Cement kiln bypass exhaust ash chloride removal and resource utilization system and method

Abstract

The invention relates to the technical field of exhaust ash treatment, in particular to a cement kiln bypass exhaust ash chloride removal and resource utilization system and method.The cement kiln bypass exhaust ash chloride removal and resource utilization system comprises an air taking device, a grading separation device, a desalting device and a drying device; the air taking device is arranged in a smoke chamber of the cement kiln rotary kiln; the grading separation device is connected with the output end of the air taking device, and is used for carrying out multi-stage separation on bypass exhaust ash, returning coarse particles with low chloride concentration to the preheater, and collecting fine particles with high chloride concentration; the desalting device is connected with the grading separation device, and the drying device is connected with the desalting device; according to the system, accurate grading and differentiated treatment of particles with different chloride concentrations are realized, the problems of low efficiency and high cost caused by non-differentiated treatment in the prior art are solved, and meanwhile, resource utilization and closed-loop recycling of wastes are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of vent ash treatment, and in particular to a system and method for removing chlorides from cement kiln bypass vent ash and recycling them as resources. Background Art

[0002] During cement production, raw materials contain volatile components like chlorine, potassium, and sodium. These volatilize during high-temperature calcination and accumulate in the preheater system. When their concentrations reach a certain level, they can negatively impact cement clinker quality and potentially lead to production problems such as preheater crusting and blockage. To maintain stable system operation, cement plants typically employ bypass ventilation technology, discharging some kiln gas containing high concentrations of chlorides (alkali metal salts, primarily potassium chloride) from the preheater system. This exhaust also carries with it a significant amount of dust, creating bypass ash.

[0003] Bypass ash typically accounts for 2-5% of cement clinker production, with chloride content reaching 15-30%, primarily in the form of potassium chloride and sodium chloride. Due to this high chloride content, bypass ash cannot be directly reused in cement production. Traditionally, it has been treated as industrial waste and landfilled or stored in stockpiles, resulting in significant resource waste and environmental risks.

[0004] Currently, the main treatment technologies for bypass vent ash include direct discharge, multi-stage water washing, and integrated treatment. While direct discharge is simple to operate, it results in significant resource waste and environmental pollution. Multi-stage water washing uniformly washes all bypass vent ash without distinguishing between chloride concentrations. This results in large bypass ash treatment volumes, high water consumption from multi-stage washing, and ultimately high costs and poor results.

[0005] The main problem with the existing technology is the lack of effective separation technology to distinguish particles with different chloride concentrations in bypass vent ash. Bypass vent ash is a complex multi-component mixture, which contains both fine particles with a chloride content of up to 40-60% and coarse particles with a chloride content of only 5-10%. The traditional treatment method treats all particles as homogeneous materials and ignores the significant differences in chloride concentrations between particles. This indiscriminate treatment method results in a large amount of particles with low chloride concentrations, a large amount of materials that need to be disposed of, high water consumption and easy to be over-processed, which not only increases unnecessary processing costs, but also reduces the recovery of these particles that can be directly reused, making it difficult to achieve effective resource utilization.

[0006] Therefore, it is necessary to develop a technology that can accurately grade and separate particles in bypass vent ash based on the differences in chloride concentration, so as to achieve differentiated treatment of particles with different chloride contents. This will not only allow particles with low chloride content to be directly reused in cement production, but also achieve efficient desalination and resource utilization of particles with high chloride content, thereby solving the technical problems of low efficiency and poor economy in bypass vent ash treatment. Summary of the Invention

[0007] The present invention provides a system and method for removing chlorides from cement kiln bypass vent ash and for resource utilization. The system for removing chlorides from cement kiln bypass vent ash and for resource utilization realizes accurate classification and differentiated treatment of particles with different chloride concentrations, thereby solving the problems of low efficiency and high cost caused by indiscriminate treatment in the prior art, and at the same time realizes resource utilization and closed-loop reuse of waste materials.

[0008] In a first aspect, an embodiment of the present invention provides a system for removing chlorides from cement kiln bypass vent ash and for resource utilization, comprising: an air intake device, arranged in a smoke chamber of a cement kiln rotary kiln, for taking out chloride-containing bypass vent ash; a grading and separation device, connected to the output end of the air intake device, for performing multi-stage separation on the bypass vent ash, returning coarse particles with low chloride concentration to a preheater, and collecting fine particles with high chloride concentration; a desalting device, connected to the grading and separation device, for washing and desalting the collected fine particles to obtain desalted solids and a saline solution; a drying device, connected to the desalting device, for drying the saline solution to prepare a potassium salt product; wherein the desalted solids are reused in cement production.

[0009] In one possible implementation, the graded separation device includes: a cyclone separator connected to the output end of the air intake device, for preliminarily separating coarse particles; and an electrostatic separator arranged in series with the cyclone separator, for further separating high-chloride components and low-chloride components in fine particles based on conductivity differences.

[0010] In one possible implementation, the electrostatic separator includes: a cylinder having a separation chamber and a feed port, a first discharge port and a second discharge port connected to the separation chamber, the feed port being connected to a cyclone separator; an electrode device, arranged on the cylinder, for generating a separation electric field; a separation plate, for guiding the separation path of particles with different conductive properties; wherein the first discharge port is arranged at the bottom of the cylinder, for outputting low-chloride components to the preheater, and the second discharge port is arranged at the top of the cylinder, for outputting high-chloride components.

[0011] In a possible implementation, the separation plate has a sharp corner portion, which is arranged toward the feed port, with an angle of 20° to 40°, and a feed speed of the electrostatic separator is 10 to 30 m / s.

[0012] In a possible implementation, the separation plate further includes an arc portion, one end of the arc portion is connected to the sharp corner portion, and the other end forms a side of the first discharge port facing the feed port, for guiding the separated particles to flow toward the first discharge port.

[0013] In one possible implementation, the electrostatic separator further includes a discharge pipe, one end of which extends into the separation chamber and forms a second discharge port; wherein the electrode device is arranged around the discharge pipe.

[0014] In a possible implementation, the electrostatic separator further includes: a blower for cleaning the electrode device.

[0015] In one possible implementation, the graded separation device further includes: a cooler connected to the second discharge port for cooling the separated fine particles; a bag dust collector connected to the cooler for collecting the fine particles; and a storage device connected to the bag dust collector for storing the collected fine particles and supplying them to the desalination device.

[0016] In a possible implementation, the method further includes: a quenching device connected to the air intake device, for cooling the air intake device.

[0017] In a possible implementation, the drying device is a spray dryer, and the high-temperature gas generated by the cooler is used as a heat source for the drying device.

[0018] In a second aspect, an embodiment of the present invention provides a method for removing chlorides from cement kiln bypass vent ash and utilizing it as a resource using the above-mentioned system, comprising the following steps: removing chloride-containing bypass vent ash from the smoke chamber of a cement kiln rotary kiln; subjecting the removed bypass vent ash to a graded treatment using a multi-stage separation method, returning coarse particles with a low chloride concentration to a preheater, and collecting fine particles with a high chloride concentration; subjecting the collected fine particles to a water washing and desalting treatment to obtain a desalted solid and a salt-containing solution; drying the salt-containing solution to obtain a potassium salt product; and reusing the desalted solid as a raw material for cement clinker calcination.

[0019] In one possible implementation, the multi-stage separation includes: first-stage separation: using the cyclone separation principle to separate coarse particles; second-stage separation: using the electrostatic separation principle to separate high-chloride fine particles and low-chloride particles based on the difference in particle conductivity.

[0020] In a possible implementation, the water washing desalination treatment adopts a single-stage water washing process, and chloride removal is achieved through the first-stage water washing treatment.

[0021] In one possible implementation, the desalinated solids are recycled through the raw meal grinding process for cement clinker calcination.

[0022] The present invention provides a system for removing chlorides from bypass vent ash and for resource utilization. By constructing a complete system comprising an air intake device 1, a grading and separation device 3, a desalination device 4, and a drying device 5, the system solves the technical problems of low efficiency and poor economy caused by the indiscriminate treatment of bypass vent ash in the prior art, and achieves a technical breakthrough in accurate grading and differentiated treatment based on the difference in chloride concentration of the particles. The grading and separation device 3 adopts a multi-stage separation technology, which can accurately distinguish coarse particles with low chloride concentration from fine particles with high chloride concentration in the bypass vent ash based on the physical properties and chemical composition differences of the particles, thereby avoiding the drawback of uniform treatment of all particles in the traditional method. After separation, the coarse particles with low chloride concentration can be directly returned to the preheater 21 for reuse, avoiding unnecessary desalination treatment and significantly reducing the treatment cost. The fine particles with high chloride concentration are collected and enter the special desalination device 4 for water washing and desalination. Due to the high chloride concentration and low impurities, the desalination efficiency is significantly improved. Desalination unit 4 effectively separates chloride from fine particles through a water washing process, producing a desalted solid with a chloride content that meets recycling requirements and a saline solution rich in potassium salts, achieving effective separation and utilization of the solid-liquid phase. Drying unit 5 dries the saline solution to produce a potassium salt product, transforming waste into a valuable product. The potassium salt product can be sold as agricultural fertilizer or a chemical raw material, creating significant economic value. Due to the significantly reduced chloride content, the desalted solid meets the quality requirements for reuse as raw material in cement production. This reuse achieves a closed-loop utilization of raw materials, saving on natural raw material consumption and eliminating solid waste emissions. The entire system uses multi-stage separation technology to precisely classify bypass ash, allowing approximately 60-70% of the low-chloride particles to be directly reused, while only 30-40% of the high-chloride particles undergo desalination. Compared to traditional full-scale treatment methods, this reduces processing costs by over 50%. Furthermore, the production of the potassium salt product generates additional revenue, transforming bypass ash from a waste material into a resource, providing an effective technical solution for clean production and circular economic development in the cement industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to 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.

[0024] Figure 1 The present invention provides a schematic diagram of a system for removing chlorides from cement kiln bypass ash and for resource utilization.

[0025] Figure 2It is a structural schematic diagram of an electrostatic separator provided by the present invention.

[0026] Figure 3 The present invention provides a flow chart of a method for removing chlorides from cement kiln bypass ash and utilizing them as resources.

[0027] Reference numerals: 1. Air intake device; 2. Rotary kiln; 21. Preheater; 3. Grading separation device; 31. Cyclone separator; 32. Electrostatic separator; 321. Cylinder; 3211. Separation chamber; 3212. Feed port; 3213. First discharge port; 322. Electrode assembly; 323. Separation plate; 3231. Sharp corner; 3232. Curved portion; 324. Discharge pipe; 325. Blower; 33. Cooler; 331. Cooling fan; 34. Bag dust collector; 35. Storage device; 36. Fan; 4. Desalination unit; 5. Drying device; 6. Quenching device; 7. Cooling machine. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0029] The following combination Figure 1-2 Description: The embodiment of the present invention provides a system for removing chlorides from cement kiln bypass ash and recycling them as resources, comprising an air intake device 1, a classification and separation device 3, a desalination device 4, and a drying device 5, wherein: The air intake device 1 is arranged in the smoke chamber of the cement kiln rotary kiln 2 and is used to take out the bypass vent ash containing chlorides.

[0030] The graded separation device 3 is connected to the air intake device 1 and is used to perform multi-stage separation on the bypass ash, return the coarse particles with low chloride concentration to the preheater 21, and collect the fine particles with high chloride concentration.

[0031] The desalination device 4 is connected to the classification and separation device 3 and is used to wash and desalinate the collected fine particles to obtain desalted solids and a salt solution.

[0032] The drying device 5 is connected to the desalination device 4 and is used to dry the saline solution to prepare a potassium salt product; wherein the desalted solid is recycled for cement production.

[0033] In the present invention, by constructing a complete system including an air intake device 1, a grading and separation device 3, a desalting device 4 and a drying device 5, the precise removal of chlorides from the cement kiln bypass vent ash and efficient resource utilization are achieved. The core of the system is that the grading and separation device 3 performs multi-stage separation on the bypass vent ash, returns the coarse particles with low chloride concentration to the preheater 21, and collects the fine particles with high chloride concentration, thereby solving the problems of low efficiency and high cost caused by the indiscriminate treatment of particles with different chloride concentrations in the prior art. Multi-stage separation technology can achieve accurate classification based on the differences in the physical properties and chemical composition of the particles, significantly improve the chloride enrichment efficiency, and avoid excessive treatment of particles with low chloride content.

[0034] Specifically, the air intake device 1 is arranged in the smoke chamber of the cement kiln rotary kiln 2, and uses negative pressure to extract the chloride-containing bypass vent ash, ensuring a stable supply of raw materials. The grading and separation device 3 is connected to the air intake device 1. After receiving the bypass vent ash, the coarse particles and fine particles are first preliminarily separated by the physical separation principle, and then fine separation is performed based on the difference in conductivity of the particles to achieve accurate classification of chloride concentration. The desalination device 4 is connected to the grading and separation device 3, which is specially used to process the collected high-chloride fine particles, remove the chlorides through a water washing desalination process, and obtain desalted solids and saline solutions. The drying device 5 is connected to the desalination device 4 to dry the saline solution and prepare it into a potassium salt product, realizing the resource conversion of waste materials. The desalted solids are reused in cement production, forming a closed-loop utilization of raw materials.

[0035] In one specific example, during operation of a 5,000 t / d production line at a cement plant, the daily output of bypass ash was approximately 150-200 tons, with an average chloride content of 15-25%. Conventional treatment methods involve discharging all of the bypass ash as waste or simply landfilling it. Using the system of the present invention, multi-stage separation technology allows approximately 60-70% of the coarse particles with low chloride concentrations (chloride content <8%) to be directly returned to the preheater 21 for reuse, while the remaining 30-40% of the fine particles with high chloride concentrations (chloride content >35%) are processed in the desalination unit 4. After desalination, the chloride content of the solids is reduced to below 1%, meeting cement production requirements and allowing 100% reuse. The resulting potassium salt product achieves industrial-grade purity, yielding approximately 40-60 kg of potassium salt per ton of bypass ash, creating significant economic value.

[0036] In the related art, the existing bypass vent ash treatment methods mainly include direct discharge, simple water washing or overall incineration. Although the direct discharge method is simple, it causes waste of resources and environmental pollution, which does not meet the requirements of sustainable development. The simple water washing method uniformly washes all bypass vent ash without distinguishing the differences in chloride concentration, resulting in high treatment costs and uneven water washing effects. Particles with low chloride content are over-treated, and particles with high chloride content are not treated sufficiently. Although the overall incineration method can reduce the volume of waste, it consumes huge energy and cannot recover the valuable components therein. At the same time, the flue gas generated requires additional purification treatment. These traditional methods all have problems such as low resource utilization, high treatment costs, and large environmental impact.

[0037] In the embodiment of the present invention, through the application of multi-stage separation technology, the problem of indiscriminate treatment in the prior art is first solved, and the accurate classification of particles with different chloride concentrations is achieved, so that coarse particles with low chloride concentrations can be directly returned to the production system for reuse, avoiding unnecessary desalination treatment and greatly reducing processing costs. Secondly, a special desalination treatment is carried out for fine particles with high chloride concentrations, which improves desalination efficiency and product quality and ensures the quality of recycled materials. Again, the saline solution is prepared into a potassium salt product through the drying device 5, realizing the conversion of waste into product, turning waste into treasure, and creating additional economic value. Finally, the entire system forms a closed-loop utilization without solid waste discharge, meets the requirements of clean production and circular economy, and has significant environmental and social benefits.

[0038] In some embodiments, the graded separation device 3 includes: a cyclone separator 31, connected to the output end of the air intake device 1, for preliminarily separating coarse particles; an electrostatic separator 32, arranged in series with the cyclone separator 31, for further separating high chloride components and low chloride components in fine particles based on conductivity differences.

[0039] In the present invention, efficient and precise separation of bypass ash is achieved through the two-stage separation structure design of the graded separation device 3, which includes a cyclone separator 31 and an electrostatic separator 32. The cyclone separator 31 is connected to the output end of the air intake device 1, and uses centrifugal force to perform preliminary separation on the incoming bypass ash, effectively removing coarse particles and creating good conditions for the subsequent fine separation by the electrostatic separator 32. The electrostatic separator 32 is arranged in series with the cyclone separator 31. Based on the unique physical property of the difference in particle conductivity, it further separates the high-chloride component and the low-chloride component in the fine particles, achieving a fine classification effect that is difficult to achieve with traditional physical separation methods.

[0040] Specifically, when the cyclone separator 31 is operating, the dust-laden airflow enters the separator at a certain speed, forming a strong rotational motion inside. Coarse particles are thrown toward the wall under the action of centrifugal force, descend along the wall surface and are discharged from the bottom, while fine particles continue to move upward with the airflow and enter the electrostatic separator 32 through the top. An electrode device 322 is provided inside the electrostatic separator 32 to generate a high-voltage electric field. When fine particles containing different conductivity enter the electric field, high-chloride particles with good conductivity are more likely to obtain charge and are deflected to specific electrodes under the action of the electric field force. Low-chloride particles with poor conductivity are less affected by the electric field and move along the original trajectory, thereby achieving precise separation based on conductivity differences. The series configuration of the two-stage separation ensures the continuity and efficiency of the separation process.

[0041] Conventional separation methods in the related art primarily rely on a single physical separation principle, such as using only a cyclone separator 31 or screening equipment for particle size separation. This method cannot effectively distinguish particles of the same size but different chloride contents. This separation method suffers from low separation accuracy and poor chloride enrichment, resulting in complex and costly subsequent processing. Some technologies have attempted to use gravity separation or magnetic separation methods, but these methods have limited separation effects on chloride components and are difficult to meet the requirements of fine classification.

[0042] In the embodiment of the present invention, the two-stage series separation design of the cyclone separator 31 and the electrostatic separator 32 is used to give full play to the advantages of different separation principles and achieve complementary advantages. The cyclone separator 31 uses the difference in particle size to perform preliminary separation, effectively removes coarse particles with low chloride content, reduces the processing load of the electrostatic separator 32, and improves the overall separation efficiency. The electrostatic separator 32 performs fine separation based on the difference in conductivity, and can accurately distinguish fine particles with the same particle size but different chloride content, achieving a separation accuracy that cannot be achieved by traditional physical separation methods. The synergistic effect of the two-stage separation enables the entire graded separation device 3 to have higher separation efficiency, better chloride enrichment effect and stronger adaptability, laying a solid foundation for subsequent desalination and resource utilization.

[0043] In some embodiments, the electrostatic separator 32 includes: a cylinder 321, having a separation chamber 3211 and a feed port 3212, a first discharge port 3213 and a second discharge port connected to the separation chamber 3211, the feed port 3212 is connected to the cyclone separator 31; an electrode device 322, arranged on the cylinder 321, for generating a separation electric field; a separation plate 323, for guiding the separation path of different conductive particles; wherein, the first discharge port 3213 is arranged at the bottom of the cylinder 321, for outputting low chloride components to the preheater 21, and the second discharge port is arranged at the top of the cylinder 321, for outputting high chloride components.

[0044] In the present invention, high-precision particle separation based on conductivity differences is achieved through the structural design of the electrostatic separator 32, which includes a cylinder 321, an electrode device 322, and a separation plate 323. The cylinder 321 provides a stable separation environment, and the separation chamber 3211 inside it provides sufficient space and time for the particle separation process. The reasonable layout of the feed port 3212, the first discharge port 3213, and the second discharge port ensures the orderliness of the material flow and the effective collection of the separated products. The separation electric field generated by the electrode device 322 is the core of achieving conductive separation. By precisely controlling the electric field strength and distribution, different electric field forces can be applied to particles of different conductivity. The provision of the separation plate 323 further optimizes the separation path of the particles, improves the separation efficiency and product purity.

[0045] Specifically, the barrel 321 is designed as a cylindrical structure, with a sealed separation chamber 3211 formed inside, ensuring the stability of the electric field and the controllability of the separation process. A feed port 3212 is located on the side of the barrel 321 and connected to the cyclone separator 31, ensuring a continuous supply of fine particles. A first discharge port 3213 is located at the bottom of the barrel 321, primarily for discharging low-chloride components with poor conductivity. These particles experience less force in the electric field and sink primarily due to gravity. A second discharge port is located at the top of the barrel 321, for discharging high-chloride components with better conductivity. These particles acquire a stronger charge in the electric field and move upward under the influence of the electric field force. The electrode assembly 322 typically adopts a plate or rod structure to generate a uniform and stable high-voltage electric field, the field strength of which can be adjusted according to the separation requirements. The separation plate 323 serves as an auxiliary separation element, guiding the differently conductive particles along a predetermined path through its unique geometric shape, thereby preventing particle mixing and cross-contamination.

[0046] In the related technologies, traditional particle separation equipment mainly relies on physical methods such as gravity separation, screening or air flow separation. These methods are mainly based on the physical properties of particles such as particle size and density for separation, and have limited effect on the separation of particles with similar chemical composition but different chloride content. Some technologies have tried to use chemical separation methods such as flotation, but these methods usually require the addition of chemical reagents, which increases processing costs and environmental burdens, and are not suitable for dry processing. Existing electrostatic separation equipment is mostly used for metal mineral separation, and its structural design and operating parameters are not suitable for the special needs of cement kiln bypass ash.

[0047] In the embodiment of the present invention, the structural design of the electrostatic separator 32 fully considers the special properties and separation requirements of the bypass ash, ensures sufficient separation time through the reasonable size of the cylinder 321, and realizes the orderly flow of materials and effective separation of products through the optimized layout of the inlet and outlet. The configuration of the electrode device 322 and the setting of the electric field parameters are specially optimized for the conductivity characteristics of the chloride component, and can achieve efficient separation without adding any chemical reagents. The setting of the separation plate 323 further improves the separation accuracy and avoids the common product cross-contamination problem in traditional electrostatic separation. The overall structural design is compact and reasonable, easy to operate and maintain, suitable for the requirements of industrial continuous production, and provides an effective technical solution for clean production and resource recycling in the cement industry.

[0048] In some embodiments, the separation plate 323 has a sharp corner portion 3231, which is disposed toward the feed port 3212, with an angle of 20° to 40°. The feed speed of the electrostatic separator 32 is 15 to 30 m / s.

[0049] In the present invention, the design of the sharp corner portion 3231 of the separation plate 323 with a specific geometric shape and optimized feed rate control achieves precise guidance and efficient separation of particles in the electrostatic separator 32. The sharp corner portion 3231 is positioned toward the feed port 3212, forming a geometry that is conducive to particle flow and separation. The sharp corner angle of 20° to 40°, verified through precise calculations and experiments, effectively guides the separation direction of particles while preventing particle accumulation and clogging at the sharp corner. A feed rate of 10 to 30 meters per second ensures that the particles have sufficient residence time in the electric field for full separation, while maintaining a certain speed to ensure appropriate processing capacity, achieving an optimal balance between separation effect and processing efficiency.

[0050] Specifically, the design of the pointed corner 3231 is based on the principles of fluid mechanics and electric field distribution. When a mixture of particles with different conductivities enters the separation chamber 3211 at a certain speed, the wedge-shaped structure of the pointed corner 3231 can guide the particle flow, allowing the particles to enter the electric field separation area along a predetermined trajectory. The angle range of 20° to 40° is the optimal parameter determined through a large number of experiments and computational fluid dynamics simulations. Although angles less than 20° can produce a stronger guiding effect, they are prone to causing particle aggregation and blockage at the sharp corners. Although angles greater than 40° can reduce the risk of blockage, the guiding effect is poor, affecting separation accuracy. Controlling the feed rate is also critical. The speed range of 10 to 30 meters per second ensures that the particles reside in the electric field for between 0.2 and 0.5 seconds. This time is sufficient for particles with different conductivities to produce significant trajectory differences under the action of the electric field force, but it does not affect processing capacity due to excessive residence time.

[0051] Traditional electrostatic separation equipment typically utilizes flat electrodes or simple guide plates, lacking specialized particle guidance designs. This results in uneven particle distribution upon entering the electric field, impacting separation effectiveness. While some devices incorporate guide structures, their geometric parameters lack scientific basis, often resulting in angles that are either too large or too small, making it difficult to achieve ideal separation results. Feed rate control also often relies on empirical settings, lacking theoretical guidance. This can lead to either excessively fast speeds, resulting in insufficient separation time, or excessively slow speeds, impacting processing capacity.

[0052] In the embodiment of the present invention, through precise geometric design and parameter optimization, the sharp corner 3231 of the separation plate 323 not only plays a role in guiding the particles, but also can optimize the electric field distribution and improve the separation efficiency. The angle range of 20°~40° is the optimal parameter verified by theoretical analysis and experiments, which not only ensures a good guiding effect but also avoids the clogging problem. The feed speed control of 10~30 m / s ensures the full separation of the particles in the electric field while maintaining a high processing capacity. This precise parameter control enables the electrostatic separator 32 to operate stably and efficiently, and the separation accuracy and processing capacity are significantly better than traditional equipment, providing a reliable technical guarantee for the efficient separation of bypass ash and subsequent resource utilization.

[0053] In some embodiments, the separation plate 323 further includes an arc portion 3232 , one end of the arc portion 3232 is connected to the pointed portion 3231 , and the other end forms the side of the first discharge port 3213 facing the feed port 3212 , for guiding the separated particles to flow toward the first discharge port 3213 .

[0054] In the present invention, the design of the separation plate 323 also including an arcuate portion 3232 further optimizes the particle separation path and significantly improves the separation effect. One end of the arcuate portion 3232 is connected to the sharp-angled portion 3231, and the other end forms the first discharge port 3213 on the side facing the feed port 3212. This geometric structure design is based on the principles of fluid mechanics and can provide a smooth flow channel for the separated particles, effectively guiding the particles to flow toward the first discharge port 3213, thereby avoiding the retention and mixing of particles during the separation process. The curved design of the arcuate portion 3232 eliminates flow blind spots, reduces particle accumulation and cross-contamination, and improves the collection efficiency and purity of low-chloride components.

[0055] Specifically, the arc portion 3232 adopts a smooth curve transition design, and its curvature radius has been precisely calculated, which can not only maintain the continuity of the particle flow, but also adapt to the geometric requirements of the first discharge port 3213. When the low-chloride particles with poor conductivity basically maintain their original trajectory in the electric field, the guiding effect of the arc portion 3232 enables these particles to flow smoothly to the first discharge port 3213, avoiding the eddy currents and particle accumulation that may occur at right-angle or sharp-angle structures. The presence of the arc portion 3232 can also improve the airflow distribution in the separation chamber 3211, reduce the generation of turbulence, and create better environmental conditions for the stable separation of particles. The connection between the arc portion 3232 and the sharp-angled portion 3231 adopts a smooth transition design to avoid the flow resistance and particle collision losses that may be caused by the sudden change structure.

[0056] Conventional electrostatic separation equipment typically utilizes simple linear guide plates or baffles, which present significant deficiencies in particle guidance. These linear structures often create flow resistance and eddy currents at corners, leading to uneven particle distribution and localized accumulation. While some devices incorporate flow characteristics, their designs are overly simplified and lack optimization for specific separation requirements. These issues result in low separation efficiency and low product purity, compromising the effectiveness of subsequent processing steps.

[0057] In the embodiment of the present invention, the design of the arc portion 3232 fully considers the physical characteristics of the particle flow and the actual needs of the separation process, and effectively eliminates the flow dead corners and eddy current phenomena through smooth curve transitions. The integrated design of the arc portion 3232 and the sharp corner portion 3231 forms a complete particle guiding system, which not only plays the diversion effect of the sharp corner portion 3231, but also utilizes the flow guidance advantage of the arc portion 3232 to achieve the optimization of particle separation and collection. This design not only improves the separation efficiency and product quality, but also reduces the wear and maintenance requirements of the equipment and extends the service life of the equipment. The application of the arc portion 3232 enables the electrostatic separator 32 to better adapt to different material properties and operating conditions, providing a more reliable and efficient technical solution for the fine separation of bypass ash.

[0058] In some embodiments, the electrostatic separator 32 further includes a discharge pipe 324 , one end of which extends into the separation chamber 3211 to form a second discharge port; wherein the electrode device 322 is arranged around the discharge pipe 324 .

[0059] In the present invention, the electrostatic separator 32 also includes a discharge pipe 324, which realizes the accurate collection of high chloride components and the significant improvement of separation effect. One end of the discharge pipe 324 extends into the separation chamber 3211 for a distance. Compared with the traditional method of directly arranging the second discharge port on the barrel 321, it can go deep into the enrichment area of ​​high chloride particles for collection, greatly improving collection efficiency and product purity. The configuration of the electrode device 322 arranged around the discharge pipe 324 further strengthens the local electric field intensity, creating more favorable conditions for the gathering and collection of high chloride particles. This design of the in-depth discharge pipe 324 avoids the dispersion and loss of particles during transportation, ensuring the accurate separation and efficient collection of high chloride components.

[0060] Specifically, the depth of insertion of the discharge pipe 324 is optimized according to the size of the separation chamber 3211 and the electric field distribution. The insertion depth is usually 20-40% of the diameter of the cylinder 321. This range can effectively cover the main enrichment area of ​​high chloride particles without causing excessive interference to the electric field distribution. At the same time, it also has a separation effect on large particles. When the high chloride particles with good conductivity move upward under the action of the electric field force, since the negative pressure and wind speed in the discharge pipe 324 are higher than the values ​​in the separation chamber, these particles can be more easily extracted and enter the next device cooler 33, reducing the dispersion and drift of particles at the top of the cylinder 321. The annular arrangement of the electrode device 322 around the discharge pipe 324 forms a concentrated high-intensity electric field area. The electric field intensity in this area is 20-30% higher than that in the ordinary area, which can produce a stronger electric field force on the high chloride particles and increase the probability of particle collection. The smooth design of the inner wall of the discharge pipe 324 ensures the smooth discharge of particles and avoids blockage and accumulation.

[0061] In an embodiment of the present invention, the design of the discharge pipe 324 extending into the separation chamber 3211 fundamentally solves the problems existing in the traditional method. By moving the collection point forward to the particle enrichment area, the pertinence and accuracy of the collection are greatly improved. The arrangement of the electrode device 322 around the discharge pipe 324 forms a local enhanced electric field, which further improves the separation and collection effect of high chloride particles. This design avoids the disordered dispersion of particles at the top of the cylinder 321, reduces the chance of mixing of different types of particles, and ensures the high purity of the product. The adjustability of the discharge pipe 324 also enables the equipment to adapt to different material properties and separation requirements, improving the adaptability and flexibility of the equipment. The entire design not only improves the separation efficiency, but also ensures product quality, providing an important technical guarantee for the efficient treatment of cement kiln bypass ash.

[0062] In some embodiments, the electrostatic separator 32 further includes a blower 325 for cleaning the electrode assembly 322 .

[0063] In the present invention, the electrostatic separator 32 also includes a purge 325, which enables regular cleaning of the electrode assembly 322 and long-term stability of separation performance. The purge 325 is specifically designed to clean the surface of the electrode assembly 322, effectively removing particles and dust accumulated on the electrodes and preventing a decrease in electric field strength and deterioration in separation performance due to electrode contamination. When the electrostatic separator 32 operates long-term in a dusty environment, the cleanliness of the electrode surface directly affects the stability of the electric field and the separation accuracy. The provision of the purge 325 ensures that the device can maintain stable separation performance under various operating conditions, extending the device's service life and reducing maintenance costs.

[0064] Specifically, the blower 325 usually adopts a compressed air injection system to clean the electrode device 322 through a timing or constant pressure difference control method. During the cleaning process, high-pressure compressed air is sprayed onto the electrode surface at a certain angle and pressure through a specially designed nozzle, blowing off the accumulated particles and carrying them out of the separation chamber 3211 with the air flow. The nozzle arrangement of the blower 325 takes into account the geometric shape of the electrode and the accumulation characteristics of the particles to ensure the comprehensiveness and effectiveness of the cleaning. The purge cycle can be adjusted according to the material properties and operating conditions, and is usually set to clean once every 2-6 hours, with each cleaning time of 30-90 seconds. The start-up of the blower 325 can be automatically triggered by changes in electrode current, pressure difference or timing control, thereby realizing the intelligent operation of the equipment.

[0065] In some embodiments, the grading separation device 3 also includes: a cooler 33, connected to the second discharge port, for cooling the separated fine particles; a bag dust collector 34, connected to the cooler 33, for collecting fine particles; a storage device 35, connected to the bag dust collector 34, for storing the collected fine particles and supplying them to the desalination device 4.

[0066] Specifically, a fan 36 is provided at the gas output end of the bag dust collector 34, and the fan 36 provides power for the air ash to flow throughout the system.

[0067] In the present invention, the system configuration of the graded separation device 3 also includes a cooler 33, a bag dust collector 34 and a storage device 35, thereby achieving complete processing and efficient collection of fine particles after separation. The cooler 33 is connected to the second discharge port, which can quickly reduce the temperature of the fine particles after high-temperature separation, create suitable working conditions for the subsequent bag dust collector 34, and avoid damage to the dust collection equipment due to high temperature. The bag dust collector 34 is connected to the cooler 33, and utilizes a filtering mechanism to efficiently collect fine particles, ensuring zero loss of materials and a clean environment. The storage device 35 is connected to the bag dust collector 34, providing buffering and feeding functions, ensuring stable and continuous feeding to the desalination device 4, and achieving coordination and unification of the entire treatment process.

[0068] Specifically, the cooler 33 uses a cooling fan 331 for heat exchange cooling, and adopts an indirect cooling method. The temperature of the high-temperature fine particles is reduced from 200-300°C to 80-120°C through a heat exchanger. During the cooling process, there is no direct contact with the particles, thus avoiding secondary pollution. A multi-stage heat exchange structure is provided inside the cooler 33, which can fully recover the sensible heat of the particles and improve energy utilization efficiency. The bag dust collector 34 uses a high-temperature corrosion-resistant filter bag. The filter bag material is polytetrafluoroethylene coated glass fiber, which can work stably for a long time at a temperature of 120°C. The filtration accuracy can reach more than 99.9%, ensuring the collection of fine particles. The dust collector is equipped with a pulse cleaning system to regularly back-blow and clean the filter bags to maintain filtration efficiency. The storage device 35 adopts a closed silo design. The volume is determined according to the processing capacity, usually 4-8 hours of material storage capacity. The bottom of the silo is equipped with a quantitative feeding device, which can provide a stable material supply to the desalination device 4.

[0069] In the embodiment of the present invention, a complete particle collection and pretreatment system is formed through the system integration of the cooler 33, the bag dust collector 34 and the storage device 35. The provision of the cooler 33 not only protects the subsequent equipment, but also recovers the thermal energy of the particles, thereby improving energy utilization efficiency. The efficient filtration of the bag dust collector 34 ensures the collection of fine particles, avoids material loss and environmental pollution. The buffering effect of the storage device 35 balances the difference in processing capacity between the previous and next processes, ensuring the stable operation of the entire system. The coordinated work of the three devices realizes the complete transformation from high-temperature particles to room-temperature clean particles, creating ideal conditions for subsequent desalination treatment. This systematic design not only improves processing efficiency and product quality, but also reduces equipment failure rate and maintenance costs, providing reliable technical support for the industrial treatment of bypass ash.

[0070] In some embodiments, it further includes: a quenching device 6 connected to the air intake device 1 for cooling the air intake device 1 .

[0071] In the present invention, by also including a configuration in which a quenching device 6 is connected to the air intake device 1, effective protection of the air intake device 1 and long-term stability of the system operation are achieved. The quenching device 6 is specifically used to cool the air intake device 1, and can effectively reduce the operating temperature of the air intake device 1 in a high-temperature environment, preventing the equipment from malfunctioning or performance degradation due to overheating. In the high-temperature environment of the smoke chamber of the cement kiln rotary kiln 2, the air intake device 1 is exposed to high temperatures of 200-400°C for a long time. The provision of the quenching device 6 ensures that the air intake device 1 can operate stably within a safe temperature range, extending the service life of the equipment and improving the reliability and availability of the system.

[0072] Specifically, the quenching device 6 usually uses forced air cooling or water cooling to cool the air intake device 1. The air cooling system sends room temperature air to the air intake device 1 through a high-pressure fan, and uses convection heat exchange to remove the heat of the equipment, so that the surface temperature of the air intake device 1 is controlled below 100°C. The water cooling system forms a cooling circuit inside or outside the air intake device 1 through circulating cooling water, and uses the high specific heat capacity and latent heat of water for efficient heat exchange, and the cooling effect is more significant. The quenching device 6 is equipped with a temperature monitoring system that can monitor the operating temperature of the air intake device 1 in real time, and automatically start the cooling program when the temperature exceeds the set threshold. The flow rate and temperature of the cooling medium can be adjusted according to the working conditions to ensure the optimization of the cooling effect. The quenching device 6 also has an emergency cooling function, which can provide additional cooling capacity under abnormally high temperature conditions.

[0073] In some embodiments, the drying device 5 is a spray dryer, and the high-temperature gas generated by the cooler 33 is used as a heat source for the drying device 5 .

[0074] In the present invention, the energy-saving design of the drying device 5 being a spray dryer and utilizing the high-temperature gas generated by the cooler 33 as a heat source achieves the recycling of internal heat energy and significant energy savings. The spray dryer is a key device for preparing potassium salt products. By atomizing the salt solution and rapidly drying it in a hot air flow, a potassium salt product with uniform particles and high purity can be obtained. Utilizing the high-temperature gas generated by the cooler 33 as a drying heat source not only reduces the need for an external heat source, but also achieves the effective recycling of waste heat, significantly reducing the energy consumption of the system and embodying the design concept of energy conservation and environmental protection.

[0075] Specifically, in the process of cooling the high-temperature fine particles in the cooler 33, the temperature of the hot gas generated is usually between 150-250°C, and this temperature range is just suitable as a heat source for the spray dryer. The hot gas is transported to the spray dryer through a special hot air pipe, and heat and mass exchange is carried out with the atomized salt solution in the drying tower to achieve rapid evaporation and drying of the solution. The spray dryer is equipped with a precision atomizer that can atomize the salt solution into tiny droplets of 5-50 microns, which increases the heat and mass transfer area and improves the drying efficiency. During the drying process, water evaporates rapidly, potassium salt crystals precipitate and form a granular product. The recycling of hot gas means that the drying process does not require additional fuel or electric heating, and the drying requirements can be met only by recycling the waste heat within the system.

[0076] In the related technologies, traditional spray drying systems usually use independent heating devices, such as gas furnaces, electric heaters or steam heaters. Although these heating methods are mature in technology, they have problems of high energy consumption and high operating costs. Gas heating consumes a large amount of natural gas, which increases operating costs and carbon emissions. Although electric heating is clean, the cost of electricity is high and the economy is poor. Steam heating requires a supporting boiler system, which requires large equipment investment and a complex system. These traditional heating methods do not consider the recovery and utilization of waste heat within the system, resulting in energy waste. Some technologies have attempted to recover heat, but the recovery efficiency is low and the economic benefits are not obvious.

[0077] In the embodiment of the present invention, through a clever system integration design, the waste heat of the cooler 33 is directly used as the heat source of the spray dryer, thereby achieving efficient recycling of energy. This waste heat utilization method does not require additional fuel consumption, which greatly reduces operating costs. The temperature and flow rate of the waste heat are highly matched with the requirements of spray drying, ensuring the drying effect and product quality. The thermal integration design of the system also simplifies the overall structure, reduces equipment investment and floor space. Through the utilization of waste heat, the energy utilization efficiency of the system is significantly improved, and carbon emissions are greatly reduced, which meets the requirements of green production and sustainable development. This energy-saving design not only brings significant economic benefits, but also embodies the concept of circular economy, and provides a useful reference and reference for energy-saving transformation in the chemical, building materials and other industries.

[0078] The gas generated by the drying device 5 is returned to the rotary kiln 2 through the cooler 7 .

[0079] In the present invention, a gas circulation design returns the gas generated by the drying device to the rotary kiln via a cooler, achieving closed-loop utilization of the system's internal gas and further recovery of heat energy. During the drying process of the saline solution to produce potassium salt products, the drying device generates a large amount of waste gas containing water vapor and heat energy. The temperature of this waste gas is typically between 80-120°C, with a certain calorific value. Cooling this waste gas in a cooler before returning it to the rotary kiln not only recovers the sensible heat in the waste gas, but also reduces the rotary kiln's demand for external air, thereby improving the thermal efficiency of the entire system.

[0080] Specifically, the exhaust gas generated by the drying unit is primarily composed of water vapor, a small amount of potassium salt dust, and hot air. After being processed in a cooler, the temperature of this exhaust gas is reduced to 40-60°C, and the heat energy is recovered and reused. The cooled gas is clean and free of harmful substances, meeting the quality requirements for rotary kiln gas. After returning to the rotary kiln, the exhaust gas can be used as combustion air or cooling air, reducing the rotary kiln system's demand for fresh air. This gas recycling method not only saves energy but also reduces exhaust emissions, meeting environmental requirements.

[0081] like Figure 3As shown, an embodiment of the present invention provides a method for removing chlorides from cement kiln bypass ash and recycling them using the above system, comprising the following steps: S1, take out the bypass vent ash containing chloride from the smoke chamber 2 of the cement kiln rotary kiln; S2. The bypass ash removed is subjected to a multi-stage separation process, and the coarse particles with low chloride concentration are returned to the preheater 21, while the fine particles with high chloride concentration are collected; S3, washing and desalting the collected fine particles to obtain desalted solids and a saline solution; S4, drying the saline solution to obtain a potassium salt product; S5. Reuse the desalted solid as raw material for cement clinker calcination.

[0082] In the present invention, a systematic treatment of chloride removal and resource utilization of cement kiln bypass vent ash is achieved through a complete method flow. The method includes the entire process from removing the chloride-containing bypass vent ash to finally obtaining the potassium salt product and recycling the desalted solid, forming a process scheme with a clear technical route and strong operability. The core of the method lies in the application of multi-stage separation technology. Through precise classification treatment, differentiated treatment of particles with different chloride concentrations is achieved, which not only ensures the effective recycling of low-chloride particles, but also realizes the resource utilization of high-chloride particles, solving the problems of low treatment efficiency and resource waste existing in traditional methods.

[0083] Specifically, the entire method process has a clear sequence of steps and technical requirements. First, the high-temperature chloride-containing bypass vent ash is taken out from the smoke chamber 2 of the cement kiln rotary kiln. This step ensures the stable supply and quality control of raw materials. The bypass vent ash taken out is then graded using a multi-stage separation method. This is the core link of the entire method. Through the combination of cyclone separation and electrostatic separation, precise separation of particles of different properties is achieved. The collected fine particles are then washed and desalted. The chlorides are effectively removed through the water washing process to obtain clean desalted solids and a solution rich in potassium salts. The salt-containing solution is then dried and a potassium salt product is produced by spray drying technology. Finally, the desalted solids are reused as raw materials for cement clinker calcination, realizing closed-loop utilization of materials.

[0084] In the related technologies, the traditional bypass ash treatment method has many technical defects and economic problems. Although the simple discharge method is simple to operate, it causes serious waste of resources and environmental pollution, and does not meet modern environmental protection requirements. The unified water washing method treats all materials in the same way, ignoring the differences in material composition, resulting in high treatment costs and poor results. Although the incineration treatment method can reduce the amount of treatment, it consumes a lot of energy and cannot recover valuable components. Although the concept of graded treatment is reflected in some technologies, it lacks effective separation means and a complete process route, making it difficult to achieve industrial application.

[0085] In the embodiments of the present invention, various problems existing in traditional technologies are solved through systematic method design. The application of multi-stage separation technology realizes the accurate classification of materials, avoiding the low efficiency and high cost problems caused by indiscriminate treatment. The water washing desalination process specifically treats high-chloride particles, thereby improving the desalination efficiency and resource utilization. The application of spray drying technology realizes the efficient conversion of saline solutions and prepares high-quality potassium salt products. The reuse of desalted solids realizes the recycling of materials and embodies the concept of circular economy. The whole method is technologically advanced, economically reasonable, and environmentally friendly. It provides an effective technical solution for the clean production and sustainable development of the cement industry and has broad promotion and application value.

[0086] In some embodiments, the multi-stage separation includes: first stage separation: using cyclone separation principle to separate coarse particles; second stage separation: using electrostatic separation principle to separate high chloride fine particles and low chloride particles based on the difference in particle conductivity.

[0087] The present invention achieves high-precision classification of bypass ash through a multi-stage separation process, including a first-stage cyclonic separation and a second-stage electrostatic separation. The first-stage separation utilizes the cyclonic separation principle, exploiting the centrifugal force differences between particles in a rotating airflow to separate coarse particles. These coarse particles primarily consist of larger silicates (such as limestone) and aluminate minerals with low chloride content. The second-stage separation utilizes the electrostatic separation principle, separating high-chloride fine particles from low-chloride particles based on differences in particle conductivity. This method leverages the significant difference in electrical properties between chloride and silicate components. This organic combination of two stages achieves progressive separation from coarse to fine, and from physical to electrical, achieving high levels of separation precision and efficiency.

[0088] Specifically, during the first-stage cyclonic separation process, the dust-laden airflow forms a strong spiral motion within the cyclone separator 31. The centrifugal force on coarse particles is proportional to their mass. Large particles experience greater centrifugal force, tending to be flung toward the walls and settling, while fine particles experience less centrifugal force and continue upward with the airflow. The separation particle size of the cyclone separator 31 is typically set between 80 and 120 microns, effectively separating most coarse particles. During the second-stage electrostatic separation process, fine particles acquire different charges in a high-voltage electric field based on their conductivity. Fine particles with high chloride content (such as potassium chloride and sodium chloride) have good conductivity and are more easily charged in their molten state, resulting in deflection under the action of the electric field. Limestone, sandstone, and decomposition products, on the other hand, have poor conductivity, large particle size, and low charge, essentially maintaining their original trajectory. Parameter matching and process optimization for the two-stage separation ensure maximum separation efficiency.

[0089] In some embodiments, the water washing desalination treatment adopts a single-stage water washing process, and chloride removal is achieved through a one-stage water washing process (one or two backwashings are added as necessary to clean the residue).

[0090] In the present invention, a single-stage water washing process is used for water washing and desalination, achieving efficient chloride removal and significantly simplifying the process flow. The single-stage water washing process can effectively remove chloride through a single water washing process, greatly simplifying the process flow and reducing equipment investment and operating costs compared to traditional multi-stage water washing processes. This process design is based on the high solubility of chloride and utilizes the strong solubility of water for chloride. Under appropriate water-cement ratio and stirring conditions, most of the chloride can be dissolved and separated in a single water washing process, achieving ideal desalination effect.

[0091] Specifically, the single-stage water washing process adopts a mixed washing method, mixing the high-chloride fine particles that have been graded and separated with clean water in a certain proportion, usually with a water-cement ratio controlled between 1:1 and 2.5:1. The mixture is fully mixed in a stirring tank for 2-10 minutes, and the stirring is performed to ensure that the particles are fully mixed with water. During the water washing process, soluble chlorides such as potassium chloride and sodium chloride are rapidly dissolved into the liquid phase, while insoluble components such as silicates and aluminates are retained in the solid phase. After washing is completed, the desalted solids and the saline solution are separated by solid-liquid separation methods such as sedimentation, filtration or centrifugation. The desalted solids can be directly reused in cement production, and the saline solution enters the drying device 5 to prepare the potassium salt product.

[0092] In some embodiments, the desalinated solids are recycled back into cement clinker calcination via raw grinding.

[0093] In this invention, desalinated solids are recycled through a raw mill for cement clinker calcination, achieving complete recycling of treated solid waste and effectively supplementing raw materials for cement production. Raw mills are key equipment in cement production, capable of grinding various raw materials to the required fineness and thoroughly mixing them. Recycling desalinated solids through the raw mill ensures uniform mixing of desalinated solids with other cement raw materials, guaranteeing the quality and stability of the recycled materials. This recycling method not only achieves zero solid waste emissions but also reduces the demand for natural raw materials in cement production, embodying the concepts of a circular economy and sustainable development.

[0094] Specifically, after the desalted solids are washed and desalted, their chemical composition is mainly silicate and aluminate minerals or oxides, etc. These components are basically consistent with the main components of cement raw materials, and have the basic conditions for reuse in cement production.

[0095] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. That is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A system for removing chloride from cement kiln bypass ash and recycling it, characterized in that: include: An air intake device (1) is provided in a smoke chamber of a cement kiln rotary kiln (2) and is used to take out bypass ash containing chlorides; A graded separation device (3) is connected to the output end of the air intake device (1) and is used to perform multi-stage separation on the bypass ash, return the coarse particles with low chloride concentration to the preheater (21), and collect the fine particles with high chloride concentration; A desalting device (4) is connected to the fractionation and separation device (3) and is used to wash and desalinate the collected fine particles to obtain desalted solids and a salt solution; A drying device (5), connected to the desalination device (4), for drying the saline solution to prepare a potassium salt product; Wherein, the desalted solids are recycled for cement production.

2. The cement kiln bypass ash chloride removal and resource utilization system according to claim 1 is characterized in that: The fractionation separation device (3) comprises: A cyclone separator (31) is connected to the output end of the air intake device (1) and is used to initially separate coarse particles; The electrostatic separator (32) is connected to the output end of the cyclone separator (31) and is used to further separate the high chloride component and the low chloride component in the fine particles based on the difference in conductivity.

3. The cement kiln bypass ash chloride removal and resource utilization system according to claim 2, characterized in that: The electrostatic separator (32) comprises: A cylinder (321) having a separation chamber (3211) and a feed port (3212), a first discharge port (3213), and a second discharge port communicated with the separation chamber (3211), wherein the feed port (3212) is connected to the cyclone separator (31); An electrode device (322), disposed on the cylinder (321), for generating a separation electric field; A separation plate (323) for guiding separation paths of particles of different conductive properties; The first discharge port (3213) is provided at the bottom of the cylinder (321) for discharging low-chloride components to the preheater (21), and the second discharge port is provided at the top of the cylinder (321) for discharging high-chloride components.

4. The cement kiln bypass ash chloride removal and resource utilization system according to claim 3, characterized in that: The separation plate (323) has a pointed corner (3231), the pointed corner (3231) is arranged toward the feed port (3212), the pointed angle is 20° to 40°, and the feed speed of the electrostatic separator (32) is 10 to 30 m / s.

5. The cement kiln bypass ash chloride removal and resource utilization system according to claim 4 is characterized in that: The separation plate (323) further comprises an arc-shaped portion (3232), one end of the arc-shaped portion (3232) being connected to the pointed portion (3231), and the other end forming a side surface of the first discharge port (3213) facing the feed port (3212), for guiding the separated particles to flow toward the first discharge port (3213).

6. The cement kiln bypass ash chloride removal and resource utilization system according to claim 3, characterized in that: The electrostatic separator (32) further includes a discharge pipe (324), one end of which extends into the separation chamber (3211) to form the second discharge port; Wherein, the electrode device (322) is arranged around the discharge pipe (324).

7. The system for removing chlorides from bypass ash and recycling them as resources according to any one of claims 3 to 6, characterized in that: The electrostatic separator (32) further comprises: A blower (325) is used to clean the electrode device (322).

8. The system for removing chlorides from bypass ash and recycling them as resources according to any one of claims 3 to 6, characterized in that: The fractionation separation device (3) further comprises: a cooler (33), connected to the second discharge port, for cooling the separated fine particles; a bag dust collector (34), connected to the cooler (33), for collecting fine particles; A storage device (35) is connected to the bag dust collector (34) and is used to store the collected fine particles and supply them to the desalination device (4).

9. The cement kiln bypass ash chloride removal and resource utilization system according to claim 8, characterized in that: The drying device (5) is a spray dryer, and the high-temperature gas generated by the cooler (33) is used as a heat source for the drying device (5).

10. A method for removing chlorides from cement kiln bypass ash and recycling them using the system according to any one of claims 1 to 9, characterized in that: The following steps are involved: Remove the chloride-containing bypass ash from the smoke chamber of the cement kiln (2); The bypass ash removed is graded using a multi-stage separation method, with coarse particles with low chloride concentrations returned to the preheater (21) and fine particles with high chloride concentrations collected; The collected fine particles are subjected to water washing and desalination treatment to obtain desalted solids and saline solution; Drying the saline solution to obtain a potassium salt product; The desalted solid is recycled as raw material for cement clinker calcination.

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