gravel aggregate, and if the moisture content of the raw sand and gravel aggregate is less than 15%, spraying water into the raw sand and gravel aggregate to increase the moisture content to more than 15%.

[0018] In the dry desliming method utilizing high-frequency screening and cyclone separation in this application embodiment, firstly, wet sand and gravel aggregate with a moisture content of more than 15% is provided, allowing the fine mud powder adhering to the surface of the sand and gravel aggregate to agglomerate and bind into a mud layer under the action of water. Subsequently, the wet sand and gravel aggregate is heated to above 60°C, reducing its moisture content to below 10%, causing the mud layer to initially dry and gradually crack. Secondly, after the wet sand and gravel aggregate is introduced into the feed end of a vibrating screen, the mud layer, after initial drying and cracking, is peeled off entirely from the surface of the sand and gravel aggregate under the action of high-frequency vibration, thereby removing the highly adhesive fine mud powder from the sand and gravel aggregate. After the prior drying and high-frequency screening, the material above the vibrating screen is relatively large-particle-size (larger than the aperture of the vibrating screen) and relatively clean oversize aggregate, while the material below the vibrating screen includes smaller-particle-size (smaller than the aperture of the vibrating screen) sand and gravel aggregate, sand particles, mud powder, etc. The overall particle size of the undersize material is relatively small, which can be carried by gas and sent into the primary cyclone separator. The mud powder and sand and gravel aggregates are relatively loose. The mud powder is separated from the sand and gravel aggregates by the centrifugal force field of the primary cyclone separator, so that cyclone-separated aggregates with smaller particle size (smaller than the aperture of the vibrating screen) can also be collected.

[0019] The dry desliming method utilizing high-frequency screening and cyclone separation in this application embodiment mainly adopts the following technical concept: First, moisture is used to cause the mud powder in the sand and gravel aggregate to agglomerate and adhere into a mud layer. Then, drying is used to cause the mud layer to crack. Simultaneously, high-frequency vibration is used to peel the cracked mud layer off the surface of the sand and gravel aggregate. Because the cohesive force of the mud layer generated by the mud powder under the action of moisture is significantly stronger than the adhesion force between the mud layer and the sand and gravel aggregate, the cracked mud layer can be peeled off as a whole under the combined action of drying and high-frequency vibration. Therefore, this dry desliming method can effectively remove the fine mud powder adhering to the surface of the sand and gravel aggregate, obtaining relatively clean oversize aggregate. Furthermore, the overall particle size of the undersize material is small, and it can be carried by gas and sent to a primary cyclone separator for further separation, thus further forming relatively clean cyclone-separated aggregate. Detailed Implementation

[0020] To facilitate understanding of this application, a more complete description will be provided below. Preferred embodiments of this application are shown below. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0023] As described in the background section, dry desliming methods in related technologies mainly rely on wind separation. While wind separation is effective in separating coarse aggregates from fine dust, it generally suffers from the following problems: 1. Low efficiency in peeling and separating finely adhered mud powder; 2. Equipment prone to clogging, resulting in poor stability during continuous operation; 3. The overall process is crude, making it difficult to simultaneously meet the requirements of high aggregate cleanliness and high powder recovery rate. This application provides a dry desliming method utilizing a high-frequency screen and cyclone separation. This dry desliming method can effectively peel off fine mud powder adhering to the surface of sand and gravel aggregates, improving the cleanliness of the produced sand and gravel aggregates, and also producing sand and gravel aggregates with different particle size distributions. To improve the problems existing in the aforementioned wind separation desliming method, this application provides a dry desliming method utilizing a high-frequency screen and cyclone separation.

[0024] According to an embodiment of this application, the dry sludge removal method using high-frequency screen and cyclone separation includes the following steps S1 to S4.

[0025] Step S1: Provide wet sand and gravel aggregate with a moisture content of 15% or more.

[0026] In some embodiments of this application, the step of providing wet sand and gravel aggregate with a moisture content of 15% or more includes: providing raw sand and gravel aggregate; detecting the moisture content of the raw sand and gravel aggregate; and if the moisture content of the raw sand and gravel aggregate is less than 15%, spraying water into the raw sand and gravel aggregate to increase the moisture content to 15% or more. It is understood that mined raw sand and gravel aggregate usually contains a certain amount of moisture, but this moisture is usually insufficient for the mud powder in the raw sand and gravel aggregate to form a mud layer or mud lumps. In this case, additional water spraying is required to increase its moisture content. If the moisture content of the raw sand and gravel aggregate has reached 15% or more, the raw sand and gravel aggregate can also be directly used as wet sand and gravel aggregate.

[0027] Raw sand and gravel aggregate refers to a mixture containing sand and gravel particles formed after primary crushing and other treatments. Raw sand and gravel aggregate can be formed from sand and gravel raw materials through crushing, and typically contains sand and gravel particles, soil, and a small amount of moisture. In a further embodiment of this application, the step of providing raw sand and gravel aggregate may include: conveying the sand and gravel particles obtained after primary crushing and magnetic separation to remove iron from the sand and gravel raw materials to a closed feed hopper as raw sand and gravel aggregate.

[0028] The main purpose of controlling the moisture content of wet sand and gravel aggregates to above 15% is to allow the fine mud powder adhering to the surface of the aggregates to fully agglomerate and bind into a mud layer under the action of water, thus enabling the mud layer to peel off from the surface of the aggregates as a whole. After subsequent drying and high-frequency vibration treatment, the mud layer can be detached in sheets or blocks, thereby avoiding the problem of mud powder adhering to the surface of the aggregates and being difficult to remove.

[0029] In some embodiments of this application, the moisture content of the wet sand and gravel aggregate is 15% to 40%.

[0030] In some embodiments of this application, the wet aggregate may include sand and gravel particles, mud powder, and water. The mud powder accounts for 5% to 15% of the mass of the wet aggregate. The D50 particle size of the sand and gravel particles is 5 mm to 31.5 mm. If the particle size of the sand and gravel particles is too large, it is not suitable for subsequent high-frequency vibration treatment and should be crushed first before further processing.

[0031] It is understandable that wet sand and gravel aggregates can be placed in a vibrating feeder so that they can be delivered to subsequent processes at a stable and controllable flow rate.

[0032] Step S2: Heat the wet sand and gravel aggregate to above 60°C and reduce the moisture content of the wet sand and gravel aggregate to below 10%. Introduce the wet sand and gravel aggregate into the feed end of the vibrating screen and control the vibration frequency of the vibrating screen to above 45Hz to perform high-frequency vibration treatment on the wet sand and gravel aggregate, forming the oversize aggregate located above the vibrating screen and the undersize material falling through the vibrating screen.

[0033] In this process, wet sand and gravel aggregate is heated to above 60°C, reducing its moisture content to below 10%. Due to the uneven shrinkage between the surface and inner layers caused by the increased temperature and decreased moisture content, the mud layer gradually cracks. After being fed into the vibrating screen, the cracked mud layer, having undergone preliminary drying, is then subjected to high-frequency vibration, causing it to peel off completely from the aggregate surface. This process removes the highly adhesive fine mud powder from the sand and gravel aggregate.

[0034] In some embodiments of this application, the moisture content of the wet sand and gravel aggregate is 6% to 10% before it is introduced into the feed end of the vibrating screen. In this embodiment, controlling the moisture content of the wet sand and gravel aggregate to 6% to 10% ensures that the mud layer in the wet sand and gravel aggregate is in a state of cracking or about to crack but not pulverized. If the moisture content is below 6%, some of the mud layer in the wet sand and gravel aggregate may detach prematurely while other parts of the mud layer are difficult to detach. In fact, if the moisture content is too low, the mud layer may directly pulverize and be difficult to peel off as a whole.

[0035] In some embodiments of this application, during the high-frequency vibration treatment of wet sand and gravel aggregates, hot air at a temperature above 100°C is used to blow away the moisture in the wet sand and gravel aggregates. Using high-temperature hot air to blow away the wet sand and gravel aggregates during the high-frequency vibration treatment can slightly dry the still-moist mud layer, breaking the adhesion between the mud layer and the aggregate particles on the screen. This makes it easier to peel off the aggregate as a whole during high-frequency vibration treatment, resulting in cleaner aggregate on the screen.

[0036] In some embodiments of this application, during the high-frequency vibration treatment of wet sand and gravel aggregates, the vibration frequency of the vibrating screen is controlled at 45Hz~60Hz, and the amplitude of the vibrating screen is controlled at 2mm~4mm. The vibration frequency of 45Hz~60Hz and the amplitude of 2mm~4mm are relatively suitable. Through the action of this high-frequency micro-amplitude vibration, the vibration energy can more effectively act on the mud layer on the surface of the aggregate particles on the screen, producing a shearing and kneading effect, making it easier for the adhered mud layer to peel off the surface of the aggregate on the screen as a whole. If the amplitude is too small, the wet sand and gravel aggregates are difficult to convey forward on the vibrating screen. If the amplitude is too high, the aggregate on the screen will be thrown too high, and the mud layer will easily turn into dust and re-adhere to the surface of the aggregate on the screen, which is detrimental to the cleanliness of the aggregate on the screen.

[0037] In some embodiments of this application, during the high-frequency vibration treatment of wet sand and gravel aggregate, the moisture content of the wet sand and gravel aggregate is monitored at or before the feed end, and the vibration frequency and / or amplitude of the vibrating screen are adjusted according to the monitored moisture content. Specifically, when adjusting the vibration frequency, the vibration frequency decreases as the moisture content increases; when adjusting the amplitude, the amplitude increases as the moisture content increases. It is understood that when the moisture content is high, the adhesion between the mud layer and the sand and gravel aggregate is relatively large. Reducing the vibration frequency helps to prolong the vibration time, and increasing the amplitude helps to provide stronger crushing force to overcome the increased adhesion.

[0038] In some embodiments of this application, the screen aperture at the feed end of the vibrating screen is larger than the screen aperture at the discharge end of the vibrating screen.

[0039] In a further embodiment of this application, the screen aperture at the feed end is 4mm~8mm, and the screen aperture at the discharge end is 2.5mm~4mm. Near the feed end, the screen primarily peels off larger, cracked mud lumps, while near the discharge end, it primarily peels off smaller mud lumps or mud powder. Setting the screen aperture at the feed end to be relatively large and the screen aperture at the discharge end to be relatively small facilitates the peeled mud lumps passing through the screen to become undersize material, while also reducing the loss of aggregate on the screen. If the overall screen aperture is set to be relatively large (e.g., greater than 8mm), although the peeled mud lumps can fall sufficiently, the loss of aggregate on the screen is also greater, and the wider particle size distribution of the undersize material is not conducive to the subsequent primary separation process by the primary cyclone separator. If the overall screen aperture is set to be relatively small (e.g., less than 2.5mm), the peeled mud lumps are difficult to fall sufficiently, and the oversize material will still contain a large amount of mud lumps, which is not conducive to obtaining clean sand and gravel aggregate.

[0040] It is understood that after prior drying and high-frequency screening, the material above the vibrating screen is relatively large in particle size (greater than the aperture of the vibrating screen) and relatively clean oversize aggregate. The oversize aggregate continues to move forward along the screen surface of the vibrating screen and is eventually discharged through the discharge end. After collection, it can be used as clean sand and gravel aggregate. In some embodiments of this application, the particle size of the oversize aggregate is greater than 2.5 mm.

[0041] It is understood that the material located below the vibrating screen includes aggregates, sand, and mud with smaller particle sizes (smaller than the aperture of the vibrating screen, for example, less than 2.5 mm). The overall particle size of the material passing through the screen is relatively small. The material passing through the screen can be further separated to obtain usable aggregates with smaller particle sizes.

[0042] Step S3: The screened material is fed into a primary cyclone separator for primary separation to form cyclone separated aggregate.

[0043] In some embodiments of this application, during the process of feeding the screened material into a primary cyclone separator for primary separation, cyclone-separated aggregate and primary gas-solid mixture are separated.

[0044] In some embodiments of this application, the high-frequency vibration treatment of wet sand and gravel aggregates further includes the following steps: during the descent of the undersize material, a carrier gas is used to carry at least a portion of the undersize material, and the carrier gas and the carried undersize material are conveyed to a primary cyclone separator. In this embodiment, the carrier gas can only carry particles with smaller diameters, thus it can screen the undersize material, separating the relatively small (e.g., less than 0.6 mm) powdery undersize material from other larger blocky undersize material (mainly mud lumps). Simultaneously, the carrier gas also carries this portion of the undersize material into the primary cyclone separator. Furthermore, using carrier gas for in-situ separation during the descent of the undersize material prevents the escape of small-diameter powdery undersize material, reducing the loss of aggregate separated by the cyclone separator and lowering environmental pollution.

[0045] In some embodiments of this application, the carrier gas flow rate is 16 m / s to 22 m / s. Controlling the carrier gas flow rate helps to control the particle size range of the powdered undersize material that the carrier gas can carry, preventing excessively large particles from being sent into the primary cyclone separator, thereby preventing the primary cyclone separator from being worn or blocked by excessively large particles.

[0046] In some embodiments of this application, the carrier gas enters the primary cyclone separator tangentially. The primary cyclone separator is designed as a standard tangential reverse flow type, and its cylinder diameter is determined according to the system's processing air volume and the target cutting particle size.

[0047] In some embodiments of this application, the D50 particle size of the cyclone separator aggregate is 0.15 mm to 0.6 mm. During the primary separation process, the high-speed rotating airflow generates a strong centrifugal force. Larger, denser aggregate particles are thrown against the separator wall under centrifugal force and ultimately discharged from the discharge port of the primary cyclone separator as cyclone separator aggregate. Meanwhile, mud lumps are further broken down into finer mud powder under centrifugal force, and this finer mud powder remains in the carrier air. Therefore, the cyclone separator aggregate has a lower mud content and a higher degree of cleanliness. The cyclone separator aggregate can be used for low-grade mortar or roadbed materials, depending on its quality.

[0048] After primary separation, most of the relatively large-sized aggregates in the undersize material are discharged from the discharge port of the primary cyclone separator as cyclone separated aggregate. The carrier gas mainly carries the remaining finer particles (mud powder with a particle size of less than 0.15 mm), forming a primary gas-solid mixture. The separated carrier gas is discharged from the exhaust pipe of the primary cyclone separator.

[0049] In some embodiments of this application, the primary separation process further includes a step of monitoring the dust concentration of the carrier gas discharged from the primary cyclone separator, and adjusting the carrier gas flow rate based on the monitored dust concentration. It is understood that if the dust concentration is abnormally high, it indicates a decrease in the separation effect of the primary separation process, possibly because the carrier gas flow rate deviates from the design value. Adjusting the carrier gas flow rate in this case can prevent excessively high dust concentrations in the discharged carrier gas.

[0050] Since the carrier gas after separation still contains a significant amount of fine mud particles, it is not suitable for direct discharge and requires further treatment. This application further provides the following step S4 in its embodiments.

[0051] Step S4: The primary gas-solid mixture is fed into a secondary cyclone separator for secondary separation to separate at least a portion of the mud powder from the primary gas-solid mixture. The D50 particle size of the separated mud powder is smaller than the D50 particle size of the aggregate separated by the cyclone separator. The cylinder diameter of the secondary cyclone separator is smaller than that of the primary cyclone separator.

[0052] In this application, the main function of the secondary cyclone separator is to remove finer particles of sludge from the primary gas-solid mixture, thereby reducing its air pollution. The primary gas-solid mixture, after being processed by the secondary cyclone separator, can be discharged into filters or other equipment or structures for final purification.

[0053] In some embodiments of this application, during the secondary separation process, the D50 particle size of the separated mud powder is less than 0.15 mm.

[0054] After steps S1 to S4, a dry desliming method using high-frequency screening and cyclone separation can be completed. It can be understood that this dry desliming method only requires a certain moisture content in the initial raw materials. In the actual desliming process, the moisture in the sand and gravel aggregates will be removed, and there is no need to introduce additional water for washing; therefore, it is a dry desliming method.

[0055] The dry desliming method utilizing high-frequency screening and cyclone separation in this application mainly adopts the following technical concept: First, moisture is used to cause the mud powder in the sand and gravel aggregate to agglomerate and adhere into a mud layer. Then, drying is used to cause the mud layer to crack. Simultaneously, high-frequency vibration is used to peel the cracked mud layer off the surface of the sand and gravel aggregate. Because the cohesive force of the mud layer generated by the mud powder under the action of moisture is significantly stronger than the adhesion force between the mud layer and the aggregate, the cracked mud layer can be peeled off as a whole under the combined action of drying and high-frequency vibration. Therefore, this dry desliming method can effectively remove the fine mud powder adhering to the surface of the sand and gravel aggregate, obtaining relatively clean oversize aggregate. Furthermore, the overall particle size of the undersize material is small, allowing it to be carried by gas and sent to a primary cyclone separator for further separation, thus further forming relatively clean cyclone-separated aggregate. Compared to the wind separation method in related technologies, the dry desliming method using high-frequency screening and cyclone separation in this application embodiment can effectively remove the fine mud powder adhering to the surface of sand and gravel aggregates, improve the cleanliness of the produced sand and gravel aggregates, and also produce sand and gravel aggregates with different particle size distributions.

[0056] The above detailed description is a specific description of the feasible embodiments of this application. These embodiments are not intended to limit the patent scope of this application. All equivalent implementations or modifications that do not depart from the scope of this application should be included in the patent scope of this application.

Claims

1. A dry sludge removal method utilizing high-frequency screening and cyclone separation, characterized in that, Includes the following steps: Provide wet sand and gravel aggregates with a moisture content of 15% or higher; The wet sand and gravel aggregate is heated to above 60°C to reduce its moisture content to below 10%. The wet sand and gravel aggregate is then fed into the feed end of a vibrating screen, and the vibration frequency of the screen is controlled to be above 45Hz to subject the wet sand and gravel aggregate to high-frequency vibration treatment, forming oversize aggregate above the vibrating screen and undersize material falling through the screen; and... The screened material is fed into a primary cyclone separator for primary separation to form cyclone separated aggregate. Before the wet sand and gravel aggregate is introduced into the feed end of the vibrating screen, the moisture content of the wet sand and gravel aggregate is 6%~10%. During the high-frequency vibration treatment of the wet sand and gravel aggregate, hot air at a temperature of over 100°C is used to blow the wet sand and gravel aggregate to remove the moisture in the wet sand and gravel aggregate.

2. The dry sludge removal method using high-frequency screening and cyclone separation according to claim 1, characterized in that, During the high-frequency vibration treatment of the wet sand and gravel aggregate, the vibration frequency of the vibrating screen is controlled at 45Hz~60Hz, and the amplitude of the vibrating screen is controlled at 2mm~4mm.

3. The dry sludge removal method using high-frequency screening and cyclone separation according to claim 1, characterized in that, The mesh size at the feed end of the vibrating screen is larger than the mesh size at the discharge end of the vibrating screen.

4. The dry sludge removal method using high-frequency screening and cyclone separation according to claim 3, characterized in that, During the high-frequency vibration treatment of the wet sand and gravel aggregate, the moisture content of the wet sand and gravel aggregate is monitored at or before the feed end, and the vibration frequency and / or amplitude of the vibrating screen is adjusted according to the monitored moisture content; wherein, when adjusting the vibration frequency of the vibrating screen, the vibration frequency of the vibrating screen decreases as the moisture content increases; when adjusting the amplitude of the vibrating screen, the amplitude of the vibrating screen increases as the moisture content increases.

5. The dry sludge removal method using high-frequency screening and cyclone separation according to any one of claims 1 to 4, characterized in that, The process of high-frequency vibration treatment of the wet sand and gravel aggregate also includes the following steps: during the falling process of the undersize material, at least a portion of the undersize material is carried by carrier gas, and the carrier gas and the undersize material it carries are transported to the primary cyclone separator.

6. The dry sludge removal method using high-frequency screening and cyclone separation according to claim 5, characterized in that, The flow rate of the carrier gas is 16 m / s to 22 m / s.

7. The dry sludge removal method using high-frequency screening and cyclone separation according to claim 5, characterized in that, The primary separation process also includes monitoring the dust concentration of the carrier gas discharged from the primary cyclone separator and adjusting the flow rate of the carrier gas based on the monitored dust concentration.

8. The dry sludge removal method using high-frequency screening and cyclone separation according to claim 5, characterized in that, The D50 particle size of the cyclone-separated aggregate is 0.15mm~0.6mm.

9. The dry sludge removal method using high-frequency screening and cyclone separation according to claim 8, characterized in that, During the process of feeding the screened material into a primary cyclone separator for primary separation, cyclone-separated aggregate and primary gas-solid mixture are separated. After the primary separation, the process further includes the following step: feeding the primary gas-solid mixture into a secondary cyclone separator for secondary separation to separate at least a portion of the mud powder in the primary gas-solid mixture, wherein the D50 particle size of the separated mud powder is smaller than the D50 particle size of the cyclone-separated aggregate; wherein the cylinder diameter of the secondary cyclone separator is smaller than the cylinder diameter of the primary cyclone separator.

10. The dry desliming method using high-frequency screening and cyclone separation according to any one of claims 1 to 6 and 8 to 9, characterized in that, The steps for providing wet sand and gravel aggregate with a moisture content of 15% or more include: providing raw sand and gravel aggregate, testing the moisture content of the raw sand and gravel aggregate, and if the moisture content of the raw sand and gravel aggregate is less than 15%, spraying water into the raw sand and gravel aggregate to increase the moisture content to more than 15%.