A dry mineral processing and calcination system

Abstract

This utility model discloses a dry mineral processing calcination system, including a raw material elevator, a kiln body, a kiln body rotation drive device, a combustion device, a kiln exhaust device, and a dust removal device. The combustion device is connected to the kiln body, and the kiln body rotation drive device drives the kiln body to rotate. The kiln body includes a preheating kiln, a calcining kiln, and a cooling kiln connected in sequence. The rotating nodes of the preheating kiln, calcining kiln, and cooling kiln are provided with double-layered fish-scale plates, and a composite plate is provided between the double-layered fish-scale plates. The kiln exhaust device is located between the preheating kiln and the calcining kiln. The length of the preheating kiln is 0.3-0.5 times the length of the calcining kiln. This dry mineral processing calcination system improves the preheating effect of the material and reduces the calcination load of the rotary kiln by extending the length of the preheating kiln. Then, the double-layered fish-scale sealing reduces external air leakage from the rotary kiln system, increases internal exhaust from the rotary kiln, achieves negative pressure operation of the system, and reduces on-site dust.

Description

Technical Field

[0001] This utility model relates to the field of phosphate rock processing technology, specifically to a dry beneficiation and calcination system. Background Technology

[0002] In the dry beneficiation process of phosphate rock, a rotary kiln system is required to calcine the phosphate rock to remove moisture, organic matter, carbonates (such as CaCO3), sulfides (such as FeS2), etc., reducing acid consumption and pollution in the subsequent acidolysis process, and decomposing volatile impurities (such as fluorine and sulfur) to avoid the formation of harmful gases (such as HF and SO2) in phosphoric acid production. Calcination also improves the mineral structure by disrupting the dense structure of phosphate rock (such as apatite), increasing porosity, and improving the contact area and reactivity of the subsequent acidolysis reaction. Furthermore, calcination increases the difference in the thermal expansion coefficients of associated minerals (such as quartz and calcite), facilitating physical separation (such as crushing and screening after calcination).

[0003] The existing rotary kiln system has the following problems: 1. The rotary kiln system is under positive pressure, the pressure difference of the kiln tail bag dust collector is high, and the tail exhaust fan cannot generate enough air, resulting in serious dust emission from the system; 2. The dehydration rate and decomposition rate of the material entering the kiln are low; 3. The ventilation inside the kiln is poor, the fire cannot penetrate into the kiln, resulting in short flame burning, poor heat exchange of the material inside the kiln, resulting in low kiln output and unsatisfactory overall process production. Utility Model Content

[0004] To overcome the shortcomings of existing technologies, this utility model provides a dry mineral processing calcination system. By extending the length of the preheating kiln, the preheating effect of the material is improved, and the calcination load of the rotary kiln is reduced. Then, by using a double-layer fish-scale seal, the external air leakage of the rotary kiln system is reduced, and the internal exhaust of the rotary kiln is increased, so as to realize the negative pressure operation of the system and reduce on-site dust.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A dry mineral processing calcination system includes a raw material elevator, a kiln body, a kiln body rotation drive device, a combustion device, a kiln exhaust device, and a dust removal device. The combustion device is connected to the kiln body. The kiln body rotation drive device is used to drive the kiln body to rotate. The kiln body includes a preheating kiln, a calcining kiln, and a cooling kiln connected in sequence. The rotating nodes of the preheating kiln, calcining kiln, and cooling kiln are provided with double-layered fish-scale plates for sealing, and a composite plate is provided between the double-layered fish-scale plates. The kiln exhaust device is located between the preheating kiln and the calcining kiln. The length of the preheating kiln is 0.3-0.5 times the length of the calcining kiln.

[0007] As a further improvement to the above technical solution, the length of the calcining kiln is 40-50m, and the length of the preheating kiln is 15-20m.

[0008] As a further improvement to the above technical solution, the preheating kiln is equipped with multiple layers of material spreading plates.

[0009] As a further improvement to the above technical solution, the feed inlet of the preheating kiln is equipped with a tail gas collection device, and the tail gas collection device is connected to the dust removal device. The discharge end of the raw material elevator is connected to the feed inlet of the preheating kiln through a hopper.

[0010] As a further improvement to the above technical solution, the preheating kiln and the calcining kiln are coaxial and inclined, the cooling kiln is inclined, and the feed inlet of the cooling kiln is connected to the discharge outlet of the calcining kiln through a discharge pipe.

[0011] As a further improvement to the above technical solution, the kiln rotation drive device includes a preheating kiln rotation drive, a calcining kiln rotation drive, and a cooling kiln rotation drive, which respectively drive the preheating kiln, the calcining kiln, and the cooling kiln to rotate.

[0012] As a further improvement to the above technical solution, both the preheating kiln and the calcining kiln are equipped with bearing cooling devices. The bearing cooling devices are used to cool the bearings installed at the rotating connection points of the preheating kiln and the calcining kiln. The bearing cooling devices include cooling water channels, and the cooling water channels are connected to inlet pipes and outlet pipes.

[0013] As a further improvement to the above technical solution, the combustion device includes a burner, a pulverized coal nozzle, and an air regulating device. The air regulating device includes a Roots blower, which is connected to the burner through an air inlet pipe. A pressure regulating valve is installed on the air inlet pipe. The pulverized coal nozzle is connected to the pulverized coal feeding equipment through a fuel pipe.

[0014] As a further improvement to the above technical solution, the feed inlet of the cooling kiln is equipped with a hot air collection device, which is connected to an air heat exchanger. The air heat exchanger is connected to a heat exchange fan, a hot air recovery pipe, and a ore powder recovery pipe. The heat exchange fan is used to supply air to the air heat exchanger, and the hot air recovery pipe is connected to the ore powder conveying pipe.

[0015] As a further improvement to the above technical solution, the outlet of the cooling kiln is connected to a calcined ore buffer silo, the calcined ore buffer silo is equipped with a calcined ore elevator, the outlet end of the calcined ore elevator is connected to a calcined ore powder silo, the top of the calcined ore powder silo is equipped with a bag filter and an exhaust fan, and the bottom outlet of the calcined ore powder silo is connected to a belt scale via a vibrating feeder.

[0016] The beneficial effects of this utility model are: by increasing the length of the preheating kiln, the preheating effect of the material is improved, the firing load of the rotary kiln is reduced, and then by using double-layer fish scale sealing, the external air leakage of the rotary kiln system is reduced, the internal air extraction of the rotary kiln is increased, the negative pressure operation of the system is achieved, the dust on site is reduced, and the labor intensity of workers is reduced. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of a dry mineral processing and calcination system according to this utility model.

[0019] Attached reference numerals: 1. Raw material elevator; 2. Feed hopper; 3. Preheating kiln; 4. Exhaust gas collection device; 5. Dust removal device; 6. Preheating kiln rotary drive device; 7. Kiln exhaust device; 8. Calcination kiln; 9. Bearing cooling device; 10. Calcination kiln rotary drive device; 11. Burner; 12. Air inlet pipe; 13. Pulverized coal conveying pipe; 14. Movable support frame; 15. Cooling kiln; 16. Discharge pipe; 17. Hot air collection device; 18. Double-layer fish scale; 19. Cooling 20. Kiln rotation drive; 21. Calcinated ore buffer silo; 22. Discharge hopper; 23. First vibrating feeder; 24. Calcinated ore elevator; 25. Calcinated ore powder silo; 26. Bag filter; 27. Exhaust fan; 28. Material level detector; 29. ​​Air heat exchanger; 30. Heat exchange blower; 31. Roots blower; 32. Pressure regulating valve; 33. Temperature monitor; 34. Belt weigher; 35. Second vibrating feeder; 36. Hot air recovery pipe; 37. Ore powder recovery pipe. Detailed Implementation

[0020] The following will clearly and completely describe the concept, specific structure, and technical effects of this utility model in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are all within the scope of protection of this utility model. Furthermore, all connections / connections involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. For example, fixed connections / fixed installations can use screw connections, bolt connections, pin connections, key connections, adhesive connections, mortise and tenon connections, welding, riveting, etc., as needed. For detachable connections, screw connections, bolt connections, threaded connections, snap-fit ​​connections, mortise and tenon connections, Velcro connections, etc., can be used as needed. The various technical features in this utility model can be combined interactively without contradicting each other.

[0021] Reference Figure 1 This utility model provides a dry mineral processing calcination system, including a raw material elevator 1, a kiln body, a kiln body rotation drive device, a combustion device, a kiln exhaust device 7, and a dust removal device 5. The combustion device is connected to the kiln body, and the kiln body rotation drive device is used to drive the kiln body to rotate. The kiln body includes a preheating kiln 3, a calcining kiln 8, and a cooling kiln 15 connected in sequence. The rotating nodes of the preheating kiln 3, the calcining kiln 8, and the cooling kiln 15 are provided with double-layer fish scales 18 for sealing, and a composite plate is provided between the double-layer fish scales. The kiln exhaust device 7 is located between the preheating kiln 3 and the calcining kiln 8. The length of the preheating kiln 3 is 0.3-0.5 times the length of the calcining kiln 8.

[0022] In this invention, the length of the preheating kiln 3 is set to 0.3-0.5 times the length of the calcining kiln 8. Specifically, the length of the calcining kiln 8 is 40-50m, and the length of the preheating kiln 3 is 15-20m. Preferably, the length of the calcining kiln 8 is 45m and the diameter is 3m, and the length of the preheating kiln 3 is 15m and the diameter is 2.2m. Currently, the length of the preheating kiln 3 is 5m. By lengthening the preheating kiln 3, the preheating effect of the material is improved, and the firing load of the rotary kiln is reduced. Then, double-layer fish scales 18 for sealing are set at the rotating nodes of the preheating kiln 3, the calcining kiln 8, and the cooling kiln 15, and a composite plate is set between the double-layer fish scales 18. This reduces external air leakage of the rotary kiln system and prevents short circuits caused by air pulling at the kiln tail. In addition, the internal exhaust device 7 of the kiln increases the exhaust of the rotary kiln, realizes negative pressure operation of the system, and reduces dust on site.

[0023] Furthermore, the preheating kiln 3 is equipped with multiple layers of material spreading plates, which can increase the residence time of the material in the preheating kiln 3, improve the moisture drying rate of the material entering the kiln and achieve partial decomposition of the material, which can greatly reduce the firing load of the calcining kiln 8.

[0024] In this embodiment, the feed inlet of the preheating kiln 3 is equipped with a tail gas collection device 4, which is connected to the dust removal device 5. The dust removal device 5 is a cyclone dust collector, and the discharge port of the cyclone dust collector is connected to the feed inlet of the preheating kiln 3 through a pipeline. This allows the collected dust and powder to be directly fed into the kiln, reducing the circulating load rate. The discharge end of the raw material elevator 1 is connected to the feed inlet of the preheating kiln 3 through a hopper 2, facilitating the feeding of phosphate rock into the preheating kiln 3.

[0025] In this embodiment, the preheating kiln 3 and the calcining kiln 8 are coaxial and inclined, and the cooling kiln 15 is also inclined to facilitate material transport within the kilns. Multiple temperature monitors 32 are installed on both the preheating kiln 3 and the calcining kiln 8 to monitor the temperature at different locations in real time. The feed inlet of the cooling kiln 15 is connected to the discharge outlet of the calcining kiln 8 via a discharge pipe 16. The phosphate rock is preheated in the preheating kiln 3, and the residence time of the material in the preheating kiln 3 is increased by a spreading plate, thereby improving the preheating effect. It then enters the calcining kiln 8 for calcination. After calcination, the phosphate rock enters the cooling kiln 15 for cooling via the discharge pipe 16.

[0026] In this embodiment, the kiln rotation drive device includes a preheating kiln rotation drive device 6, a calcining kiln rotation drive device 10, and a cooling kiln rotation drive device 19. The preheating kiln rotation drive device 6, the calcining kiln rotation drive device 10, and the cooling kiln rotation drive device 19 drive the preheating kiln 3, the calcining kiln 8, and the cooling kiln 15 to rotate, respectively.

[0027] Both the preheating kiln 3 and the calcining kiln 8 are equipped with bearing cooling devices 9. These devices cool the bearings located at the rotating joints of the preheating kiln 3 and the calcining kiln 8. Each bearing cooling device 9 includes a cooling water channel connected to an inlet pipe and an outlet pipe. During the operation of the rotary kiln, the cooling water removes heat from the bearings, keeping their temperature within the normal operating range, thus ensuring normal operation and extending their service life.

[0028] In this embodiment, the combustion device is installed at the end of the combustion kiln away from the preheating kiln 3, and is mounted on a movable support frame 14 for easy transport. The combustion device includes a burner 11, a pulverized coal nozzle, and an air regulating device. The air regulating device includes a Roots blower 30, which is connected to the burner 11 via an air inlet pipe 12. A pressure regulating valve 31 is installed on the air inlet pipe 12 to regulate the air intake. The pulverized coal nozzle is connected to the pulverized coal feeding equipment via a fuel pipe.

[0029] Furthermore, the inlet of the cooling kiln 15 is equipped with a hot air collection device 17, which is connected to an air heat exchanger 28. The air heat exchanger 28 is connected to a heat exchange fan 29, a hot air recovery pipe 35, and a mineral powder recovery pipe 36. The heat exchange fan 29 is connected to the air heat exchanger 28 through a duct for conveying air. A pressure regulating valve 31 is also installed on the duct. The hot air recovery pipe 35 and the mineral powder recovery pipe 36 are respectively connected to the two outlets of the air heat exchanger 28. The mineral powder recovery pipe 36 is connected to the calcium magnesium phosphate processing system, and the hot air recovery pipe 35 is connected to the coal powder conveying pipe 13. This recovers the hot air and improves the heat circulation efficiency.

[0030] In this embodiment, the outlet of the cooling kiln 15 is connected to a calcined ore buffer silo 20. Specifically, the outlet of the cooling kiln 15 is connected to a discharge hopper 21, and a first vibrating feeder 22 is installed below the discharge hopper 21. The cooled calcined ore is discharged from the discharge hopper 21 and enters the calcined ore buffer silo 20 via the first vibrating feeder 22. A calcined ore elevator 23 is installed inside the calcined ore buffer silo 20, and the outlet end of the calcined ore elevator 23 is connected to a calcined ore powder silo 24. The calcined ore is transported to the calcined ore powder silo 24 by the calcined ore elevator 23. Two level detectors 27 are installed on the calcined ore powder silo 24 to detect the high and low levels of the calcined ore in the silo 24, respectively, to avoid detecting too much or too little calcined ore in the silo 24. A bag filter 25 and an exhaust fan 26 are installed on the top of the calcined ore powder silo 24 to achieve dust removal. The bottom outlet of the calcined ore powder silo 24 is connected to a belt weighing scale 33 through a second vibrating feeder 34. The calcined ore is transported to the belt weighing scale 33 through the second vibrating feeder 34, and the metered calcined ore is transported to a wet mill for processing.

[0031] The above is a detailed description of the preferred embodiments of the present utility model. However, the present utility model is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present utility model. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A dry mineral processing and calcination system, characterized in that: The system includes a raw material elevator, a kiln body, a kiln body rotation drive, a combustion device, a kiln exhaust device, and a dust removal device. The combustion device is connected to the kiln body. The kiln body rotation drive is used to drive the kiln body to rotate. The kiln body includes a preheating kiln, a calcining kiln, and a cooling kiln connected in sequence. The rotating nodes of the preheating kiln, calcining kiln, and cooling kiln are provided with double-layered fish-scale plates for sealing, and a composite plate is provided between the double-layered fish-scale plates. The kiln exhaust device is located between the preheating kiln and the calcining kiln. The length of the preheating kiln is 0.3-0.5 times the length of the calcining kiln.

2. The dry mineral processing and calcination system according to claim 1, characterized in that: The length of the calcining kiln is 40-50m, and the length of the preheating kiln is 15-20m.

3. The dry mineral processing and calcination system according to claim 1, characterized in that: The preheating kiln is equipped with multiple layers of material spreading plates.

4. The dry mineral processing and calcination system according to claim 1, characterized in that: The preheating kiln is equipped with a tail gas collection device at its feed inlet, and the tail gas collection device is connected to the dust removal device. The discharge end of the raw material elevator is connected to the feed inlet of the preheating kiln through a hopper.

5. The dry mineral processing and calcination system according to claim 1, characterized in that: The preheating kiln and the calcining kiln are coaxial and inclined, the cooling kiln is inclined, and the feed inlet of the cooling kiln is connected to the discharge outlet of the calcining kiln through a discharge pipe.

6. A dry mineral processing and calcination system according to claim 5, characterized in that: The kiln rotation drive device includes a preheating kiln rotation drive device, a calcining kiln rotation drive device, and a cooling kiln rotation drive device, which respectively drive the preheating kiln, the calcining kiln, and the cooling kiln to rotate.

7. A dry mineral processing and calcination system according to claim 6, characterized in that: Both the preheating kiln and the calcining kiln are equipped with bearing cooling devices. The bearing cooling devices are used to cool the bearings installed at the rotating connection points of the preheating kiln and the calcining kiln. The bearing cooling devices include cooling water channels, which are connected to inlet pipes and outlet pipes.

8. A dry mineral processing and calcination system according to claim 1, characterized in that: The combustion device includes a burner, a pulverized coal nozzle, and an air regulating device. The air regulating device includes a Roots blower, which is connected to the burner through an air inlet pipe. A pressure regulating valve is installed on the air inlet pipe. The pulverized coal nozzle is connected to the pulverized coal feeding equipment through a fuel pipe.

9. A dry mineral processing and calcination system according to claim 8, characterized in that: The inlet of the cooling kiln is equipped with a hot air collection device, which is connected to an air heat exchanger. The air heat exchanger is connected to a heat exchange fan, a hot air recovery pipe, and a ore powder recovery pipe. The heat exchange fan is used to supply air to the air heat exchanger, and the hot air recovery pipe is connected to the ore powder conveying pipe.

10. A dry mineral processing and calcination system according to claim 1, characterized in that: The outlet of the cooling kiln is connected to a calcined ore buffer silo. A calcined ore elevator is installed inside the calcined ore buffer silo. The outlet of the calcined ore elevator is connected to a calcined ore powder silo. A bag filter and an exhaust fan are installed on the top of the calcined ore powder silo. A belt scale is connected to the bottom outlet of the calcined ore powder silo via a vibrating feeder.

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