A spiral pelletizing device, a combined step-by-step pelletizing system and its application

Abstract

The present invention provides a spiral pelletizing device, a combined step-by-step pelletizing system, and applications thereof. The spiral pelletizing device includes at least one spiral pelletizing device, the spiral pelletizing device including a vertical pelletizing cylinder, a rotating shaft installed in the vertical pelletizing cylinder, a spiral auger installed on the rotating shaft in the vertical pelletizing cylinder, and a water mist nozzle installed on the inner side wall of the vertical pelletizing cylinder; the combined step-by-step pelletizing system includes at least one spiral pelletizing device and at least one cylinder-type pelletizing machine; the spiral pelletizing device and the cylinder-type pelletizing machine are interconnected; the cylinder-type pelletizing machine includes a pelletizing cylinder, the pelletizing cylinder is arranged to be inclined downward, and the cylinder-type pelletizing machine also includes a feeding mechanism and a water adding mechanism. The spiral pelletizing device of the present invention has a simple structure and is easy to operate. It is particularly suitable for the preparation of ceramsite pellets and the like, and has low equipment cost. The spiral pelletizing device and the combined step-by-step pelletizing system are both suitable for the continuous production of pellets containing a multi-layer structure and have high production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of pelletizing equipment, and in particular relates to a spiral pelletizing equipment, a combined step-by-step pelletizing system and applications thereof. Background Art

[0002] Currently, pelletizing machines are widely used in industries such as metallurgy, cement, and ceramsite. Disc pelletizers are a common device for producing raw pellets in the pelletizing process. Disc pelletizers are disc-shaped pelletizing equipment that transforms fine-grained powdered material into pellets of a size that meets the requirements of the next process. They are used in the metallurgical industry to produce ironmaking pellets and pelletize non-ferrous metal mixed concentrates, improving technical and economic performance. The pelletized material rolls and rubs within the tilted, rotating disc, driven by gravity, centrifugal force, and friction. After adding appropriate moisture, it forms pellets. The fine-grained material rolls on the moist surface of the pellets, causing them to grow and develop a certain strength. Different pellets automatically follow different paths within the disc, and finished pellets that meet the requirements are discharged from the disc.

[0003] The existing disc pelletizing machine has a complex structure and the equipment cost is high when using it to prepare ceramsite pellets. Therefore, it is very necessary to develop a pelletizing device with a simple structure, low cost, and suitable for preparing ceramsite pellets. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the above background technology and provide a spiral pelletizing equipment, a combined step-by-step pelletizing system and applications thereof.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A spiral ball-making equipment comprises at least one spiral ball-making device, wherein the spiral ball-making device comprises a vertical ball-making cylinder, wherein a coaxial rotating shaft is installed in the vertical ball-making cylinder, and the rotating shaft is driven to rotate by a rotating shaft driving device, and a spiral auger is installed on the rotating shaft in the vertical ball-making cylinder, and a water mist nozzle is installed on the inner side wall of the vertical ball-making cylinder, the upper end of the vertical ball-making cylinder is connected to a feed pipe, and the bottom end is connected to a discharge pipe, and a valve is installed on the discharge pipe.

[0007] Furthermore, the spiral pelletizing device also includes a screening machine connected to the discharge pipe and capable of screening out pellets of target particle size. The screening machine is provided with a target pellet discharge pipe for guiding the pellets of target particle size out of the screening machine.

[0008] Furthermore, the screening machine includes a screening drum, in which a vibrating screen 1 and a vibrating screen 2 are arranged in sequence from top to bottom, the screen hole diameter of the screen 1 is the maximum value of the target pellet particle size, and the screen hole diameter of the screen 2 is the minimum value of the target pellet particle size, and the bottom end of the screening drum is connected to a screening material discharge pipe; the screening drum corresponding to the top of the screen 1 is connected to a large pellet discharge pipe, and the screening drum corresponding to the screen 2 and the screen 1 is connected to the target pellet discharge pipe.

[0009] Furthermore, the spiral ball-making equipment includes a plurality of spiral ball-making devices, which are arranged in sequence from top to bottom. In the two upper and lower adjacent spiral ball-making devices, the target pellet discharge pipe of the upper spiral ball-making device is connected to the feed port of the vertical ball-making cylinder in the lower spiral ball-making device through a material guide pipe.

[0010] As a general inventive concept, the present invention provides a combined step-by-step pelletizing system, which includes at least one spiral pelletizing device and at least one drum pelletizing machine; the spiral pelletizing device and the drum pelletizing machine are interconnected;

[0011] The cylinder-type pelletizing machine includes a pelletizing cylinder, which is provided with a pelletizing cylinder feed port and a pelletizing cylinder discharge port. The pelletizing cylinder is tilted downward. The cylinder-type pelletizing machine also includes a feeding mechanism for adding materials and a water adding mechanism for adding water.

[0012] Furthermore, the pelletizing cylinder is composed of at least one rotatable pelletizing sub-cylinder along its length, the pelletizing sub-cylinder being open at both ends and having an annular baffle plate coaxial with the pelletizing sub-cylinder sealed and fixed on the inner side wall of the discharge end; the inner diameter of the pelletizing sub-cylinder is unchanged;

[0013] Two adjacent pelletizing cylinders are sealed and rotatably connected, and each of the pelletizing cylinders is driven to rotate by a pelletizing cylinder driving device; along the downward tilt of the pelletizing cylinder, the inner diameters of the plurality of annular baffles decrease in sequence.

[0014] Furthermore, a circle of sealing ring is fixed on the inner wall of the discharge end of the pelletizing cylinder, and the sealing ring is located on the outside of the corresponding annular baffle plate; the outer end of the sealing ring extends into the adjacent pelletizing cylinder below, and a clamping ring is provided between the sealing ring and the inner wall of the adjacent pelletizing cylinder below, and the clamping ring is fixedly connected to the pelletizing cylinder, and the clamping ring is pressed and rotatably connected to the sealing ring.

[0015] Furthermore, 3-8 material guide plates are evenly fixed on the inner side wall of each of the pelletizing cylinders around the axis of the pelletizing cylinder, and the material guide plates are inclined relative to the axis of the pelletizing cylinder.

[0016] Furthermore, the feeding mechanism is a screw feeder, and the screw feeder extends from the outer end of the pelletizing cylinder to the corresponding pelletizing sub-cylinder along the length direction of the pelletizing cylinder;

[0017] The water adding mechanism includes a water inlet pipe, which is fixed on the corresponding screw feeder and extends to the corresponding pelletizing cylinder. At least one water mist nozzle 2 is installed on the water inlet pipe in the pelletizing cylinder.

[0018] Furthermore, the combined step-by-step pelletizing system includes a spiral pelletizing device and a drum pelletizing machine connected in sequence, and the discharge end of the spiral pelletizing device is connected to the feed end of the drum pelletizing machine.

[0019] As a general inventive concept, the present invention provides an application of a combined step-by-step pelletizing system, wherein the combined step-by-step pelletizing system is applied to prepare ceramsite pellets;

[0020] The combined step-by-step pelletizing system for preparing the ceramsite pellets includes a spiral pelletizing device and a drum pelletizing machine; the spiral pelletizing device includes two spiral pelletizing devices, and the drum pelletizing machine's pelletizing cylinder is composed of two ball-forming sub-cylinders along its length direction; the target pellet discharge pipe of the spiral pelletizing device located at the bottom of the spiral pelletizing device is connected to the feed end of the drum pelletizing machine;

[0021] The preparation method of ceramsite pellets comprises the following steps: preparing pore-forming agent mother balls in an upper spiral pelletizing device; adhering heavy metal tailing powder I to the pore-forming agent mother balls in a lower spiral pelletizing device to form raw material balls I; adhering a mixture containing a chemical composition adjuster and heavy metal tailing powder II to the raw material balls I in a pelletizing separation cylinder located above to form raw material balls II; and finally adhering a mixture containing a flux and heavy metal tailing powder III to the raw material balls II in a pelletizing separation cylinder located below to obtain ceramsite pellets.

[0022] Furthermore, in the raw materials for preparing ceramsite pellets, based on the total mass of the pore-forming agent, chemical composition adjusting agent, fluxing agent, and heavy metal tailings powder as 100%, the pore-forming agent accounts for 5-15%, the chemical composition adjusting agent accounts for 5-40%, the fluxing agent accounts for 5-15%, and the heavy metal tailings powder accounts for 40-85%; the heavy metal tailings powder includes heavy metal tailings powder 1, heavy metal tailings powder 2, and heavy metal tailings powder 3;

[0023] The particle size range of the pore-forming agent mother ball is 2-6 mm; the pore-forming agent includes at least one of an organic pore-forming agent and an inorganic pore-forming agent; the heavy metal tailings powder includes at least one of copper tailings, lead tailings, zinc tailings, gold tailings, silver tailings, cadmium tailings, and chromium tailings; the chemical composition adjuster includes quartz; and the flux includes one or more of porcelain stone, fly ash, and zeolite.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The spiral pelletizing equipment of the present invention has a simple structure and is easy to operate. It is particularly suitable for the preparation of ceramsite pellets and the like, and has low equipment cost. The special screening machine is provided to facilitate screening and quickly collect pellets of target particle size.

[0026] 2. When the spiral pelletizing equipment of the present invention includes multiple spiral pelletizing devices, it can be applied to the continuous production of pellets with a multi-layer structure, with high production efficiency and low cost.

[0027] 3. The combined step-by-step pelletizing system of the present invention is applicable to the continuous production of pellets with multi-layer structures. It uses a spiral pelletizing device combined with a drum pelletizing machine. The spiral pelletizing device has a more refined pelletizing process and is more suitable for pellets with strict particle size requirements or multi-layer structures. During the preparation of mother balls, the pellet size is small, the material is small, and the pelletizing process requires more precision. The centrifugal force generated by the material during the spiral rotation can increase the capillary force of the bulk material and promote its ball formation. In this case, a spiral pelletizing machine is more suitable. As the pellet size increases, the amount of material added increases, and the pelletizing process becomes slightly rough. In this case, a drum pelletizing machine is more suitable. When preparing pellets, the drum pelletizing machine has slightly lower requirements for the target pellet size range and the compactness of the pellets than the spiral pelletizing device, but the drum pelletizing machine has higher efficiency. The combination of the two can achieve high efficiency while controlling the quality of the resulting pellet product within a relatively optimal range. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 It is a structural schematic diagram of the spiral pelletizing equipment in Example 1;

[0030] Figure 2 It is a structural schematic diagram of the spiral pelletizing equipment in Example 2;

[0031] Figure 3 It is a structural schematic diagram of the spiral pelletizing equipment in Example 3;

[0032] Figure 4 It is a structural diagram of a combined step-by-step pelletizing system;

[0033] Figure 5 It is a structural diagram of another combined step-by-step pelletizing system;

[0034] Figure 6 for Figure 4 Cross-sectional view of the middle-cylinder pelletizing machine;

[0035] Figure 7 It is a structural diagram of another combined step-by-step pelletizing system;

[0036] Figure 8 for Figure 7 Cross-sectional view of the middle-cylinder pelletizing machine;

[0037] Figure 9 for Figure 8 Enlarged view of point A in the middle;

[0038] Figure 10 for Figure 8 Schematic diagram of the three-dimensional structure of the middle pelletizing cylinder;

[0039] Figure 11 It is a structural schematic diagram of the annular baffle plate.

[0040] Legend:

[0041] 1. Spiral pelletizing device; 11. Vertical pelletizing cylinder; 12. Rotating shaft; 13. Rotating shaft driving device; 14. Spiral auger; 15. Water mist nozzle 1; 16. Feed pipe; 17. Discharge pipe; 18. Feed port; 19. Screening machine; 1901. Screening cylinder; 1902. Screen 1; 1903. Screen 2; 1904. Target pellet discharge pipe; 1905. Screened material discharge pipe; 1906. Large pellet discharge pipe; 2. Cylinder-type pelletizing machine; 21. Pelletizing cylinder; 2101. Pelletizing separator cylinder; 22. Annular baffle plate; 23. Feed mechanism; 24. Water adding mechanism; 2401. Water inlet pipe; 2402. Water mist nozzle 2; 25. Pelletizing separator cylinder driving device; 26. Sealing ring; 27. Pressure ring; 28. Guide plate. DETAILED DESCRIPTION

[0042] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0043] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0044] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0045] Example 1:

[0046] like Figure 1 As shown, a spiral ball-making equipment includes at least one spiral ball-making device 1, and the spiral ball-making device includes 1 including a vertical ball-making cylinder 11, in which a coaxial rotating shaft 12 is installed, and the rotating shaft 12 is driven to rotate by a rotating shaft driving device 13, and a spiral auger 14 is installed on the rotating shaft 12 in the vertical ball-making cylinder 11, and a water mist nozzle 15 is installed on the inner side wall of the vertical ball-making cylinder 11, and the upper end of the vertical ball-making cylinder 11 is connected to a feed pipe 16, and the bottom end is connected to a discharge pipe 17, and a valve is installed on the discharge pipe 17.

[0047] The spiral pelletizing equipment in this embodiment, when preparing pellets (such as ceramsite pellets), adds pellet raw materials through the feed pipe 16, and then drives the shaft 12 to rotate through the shaft driving device 13, and the shaft 12 drives the spiral auger 14 to rotate. During the rotation process, water for preparing pellets is sprayed in through the water mist nozzle 15. The pellet raw materials combined with water gradually form pellets under the high-speed rotation of the spiral auger 14, and the pellets gradually increase in size to prepare pellets within the target particle size range.

[0048] In the spiral pelletizing equipment of this embodiment, fine particles are wetted with water in a vertical pelletizing drum 11 and then formed into balls through mechanical and capillary forces. Capillary attraction, friction between particles, and molecular attraction also provide the green balls with a certain mechanical strength.

[0049] The spiral pelletizing equipment has a simple structure and is easy to operate, is particularly suitable for the preparation of ceramsite pellets, and has low equipment cost.

[0050] In this embodiment, the above-mentioned shaft driving device 13 can be a conventional driving device in the field that can drive the shaft 12 to rotate, and can specifically include a motor and a reducer. The output shaft of the motor is connected to the reducer, and the end of the output shaft of the reducer is connected to turntable 1. The upper and lower ends of the shaft 12 are respectively sealed and rotatably connected to the top plate and bottom plate of the vertical pelletizing cylinder 11. Turntable 2 is fixed on the shaft 12 located above the top plate, and turntable 1 and turntable 2 are connected by belt drive.

[0051] In this embodiment, two vertical water mist nozzles 15 are symmetrically arranged on the upper sidewall of the vertical pelletizing drum 11. Each vertical water mist nozzle 15 includes at least three water mist nozzles 15, each of which is connected to a corresponding water supply pipe. The installation of these two vertical water mist nozzles 15 ensures that the water mist injected into the vertical pelletizing drum 11 is more uniform, thereby enhancing the pelletizing effect.

[0052] In this embodiment, a feed port 18 is further provided at the upper end of the vertical pelletizing cylinder 11. The feed port 18 facilitates the addition of other materials or connection with other mechanisms.

[0053] Example 2:

[0054] like Figure 2 As shown, a spiral pelletizing device is shown. Unlike Example 1, the spiral pelletizing device 1 further includes a screening machine 19 connected to the discharge pipe 17 and capable of screening out pellets of a target particle size. The screening machine 19 is provided with a target pellet discharge pipe 1904 for guiding the pellets of the target particle size out of the screening machine 19. By providing the screening machine 19, the prepared pellets that meet the particle size requirements can be screened out and discharged through the target pellet discharge pipe 1904.

[0055] In this embodiment, the screening machine 19 can be a conventional screening machine in the technical field that can screen out the prepared pellets that meet the particle size requirements. Preferably, the screening machine 19 may include a screening drum 1901, in which a vibrating screen 1902 and a vibrating screen 2 1903 are arranged from top to bottom. The sieve hole diameter of screen 1902 is the maximum value of the target pellet particle size, and the sieve hole diameter of screen 2 1903 is the minimum value of the target pellet particle size. The bottom end of the screening drum 1901 is connected to a screening material discharge pipe 1905; the screening drum 1901 corresponding to the top of the screen 1902 is connected to a large pellet discharge pipe 1906 that can discharge the pellets that cannot pass through the sieve holes of screen 1902 from the screening drum 1901; the screening drum 1901 corresponding to the screen 2 1903 and the screen 1 1902 is connected to a target pellet discharge pipe 1904 that can discharge the pellets that cannot pass through the mesh holes of screen 2 1903 from the screening drum 1901.

[0056] The screening machine 19 has a simple structure, convenient screening, and can quickly collect pellets of target particle size. The large pellets obtained from the large pellet discharge pipe 1906 and the fine material discharged from the screening material discharge pipe 1905 can be crushed and returned to the vertical pelletizing drum 11 as raw materials for pelletization.

[0057] In this embodiment, a mounting plate is fixed at the middle lower end of screen 1902 and screen 2 1903, a vibration motor is installed at the lower end of the mounting plate, strong springs are installed at the lower ends of both sides of screen 1902 and screen 2 1903, the lower ends of the strong springs are fixedly installed on the fixed plate, and the fixed plate is fixedly connected to the side wall of the screening cylinder 1901; screen 1902 is tilted downward toward the large pellet discharge pipe 1906, and screen 2 1903 is tilted downward toward the target pellet discharge pipe 1904, which is conducive to the discharge of pellets; a guide plate is installed at the bottom end of the screening cylinder 1901 to guide the screened material screened by screen 2 1903 to the screened material discharge pipe 1905, which can facilitate the discharge of the screened material.

[0058] Example 3:

[0059] like Figure 3As shown, a spiral pelletizing device includes multiple (for example, 2-4) spiral pelletizing devices 1 in Example 2, and the multiple spiral pelletizing devices 1 are arranged in sequence from top to bottom. In the two upper and lower adjacent spiral pelletizing devices 1, the target pellet discharge pipe 1904 of the upper spiral pelletizing device 1 is connected to the feed port 18 of the vertical pelletizing cylinder 11 in the lower spiral pelletizing device 1 through a material guide pipe.

[0060] The spiral pelletizing equipment in this embodiment is suitable for producing pellets with a multi-layer structure, which include a mother ball, and multiple layers of coating layers are sequentially arranged on the outside of the mother ball. The vertical pelletizing drum 11 at the top is used to prepare the mother ball, and then the pellets of target particle size are introduced into the vertical pelletizing drum 11 below it through the corresponding screening machine 19, and the raw materials for preparing the corresponding coating layer are added through the feeding pipe 16. Then, the rotating shaft 12 is driven to rotate by the corresponding rotating shaft driving device 13, and the rotating shaft 12 drives the spiral auger 14 to rotate. During the rotation, water mist is sprayed through the water mist nozzle 15 to coat the mother ball with the raw materials for the coating layer. After the preparation is completed, the pellets of target particle size are introduced into the vertical pelletizing drum 11 below it through the corresponding screening machine 19 to continue another layer of coating.

[0061] The spiral pelletizing equipment in this embodiment is applicable to the continuous production of pellets with a multi-layer structure, and has high production efficiency and low cost.

[0062] In this embodiment, the material guide pipe may be connected to a crushed material feed port, which can facilitate the addition of some raw materials together with pellets of target particle size into the vertical pelletizing cylinder 11 below.

[0063] Example 4:

[0064] like Figure 4-11 As shown, a combined step-by-step pelletizing system includes at least one spiral pelletizing device as in Example 2 or Example 3 and at least one drum pelletizing machine 2; the spiral pelletizing device and the drum pelletizing machine 2 are connected to each other;

[0065] The drum-type pelletizing machine 2 includes a pelletizing drum 21 , which is provided with a pelletizing drum feed port and a pelletizing drum discharge port. The pelletizing drum 21 is tilted downward. The drum-type pelletizing machine 2 also includes a feeding mechanism 23 for adding materials and a water adding mechanism 24 for adding water.

[0066] In this embodiment, the pelletizing cylinder 21 is composed of at least one rotatable pelletizing sub-cylinder 2101 along its length. The pelletizing sub-cylinder 2101 is open at both ends, and an annular baffle plate 22 coaxial with the pelletizing sub-cylinder 2101 is sealed and fixed to the inner side wall of the discharge end. The inner diameter of the pelletizing sub-cylinder 2101 remains unchanged.

[0067] In the drum-type pelletizing machine 2 of this embodiment, when the pelletizing sub-drum 2101 rotates, the pelletizing material contained therein, through the combined action of various forces during the rotation process, combined with the water added by the water adding mechanism 24, can produce mother ball pellets of suitable particle size or produce pellets further coated with a coating layer on the pellets of the previous process. The pellets can only pass through the corresponding annular material baffle 22 and enter the next process after the particle size reaches the target particle size. In this embodiment, the pellets produced by each pelletizing sub-drum 2101 can only pass through the corresponding annular material baffle 22 and enter the next process after reaching the target particle size. Otherwise, they will be blocked by the annular material baffle 22 and continue to be coated with the raw materials in the corresponding ball-forming sub-drum 2101 until the particle size reaches the target particle size.

[0068] In this embodiment, the pelletizing cylinder 21 can be composed of a pelletizing sub-cylinder 2101 along its length direction (such as Figure 6 As shown). In the above combined step-by-step pelletizing system, the drum-type pelletizing machine 2 and the spiral-type pelletizing equipment can be freely combined according to the actual process. For example, Figure 4 As shown, the target pellet discharge pipe 1904 in the spiral pelletizing device is connected to the feed end of the cylinder-type pelletizing machine 2 below, and the discharge end of the cylinder-type pelletizing machine 2 is connected to the feed port 18 of the spiral pelletizing device below. The feed port 18 is provided with a feed funnel. The target pellet discharge pipe 1904 of the spiral pelletizing device is connected to the feed end of the cylinder-type pelletizing machine 2 below. Figure 5 As shown, the discharge end of the cylinder-type pelletizing machine 2 is connected to the feed port 18 of the adjacent spiral-type pelletizing equipment below, and a feed funnel may be provided on the feed port 18. The target pellet discharge pipe 1904 of the spiral pelletizing equipment is connected to the feed end of the cylinder-type pelletizing machine 2 below, and the discharge end of the cylinder-type pelletizing machine 2 is connected to the feed port 18 of the adjacent spiral pelletizing equipment below.

[0069] In this embodiment, the pelletizing cylinder 21 is composed of a plurality of (for example, 2-4) pelletizing sub-cylinders 2101 along its length direction. Two adjacent pelletizing sub-cylinders 2101 are sealed and rotatably connected, and each pelletizing sub-cylinder 2101 is driven to rotate by a pelletizing sub-cylinder driving device 25. As the pelletizing cylinder 21 tilts downward, the inner diameters of the plurality of annular baffles 22 decrease in sequence, which means that the difference between the outer diameter and the inner diameter of the plurality of annular baffles 22 increases in sequence. The further downward, the larger the particle size of the pellets that can pass through the corresponding annular baffles 22. Figure 8-11 In this embodiment, the pellets produced by each pelletizing cylinder 2101 reach the target particle size and can either pass through the corresponding annular baffle plate 22 and enter the next pelletizing cylinder 2101. Otherwise, they will be blocked by the annular baffle plate 22 and continue to coat the raw materials in the pelletizing cylinder 2101 until the particle size reaches the target.

[0070] In this embodiment, a circle of sealing ring 26 is fixed on the inner wall of the discharge end of the pelletizing cylinder 2101, and the sealing ring 26 is located on the outside of the corresponding annular baffle plate 22; the outer end of the sealing ring 26 extends into the adjacent pelletizing cylinder 2101 below, and a clamping ring 27 is provided between the sealing ring 26 and the inner wall of the adjacent pelletizing cylinder 2101 below. The clamping ring 27 is fixedly connected to the pelletizing cylinder 2101, and the clamping ring 27 is pressed and rotatably connected to the sealing ring 26.

[0071] By providing the sealing ring 26 and the clamping ring 27, the sealing performance between the adjacent pelletizing cylinders 2101 is improved, and an elastic sealing rotation connection can be achieved. During operation, the cylinder-type pelletizing machine can work more stably and have a longer service life.

[0072] In this embodiment, 3-8 guide plates 28 are evenly fixed on the inner side wall of each pelletizing cylinder 2101 around the axis of the pelletizing cylinder 2101 , and the guide plates 28 are inclined relative to the axis of the pelletizing cylinder 2101 .

[0073] The guide plate 28 prevents material in the pelletizing area from accumulating at the bottom of the pelletizing drum 2101 during its rotation, thereby further dispersing the material. The guide plate 28 is tilted relative to the axis of the pelletizing drum 2101, allowing any remaining material on the guide plate 28 to slide back into the drum 21. The height of the guide plate 28 along the radial direction of the drum 2101 is lower than the height of the corresponding inner diameter of the annular baffle plate 22.

[0074] In this embodiment, the drum-type pelletizing machine 2 includes a feed mechanism 23 for adding raw materials to each drum 2101 and a watering mechanism 24 for adding water. The feed mechanism 23 is primarily used to add raw materials to each drum 2101, while the watering mechanism 24 replenishes appropriate moisture for preparing the cue balls or coating. The feed mechanism 23 continuously supplies raw materials, while the watering mechanism 24 continuously replenishes water.

[0075] In this embodiment, the feeding mechanism 23 can be a screw feeder, which extends from the outer end of the pelletizing cylinder 21 to the corresponding pelletizing sub-cylinder 2101 along the length direction of the pelletizing cylinder 21. The feeding end of the screw feeder is located outside the pelletizing cylinder 21, and the discharge end of the screw feeder is located in the corresponding pelletizing sub-cylinder 2101; the screw feeder is suspended as a whole and supported by a corresponding bracket (the bracket is not shown in the figure).

[0076] The water adding mechanism 24 includes a water inlet pipe 2401 , which is fixed on the corresponding screw feeder and extends to the corresponding pelletizing cylinder 2101 . At least one water mist nozzle 2402 is installed on the water inlet pipe 2401 in the pelletizing cylinder 2101 .

[0077] The feeding mechanism 23 and the water adding mechanism 24 are simple in structure, easy to enter each ball-making area, and easy to operate. In this embodiment, the ball-making cylinder driving device 25 can be a conventional driving device for driving the cylinder to rotate in this field. The ball-making cylinder driving device 25 can specifically include a fixed ring, a large gear, a small gear, a reducer, a motor, and a spring plate. The ball-making cylinder 2101 passes through the fixed ring and is fixedly connected to the fixed ring. A coaxial large gear is provided outside the fixed ring. The large gear is connected to the spring steel plate through a connecting rod. The spring steel plate is connected to the outer wall of the fixed ring. The output shaft of the motor is connected to the reducer. The output shaft of the reducer is fixedly connected to the small gear. The small gear is meshed with the large gear.

[0078] Wheel tyres are fixed on the ball-making cylinders 2101 on both sides of the large gear. The ball-making cylinders 2101 pass through the wheel tyres and are fixedly connected to the wheel tyres. Support rollers that are in rolling contact with the wheel tyres are provided on both sides below the wheel tyres. Stop wheels are provided on both sides of the wheel tyres along the length direction of the ball-making cylinders 2101 to prevent the ball-making cylinders 2101 from moving along their axial direction.

[0079] In this embodiment, baffle structures (not shown in the figure) can be provided at both ends of the pelletizing cylinder 21 to prevent the pelletizing cylinder 21 from affecting the environment.

[0080] In this embodiment, the difference between the outer diameter and the inner diameter of the annular baffle plate 22 is 0.005-0.3 m, the inner diameter of the pelletizing cylinder 2101 is 1-5 m, and the inclination angle of the pelletizing cylinder 21 is 3-30°.

[0081] In this embodiment, a preferred embodiment of the combined step-by-step ball making system is as follows: the combined step-by-step ball making system includes a spiral ball making device and a drum ball making machine 2 connected in sequence, and the discharge end of the spiral ball making device is connected to the feed end of the drum ball making machine 2, such as Figure 7 The spiral ball making equipment is suitable for making small-particle ball materials, and the drum-type ball making machine 2 is suitable for making large-particle ball materials based on the small-particle ball materials.

[0082] In this embodiment, the spiral-type pelletizing equipment provides a more refined pelletizing process and is more suitable for pellets with strict particle size requirements or multi-layer structures. During the preparation of mother balls, the pellet size is small and the material is small, requiring a more precise pelletizing process. The centrifugal force generated by the spiral rotation of the material can enhance the capillary force of the bulk material, promoting its formation into balls. In this case, the spiral-type pelletizing equipment is more suitable. As the pellet size increases, the amount of material added increases, and the pelletizing process becomes slightly rougher, making the drum-type pelletizer 2 more suitable.

[0083] The drum-type pelletizer 2 is slightly less efficient than the spiral-type pelletizer in terms of target pellet size and compactness. The combination of the two ensures high efficiency while maintaining optimal pellet quality.

[0084] Example 5:

[0085] An application of the combined step-by-step pelletizing system in Example 4 is to apply the combined step-by-step pelletizing system to prepare ceramsite pellets, which include a mother ball with multiple coating layers sequentially arranged outside the mother ball.

[0086] The method for preparing ceramsite pellets includes the following steps: preparing a pore-forming agent mother ball, adhering heavy metal tailings powder (I) to the pore-forming agent mother ball to form raw material ball I; then adhering a mixture containing a chemical composition adjuster and heavy metal tailings powder (II) to raw material ball I to form raw material ball II; and finally, adhering a mixture containing a flux and heavy metal tailings powder (III) to raw material ball II to obtain ceramsite pellets. During the subsequent high-temperature roasting process, the pore-forming agent in the center of the ceramsite pellets continuously erupts and expands outward, promoting the formation of a pore structure and resulting in a ceramsite product with well-developed pores. This can minimize the density of heavy metal tailings-based ceramsite products, resulting in lightweight ceramsite that meets national standards.

[0087] In the above preparation method, the raw materials for preparing the ceramsite pellets, based on the total mass of the pore-forming agent, chemical composition adjusting agent, fluxing agent, and heavy metal tailings powder being 100%, the pore-forming agent accounts for 5-15%, the chemical composition adjusting agent accounts for 5-40%, the fluxing agent accounts for 5-15%, and the heavy metal tailings powder accounts for 40-85%. The heavy metal tailings powder includes heavy metal tailings powder 1, heavy metal tailings powder 2, and heavy metal tailings powder 3. The proportions of heavy metal tailings powder 1, heavy metal tailings powder 2, and heavy metal tailings powder 3 in the heavy metal tailings powder can be 15-35%, 15-55%, and the remainder, respectively.

[0088] In the above preparation method, the particle size range of the pore-forming agent mother ball can be 2-6 mm; the particle size of the raw material ball I, material ball II, and ceramsite pellets is determined according to the specific particle size range of the actual pore-forming agent mother ball and the specific formula amount of the raw materials of each layer, and then the corresponding difference between the outer diameter and the inner diameter of the annular baffle plate, the sieve aperture, etc. are set.

[0089] The pore-forming agent includes at least one of an organic pore-forming agent and an inorganic pore-forming agent. The organic pore-forming agent includes at least one of natural plant fibers, natural plant polysaccharides, and high molecular weight polymers. The inorganic pore-forming agent includes at least one of a combustible pore-forming agent, a mineral pore-forming agent, and a high-temperature decomposable salt pore-forming agent. Natural plant fibers include at least one of sawdust, starch, cellulose, rice husks, and fruit shells. Natural plant polysaccharides include starch. The high molecular weight polymer includes polyvinyl alcohol. The combustible pore-forming agent includes at least one of charcoal and graphite. The mineral pore-forming agent includes at least one of coal powder, perlite, zeolite, and limestone. The high-temperature decomposable salt pore-forming agent includes at least one of ammonium chloride and ammonium carbonate.

[0090] The heavy metal tailings powder includes at least one of copper tailings, lead tailings, zinc tailings, gold tailings, silver tailings, cadmium tailings, and chromium tailings. The chemical composition adjuster includes quartz. The flux includes one or more of porcelain stone, fly ash, and zeolite. The main mineral components of porcelain stone are quartz, sericite, and feldspar; the main components of fly ash are oxides of silicon, aluminum, iron, calcium, and magnesium, and the specific surface area of ​​fly ash is 400-1200m 2 / kg, the glass content in fly ash is >40%; the total mass fraction of SiO2 and Al2O3 in zeolite is above 80%, and SiO2 / Al2O3>6.

[0091] The binder used in each step of preparing ceramsite pellets includes one or more of bentonite, humic acid and sodium silicate.

[0092] As a preferred method, when preparing the above-mentioned expanded clay pellets, the pore-forming agent mother ball and raw material ball I need to control the target pellet particle size within a strict range and make the obtained pellets more compact, so a spiral pelletizing equipment is used for preparation, while the particle size and compactness of the material ball II and expanded clay pellets are lowered to a certain extent, so a drum-type pelletizing machine 2 is used for preparation.

[0093] The combined step-by-step pelletizing system for preparing the above-mentioned ceramsite pellets includes a spiral pelletizing device and a drum pelletizing machine 2; the spiral pelletizing device includes two spiral pelletizing devices 1, and the pelletizing cylinder 21 is composed of two pelletizing sub-cylinders 2101 along its length direction. The target pellet discharge pipe 1904 of the spiral pelletizing device 1 located at the bottom of the spiral pelletizing device is connected to the feed end of the drum pelletizing machine 2; specifically, Figure 7 shown.

[0094] The preparation method of ceramsite pellets includes the following steps: preparing pore-forming agent mother balls in the spiral pelletizing device 1 located above, adhering heavy metal tailings powder 1 to the pore-forming agent mother balls in the spiral pelletizing device 1 located below to form raw material balls I; adhering a mixture containing a chemical composition adjuster and heavy metal tailings powder 2 to the raw material balls I in the pelletizing separation cylinder 2101 located above to form raw material balls II; finally, adhering a mixture containing a flux and heavy metal tailings powder 3 to the raw material balls II in the pelletizing separation cylinder 2101 located below to obtain ceramsite pellets.

[0095] The specific method is as follows: the vertical pelletizing drum 11 located at the top of the spiral pelletizing equipment is used to prepare pore-forming agent mother balls of target particle size, which are screened by the screening machine 19 and then introduced into the vertical pelletizing drum 11 located at the bottom through the corresponding target pellet discharge pipe 1904, and the pore-forming agent mother balls are coated with heavy metal tailings powder I. After the coating is completed, the raw material balls I of the target particle size are screened by the screening machine 19 and then introduced into the drum-type pelletizing machine 2 located at the top through the corresponding target pellet discharge pipe 1904. In the ball separation cylinder 2101, the introduced raw ball I is coated with a chemical composition adjuster and heavy metal tailings powder II. When the prepared pellets reach the target particle size, raw ball II is obtained; the raw ball II of the target particle size can pass through the corresponding annular baffle plate 22 and enter the pelletizing separation cylinder 2101 located below, and the introduced raw ball II is coated with a flux and heavy metal tailings powder III; when the prepared pellets reach the target particle size, ceramsite pellets are obtained; the ceramsite pellets of the target particle size can pass through the corresponding annular baffle plate 22 and be collected.

[0096] In the above-mentioned spiral pelletizing equipment, the raw materials for preparing pore-forming agent-type mother balls (pore-forming agent + binder) are fed to the vertical pelletizing drum 11 located above through the corresponding feed pipe 16, and the raw materials for preparing heavy metal tailings powder layer (heavy metal tailings powder + binder) are fed to the vertical pelletizing drum 11 located below through the corresponding feed pipe 16; and the materials in the vertical pelletizing drum 11 are watered by the water mist nozzle 15 to form pellets, and the rotating shaft 12 is driven to rotate by the rotating shaft drive device 13;

[0097] In the above-mentioned drum-type pelletizing machine 2, the raw materials for preparing the chemical composition adjuster layer (a mixture of the chemical composition adjuster and heavy metal tailings powder 2 + a binder, which are mixed evenly before adding) are transported to the upper pelletizing sub-drum 2101 through the corresponding feeding mechanism 23, and the raw materials for preparing the flux layer (a mixture of the flux and heavy metal tailings powder 3 + a binder, which are mixed evenly before adding) are transported to the lower pelletizing sub-drum 2101 through the feeding mechanism 23; and water is added to each pelletizing sub-drum 2101 for pelletizing through the water adding mechanism 24, and each pelletizing sub-drum 2101 is driven to rotate by the corresponding pelletizing sub-drum driving device 25.

Claims

1. A combined step-by-step pelletizing system, characterized in that: The combined step-by-step pelletizing system comprises a spiral pelletizing device and a drum pelletizing machine (2) connected in sequence, wherein the discharge end of the spiral pelletizing device is connected to the feed end of the drum pelletizing machine (2); The spiral ball-making equipment comprises at least one spiral ball-making device (1), wherein the spiral ball-making device (1) comprises a vertical ball-making cylinder (11), wherein a coaxial rotating shaft (12) is installed in the vertical ball-making cylinder (11), wherein the rotating shaft (12) is driven to rotate by a rotating shaft driving device (13), wherein a spiral auger (14) is installed on the rotating shaft (12) in the vertical ball-making cylinder (11), wherein a water mist nozzle (15) is installed on the inner side wall of the vertical ball-making cylinder (11), wherein the upper end of the vertical ball-making cylinder (11) is connected to a feeding pipe (16), and the lower end is connected to a discharging pipe (17), wherein a valve is installed on the discharging pipe (17); The spiral pelletizing device (1) further comprises a screening machine (19) connected to the discharge pipe (17) and capable of screening out pellets of target particle size, wherein the screening machine (19) is provided with a target pellet discharge pipe (1904) for guiding the pellets of target particle size out of the screening machine (19); The cylinder-type pelletizing machine (2) comprises a pelletizing cylinder (21), the pelletizing cylinder (21) is provided with a pelletizing cylinder feed port and a pelletizing cylinder discharge port, the pelletizing cylinder (21) is arranged tilted downward, and the cylinder-type pelletizing machine (2) further comprises a feeding mechanism (23) for adding material and a water adding mechanism (24) for adding water; The pelletizing cylinder (21) is composed of at least one rotatable pelletizing sub-cylinder (2101) along its length. Both ends of the pelletizing sub-cylinder (2101) are open, and an annular baffle plate (22) coaxial with the pelletizing sub-cylinder (2101) is sealed and fixed on the inner side wall of the discharge end. The inner diameter of the pelletizing sub-cylinder (2101) remains unchanged. Two adjacent pelletizing cylinders (2101) are sealed and rotatably connected, and each of the pelletizing cylinders (2101) is driven to rotate by a pelletizing cylinder driving device (25); along the downward tilt of the pelletizing cylinder (21), the inner diameters of the plurality of annular baffle plates (22) decrease in sequence; The inner side wall of each of the pelletizing cylinders (2101) is evenly fixed with 3-8 guide plates (28) around the axis of the pelletizing cylinder (2101), and the guide plates (28) are inclined relative to the axis of the pelletizing cylinder (2101).

2. The combined step-by-step pelletizing system according to claim 1, characterized in that: The screening machine (19) comprises a screening drum (1901), wherein a vibrating screen 1 (1902) and a vibrating screen 2 (1903) are sequentially arranged in the screening drum (1901) from top to bottom, the screen hole diameter of the screen 1 (1902) being the maximum value of the target pellet particle size, and the screen hole diameter of the screen 2 (1903) being the minimum value of the target pellet particle size, and the bottom end of the screening drum (1901) being connected to a screening material discharge pipe (1905); the screening drum (1901) corresponding to the top of the screen 1 (1902) being connected to a large pellet discharge pipe (1906), and the screening drum (1901) corresponding to the screen 2 (1903) and the screen 1 (1902) being connected to a target pellet discharge pipe (1904).

3. The combined step-by-step pelletizing system according to claim 1, characterized in that: The spiral ball-making equipment comprises a plurality of spiral ball-making devices (1), wherein the plurality of spiral ball-making devices (1) are arranged in sequence from top to bottom. In two upper and lower adjacent spiral ball-making devices (1), the target pellet discharge pipe (1904) of the upper spiral ball-making device (1) is connected to the feed port (18) of the vertical ball-making cylinder (11) in the lower spiral ball-making device (1) through a material guide pipe.

4. The combined step-by-step pelletizing system according to claim 1, characterized in that: A sealing ring (26) is fixed on the inner side wall of the discharge end of the pelletizing cylinder (2101), and the sealing ring (26) is located on the outside of the corresponding annular baffle plate (22); the outer end of the sealing ring (26) extends into the lower adjacent pelletizing cylinder (2101), and a clamping ring (27) is provided between the sealing ring (26) and the inner side wall of the lower adjacent pelletizing cylinder (2101), and the clamping ring (27) is fixedly connected to the pelletizing cylinder (2101), and the clamping ring (27) is tightly and rotatably connected to the sealing ring (26).

5. The combined step-by-step pelletizing system according to any one of claims 1 to 4, characterized in that: The feeding mechanism (23) is a screw feeder, and the screw feeder extends from the outer end of the pelletizing cylinder (21) to the corresponding pelletizing sub-cylinder (2101) along the length direction of the pelletizing cylinder (21); The water adding mechanism (24) includes a water inlet pipe (2401), which is fixed on the corresponding screw feeder and extends to the corresponding pelletizing cylinder (2101). At least one water mist nozzle 2 (2402) is installed on the water inlet pipe (2401) in the pelletizing cylinder (2101).

6. An application of the combined step-by-step pelletizing system according to any one of claims 1 to 5, characterized in that: The combined step-by-step pelletizing system is applied to prepare ceramsite pellets; The combined step-by-step pelletizing system for preparing the ceramsite pellets comprises a spiral pelletizing device and a drum pelletizing machine (2); the spiral pelletizing device comprises two spiral pelletizing devices (1), the pelletizing cylinder (21) of the drum pelletizing machine (2) is composed of two pelletizing sub-cylinders (2101) along its length direction, and the target pellet discharge pipe (1904) of the spiral pelletizing device (1) located at the bottom of the spiral pelletizing device is connected to the feed end of the drum pelletizing machine (2); The preparation method of the ceramsite pellets comprises the following steps: preparing a pore-forming agent mother ball in a spiral ball-making device (1) located above, adhering heavy metal tailing powder 1 to the pore-forming agent mother ball in a spiral ball-making device (1) located below to form raw material ball I; adhering a mixture containing a chemical composition adjuster and heavy metal tailing powder 2 to the raw material ball I in a ball-making separation cylinder (2101) located above to form raw material ball II; and finally adhering a mixture containing a flux and heavy metal tailing powder 3 to the raw material ball II in a ball-making separation cylinder (2101) located below to obtain ceramsite pellets.

7. The use according to claim 6, characterized in that In the raw materials for preparing ceramsite pellets, based on the total mass of the pore-forming agent, chemical composition adjusting agent, fluxing agent, and heavy metal tailings powder being 100%, the pore-forming agent accounts for 5-15%, the chemical composition adjusting agent accounts for 5-40%, the fluxing agent accounts for 5-15%, and the heavy metal tailings powder accounts for 40-85%; the heavy metal tailings powder includes heavy metal tailings powder 1, heavy metal tailings powder 2, and heavy metal tailings powder 3; The particle size range of the pore-forming agent mother ball is 2-6 mm; the pore-forming agent includes at least one of an organic pore-forming agent and an inorganic pore-forming agent; the heavy metal tailings powder includes at least one of copper tailings, lead tailings, zinc tailings, gold tailings, silver tailings, cadmium tailings, and chromium tailings; the chemical composition adjuster includes quartz; and the flux includes one or more of porcelain stone, fly ash, and zeolite.

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