A flue gas separation and purification device for ternary precursor spray pyrolysis synthesis and a ternary precursor spray pyrolysis synthesis method

Abstract

This invention relates to the field of flue gas separation and purification technology for ternary precursor spray pyrolysis synthesis, and discloses flue gas separation and purification equipment and a method for ternary precursor spray pyrolysis synthesis, solving the technical problem of improving the quality of ternary precursor powder recovered from spray pyrolysis flue gas. It includes: a first flue gas-solid separation device, a second flue gas-solid separation device (the second flue gas-solid separation device employs a flue gas filter dust collector), a third flue gas-solid separation device (the third flue gas-solid separation device employs a wet dust collector and has an inlet channel opening adjustment mechanism), a first liquid-solid separation device, a second liquid-solid separation device, a fan device employing a variable frequency fan, and a flue gas filtration and dust removal status monitoring device. Effective separation and recovery of the ternary precursor powder before cooling is achieved, improving quality; a balance between high-efficiency dust removal and energy-saving operation is realized.

Description

Technical Field

[0001] This invention relates to the field of flue gas separation and purification technology for ternary precursor spray pyrolysis synthesis, specifically to flue gas separation and purification equipment and ternary precursor spray pyrolysis synthesis method. Background Technology

[0002] Ternary precursors for lithium-ion secondary battery cathode materials are key materials for preparing high-performance lithium-ion secondary batteries. Currently, the production of ternary precursors is highly competitive, with co-precipitation being the primary synthesis process. To innovate synthesis methods and enhance product competitiveness, several ternary precursor manufacturers have begun exploring shifting their synthesis processes to spray pyrolysis technology. Spray pyrolysis is an existing technology commonly used for the large-scale production of transition metal oxide materials. It offers unique advantages in synthesizing ternary precursors, such as atomically uniform mixing of composite materials, effective porosity control to handle large volume changes in active materials during charging and discharging, uniform particle size, higher yield, good reproducibility, and high purity. During spray pyrolysis, the furnace produces spray pyrolysis flue gas containing ternary precursor powder and acidic gases (ternary precursor spray pyrolysis synthesis flue gas). Depending on the raw material salt system, the acidic gas switches between HCl and sulfur oxides. When lithium, nickel, cobalt, and manganese salts are all chlorides, the acidic gas is HCl; when lithium, nickel, cobalt, and manganese salts are all sulfates, the acidic gas is sulfur oxides.

[0003] In actual production, manufacturers often switch between chloride-based and sulfate-based raw materials according to specific requirements. Correspondingly, in the separation and purification of flue gas from the spray pyrolysis synthesis of ternary precursors, the spray pyrolysis flue gas separation and purification equipment not only needs to adapt to both HCl and sulfur oxides—two acidic gas environments with different properties—but also needs to maintain stable treatment effects and product quality during the switching process. Therefore, water washing is currently the most common method for treating spray pyrolysis flue gas, ensuring that all ternary precursor powder in the spray pyrolysis flue gas enters the solution phase, where it is subsequently extracted. For example, in patent document CN109647310A, a cyclone separator, a tail gas absorption tower, a tail gas scrubbing tower, and an exhaust fan are sequentially installed after the spray pyrolysis furnace (from this patent document...). Figure 2 Analysis shows that the tail gas absorption tower should be a spray scrubbing tower, and the tail gas scrubbing tower should be a packed scrubbing tower.

[0004] The existing spray pyrolysis flue gas treatment technologies mentioned above mainly have the following problems: cyclone separators have low dust removal efficiency for fine particulate matter (dust concentration at the spray pyrolysis furnace outlet is 5 g / Nm³). 3 -15g / Nm 3The dust concentration at the outlet of a cyclone separator is typically 1 g / Nm³. 3 -3g / Nm 3 A large amount of ternary precursor powder has to be recovered through water washing. This powder is prone to agglomeration and clumping during cooling. Furthermore, the sudden temperature drop can lead to incomplete crystal structures, irregular particle morphology, and decreased sphericity, affecting the quality and electrochemical performance of the ternary precursor powder. Subsequent dispersion processes are complex and have limited effectiveness. In addition, the solution phase obtained from water washing has a complex composition, requiring multiple complex processes such as chemical precipitation, filtration, washing, and drying to obtain a solid product again. This process is not only lengthy and energy-intensive, but the quality of the recovered ternary precursor powder often cannot reach the quality of the ternary precursor powder produced by the spray pyrolysis furnace itself, resulting in a decline in product quality. Summary of the Invention

[0005] The purpose of this invention is to provide a ternary precursor spray pyrolysis synthesis flue gas separation and purification device and a ternary precursor spray pyrolysis synthesis method, thereby solving the technical problem of improving the quality of ternary precursor powder recovered from spray pyrolysis flue gas.

[0006] In one aspect, a ternary precursor spray pyrolysis synthesis flue gas separation and purification device is provided for separating and purifying the spray pyrolysis flue gas discharged from a spray pyrolysis furnace. The spray pyrolysis furnace prepares ternary precursor powder for lithium-ion secondary battery cathode materials through a spray pyrolysis process, generating spray pyrolysis flue gas containing ternary precursor powder and acidic gases. The device includes: a first flue gas-solid separation unit, which employs a mechanical dust collector to mechanically remove dust from the spray pyrolysis flue gas, obtaining the ternary precursor powder and acidic gases respectively. The system comprises: a first gas-solid separation dust and a first gas-solid separation flue gas; and a second flue gas-solid separation device, wherein the second flue gas-solid separation device uses a flue gas filter dust collector to filter and remove dust from the first gas-solid separation flue gas, thereby obtaining a second gas-solid separation dust and a second gas-solid separation flue gas, wherein the filtration temperature of the flue gas filter dust collector is 400℃-600℃ and high-temperature and corrosion-resistant filter materials are used, and the dust removal efficiency of the flue gas filter dust collector is set to ensure that the dust content in the second gas-solid separation flue gas is ≤50mg / Nm³. 3The third flue gas-solid separation device employs a wet scrubber to treat the second gas-solid separation flue gas, obtaining a third gas-solid separation slurry and a third gas-solid separation tail gas. The wet scrubber has an inlet channel opening adjustment mechanism to adjust the opening of the inlet channel, which guides the second gas-solid separation flue gas into the wet scrubbing zone of the wet scrubber. The first liquid-solid separation device employs a cross-flow filter to treat the second gas-solid separation flue gas. The third gas-solid separation slurry undergoes cross-flow filtration to obtain a first liquid-solid separation clarified liquid and a first liquid-solid separation concentrated liquid. A second liquid-solid separation device uses a filter press to filter the first liquid-solid separation concentrated liquid, obtaining a second liquid-solid separation clarified liquid and a second liquid-solid separation filter cake. A fan device is installed between the flue gas filter dust collector and the wet scrubber or on the third gas-solid separation tail gas emission channel to provide airflow power for the ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment. The system employs a variable frequency fan and a flue gas filtration and dust removal status monitoring device. This device monitors the operation of the flue gas filtration and dust removal system, thereby analyzing the dust content in the second gas-solid separation flue gas and generating analysis results. The first liquid-solid separation clarified liquid is returned to the wet scrubber for recycling via a first pipeline, and the second liquid-solid separation clarified liquid is returned to the third gas-solid separation slurry via a second pipeline. The first gas-solid separation dust, the second gas-solid separation dust, and the second liquid-solid separation filter cake are used as products. The third gas-solid separation exhaust gas is recovered and discharged directly or after subsequent treatment. During operation, when the analysis result indicates that the dust content in the second gas-solid separation flue gas reaches a preset low level, the air intake channel opening adjustment mechanism controls the opening of the air intake channel to a larger value and the variable frequency fan operates at a lower frequency; when the analysis result indicates that the dust content in the second gas-solid separation flue gas reaches a preset high level, the air intake channel opening adjustment mechanism controls the opening of the air intake channel to a smaller value and the variable frequency fan operates at a higher frequency.

[0007] As an optimization and / or instantiation of the above-mentioned ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment, further: the wet dust collector is an impact wet dust collector, and the shell of the impact wet dust collector is divided into an S-shaped channel by a partition assembly. The transverse channel at the bottom of the S-shaped channel constitutes the air inlet channel, and the transverse channel is located below the design liquid level during operation; wherein, at least one of the upper partition and the lower partition constituting the transverse channel is installed in the shell in a movable manner and connected to the air inlet channel opening adjustment drive device, thereby forming the air inlet channel opening adjustment mechanism.

[0008] As an optimization and / or instantiation of the above-mentioned ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment, further: at least one of the upper partition and the lower partition is rotatably mounted in the housing via a horizontal rotating shaft perpendicular to the flow direction of the transverse channel; the air inlet channel opening adjustment drive device is used to drive the horizontal rotating shaft to rotate.

[0009] As an optimization and / or instantiation of the above-mentioned ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment, further: acidic gases are switched between HCl and sulfur oxides.

[0010] As an optimization and / or instantiation of the above-mentioned ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment, further: the mechanical dust collector specifically adopts a cyclone dust collector.

[0011] As an optimization and / or instantiation of the above-mentioned ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment: the filter material comprises a metal filter membrane made of Hastelloy, nickel-copper alloy or titanium alloy.

[0012] As an optimization and / or instantiation of the above-mentioned ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment, further: the cross-flow filter adopts a ceramic filter element.

[0013] As an optimization and / or instantiation of the above-mentioned ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment, further: the cross-flow filter adopts a silicon carbide ceramic filter element.

[0014] Secondly, a method for synthesizing a ternary precursor by spray pyrolysis is provided, comprising: a mixed solution preparation step: preparing a mixed solution by mixing lithium salt, nickel salt, cobalt salt, and manganese salt in a molar ratio, wherein the molar ratio of nickel, cobalt, and manganese is x:y:z, and x+y+z=1, 0.5≤x≤0.8, 0.1≤y≤0.3, and 0.1≤z≤0.3; and a spray pyrolysis step: atomizing the mixed solution through an atomizer and then feeding it into a spray pyrolysis furnace, where a spray pyrolysis reaction is carried out at a temperature of 600℃-1000℃ to obtain the ternary precursor. The process involves: 1) ternary precursor powder and spray pyrolysis flue gas containing acidic gases; 2) Flue gas separation and purification step: The spray pyrolysis flue gas is separated and purified using the ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment described in the first aspect above, recovering the first gas-solid separation dust, the second gas-solid separation dust, and the second liquid-solid separation filter cake; 3) Product collection step: The ternary precursor powder obtained in the spray pyrolysis step is collected together with the first gas-solid separation dust, the second gas-solid separation dust, and the second liquid-solid separation filter cake recovered in the flue gas separation and purification step to obtain the ternary precursor product.

[0015] As an optimization and / or instantiation of the above-mentioned ternary precursor spray pyrolysis synthesis method, further: the lithium salt, nickel salt, cobalt salt, and manganese salt are all chlorides or sulfates; when the lithium salt, nickel salt, cobalt salt, and manganese salt are all chlorides, the acidic gas is HCl; when the lithium salt, nickel salt, cobalt salt, and manganese salt are all sulfates, the acidic gas is sulfur oxides.

[0016] The present invention has the following technical effects:

[0017] (1) By setting up a second flue gas gas-solid separation device, the present invention uses a flue gas filter dust collector to perform flue gas filtration and dust removal treatment on the first gas-solid separation flue gas under high temperature conditions of 400℃-600℃. This can effectively separate and recover the ternary precursor powder before cooling, avoiding the problems of agglomeration, clumping, incomplete crystal structure, irregular particle morphology and decreased sphericity that occur in the ternary precursor powder during the cooling process in the prior art. This significantly improves the quality of the ternary precursor powder recovered from the spray pyrolysis flue gas and maintains good particle characteristics and electrochemical performance.

[0018] (2) The present invention employs a three-stage gas-solid separation process consisting of a first flue gas gas-solid separation device (mechanical dust collector), a second flue gas gas-solid separation device (flue gas filter dust collector), and a third flue gas gas-solid separation device (wet dust collector), as well as a two-stage liquid-solid separation process consisting of a first liquid-solid separation device (cross-flow filter) and a second liquid-solid separation device (filter press), forming a complete multi-stage separation system. This maximizes the recovery of dust from the first gas-solid separation, dust from the second gas-solid separation, and filter cake from the second liquid-solid separation, significantly improving the overall recovery efficiency of the ternary precursor powder.

[0019] (3) The flue gas separation and purification equipment of the present invention can adapt to the switching between acidic gases HCl and sulfur oxides. By using high temperature and corrosion resistant filter materials (such as metal filter membranes made of Hastelloy, nickel-copper alloy or titanium alloy), the equipment can maintain stable processing effect and product quality under different acidic gas environments, and meet the switching needs of chloride system raw materials and sulfate system raw materials in actual production.

[0020] (4) Compared with the complex process flow of existing technologies that rely entirely on water washing and recycling, the present invention can greatly simplify the subsequent complex chemical precipitation, filtration, washing, drying and other process steps through direct gas-solid separation at high temperature, which greatly simplifies the process flow, reduces energy consumption and production costs, and further improves resource utilization efficiency through the recycling of the first liquid-solid separation clear liquid and the second liquid-solid separation clear liquid.

[0021] (5) This invention monitors the operation of the flue gas filtration and dust removal device, enabling real-time analysis of the dust content in the second gas-solid separation flue gas. Combined with the coordinated control of the inlet channel opening adjustment mechanism and the variable frequency fan, it achieves collaborative operation between the second and third flue gas-solid separation devices. Although the flue gas filtration and dust removal device has high dust removal efficiency, its operational stability fluctuates (mainly due to the high operating temperature and strong corrosiveness of acidic gases, which easily damages the filter material). This invention uses a wet scrubber to work in conjunction with it to ensure the stability of the overall dust removal effect. When the dust content in the second gas-solid separation flue gas is low, it indicates that the flue gas filter dust collector is operating well. At this time, the inlet channel opening adjustment mechanism controls the opening of the inlet channel to a larger value, the variable frequency fan operates at a lower frequency, and the wet scrubber operates in a low-load mode to reduce energy consumption. When the dust content is high, it indicates that the dust removal effect of the flue gas filter dust collector is fluctuating. At this time, the inlet channel opening adjustment mechanism controls the opening of the inlet channel to a smaller value, the variable frequency fan operates at a higher frequency, and the wet scrubber operates in a high-efficiency dust removal mode. By strengthening the wet scrubbing process, the instability of the flue gas filter dust collector effect is compensated, thereby achieving a balance between high-efficiency dust removal and energy-saving operation, and ensuring the stability of the dust removal effect of the entire ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment.

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages provided by the present invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, are used to aid in understanding the invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the invention, but do not constitute an undue limitation of the invention.

[0024] Figure 1 This is a schematic diagram of a ternary precursor spray pyrolysis synthesis flue gas separation and purification device according to an embodiment of the present invention.

[0025] Figure 2 for Figure 1 Overall view of a medium-wet dust collector.

[0026] Figure 3 for Figure 2 The image shows an overall view of the wet scrubber with the casing made transparent.

[0027] Figure 4 for Figure 3 The image shows a front view of the wet scrubber behind the concealed air intake channel opening adjustment drive.

[0028] Figure 5 for Figure 3 The image shows an enlarged view of the wet scrubber at the inlet channel opening adjustment drive device.

[0029] Figure 6 for Figure 5 The three-dimensional view of the portion shown.

[0030] Figure 7 for Figure 3 The diagram shows the opening adjustment mechanism of the wet scrubber's air inlet channel at the first opening.

[0031] Figure 8 for Figure 3 The diagram shows the opening adjustment mechanism of the wet scrubber's air inlet channel at the second opening position.

[0032] Figure 9 for Figure 1 The diagram shows the control system of the ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment.

[0033] The components in the diagram are labeled as follows: First flue gas gas-solid separation device 1, Second flue gas gas-solid separation device 2, Third flue gas gas-solid separation device 3, Shell 31, Second gas-solid separation flue gas inlet 311, Third gas-solid separation tail gas outlet 312, Third gas-solid separation slurry outlet 313, S-shaped channel 32, Horizontal channel 33, Design liquid level 34, Upper baffle 35, Lower baffle 36, Horizontal rotating shaft 37, Inlet channel opening adjustment drive device 38, Motor 381, First gear pair 382, ​​Second gear pair 383, First liquid-solid separation device 4, First pipeline 41, Second liquid-solid separation device 5, Fan device 6, Flue gas filtration and dust removal status monitoring device 7, Spray pyrolysis furnace 8, Feeding system 81, Heating system 82, PLC controller 9, Chimney 10, Drying oven 11. Detailed Implementation

[0034] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0035] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0036] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0037] The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0038] Figure 1 This is a schematic diagram of a ternary precursor spray pyrolysis synthesis flue gas separation and purification device according to an embodiment of the present invention. Figure 2 for Figure 1 Overall view of a medium-wet dust collector. Figure 3 for Figure 2 The image shows an overall view of the wet scrubber with the casing made transparent. Figure 4 for Figure 3 The image shows a front view of the wet scrubber behind the concealed air intake channel opening adjustment drive. Figure 5 for Figure 3 The image shows an enlarged view of the wet scrubber at the inlet channel opening adjustment drive device. Figure 6 for Figure 5 The three-dimensional view of the portion shown. Figure 7 for Figure 3 The diagram shows the opening adjustment mechanism of the wet scrubber's air inlet channel at the first opening. Figure 8 for Figure 3 The diagram shows the wet scrubber's inlet passage opening adjustment mechanism at the second opening position. Figures 1-8 As shown, the ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment includes: a first flue gas gas-solid separation device 1, a second flue gas gas-solid separation device 2, a third flue gas gas-solid separation device 3, a first liquid-solid separation device 4, a second liquid-solid separation device 5, a fan device 6, and a flue gas filtration and dust removal status monitoring device 7.

[0039] The first flue gas gas-solid separation device 1 employs a mechanical dust collector, specifically a cyclone dust collector, to mechanically remove dust from the spray pyrolysis flue gas from the spray pyrolysis furnace 8. This cyclone dust collector separates larger ternary precursor powder particles from the spray pyrolysis flue gas using centrifugal force, resulting in first gas-solid separation dust and first gas-solid separation flue gas. The first gas-solid separation dust is collected through the discharge port at the bottom of the cyclone dust collector, while the first gas-solid separation flue gas is discharged from the top outlet into subsequent processing units.

[0040] The second flue gas gas-solid separation device 2 employs a flue gas filter dust collector to treat the first gas-solid separation flue gas, resulting in second gas-solid separation dust and second gas-solid separation flue gas. The filtration temperature of this flue gas filter dust collector is set at 400℃-600℃, and it uses high-temperature and corrosion-resistant filter materials, specifically including a metal filter membrane made of Hastelloy (the metal filter membrane is wrapped around a support to form a metal membrane cylinder). The dust removal efficiency of this flue gas filter dust collector is set to ensure that the dust content in the second gas-solid separation flue gas is ≤50mg / Nm³. The second gas-solid separation dust is collected through a back-flushing cleaning system.

[0041] like Figures 1-8 As shown, the third flue gas gas-solid separation device 3 employs a wet dust collector, specifically an impact wet dust collector, to perform wet dust removal treatment on the second gas-solid separation flue gas, resulting in the third gas-solid separation slurry and the third gas-solid separation tail gas. The third gas-solid separation tail gas is discharged through the chimney 10.

[0042] The impact wet dust collector includes a shell 31 (the upper two sides of the shell 31 are respectively provided with a second gas-solid separation flue gas inlet 311 and a third gas-solid separation tail gas outlet 312, and the bottom of the conical hopper below the shell 31 is provided with a third gas-solid separation slurry outlet 313), and the shell 31 is divided into S-shaped channels 32 by a partition assembly. Figure 3 and Figure 4 As shown, the transverse channel 33 at the bottom of the S-shaped channel 32 forms an air intake channel. During operation, the transverse channel 33 is located below the designed liquid level 34 (the blue part in the figure represents water).

[0043] The working principle of this impact wet scrubber is as follows: the second gas-solid separation flue gas enters the shell 31 through the second gas-solid separation flue gas inlet 311, and then passes through the transverse channel 33 (inlet channel) located below the design liquid level 34, generating strong bubbling and impact in the water. Subsequently, the flue gas carries some liquid droplets and flows upward along the S-shaped channel 32. During the multiple turns in the S-shaped channel, the flue gas and liquid droplets undergo further collision and separation. The purified third gas-solid separation tail gas is discharged from the third gas-solid separation tail gas outlet 312, while the third gas-solid separation slurry settles to the bottom of the conical hopper by gravity and is discharged through the third gas-solid separation slurry outlet 313 to enter the subsequent liquid-solid separation treatment.

[0044] The lower partition 36 constituting the transverse channel 33 is movably installed in the housing 31. The lower partition 36 is rotatably installed in the housing 31 via a horizontal rotating shaft 37 perpendicular to the flow direction of the transverse channel 33. An inlet channel opening adjustment drive 38 drives the horizontal rotating shaft 37 to rotate, thereby forming an inlet channel opening adjustment mechanism. This inlet channel opening adjustment mechanism is used to adjust the opening of the inlet channel (i.e., the transverse channel 33) of the wet scrubber; the inlet channel opening adjustment drive 38 drives the opening adjustment action of the inlet channel opening adjustment mechanism.

[0045] When the air inlet passage opening adjustment mechanism of the wet scrubber is operating at its first opening, a larger air inlet passage opening is formed between the upper baffle 35 and the lower baffle 36 (e.g., Figure 7 As shown), this is suitable for applications where the dust content in the flue gas from the second gas-solid separation is relatively low. When the inlet channel opening adjustment mechanism of the wet scrubber is operating at the second opening, a smaller inlet channel opening is formed between the upper baffle 35 and the lower baffle 36 (as shown). Figure 8 As shown in the figure, it is suitable for working conditions where the dust content in the flue gas of the second gas-solid separation is high.

[0046] Under constant gas flow rate, when the dust content in the second gas-solid separation flue gas is low, a larger inlet channel opening is adopted. According to the continuity equation Q=v×A (where Q is the gas volumetric flow rate, v is the airflow velocity, and A is the channel cross-sectional area), the larger channel area A reduces the airflow velocity v, thereby significantly reducing dynamic pressure loss (ΔP∝v², where ΔP is the pressure loss and v is the airflow velocity), reducing system resistance and energy consumption. Although the mass transfer efficiency is relatively low, it is sufficient to meet the dust removal requirements for low dust content conditions. When the dust content in the second gas-solid separation flue gas is high, a smaller inlet channel opening is adopted, forcing the airflow to pass through the narrow channel at a higher velocity. This increases dynamic pressure loss and energy consumption, but the strong turbulence generated by the high flow velocity can significantly improve the gas-liquid mass transfer coefficient and bubble dispersion effect, ensuring that high-concentration dust is fully captured. This design, which automatically adjusts the channel opening according to the dust content, achieves energy-saving operation under low dust content conditions and high-efficiency dust removal under high dust content conditions, reflecting a dynamic balance strategy of optimizing energy consumption and ensuring dust removal effect.

[0047] like Figures 5-6As shown, the intake passage opening adjustment drive device 38 adopts a transmission structure of motor 381 driving gearbox, mainly composed of motor 381, first gear pair 382 (bevel gear pair), second gear pair 383 (cylindrical gear pair) and horizontal rotating shaft 37. During operation, motor 381 drives first gear pair 382 (bevel gear pair) through vertically mounted output shaft, converting vertical rotational motion into horizontal rotational motion. The driven gear in first gear pair 382 and the driving gear in second gear pair 383 are coaxially mounted, and further deceleration and torque increase are achieved through second gear pair 383 (cylindrical gear pair), finally driving the intake passage opening adjustment mechanism through horizontal rotating shaft 37 (i.e., output shaft).

[0048] from Figures 3-8 As can be seen, the transverse channel 33 adopts a variable-diameter, tapering design. The transverse channel 33 gradually narrows from a wider inlet (with a tapered surface design) to its smallest cross-section (throat), then forms an adjustable outlet between the upper baffle 37 and the lower baffle 36. The main purpose of this venturi-like design is to utilize fluid dynamics principles to increase airflow velocity and enhance gas-liquid contact: when the second gas-solid separation flue gas passes through the contracting section of the transverse channel 33, the airflow velocity increases, thus forming a higher-speed airflow at the throat. This not only enhances the intensity of collision with water and improves dust removal efficiency but also generates a certain negative pressure effect, which is beneficial for guiding and stabilizing the airflow. The lower baffle 36... Figure 7 The state shown is rotated counterclockwise to Figure 8 In the state shown, the inlet of the transverse channel 33 becomes larger and the outlet becomes smaller, which enhances the Venturi effect.

[0049] The first liquid-solid separation device 4 employs a cross-flow filter, specifically a silicon carbide ceramic filter element, to perform cross-flow filtration on the third gas-solid separation slurry, obtaining a first liquid-solid separation clarified liquid and a first liquid-solid separation concentrated liquid. The first liquid-solid separation clarified liquid is returned to the wet scrubber for recycling through the first pipeline 41.

[0050] The second liquid-solid separation device 5 uses a filter press to filter the first liquid-solid separation concentrate, obtaining a second liquid-solid separation clarified liquid and a second liquid-solid separation filter cake. The second liquid-solid separation clarified liquid is returned to the third gas-solid separation slurry for recycling through a second pipeline (not shown in the figure).

[0051] The fan unit 6 is located between the flue gas filter dust collector and the wet dust collector. It adopts a variable frequency fan and is used to provide airflow power for the flue gas separation and purification equipment for the ternary precursor spray pyrolysis synthesis.

[0052] The flue gas filtration and dust removal status monitoring device 7 is installed at the outlet of the second flue gas gas-solid separation device 2 to monitor the operation of the flue gas filtration and dust removal device, thereby analyzing the dust content in the flue gas of the second gas-solid separation and generating analysis results. The flue gas filtration and dust removal status monitoring device 7 can use a laser scattering dust concentration detector to monitor the particulate matter concentration in the flue gas of the second gas-solid separation in real time.

[0053] Figure 9 for Figure 1 The diagram shows the control system of a ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment. Figure 9 As shown, the ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment is equipped with a PLC control system, which uses a SIMATIC S7-1200 CPU1214C DC / DC / DC PLC controller 9. This PLC controller 9 is a compact programmable logic controller manufactured by Siemens.

[0054] The input module of the PLC controller 9 receives a 4-20mA current signal from the laser scattering dust concentration detector via analog input AI0, corresponding to a dust content of 0mg / Nm³. 3 -100mg / Nm 3 The detection range.

[0055] The logic processing unit of the PLC controller 9 judges the dust content analysis results according to the preset control logic. The control logic is as follows: AI0≤12mA (low dust content) → DQ0=ON+DQ1=OFF+AQ0=3V-5V (low frequency); AI0>12mA (high dust content) → DQ0=ON+DQ1=ON+AQ0=6V-8V (high frequency).

[0056] The output control module of the PLC controller 9 includes digital outputs DQ0 and DQ1, and analog output AQ0. Digital outputs DQ0 and DQ1 control the motor 381 in the air intake channel opening adjustment drive device 38, with DQ0 controlling the start and stop of motor 381 and DQ1 controlling the direction of motor 381. It is powered by a 24VDC power supply. Analog output AQ0 controls the frequency converter of the variable frequency fan, with an output range of 0V-10V.

[0057] When the ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment is running, and the analysis results of the laser scattering dust concentration detector indicate that the dust content in the second gas-solid separation flue gas has reached a preset low level (AI0≤12mA, corresponding to a dust content≤50mg / Nm³), the dust content in the flue gas should be within the specified range. 3The intake channel opening adjustment mechanism controls the intake channel opening to a larger value and the variable frequency fan operates at a lower frequency. Specifically, the PLC controller 9 outputs DQ0=ON and DQ1=OFF, driving the intake channel opening adjustment drive device 38 to adjust the lower partition 36 to the first opening position. At the same time, the PLC controller 9 outputs AQ0=3V-5V, causing the variable frequency fan to operate at a lower frequency.

[0058] When the ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment is running, if the analysis results of the laser scattering dust concentration detector indicate that the dust content in the second gas-solid separation flue gas has reached a preset high level (AI0 > 12mA, corresponding to a dust content > 50mg / Nm³), the dust content in the flue gas should be considered within a certain range. 3 The intake channel opening adjustment mechanism controls the intake channel opening to a smaller value and the variable frequency fan operates at a higher frequency. Specifically, the PLC controller 9 outputs DQ0=ON and DQ1=ON, driving the intake channel opening adjustment drive device 38 to adjust the lower partition 36 to the second opening position, and simultaneously outputs AQ0=6V-8V, causing the variable frequency fan to operate at a higher frequency.

[0059] Combination Figures 7-8 As shown, the specific meanings of digital outputs DQ0 and DQ1 are as follows: DQ0 is the start / stop control signal for motor 381. When DQ0=ON, motor 381 is started to drive the intake passage opening adjustment drive device 38, causing the lower partition 36 to begin adjustment. DQ1 is the direction control signal for motor 381. When DQ1=OFF, motor 381 rotates forward, causing the lower partition 36 to adjust to the first opening position (the outlet end of the lower partition 36 is horizontal, such as...). Figure 7 As shown, a larger intake channel opening is formed. When DQ1=ON, motor 381 reverses to further adjust the lower baffle 36 to the second opening position (the outlet end of the lower baffle 36 is more inclined, as shown). Figure 8 As shown, a smaller intake channel opening is formed, so DQ0 controls the start and stop of motor 381, and DQ1 controls the direction of motor 381 to achieve the specific angle positioning of lower partition 36.

[0060] like Figure 1As shown, the spray pyrolysis furnace 8 mainly includes a feeding system 81, a heating system 82, and a reaction chamber. When the feeding system 81 is working, a pre-prepared mixed solution is injected into the atomizer of the spray pyrolysis furnace 8 via a feeding pump, forming fine droplets under the action of the atomizer. When the heating system 82 is working, air is added to the heating furnace via a supplementary air fan. The heating furnace heats the air to a set temperature and then injects it into the reaction chamber of the spray pyrolysis furnace 8, providing a high-temperature environment for the spray pyrolysis reaction. Under high-temperature conditions of 600℃-1000℃, the atomized mixed solution droplets rapidly evaporate and decompose, forming ternary precursor powder particles through a series of chemical reactions. The spray pyrolysis flue gas generated during the reaction contains ternary precursor powder and acidic gases (HCl or sulfur oxides) generated depending on the raw material salt system. This spray pyrolysis flue gas enters the ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment of the above embodiment through the outlet of the spray pyrolysis furnace 8 for subsequent separation and purification treatment.

[0061] The ternary precursor spray pyrolysis synthesis method provided in this embodiment of the invention includes the following steps: First, a mixed solution preparation step is performed, in which lithium salt, nickel salt, cobalt salt, and manganese salt are prepared into a mixed solution in a molar ratio, wherein the molar ratio of nickel, cobalt, and manganese is x:y:z, and x+y+z=1, 0.5≤x≤0.8, 0.1≤y≤0.3, and 0.1≤z≤0.3, wherein the lithium salt, nickel salt, cobalt salt, and manganese salt are all chlorides or sulfates; then, a spray pyrolysis step is performed, in which the mixed solution is atomized by an atomizer and sent into a spray pyrolysis furnace 8, where a spray pyrolysis reaction is performed at a temperature of 600℃-1000℃ to obtain ternary precursor powder and spray pyrolysis flue gas containing acidic gas. When the lithium salt, nickel salt, cobalt salt, and manganese salt are all chlorides, the acidic gas is HCl; when the lithium salt, nickel salt, cobalt salt, and manganese salt are all sulfates... The acidic gas in the salt solution is sulfur oxide. Next, a flue gas separation and purification step is performed. The flue gas from the spray pyrolysis synthesis of the ternary precursor is separated and purified using the aforementioned ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment. This involves three stages of gas-solid separation (first, second, and third stages) and two stages of liquid-solid separation (first and second stages). The first gas-solid separation dust, the second gas-solid separation dust, and the second liquid-solid separation filter cake are recovered. Finally, a product collection step is performed, where the ternary precursor powder obtained from the spray pyrolysis step is collected along with the first gas-solid separation dust, the second gas-solid separation dust, and the second liquid-solid separation filter cake recovered from the flue gas separation and purification step (the second liquid-solid separation filter cake can be dried in oven 11) to obtain the ternary precursor product.

[0062] The above embodiments of the present invention, by setting up a second flue gas gas-solid separation device 2 and using a flue gas filter dust collector to perform flue gas filtration and dust removal treatment on the first gas-solid separation flue gas under high temperature conditions of 400℃-600℃, can effectively separate and recover the ternary precursor powder before cooling. This avoids the problems of agglomeration, clumping, incomplete crystal structure, irregular particle morphology, and decreased sphericity that occur in the ternary precursor powder during the cooling process in the prior art. It significantly improves the quality of the ternary precursor powder recovered from the spray pyrolysis flue gas and maintains good particle characteristics and electrochemical performance.

[0063] The above embodiments of the present invention employ a three-stage gas-solid separation process consisting of a first flue gas-solid separation device 1 (cyclone dust collector), a second flue gas-solid separation device 2 (flue gas filter dust collector), and a third flue gas-solid separation device 3 (impact wet dust collector), as well as a two-stage liquid-solid separation process consisting of a first liquid-solid separation device 4 (silicon carbide ceramic filter element cross-flow filter) and a second liquid-solid separation device 5 (filter press), forming a complete multi-stage separation system. This maximizes the recovery of dust from the first gas-solid separation, dust from the second gas-solid separation, and filter cake from the second liquid-solid separation, significantly improving the overall recovery efficiency of the ternary precursor powder.

[0064] The flue gas separation and purification equipment of the above embodiments of the present invention can adapt to the switching between acidic gases HCl and sulfur oxides. By using high-temperature and corrosion-resistant filter materials (such as metal filter membranes made of Hastelloy), the equipment can maintain stable treatment effect and product quality under different acidic gas environments, thus meeting the switching requirements between chloride system raw materials and sulfate system raw materials in actual production.

[0065] Compared to the complex process of existing technologies that rely entirely on water washing and recycling, this invention simplifies the subsequent complex chemical precipitation, filtration, washing, drying and other process steps by directly separating gas and solid at a high temperature stage. This greatly simplifies the process, reduces energy consumption and production costs, and further improves resource utilization efficiency through the recycling of the first and second liquid-solid separation clarified liquids.

[0066] In the above embodiments of the present invention, the operation of the second flue gas gas-solid separation device 2 is monitored in real time by the flue gas filtration and dust removal status monitoring device 7 (laser scattering dust concentration detector). It can analyze the dust content in the flue gas of the second gas-solid separation in real time. Combined with the coordinated control of the air inlet channel opening adjustment mechanism (the lower partition 36 is adjusted in angle through the horizontal rotating shaft 37 and the air inlet channel opening adjustment drive device 38) and the variable frequency fan 6, the second flue gas gas-solid separation device 2 and the third flue gas gas-solid separation device 3 are realized to work together. Through the intelligent control logic of PLC controller 9, when the dust content in the second gas-solid separation flue gas is low (AI0≤12mA), the inlet channel opening adjustment mechanism controls the opening of the transverse channel 33 to a larger value and the variable frequency fan 6 operates at a lower frequency, while the wet scrubber operates in a low-load mode to reduce energy consumption. When the dust content is high (AI0>12mA), the inlet channel opening adjustment mechanism controls the opening of the transverse channel 33 to a smaller value and the variable frequency fan 6 operates at a higher frequency, while the wet scrubber operates in a high-efficiency dust removal mode. By strengthening the wet scrubbing process to compensate for the instability of the flue gas filtration dust collector effect, a balance between high-efficiency dust removal and energy-saving operation is achieved, ensuring the stability of the dust removal effect of the entire ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment.

[0067] Based on current market research on ternary precursor materials, the annual production capacity of mainstream manufacturers is mostly concentrated between 5,000 and 20,000 tons. Considering that spray pyrolysis technology is relatively new and requires significant equipment investment, companies initially investing in production typically choose a medium-sized scale to reduce risk. Therefore, an annual production capacity of 10,000 tons is set as a typical example. Due to the characteristics of the spray pyrolysis process, the equipment needs to operate continuously and stably to ensure product quality. Excluding factors such as equipment maintenance and raw material supply interruptions, an annual effective operating time of approximately 8,000 hours is consistent with industry practice. Based on the operating characteristics of the second flue gas gas-solid separation device 2 (flue gas filter dust collector) during the ternary precursor spray pyrolysis process, due to the high-temperature and highly corrosive environment causing fluctuations in filter material performance, a setting is made to maintain good dust removal efficiency for 65% of the time (dust content in the second gas-solid separation flue gas ≤ 50 mg / Nm³). 3 The system experiences performance degradation for 35% of the time, requiring enhanced treatment by a third flue gas-solid separation device 3 (wet scrubber). The fan unit 6 uses a 90kW centrifugal variable frequency fan to meet system resistance requirements, with a rated operating frequency of 50Hz and an air volume of 30,000 m³ / h. 3 / h, total pressure 3000Pa, mechanical efficiency 80%.

[0068] Under stable operation conditions of the spray pyrolysis furnace 8, the flue gas generation is basically constant. Intelligent regulation is achieved through the coordinated control of the inlet channel opening adjustment mechanism and the fan device 6: the inlet channel opening adjustment mechanism adjusts the local airflow velocity and resistance characteristics by changing the cross-sectional area of ​​the transverse channel 33, and the fan device 6 matches different system resistance requirements through frequency conversion adjustment. The coordinated work of the two ensures the stability of the total system flow rate and optimizes the dust removal efficiency. In the above embodiment, the lower baffle 36 is adjusted from the first opening (horizontal state) to the second opening (tilted by about 30°), reducing the opening of the transverse channel 33 (inlet channel) by half. Under the premise of constant flow rate, according to the continuity equation Q=v×A (Q is the gas volume flow rate, v is the airflow velocity, and A is the channel cross-sectional area), the airflow velocity increases by 2 times at the second opening, the corresponding dynamic pressure loss increases by 4 times, and the total system resistance increases from 1200Pa to 1800Pa. In low-frequency mode (15Hz-25Hz, average 20Hz), the theoretical power of the variable frequency fan is 90×(20 / 50). 3 =5.76kW, considering the mechanical efficiency drops to 72% during inverter operation and system resistance correction, the actual power is approximately 18kW. In high-frequency mode (30Hz-40Hz, average 35Hz), the theoretical inverter power is 90×(35 / 50). 3 =30.9kW, considering the mechanical efficiency of 75% and the greater system resistance during variable frequency operation, the actual power is about 55kW.

[0069] To ensure the final emission standard is 10 mg / Nm 3 If the variable frequency fan always operates at a high power of 55kW, the annual power consumption is 55kW × 8000h = 440000kWh. In the above embodiment, the PLC controller 9 automatically controls the intake channel opening adjustment mechanism and the fan device 6 to switch operating modes in coordination based on the real-time monitoring results of the flue gas filtration and dust removal status monitoring device 7: under low dust content conditions, the first opening is used in conjunction with 18kW low-frequency operation for 5200 hours; under high dust content conditions, the second opening is used in conjunction with 55kW high-frequency operation for 2800 hours. The total annual power consumption is 18kW × 5200h + 55kW × 2800h = 247600kWh. The annual power saving can reach 192400kWh, with an energy saving rate of 43.7%. At the same time, intelligent adjustment reduces the high-load operation time of the equipment.

[0070] The present invention has been described above. Those skilled in the art will be able to implement the present invention based on these descriptions. All other embodiments obtained by those skilled in the art based on the above description without inventive effort should fall within the scope of the present invention.

Claims

1. A ternary precursor spray pyrolysis synthesis flue gas separation and purification device, used to separate and purify the spray pyrolysis flue gas discharged from a spray pyrolysis furnace, wherein the spray pyrolysis furnace prepares ternary precursor powder for lithium-ion secondary battery cathode materials through a spray pyrolysis process, and generates spray pyrolysis flue gas containing ternary precursor powder and acidic gases; characterized in that: include: The first flue gas gas-solid separation device uses a mechanical dust collector to mechanically remove dust from the spray pyrolysis flue gas, thereby obtaining first gas-solid separation dust and first gas-solid separation flue gas. The second flue gas gas-solid separation device employs a flue gas filter dust collector to treat the first gas-solid separation flue gas, resulting in second gas-solid separation dust and second gas-solid separation flue gas. The flue gas filter dust collector operates at a filtration temperature of 400℃-600℃ and uses high-temperature and corrosion-resistant filter materials. The dust removal efficiency of the flue gas filter dust collector is set to ensure that the dust content in the second gas-solid separation flue gas is ≤50mg / Nm³. 3 The filter material comprises a metal filter membrane made of Hastelloy, nickel-copper alloy or titanium alloy; The third flue gas gas-solid separation device uses a wet scrubber to perform wet scrubbing treatment on the second gas-solid separation flue gas, obtaining a third gas-solid separation slurry and a third gas-solid separation tail gas respectively. The wet scrubber has an air inlet channel opening adjustment mechanism, which is used to adjust the opening of the air inlet channel of the wet scrubber. The air inlet channel is used to introduce the second gas-solid separation flue gas into the wet scrubbing zone of the wet scrubber. The first liquid-solid separation device uses a cross-flow filter to perform cross-flow filtration on the third gas-solid separation slurry to obtain a first liquid-solid separation clear liquid and a first liquid-solid separation concentrate, respectively. The second liquid-solid separation device uses a filter press to filter the first liquid-solid separation concentrate to obtain a second liquid-solid separation clear liquid and a second liquid-solid separation filter cake. A fan unit is installed between the flue gas filter dust collector and the wet dust collector or on the third gas-solid separation tail gas emission channel to provide airflow power for the flue gas separation and purification equipment for the ternary precursor spray pyrolysis synthesis. The fan unit adopts a variable frequency fan. A flue gas filtration and dust removal status monitoring device is used to monitor the operation of the flue gas filtration and dust removal device, thereby analyzing the dust content in the second gas-solid separation flue gas and generating analysis results; The first liquid-solid separation clarified liquid is returned to the wet dust collector for recycling through the first pipeline, the second liquid-solid separation clarified liquid is returned to the third gas-solid separation slurry through the second pipeline, the first gas-solid separation dust, the second gas-solid separation dust and the second liquid-solid separation filter cake are recovered as products, and the third gas-solid separation tail gas is discharged directly or after subsequent treatment. During operation, when the analysis results indicate that the dust content in the second gas-solid separation flue gas has reached a preset low level, the air inlet channel opening adjustment mechanism controls the opening of the air inlet channel to a larger value and the variable frequency fan operates at a lower frequency; when the analysis results indicate that the dust content in the second gas-solid separation flue gas has reached a preset high level, the air inlet channel opening adjustment mechanism controls the opening of the air inlet channel to a smaller value and the variable frequency fan operates at a higher frequency. The wet scrubber is an impact wet scrubber. The casing of this impact wet scrubber is divided into S-shaped channels by a baffle assembly. The transverse channel at the bottom of the S-shaped channel constitutes the air inlet channel, which is located below the designed liquid level during operation. At least one of the upper and lower baffles constituting the transverse channel is movably installed in the casing and connected to the air inlet channel opening adjustment drive device, thus forming the air inlet channel opening adjustment mechanism. At least one of the upper and lower baffles is rotatably installed in the casing via a horizontal rotating shaft perpendicular to the flow direction of the transverse channel. The air inlet channel opening adjustment drive device drives the horizontal rotating shaft to rotate. The transverse channel adopts a variable diameter and tapering design, gradually narrowing from a wide inlet with a tapered surface to a minimum cross-section, then forming an adjustable opening outlet between the upper and lower baffles. When the outlet becomes smaller, the inlet becomes larger, which enhances the Venturi effect. The spray pyrolysis furnace has a reaction chamber in which, under high temperature conditions of 600℃-1000℃, the mixed solution droplets atomized by the atomizer of the spray pyrolysis furnace rapidly evaporate and decompose to form ternary precursor powder particles.

2. The ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment as described in claim 1, characterized in that: The acidic gas switches between HCl and sulfur oxides.

3. The ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment as described in claim 1, characterized in that: The mechanical dust collector specifically adopts a cyclone dust collector.

4. The ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment as described in claim 1, characterized in that: The cross-flow filter uses a ceramic filter element.

5. The ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment as described in claim 4, characterized in that: The cross-flow filter uses a silicon carbide ceramic filter element.

6. A method for the spray pyrolysis synthesis of ternary precursors, characterized in that: include: Preparation steps of mixed solution: Prepare a mixed solution by mixing lithium salt, nickel salt, cobalt salt and manganese salt in a molar ratio, wherein the molar ratio of nickel, cobalt and manganese is x:y:z, and x+y+z=1, 0.5≤x≤0.8, 0.1≤y≤0.3, 0.1≤z≤0.3; Spray pyrolysis step: The mixed solution is atomized by an atomizer and sent into the reaction chamber of the spray pyrolysis furnace. The spray pyrolysis reaction is carried out at a temperature of 600℃-1000℃ to obtain ternary precursor powder and spray pyrolysis flue gas containing acidic gas. Flue gas separation and purification steps: The ternary precursor spray pyrolysis synthesis flue gas separation and purification equipment described in any one of claims 1-5 is used to separate and purify the spray pyrolysis flue gas, and the first gas-solid separation dust, the second gas-solid separation dust, and the second liquid-solid separation filter cake are recovered. Product collection steps: The ternary precursor powder obtained from the spray pyrolysis step is collected together with the first gas-solid separation dust, the second gas-solid separation dust, and the second liquid-solid separation filter cake recovered from the flue gas separation and purification step to obtain the ternary precursor product.

7. The method for ternary precursor spray pyrolysis synthesis as described in claim 6, characterized in that: The lithium salt, nickel salt, cobalt salt, and manganese salt are all chlorides or sulfates. When the lithium salt, nickel salt, cobalt salt, and manganese salt are all chlorides, the acidic gas is HCl. When the lithium salt, nickel salt, cobalt salt, and manganese salt are all sulfates, the acidic gas is sulfur oxides.

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