Dolomite calcination process

Abstract

This invention belongs to the technical field of dolomite calcination equipment, and particularly relates to a dolomite calcination process, which includes the following steps: raw material pretreatment, preheating, material feeding into the kiln, high-temperature calcination, finished product cooling, and discharge. Preheating employs a separate, independent preheating method, where dolomite and anthracite are fed separately into independent sealed chambers of a vertical preheater for counter-current heat exchange. Material feeding into the kiln utilizes a double-chamber, counter-rotating material feeder arranged coaxially. After preheating, the materials enter the upper dolomite chamber and the lower coal chamber respectively. The two chambers rotate in opposite directions around a central column to achieve separate material feeding. The falling dolomite and anthracite enter a shearing and mixing zone for forced shearing and tumbling mixing, and are then evenly distributed into the kiln by a lower double-ring counter-guided shearing rake. This invention, through systematic structural optimization, avoids material segregation and cross-contamination, achieving forced uniform mixing of materials, improving calcination quality and equipment operational stability, resulting in stable calcination quality suitable for continuous industrial production.

Description

Technical Field

[0001] This invention belongs to the technical field of dolomite calcination equipment, and particularly relates to a dolomite calcination process. Background Technology

[0002] In the vertical kiln calcination process of dolomite, the rotary distributor is the core equipment to ensure uniform material distribution within the kiln and stable calcination quality. Currently, the mainstream vertical kiln distributors for dolomite are mainly divided into two categories: The first type is the premixed rotary feeder, which mixes dolomite and anthracite in advance and then feeds the material into the kiln through a rotary chute. This type of equipment has certain drawbacks: the density and particle size of dolomite and coal are very different, and serious centrifugal segregation will occur during the rotary feeding process. This will eventually result in a low proportion of coal in the outer ring of the kiln cross section and an excessively high proportion of coal in the center, causing the dolomite in the outer ring to be underburned and the dolomite in the center to be overburned, which will affect the qualification rate and consistency of the calcined products.

[0003] The second type is the branched rotary feeder, which uses two compartments to separately convey dolomite and coal, and distributes the materials into the kiln in separate channels. This solves the problem of premixed segregation to some extent, but existing branched feeders also have certain drawbacks: The common practice is to use a double-compartment structure with the dolomite compartment located directly above the coal compartment. During the fall of the dolomite, it is very easy to impact and wear the top shell of the coal compartment, resulting in a short service life of the equipment. It is also prone to problems such as material cross-contamination and premature mixing, making it impossible to achieve precise distribution of materials. Based on the above distribution of materials, the dolomite and coal cannot be forcibly and uniformly mixed. After the materials enter the kiln, the solid-solid contact is insufficient, the calcination reaction efficiency is low, and there is a problem of local underburning, which affects the production process. Summary of the Invention

[0004] This invention addresses the technical problems existing in the dolomite calcination process mentioned above by proposing a dolomite calcination process that is rationally designed, simple in structure, easy to process, and improves the activity of the calcined dolomite product through systematic structural optimization. The dual-compartment linkage reverse shear rake mechanism enables forced uniform mixing of materials, ensures the falling effect of materials, improves calcination quality and equipment operation stability, and is suitable for the needs of large-scale industrial continuous production.

[0005] To achieve the above objectives, the technical solution adopted by this invention is a dolomite calcination process, which sequentially includes a raw material pretreatment step, a preheating step, a material feeding into the kiln step, a high-temperature calcination step, a finished product cooling step, and a discharge step. The preheating step adopts independent preheating in separate channels, and the material feeding into the kiln step is implemented using a double-compartment counter-rotating material feeder. Specifically, it includes the following steps: (1) Separate preheating: The pretreated dolomite particles and anthracite particles are fed into two independent sealed chambers of the vertical preheater and preheated by countercurrent heat exchange to obtain preheated dolomite and anthracite materials. (2) Dual-compartment feeding: The preheated dolomite material is fed into the upper dolomite compartment of the dual-compartment reverse rotary feeder through the feeder compartment, and the preheated anthracite material is fed into the lower coal compartment of the dual-compartment reverse rotary feeder through the built-in pipe. The upper dolomite compartment and the lower coal compartment are coaxially arranged in an upper and lower structure on the outside of the central fixed column in the vertical kiln. (3) Reverse rotation of material distribution: The upper dolomite bin rotates clockwise around the central fixed column, and the lower coal bin rotates counterclockwise around the central fixed column, so as to realize the reverse synchronous distribution of material distribution in both bins. (4) Reverse forced shearing and mixing: Dolomite material falls through the first chute at the bottom of the upper dolomite silo, and anthracite material falls through the second chute at the bottom of the lower coal silo. The two materials enter the reverse shearing and mixing zone. The upper shearing rake, which is linked with the upper dolomite silo and rotates in the opposite direction synchronously, and the uniform feeder, which is linked with the lower coal silo and rotates in the opposite direction synchronously, continuously reverse shear and tumble the two falling materials to obtain a uniformly mixed material. (5) Leveling and entering the kiln: The uniformly mixed material falls through the lower layer of shearing rake frame with double-ring reverse guidance, so that the material is evenly distributed into the kiln of the dolomite vertical kiln. (6) Gradient calcination: After the material is fed, it slowly moves down with the material layer in the kiln and passes through the preheating zone, high-temperature calcination zone and cooling zone in sequence to complete the gradient calcination and obtain dolomite clinker.

[0006] Preferably, the sealed chamber includes a dolomite silo and an anthracite silo designed in an inverted cone shape. Two sets of dolomite silos are provided and are symmetrically arranged with respect to the anthracite silos. A discharge pipe is provided below both the dolomite silos and the anthracite silos. A preheating chamber is provided below the discharge pipe in a split configuration. A heat exchange component is provided on the outside of the preheating chamber. A discharge mechanism is provided below the preheating chamber corresponding to the dolomite silo. A stone chute with an inclined arrangement is opened in the distribution chamber. The internal pipe is located at the geometric center of the distribution chamber and is connected to the preheating chamber at the drop position of the anthracite silo.

[0007] Preferably, the material discharge mechanism includes a receiving bin, a material distribution plate with an inverted cone shape is provided below the receiving bin, rotating rods are provided in the receiving bins on both sides of the material distribution plate, a swing plate is provided on the same side of the two rotating rods, a linkage rod is provided below the swing plate, and a drive motor is provided on one side of one of the rotating rods.

[0008] Preferably, the upper dolomite bin is located inside the vertical kiln and includes a rotating sleeve fitted around the outside of the central fixed column. An upper rotating bin is located on the outside of the rotating sleeve. A guide cover is located above the upper rotating bin. A feed hole is located at the top inside the upper rotating bin. A first chute is located on the bottom outside of the upper rotating bin and is connected to the inside of the upper rotating bin.

[0009] Preferably, the kiln body is provided with a first double-ring frame, the first double-ring frame including a first outer ring frame, an upper support frame provided on the inner side of the first outer ring frame, an upper cone frame provided on the inner side of the upper support frame, the upper shear rake frame including a rotating sleeve sleeved on the outside of the rotating sleeve, an installation plate provided on the outside of the rotating sleeve, two sets of upper rotating frames with a figure-6 shape and arranged centrally symmetrically on the outside of the installation plate, an upper rake plate provided on the upper rotating frame, and a linkage mechanism for realizing the reverse rotation of the upper shear rake frame with the upper dolomite bin is provided below the upper shear rake frame.

[0010] Preferably, the linkage mechanism includes a protective cover set above the upper cone frame, a first drive gear connected to the rotating sleeve is arranged below the protective cover, a second drive gear is arranged on one side of the first drive gear, a third drive gear is arranged on the rear side of the second drive gear, and a fourth drive gear is arranged below the rotating sleeve and meshes with the third drive gear.

[0011] Preferably, a hollow rotating platform is provided at the lower part of the upper conical frame, and a hollow rotating rod is provided at the output end of the hollow rotating platform. The lower coal bunker includes a lower rotating chamber connected to the rotating rod. A connecting rod is provided above the lower rotating chamber and is slidably positioned relative to the upper conical frame. A cone-shaped feeding platform is provided inside the lower rotating chamber. A second chute is provided in the gap between the feeding platform and the lower rotating chamber. The built-in pipe is provided through the central fixed column and extends into the lower rotating chamber. A discharge chute is provided below the built-in pipe.

[0012] Preferably, a drive mechanism is provided between the feeder and the lower coal bunker. A second double-ring frame is provided on the outside of the drive mechanism. The drive mechanism includes a rotating rod connected to the lower swirl chamber. A support frame with a π-shaped design is provided above the second double-ring frame. A first bevel gear is provided below the rotating rod. A second bevel gear and a third bevel gear are provided on both sides of the support frame, respectively.

[0013] Preferably, the feed equalizer includes a stabilizing seat connected to a second double-ring frame. A rotating rod is disposed within the stabilizing seat. A fourth bevel gear is disposed above the rotating rod. An adjustable lifting rod is disposed within the rotating rod. A ring frame is disposed above the lifting rod. An adjusting rod is disposed on the outer side of the ring frame. An L-shaped seat is disposed on the outer side of the support frame. The adjusting rod is rotatably connected to the L-shaped seat. A support rod is disposed on the outer side of the rotating rod. An extension rod is disposed below the lifting rod. A universal ball joint is disposed above the extension rod. A rotating blade is disposed at the end of the support rod. A connecting seat is disposed on one side of the rotating blade and is connected to the upper part of the universal ball joint.

[0014] Preferably, the lower shearing rake frame includes a stabilizing frame, a second outer ring frame is provided on the outside of the stabilizing frame, a first diversion plate arranged in a downward left direction is provided on the outside of the second outer ring frame, a third outer ring frame is provided on the outside of the first diversion plate, and a second diversion plate arranged in a downward right direction is provided on the outside of the third outer ring frame.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are as follows: 1. The dolomite calcination process provided by this invention adopts a dual-compartment reverse material distribution structure with separate preheating and upper and lower layered coaxial structure, which realizes the separate transportation of dolomite and anthracite from preheating to kiln entry. This avoids the centrifugal segregation problem caused by material density and particle size differences in the premixed material distribution process. At the same time, the upper and lower layered coaxial layout fundamentally eliminates the equipment wear problem caused by dolomite falling and impacting the coal bunker. The independent sealing structure between the two compartments avoids the safety hazards of material cross-contamination and premature combustion of anthracite, which greatly improves the operational stability and service life of the equipment. 2. Through a multi-stage gear meshing linkage mechanism with reversing function, the upper shear rake and the upper dolomite silo are rotated synchronously in opposite directions by a single power source. In conjunction with the material equalizer linked to the lower coal silo, a stable reverse shearing and mixing field is formed. The dolomite and anthracite falling from the branch are continuously sheared, turned and mixed, which solves the defect of uneven material mixing in the existing branch material distribution process, ensures full solid-solid contact between the two materials, and significantly improves the calcination reaction efficiency and product quality consistency. 3. The adjustable feeder adopts a bevel gear synchronous transmission and universal ball joint angle adjustment structure, which can adjust the pitch angle of the rotating blades online during continuous operation of the equipment, accurately control the radial distribution of materials, adapt to different material flow and particle size working conditions, eliminate blind spots in material distribution, ensure uniform material layer thickness across the entire cross section of the kiln, avoid uneven material surface causing wind and burning problems, and improve production continuity and operation and maintenance efficiency. 4. The established material discharge mechanism adopts a double swing plate linkage reciprocating material feeding structure, which can accurately control the amount of dolomite discharged, avoid material blockage, and realize precise linkage between material discharge and material distribution; the double-layer support structure of the first double ring frame and the second double ring frame provides a stable installation benchmark and material guidance for the core transmission and mixing components, ensuring the coaxiality and operational stability of each component, and further improving the reliability of the process. 5. This overall process, through systematic structural optimization, improves the activity of calcined dolomite, ensures product qualification rate, and adapts to the needs of large-scale industrial continuous production. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of a dolomite calcination process; Figure 2 A front view of the structure of a dolomite calcination process; Figure 3 A partial front view of the internal structure of a dolomite calcination process; Figure 4 for Figure 3 A magnified view of a portion of the structure at point A in the middle; Figure 5 This is a structural diagram of the sealed chamber; Figure 6 This is a schematic diagram of the material discharge mechanism; Figure 7 This is a schematic diagram of the upper dolomite warehouse. Figure 8 This is a partial internal structure diagram of the lower coal bunker. Figure 9 A schematic diagram of the internal structure of a dual-compartment counter-rotating fabric distributor; Figure 10 This is a schematic diagram of the upper shearing rake frame; Figure 11 This is a schematic diagram of the lower-level shearing rake frame; Figure 12 This is a schematic diagram of the drive mechanism; Figure 13 This is a schematic diagram of the material equalizer. In the above figures, 1. Sealed silo; 1a. Dolomite silo; 1b. Anthracite material silo; 12. Discharge mechanism; 121. Receiving silo; 122. Distributor plate; 123. Rotating rod; 124. Swing plate; 125. Linkage rod; 126. Drive motor; 13. Drop pipe; 14. Preheating silo; 15. Heat exchange assembly; 16. Distributor silo; 161. Rock drop chute; 17. Internal pipe; 171. Discharge chute; 2. Double-silo counter-rotating material distributor; 21. Upper dolomite bin; 211. Rotating sleeve; 212. Upper rotary bin; 213. Guide hood; 214. Feed hole; 215. First chute; 22. Lower coal bin; 221. Lower rotary bin; 222. Connecting rod; 223. Feeding platform; 224. Second chute; 3. Dolomite vertical kiln; 31. Central fixed column; 32. Kiln body; 4. Upper shear rake frame; 41. Rotating sleeve; 42. Mounting plate; 43. Upper rotary frame; 44. Upper rake plate 5. Feed equalizer; 51. Stabilizer; 52. Rotating rod; 53. Fourth bevel gear; 54. Lifting rod; 55. Ring frame; 56. Adjusting rod; 57. Support rod; 58. Extending rod; 59. Universal ball joint; 510. Rotating blade; 511. Connecting seat; 6. Lower shearing rake frame; 61. Stabilizer; 62. Second outer ring frame; 63. First diversion plate; 64. Third outer ring frame; 65. Second diversion plate; 7. Linkage mechanism; 71. Protective cover; 7 2. First drive gear; 73. Second drive gear; 74. Third drive gear; 75. Fourth drive gear; 8. First double ring frame; 81. First outer ring frame; 82. Upper support frame; 83. Upper cone frame; 9. Hollow rotating platform; 91. Rotating rod; 10. Drive mechanism; 101. Rotating rod; 102. First bevel gear; 103. Second bevel gear; 104. Third bevel gear; 11. Second double ring frame; 111. Support frame; 112. L-shaped seat. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0019] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0020] Examples, such as Figures 1-13As shown, a dolomite calcination process includes, in sequence, a raw material pretreatment step, a preheating step, a material feeding step, a high-temperature calcination step, a finished product cooling step, and a discharge step. From top to bottom, the system includes a branch-independent preheating unit, a double-compartment reverse-rotation material feeding unit, a reverse shearing homogenization unit, and a vertical kiln calcination unit. The vertical kiln calcination unit is a conventional technology in existing dolomite calcination equipment, consisting of a preheating zone, a high-temperature calcination zone, and a cooling zone, along with a kiln tail induced draft and cooling air intake system. The specific internal structure is not detailed here. This embodiment aims to solve the mixing and material feeding process of dolomite and coal materials.

[0021] To achieve sufficient preheating of the materials, this embodiment provides a separate preheating unit, which includes two sets of symmetrical inverted conical dolomite silos 1a and one set of centrally located anthracite material silos 1b. The two silos are independent of each other, completely sealed and without connection. Each silo is equipped with an independent discharge pipe 13 and a separate preheating silo body 14. The outer wall of the preheating silo body 14 is equipped with a kiln tail flue gas heat exchange component 15. A discharge mechanism 12 is set below the dolomite preheating silo, including a receiving silo 121, an inverted conical distribution plate 122 inside the silo, and rotating rods 123 with swing plates 124 on both sides of the distribution plate 122. In addition, a material-pulling plate is also provided on the rotating rod 123 for isolating the material inside the discharge mechanism 12. The material is temporarily blocked and, in conjunction with the lower end of the distribution plate 122, the material falls during rotation. Two sets of rotating rods 123 are synchronously driven by a linkage rod 125. A single set of rotating rods 123 is equipped with a drive motor 126 to achieve quantitative material discharge. Specifically, the discharge mechanism 12 is located below the dolomite preheating chamber 14 and is used to achieve quantitative and controllable discharge of preheated dolomite material. The specific operation process is as follows: When preheated dolomite needs to be conveyed to the upper dolomite chamber 21 of the double-chamber reverse rotating material distributor 2, the drive motor 126 is started. The output shaft of the drive motor 126 drives the connected rotating rod 123 to rotate circumferentially. This rotating rod 123... The swing plate 124 at the end drives the linkage rod 125 to move synchronously, which in turn drives another symmetrically arranged rotating rod 123 to rotate synchronously. This causes the two sets of swing plates 124 to swing synchronously in the receiving bin 121 around the rotating rod 123 as the axis. Of course, the output power of the drive motor 126 is reciprocating. The inverted conical distribution plate 122 in the receiving bin 121 diverts the dolomite material falling from the preheating bin 14 to both sides of the bin. During the rotation, the two sets of swing plates 124 quantitatively distribute and disperse the material on both sides of the distribution plate 122 through the reciprocating swing of the plates: when the swing plate 124 swings towards the center of the bin, it pushes the material towards the bottom of the receiving bin 121. The material inlet moves; when the swing plate 124 swings towards the side wall of the bin, it reserves space for the material to fall, and at the same time breaks up the clumps of material to avoid material blockage. By controlling the speed and swing frequency of the drive motor 126, the discharge amount and discharge speed of the dolomite material can be precisely adjusted so that the discharge amount is precisely matched with the material distribution speed of the upper dolomite bin 21, so as to achieve continuous and stable quantitative discharge, avoid uneven material distribution caused by excessive discharge, or material interruption in the kiln caused by insufficient discharge, and ensure the continuous and stable operation of the dolomite calcination process. Of course, the discharge mechanism 12 can also be set between the anthracite material bin 1b and the built-in pipe 17 to achieve continuous and stable discharge of anthracite material.Below the receiving hopper 121 is a distribution hopper 16. An inclined stone drop chute 161 is located within the distribution hopper 16. A through-type internal pipe 17 is installed at the geometric center of the distribution hopper 16. The upper end of the pipe connects to the anthracite preheating hopper, and the lower end extends into the vertical kiln, specifically connecting to the lower coal combustion hopper 22. This ensures the smooth flow of anthracite material. In this process, independent preheating and quantitative discharge of dolomite and anthracite are achieved, with no contact throughout, thus eliminating the safety hazards of premature combustion and coking of the anthracite. Simultaneously, the preheating temperature of both materials can be precisely controlled.

[0022] To achieve uniform material distribution, a dual-compartment counter-rotating material distribution unit is provided: It is coaxially positioned outside the central fixed column 31 within the dolomite vertical kiln 3, forming a layered, coaxial structure to prevent material from impacting the compartments. The upper dolomite compartment 21 is located within the kiln body 32 of the dolomite vertical kiln 3 and includes a rotating sleeve 211 fitted around the central fixed column 31. An upper rotating compartment 212 is located outside the rotating sleeve 211, with a guide cover 213 above it. A feed hole 214 is located above the upper rotating compartment 212, and a first chute 215 is positioned at the bottom of the upper rotating compartment 212. The upper dolomite bin 212 is connected to the upper rotating bin 212. To elaborate further, a drive wheel can be installed on the upper outer side of the upper rotating bin 212, and an electric motor is installed on the outside of the kiln body 32. The output end of the electric motor is connected to the upper outer side of the upper rotating bin 212 by a synchronous belt, so that the upper rotating bin 212 can rotate relative to the central fixed column 31. The rotation direction is clockwise horizontal circumferential rotation. In addition, the internal structure of the upper dolomite bin 21 is the same as that of the lower coal bin 22 in this embodiment. It can not only receive the material, but also allow the material to be discharged in accordance with the internal structure, thus improving the smoothness of the material falling.

[0023] To ensure the smooth introduction of anthracite material, a hollow rotating platform 9 is installed at the bottom of the upper cone frame 83. The output end of the hollow rotating platform 9 has a hollow rotating rod 91. The lower coal bunker 22 includes a hollow rotating rod 91 installed on the outside of the central fixed column 31 via the hollow rotating platform 9. The bottom of the rotating rod 91 is fixed to the lower rotating bin 221. A conical feeding platform 223 is installed inside the bin. The annular gap between the feeding platform 223 and the bin wall is an inclined platform surface, corresponding to the second chute 224. An internal pipe 17 passes through the interior of the central fixed column 31, extending its lower end into the lower rotating bin 221. A discharge chute 171 is opened at the bottom to achieve closed-loop feeding of anthracite. In other words, driving the hollow rotating platform 9 causes it to act on the rotating rod 91, thereby driving the lower... The swirl bin 221 rotates continuously counterclockwise around the central fixed column 31. The preheated anthracite material is conveyed to the lower swirl bin 221 through the built-in pipe 17 that runs through the central fixed column 31 in a completely sealed manner. It is then discharged into the lower swirl bin 221 through the discharge chute 171 at the bottom of the pipe. The conical feeding platform 223 in the lower swirl bin 221 diverts the anthracite material to the four sides of the bin. During the counterclockwise rotation of the lower swirl bin 221, the anthracite material in the bin falls into the reverse shear mixing zone below through the second chute 224 under the combined action of centrifugal force and gravity. This achieves continuous distribution of anthracite material. In the above process, the two bins rotate independently, achieving full-section distribution of material, avoiding material cross-binning and impact wear, and improving the accuracy of the distribution range.

[0024] To ensure effective mixing of falling materials, a reverse shearing mixing unit is established. From top to bottom, it includes an upper shearing rake frame 4, a reversing linkage mechanism 7, an adjustable angle material equalizer 5, and a lower double-ring shearing rake frame 6. A first double-ring frame 8 is installed inside the kiln body 32. The first double-ring frame 8 includes a first outer ring frame 81, an upper support frame 82 inside the first outer ring frame 81, and an upper conical frame 83 inside the upper support frame 82. The first double-ring frame 8 serves as the mounting base for the upper mechanism and is fixed to a pre-set installation position inside the dolomite vertical kiln 32. The first outer ring frame 81 is an outer rigid ring used to connect to the inner wall of the kiln body 32 or a fixed bracket, providing... The upper cone frame 83 is a rigid frame with an inner cone shape, which is centrally mounted on the central fixed column 31 and fixedly connected to the first outer ring frame 81 through the upper support frame 82 to form a stable double ring support structure. At the same time, it also provides radial support and circumferential guidance for the upper shear rake frame 4, so that it can rotate stably around the central fixed column 31, ensuring that the path swept by the rake teeth is accurate and continuous, and ensuring that the shearing action on the falling material covers the entire central falling area, avoiding missed shearing or local accumulation. In other words, the upper shear rake frame 4 is mounted on the outside of the rotating sleeve 211 through the rotating sleeve 41. The outer side of the sleeve is fixedly mounted with a plate 42. Two sets of 6-shaped centrally symmetrical upper rotating frames 43 are symmetrically arranged on the outside of the plate. The frame is fixed with the upper rake plate 44. The upper shear rake frame 4 and the upper dolomite bin 21 are driven to rotate synchronously in opposite directions by the linkage mechanism 7 with reversing function.

[0025] To achieve synchronous counter-rotation between the upper shear rake frame 4 and the upper dolomite bin 21, the linkage mechanism 7 includes a protective cover 71 positioned above the upper cone frame 83. A first drive gear 72, connected to the rotating sleeve 211, is located below the protective cover 71. A second drive gear 73 is positioned on one side of the first drive gear 72, and a third drive gear 74 is positioned behind the second drive gear 73. A fourth drive gear 75 is positioned below the rotating sleeve 41 and meshes with the third drive gear 74. The specific working principle is as follows: when the rotating sleeve 211 of the upper dolomite bin 21 rotates clockwise horizontally around the central fixed column 31… The first drive gear 72 connected to its lower end rotates clockwise synchronously. The first drive gear 72 meshes with the second drive gear 73 on one side, achieving the first reversal through gear meshing, causing the second drive gear 73 to rotate counterclockwise. The rotation of the second drive gear 73 meshes with the third drive gear 74, keeping the third drive gear 74 rotating synchronously with the second drive gear 73. The third drive gear 74 meshes with the fourth drive gear 75 at the lower end of the rotating sleeve 41, without contacting the first drive gear 72. Through the second meshing reversal, the fourth drive gear 75, the rotating sleeve 41, and the upper shear rake frame 4 are finally driven as a whole around the center. The fixed column 31 rotates counterclockwise horizontally to achieve reverse synchronous transmission between the upper shear rake 4 and the upper dolomite bin 21. The specific linkage operation process is as follows: During the clockwise rotation of the upper dolomite bin 21, power is input to the linkage mechanism 7 with reversing function via the first drive gear 72. After two-stage gear meshing and reversing, the upper shear rake 4 obtains a rotation direction completely opposite to that of the upper dolomite bin 21, and their speeds remain synchronized. During the counterclockwise rotation of the upper shear rake 4, it forms a reverse shearing field with the material equalizer 5, which rotates counterclockwise synchronously with the lower coal bin 22. This field affects the dolomite material falling through the first chute 215 and the material flowing through the second chute 215. The anthracite material falling from the trough 224 is continuously sheared and tumbled to mix, ensuring full contact and mixing of the two materials. This avoids material stratification and local accumulation caused by separate material distribution. The aforementioned drive mechanism 10 uses multi-stage gear meshing to achieve power reversal, simplifying the transmission structure. Moreover, the gear set is completely enclosed in the protective cover 71 above the upper cone frame 83, completely isolated from the material falling path, preventing high-temperature dust from corroding the transmission components, ensuring transmission accuracy and equipment service life. At the same time, through the precise meshing of the gear set, the reverse synchronization of the upper shear rake frame 4 and the upper dolomite bin 21 is ensured, providing a stable and reliable power guarantee for the forced uniform mixing of materials.

[0026] To improve the interoperability between equipment components, a drive mechanism 10 is installed between the feeder 5 and the lower coal bunker 22. A second double-ring frame 11 is installed on the outside of the drive mechanism 10 to provide support for the installation of equipment components and to allow the material after shearing and mixing to fall smoothly. Specifically, the drive mechanism 10 includes a rotating rod 101 connected to the lower rotating chamber 221. A support frame 111 with a π-shaped design is installed above the second double-ring frame 11. A first bevel gear 102 is installed below the rotating rod 101. A second bevel gear 103 and a third bevel gear 104 are respectively installed on both sides of the support frame 111. When the lower rotating chamber 221 rotates, the rotational power is applied to the first bevel gear 102 via the rotating rod 101 at its bottom, and then transmitted through the second bevel gear 103 and the third bevel gear 104. The reversing transmission of the three bevel gears 104 meshes with the fourth bevel gear 53 to realize the transmission of driving power, thereby driving the rotating rod 52 to rotate synchronously with the lower swirl chamber 221. That is to say, when the lower coal bunker 22 (lower swirl chamber 221) rotates counterclockwise, it drives the rotating rod 101 at the bottom of the bunker to rotate synchronously. The first bevel gear 102 at the bottom of the rotating rod 101 meshes with and drives the second bevel gear 103 and the third bevel gear 104 to rotate in opposite directions. The second bevel gear 103 and the third bevel gear 104 both mesh with the fourth bevel gear 53 to rotate, ultimately driving the rotating rod 52 of the feeder 5 to rotate synchronously with the lower swirl chamber 221 around the central axis. The rotating rod 52 drives the outer wall support rod 57 and the end hinged rotating blade 510 to rotate synchronously in a circumferential direction, which disperses and distributes the falling material in a circumferential direction.

[0027] To improve the uniformity of material distribution by adjusting the pre-mixed material at multiple angles, the adjustable feeding angle feeder 5 includes a stabilizing seat 51 connected to the second double-ring frame 11. A rotating rod 52 is installed inside the stabilizing seat 51, and a fourth bevel gear 53 is installed above the rotating rod 52. This gear receives the driving power transmitted from the drive mechanism 10, allowing the feeder 5 to rotate circumferentially to achieve uniform distribution of the falling material. An adjustable lifting rod 54 is installed inside the rotating rod 52. A ring frame 55 is installed above the lifting rod 54, and an adjusting rod 56 is installed on the outer side of the ring frame 55. The end of the adjusting rod 56 is concave and corresponds to the annular groove of the ring frame 55. The lifting rod 54 can move with the rotating rod 52. While rotating in the same circumferential direction, the adjusting rod 56 can also act on the lifting rod 54 during rotational adjustment relative to the L-shaped seat 112, allowing it to be adjusted vertically. An L-shaped seat 112 is provided on the outer side of the support frame 111, and the adjusting rod 56 is rotatably connected to the L-shaped seat 112. For the vertical adjustment of the lifting rod 54: a drive cylinder can be installed on the support frame 111, with its output end connected to the end of the adjusting rod 56. By controlling the extension and retraction of the drive cylinder, the geometric center of the adjusting rod 56 rotates relative to the L-shaped seat 112, thereby driving the lifting rod 54 to be adjusted vertically, facilitating the adjustment of the rotating blade 510. Alternatively, an electric push rod can be installed above the second double-ring frame 11, and connected to... The ends of the adjusting rod 56 are connected to control the rotation adjustment process of the adjusting rod 56 relative to the L-shaped seat 112. A support rod 57 is provided on the outside of the rotating rod 52. An extension rod 58 is provided below the lifting rod 54. A universal ball joint 59 is provided above the extension rod 58. A rotating blade 510 is provided at the end of the support rod 57. A connecting seat 511 is provided on one side of the rotating blade 510 and is connected to the upper part of the universal ball joint 59. Specifically, it is fixed in the kiln body 32 by the second double ring frame 11 and located below the lower coal bunker 22. The rotating rod 101 at the bottom of the lower swirl chamber 221 drives the rotating rod 52 and the lower swirl chamber 221 to rotate through the reversing transmission of the first bevel gear 102, the second bevel gear 103, the third bevel gear 104 and the fourth bevel gear 53. 21. The lifting rod 54 rotates synchronously. The bottom of the lifting rod 54 is connected to the universal ball joint 59 via the extension rod 58. The outer wall of the rotating rod 52 is fixed with the support rod 57. The end of the support rod 57 is hinged to the rotating blade 510. The connecting seat 511 on the inner side of the rotating blade 510 is hinged to the universal ball joint 59, forming an online adjustable angle adjustment mechanism. For the universal ball joint 59, its connection with the extension rod 58 and the connection base of the connecting seat 511 can be adjusted in both the horizontal and vertical directions. The lifting rod 54 is adjusted in height within the rotating rod 52, and the universal ball joint 59 acts on the connecting seat 511, so that the rotating blade 510 can be adjusted to different angles relative to the support rod 57 to meet the adjustment of the guiding direction of the falling material.The specific working method is as follows: When it is necessary to adjust the radial distribution of materials and adapt to changes in material flow / particle size, the adjusting rod 56 is driven to rotate relative to the L-shaped seat 112 by a drive cylinder or electric push rod, so that the lifting rod 54 moves axially up and down within the hollow rotating rod 52, acting on the angle adjustment mechanism below to achieve real-time adjustment of the angle of the rotating blade 510. The adjustment process can be completed online during rotation without stopping the kiln. When the lifting rod 54 moves downward, it drives the extension rod 58 and the universal ball joint 59 to move downward synchronously. Through the connecting rod on the universal ball joint 59, the connecting seat 511 of the rotating blade 510 is pulled, so that the rotating blade... The blade 510 deflects downwards at the hinge point at the end of the support rod 57, reducing the blade pitch angle and guiding the material towards the central area of ​​the kiln body 32. When the lifting rod 54 moves upwards, it drives the universal ball joint 59 to move upwards synchronously. Through the connecting rod on the universal ball joint 59, the rotating blade 510 is pushed upwards, increasing the blade pitch angle and guiding the material towards the outer ring area of ​​the kiln body 32. The synchronous adjustment of multiple sets of rotating blades 510 can precisely control the radial distribution range of the material, eliminate blind spots in the distribution, and correct material surface deviations in real time. The establishment of the above-mentioned distributor enables online angle adjustment while rotating the material distribution, accurately adapting to changes in working conditions and improving the uniformity of material distribution.

[0028] To ensure the uniformity of material falling, the lower shear rake frame 6 includes a stabilizing frame 61, and a connecting frame is also provided on its outer side and stably connected to the inner phase of the kiln body 32 to ensure the stability of the device. A second outer ring frame 62 and a third outer ring frame 64 are also arranged in sequence on the outer side of the stabilizing frame 61. A first diversion plate 63 with a left-lower inclination is provided on the outer side of the second outer ring frame 62, and a second diversion plate 65 with a right-lower inclination is provided on the outer side of the third outer ring frame 64, forming an upper and lower double-ring reverse guiding structure.

[0029] In the above process, the three-stage adjustment structure of reverse shearing, adjustable uniform distribution, and double-ring diversion achieves forced uniform mixing and full-section leveling of materials, effectively improving the uniformity of material mixing and reducing the error of the thickness of the falling material layer, thereby eliminating dead corners in material distribution and the risk of uneven burning.

[0030] The dolomite calcination process in this embodiment includes the following steps in sequence, with each step supported by synchronous equipment: Step 1: Raw material pretreatment The raw dolomite ore is crushed and screened to uniform particles with a diameter of 40-80mm, and the anthracite is crushed and screened to particles with a diameter of 10-30mm. The screened raw materials are sent to their respective storage bins without mixing throughout the process. This is to control the particle size of the raw materials to match the air permeability and reaction efficiency of the vertical kiln calcination, and to avoid uneven particle size leading to uneven material layer airflow and local underburning, thus laying the foundation for uniform calcination.

[0031] Step 2: Independent preheating of each circuit Pretreated dolomite particles are fed into two symmetrical dolomite silos 1a, and anthracite particles are fed into the central anthracite material silo 1b. The two materials are then fed into their respective separate preheating chambers 14, where they are preheated using countercurrent heat exchange with kiln tail flue gas. The dolomite is preheated to 650-700℃ for 2 hours, while the anthracite is preheated to 450-500℃ for 1.8 hours. The two materials do not come into contact during the entire preheating process. This independent temperature control preheating method avoids premature combustion of the anthracite at high temperatures, thereby eliminating safety hazards in the preheating process and precisely controlling the preheating state of the materials.

[0032] Step 3: Dual-compartment split feeding The preheated dolomite is discharged quantitatively through the discharge mechanism 12 and sent to the upper dolomite bin 21 through the distribution bin 16, the stone drop trough 161, the guide cover 213, and the feed hole 214. The preheated anthracite is transported in a closed manner through the built-in pipe 17 and sent to the lower coal bin 22 through the bottom discharge trough 171. The two materials are transported independently throughout the process without crossing or mixing. The closed-loop feeding is precisely connected with the reverse material distribution to prevent centrifugal segregation of the material distribution caused by premature mixing of materials.

[0033] Step 4: Reverse rotation of the fabric The upper dolomite bin 21 is driven to rotate clockwise by an independent drive device, and the lower coal bin 22 is driven to rotate counterclockwise. The two bins rotate synchronously in opposite directions and distribute the material through the first chute 215 and the second chute 224 respectively, forming a spiral cross-shaped material drop trajectory. The reverse rotation of the two bins achieves precise material distribution across the entire cross section and improves the uniformity of material distribution.

[0034] Step 5: Reverse Forced Shear Mixing Dolomite and anthracite fall into the reverse shearing mixing zone via chutes. The upper shearing rake 4 rotates synchronously in the opposite direction to the upper dolomite bin 21 via the reversing linkage mechanism 7, and the uniform feeder 5 rotates synchronously with the lower coal bin 22 to form a reverse shearing field. This continuously shears, disperses, and tumbles the falling material to obtain a highly uniform mixed material. The reverse shearing forcefully breaks up the material stratification, achieving solid-solid uniform mixing and solving the defect of uneven mixing in the distribution of materials. The dolomite and anthracite are in full contact, enhancing the calcination reaction.

[0035] Step 6: Level and place in the kiln The uniformly mixed material falls through the lower shear rake frame 6 and is evenly distributed onto the surface of the material layer inside the kiln through the double-ring reverse guidance structure of the first guide plate 63 and the second guide plate 65. At the same time, the angle of the rotating blade 510 of the uniform feeder 5 is adjusted to adapt to changes in material flow rate and adjust the radial distribution of the material in real time, reducing the thickness error of the material layer across the entire cross section inside the kiln. Ultimately, it achieves uniform distribution and leveling of the material surface, eliminates dead corners in material distribution, avoids uneven airflow and uneven burning caused by uneven material surface, and improves the consistency of calcination.

[0036] Step 7: Gradient calcination After being laid out, the material slowly descends with the material layer, completing the gradient calcination in sequence: the preheating zone temperature is 750~1000℃, the high-temperature calcination zone temperature is 1180~1220℃, and the cooling zone uses counter-current cold air cooling. After heat exchange, the cooling air is used as secondary air to assist combustion, and finally active dolomite clinker is obtained. The above gradient temperature control ensures that the dolomite is fully decomposed and improves the activity of the finished product.

[0037] In the above process: A separate preheating and coaxial double-compartment reverse feeding structure with upper and lower layers is adopted to achieve separate conveying of dolomite and anthracite from preheating to kiln entry, avoiding centrifugal segregation problems caused by differences in material density and particle size in the premixed feeding process. Simultaneously, the coaxial layout with upper and lower layers fundamentally eliminates equipment wear caused by dolomite falling and impacting the coal combustion chamber. The independent sealing structure between the two compartments avoids the safety hazards of material cross-contamination and premature combustion of anthracite, significantly improving the equipment's operational stability and service life. Through a multi-stage gear meshing linkage mechanism 7 with reversing function, A single power source enables the upper shear rake frame 4 and the upper dolomite bin 21 to rotate synchronously in opposite directions. This, combined with the feeder 5 linked to the lower coal bin 22, forms a stable reverse shearing and mixing field. This continuously shears, tumbles, and mixes the dolomite and anthracite falling from the distribution channels, solving the problem of uneven material mixing in existing distribution processes. It ensures sufficient solid-solid contact between the two materials, significantly improving calcination reaction efficiency and product quality consistency. The adjustable feeder 5 uses a bevel gear synchronous drive and a universal ball joint 59 angle adjustment structure, allowing for online adjustment of the rotating blades during continuous operation. The 510° pitch angle precisely controls the radial distribution of materials, adapting to changes in material flow rate and particle size, eliminating blind spots, ensuring uniform material layer thickness across the entire kiln cross section, avoiding issues like uneven airflow and burning caused by uneven material surfaces, and improving production continuity and operational efficiency. The established discharge mechanism 12 adopts a double swing plate 124 linkage reciprocating material feeding structure, which can precisely control the dolomite discharge volume, avoid material blockage, and achieve precise linkage between discharge and distribution. The double-layer support structure of the first double ring frame 8 and the second double ring frame 11 provides a stable installation for the core transmission and mixing components. The reference and material guidance system ensures the coaxiality and operational stability of each component, further improving the reliability of the process. The device is reasonably designed, simple in structure, and easy to process. It adopts a double-compartment structure on the same plane to realize the diversion of material feeding and prevent material cross-contamination. At the same time, the double-compartment linkage reverse shear rake mechanism realizes forced uniform mixing of materials, ensures the material falling effect, improves calcination quality and equipment operation stability. In addition, the overall process improves the activity of calcined dolomite products through systematic structural optimization, ensures product qualification rate, and adapts to the needs of large-scale industrial continuous production.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A dolomite calcination process, comprising, in sequence, a raw material pretreatment step, a preheating step, a material feeding into the kiln step, a high-temperature calcination step, a finished product cooling step, and a discharge step, characterized in that, The preheating step employs independent preheating in separate circuits, and the material feeding step is implemented using a dual-compartment counter-rotating material feeder, specifically including the following procedures: (1) Separate preheating: The pretreated dolomite particles and anthracite particles are fed into two independent sealed chambers of the vertical preheater and preheated by countercurrent heat exchange to obtain preheated dolomite and anthracite materials. (2) Dual-compartment feeding: The preheated dolomite material is fed into the upper dolomite compartment of the dual-compartment reverse rotary feeder through the feeder compartment, and the preheated anthracite material is fed into the lower coal compartment of the dual-compartment reverse rotary feeder through the built-in pipe. The upper dolomite compartment and the lower coal compartment are coaxially arranged in an upper and lower structure on the outside of the central fixed column in the vertical kiln. (3) Reverse rotation of material distribution: The upper dolomite bin rotates clockwise around the central fixed column, and the lower coal bin rotates counterclockwise around the central fixed column, so as to realize the reverse synchronous distribution of material distribution in both bins. (4) Reverse forced shearing and mixing: Dolomite material falls through the first chute at the bottom of the upper dolomite silo, and anthracite material falls through the second chute at the bottom of the lower coal silo. The two materials enter the reverse shearing and mixing zone. The upper shearing rake, which is linked with the upper dolomite silo and rotates in the opposite direction synchronously, and the uniform feeder, which is linked with the lower coal silo and rotates in the opposite direction synchronously, continuously reverse shear and tumble the two falling materials to obtain a uniformly mixed material. (5) Leveling and entering the kiln: The uniformly mixed material falls through the lower layer of shearing rake frame with double-ring reverse guidance, so that the material is evenly distributed into the kiln of the dolomite vertical kiln. (6) Gradient calcination: After the material is fed, it slowly moves down with the material layer in the kiln and passes through the preheating zone, high-temperature calcination zone and cooling zone in sequence to complete the gradient calcination and obtain dolomite clinker.

2. The dolomite calcination process according to claim 1, characterized in that, The sealed chamber includes a dolomite silo and an anthracite silo with an inverted cone shape. Two sets of dolomite silos are provided and are symmetrically arranged with respect to the anthracite silos. A discharge pipe is provided below both the dolomite silos and the anthracite silos. A preheating chamber with a split design is provided below the discharge pipe. A heat exchange component is provided on the outside of the preheating chamber. A discharge mechanism is provided below the preheating chamber corresponding to the dolomite silo. A stone chute with an inclined arrangement is opened in the distribution chamber. The internal pipe is located at the geometric center of the distribution chamber and is connected to the preheating chamber at the drop position of the anthracite silo.

3. The dolomite calcination process according to claim 2, characterized in that, The material discharge mechanism includes a receiving bin, a material distribution plate with an inverted cone shape is arranged below the receiving bin, rotating rods are arranged in the receiving bins on both sides of the material distribution plate, a swing plate is arranged on the same side of the two rotating rods, a linkage rod is arranged below the swing plate, and a drive motor is arranged on one side of one of the rotating rods.

4. The dolomite calcination process according to claim 3, characterized in that, The upper dolomite bin is located inside the vertical kiln and includes a rotating sleeve fitted on the outside of the central fixed column. The upper rotating bin is located on the outside of the rotating sleeve. A guide cover is located above the upper rotating bin. A feed hole is located at the top of the upper rotating bin. The first chute is located on the bottom outside of the upper rotating bin and is connected to the inside of the upper rotating bin.

5. The dolomite calcination process according to claim 4, characterized in that, The kiln body is equipped with a first double-ring frame, which includes a first outer ring frame. An upper support frame is provided on the inner side of the first outer ring frame, and an upper cone frame is provided on the inner side of the upper support frame. The upper shear rake frame includes a rotating sleeve sleeved on the outside of the rotating sleeve. An installation plate is provided on the outside of the rotating sleeve. Two sets of upper rotating frames with a figure-6 shape and arranged symmetrically on the outside of the installation plate are provided. An upper rake plate is provided on the upper rotating frame. A linkage mechanism for realizing the reverse rotation of the upper shear rake frame with the upper dolomite bin is provided below the upper shear rake frame.

6. The dolomite calcination process according to claim 5, characterized in that, The linkage mechanism includes a protective cover set above the upper cone frame. A first drive gear connected to the rotating sleeve is arranged below the protective cover. A second drive gear is arranged on one side of the first drive gear. A third drive gear is arranged on the rear side of the second drive gear. A fourth drive gear is arranged below the rotating sleeve and meshes with the third drive gear.

7. The dolomite calcination process according to claim 6, characterized in that, A hollow rotating platform is provided below the upper conical frame. The output end of the hollow rotating platform is provided with a hollow rotating rod. The lower coal bunker includes a lower rotating chamber connected to the rotating rod. A connecting rod is provided above the lower rotating chamber and is slidably positioned relative to the upper conical frame. A cone-shaped feeding platform is provided inside the lower rotating chamber. A second chute is provided in the gap between the feeding platform and the lower rotating chamber. The built-in pipe passes through the central fixed column and extends into the lower rotating chamber. A discharge chute is provided below the built-in pipe.

8. The dolomite calcination process according to claim 7, characterized in that, A drive mechanism is provided between the feed equalizer and the lower coal bunker. A second double-ring frame is provided on the outside of the drive mechanism. The drive mechanism includes a rotating rod connected to the lower swirl chamber. A support frame with a π-shaped design is provided above the second double-ring frame. A first bevel gear is provided below the rotating rod. A second bevel gear and a third bevel gear are provided on both sides of the support frame, respectively.

9. The dolomite calcination process according to claim 8, characterized in that, The feed equalizer includes a stabilizing seat connected to a second double-ring frame. A rotating rod is disposed inside the stabilizing seat. A fourth bevel gear is disposed above the rotating rod. An adjustable lifting rod is disposed inside the rotating rod. A ring frame is disposed above the lifting rod. An adjusting rod is disposed on the outer side of the ring frame. An L-shaped seat is disposed on the outer side of the support frame. The adjusting rod is rotatably connected to the L-shaped seat. A support rod is disposed on the outer side of the rotating rod. An extension rod is disposed below the lifting rod. A universal ball joint is disposed above the extension rod. A rotating blade is disposed at the end of the support rod. A connecting seat is disposed on one side of the rotating blade and is connected to the upper part of the universal ball joint.

10. The dolomite calcination process according to claim 9, characterized in that, The lower shearing rake frame includes a stabilizing frame, a second outer ring frame is provided on the outside of the stabilizing frame, a first diversion plate is provided on the outside of the second outer ring frame in a left-lower inclined position, a third outer ring frame is provided on the outside of the first diversion plate, and a second diversion plate is provided on the outside of the third outer ring frame in a right-lower inclined position.

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