Washing method of ternary precursor

Abstract

A method for washing a ternary precursor comprises: performing solid-liquid separation on a ternary precursor slurry; performing alkali washing on the material after solid-liquid separation with a dilute alkali solution; performing a stirring and soaking operation on low-salt wastewater and the material after alkali washing, wherein the time of the stirring and soaking operation is a first preset time; performing a first soaking and solid-liquid separation on the slurry after the first stirring and soaking, and then performing a second stirring and soaking operation on the material after solid-liquid separation with low-salt wastewater, wherein the time of the second stirring and soaking operation is a second preset time; performing a second soaking and solid-liquid separation on the slurry after the second stirring and soaking operation; performing a rinsing operation on the material after the second soaking and solid-liquid separation with a butanone and butylamine aqueous solution; washing the material after the rinsing operation with pure water, and drying the washed material to obtain a dry sample of the ternary precursor.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and in particular to a method for washing a ternary precursor. Background Art

[0002] Lithium-ion batteries are mainly composed of four main materials: positive electrode, negative electrode, electrolyte and separator. Among them, positive electrode material is the core component of lithium-ion batteries, and positive electrode material has a direct impact on many core performance indicators of lithium-ion batteries, including capacity, life, rate, safety, etc. Positive electrode materials include lithium cobalt oxide, lithium manganese oxide, ternary positive electrode, lithium iron phosphate, etc. The ternary precursor is the main raw material of the ternary positive electrode, and the quality of the ternary precursor directly affects the performance of the ternary positive electrode material.

[0003] In addition to the conventional properties of the ternary precursor, such as main content, particle size, morphology, tap density and specific surface area, its impurities such as Na + 、SO4 2- The content of will also affect the performance of the ternary cathode material. At present, most companies use centrifuges or filter presses for alkaline washing and then water washing to remove most of the Na in the ternary precursor. + and SO4 2- For example, Chinese patent publication number CN114388776A discloses a method for washing a nickel-cobalt-manganese ternary precursor to remove sodium impurities.

[0004] However, the conventional washing method has Na + Content and SO4 2- The content is high and there is a problem of high water consumption. For example, the Na content of the precursor of NCM811 is about 350ppm, the S content is about 2500ppm, and the water consumption is about 10 m³ / ton. Summary of the invention

[0005] Based on this, it is necessary to provide a method that can reduce the Na + Content and SO4 2- A washing method for a ternary precursor that can reduce water consumption while increasing the content.

[0006] A method for washing a ternary precursor, comprising:

[0007] Performing solid-liquid separation on the ternary precursor slurry;

[0008] Using a dilute alkaline solution to perform alkaline washing on the material after solid-liquid separation;

[0009] Performing a stirring and soaking operation on the low-salt wastewater and the material after alkali washing, wherein the time of the stirring and soaking operation is a first preset time;

[0010] The slurry after the first stirring and soaking is subjected to a first soaking solid-liquid separation, and then the solid-liquid separated material and low-salt wastewater are subjected to a second stirring and soaking operation, wherein the time of the second stirring and soaking operation is a second preset time;

[0011] The slurry after the secondary stirring and soaking operation is subjected to secondary soaking solid-liquid separation;

[0012] The material after the second soaking solid-liquid separation is rinsed with butanone and butylamine aqueous solution;

[0013] The material after the rinsing operation is washed with pure water, and the washed material is dried to obtain a dry sample of the ternary precursor.

[0014] In one embodiment, the steps of performing solid-liquid separation on the slurry after the first stirring and soaking, and then performing a second stirring and soaking operation on the material after the solid-liquid separation and the low-salt wastewater are repeated more than twice.

[0015] In one embodiment, after the step of drying the washed material, the washing method further comprises:

[0016] The butanone and butylamine waste liquids produced by the flushing operation are distilled to obtain butanone, butylamine and water respectively.

[0017] In one embodiment, after the step of distilling the butanone and butylamine waste liquids generated by the flushing operation, the washing method further comprises:

[0018] The butanone, butylamine and water are reconstituted to obtain a butanone and butylamine aqueous solution.

[0019] In one embodiment, after the step of reconstituting butanone, butylamine and water to obtain an aqueous solution of butanone and butylamine, the washing method further comprises:

[0020] The prepared butanone and butylamine aqueous solution is used in the flushing operation.

[0021] In one embodiment, the low-salt wastewater from the first stirring and soaking operation and the low-salt wastewater from the second stirring and soaking operation come from the same low-salt wastewater source.

[0022] In one embodiment, the low-salt wastewater from the first stirring and soaking operation and the low-salt wastewater from the second stirring and soaking operation are generated by the washing operation.

[0023] In one embodiment, the first preset time is 15 minutes to 90 minutes.

[0024] In one embodiment, the second preset time is 15 minutes to 90 minutes.

[0025] In one embodiment, the high-salt wastewater generated by the secondary immersion solid-liquid separation is combined with the high-salt wastewater generated by the primary immersion solid-liquid separation.

[0026] In one embodiment, after the stirred and soaked slurry is subjected to a step of soaking solid-liquid separation, the washing method further comprises:

[0027] Treatment operations for high-salinity wastewater.

[0028] In one embodiment, the steps of subjecting the stirred and soaked slurry to a first soaking solid-liquid separation, and then subjecting the solid-liquid separated material to a second stirring and soaking operation with low-salt wastewater include:

[0029] The stirred and soaked slurry is subjected to a soaking solid-liquid separation;

[0030] The material after solid-liquid separation is subjected to secondary stirring and soaking operation with low-salt wastewater.

[0031] In one embodiment, the dilute alkaline solution is a 2% to 5% sodium hydroxide solution.

[0032] A ternary precursor is obtained by washing using the ternary precursor washing method described in any of the above embodiments.

[0033] A ternary positive electrode material is prepared using the above-mentioned ternary precursor.

[0034] A positive electrode sheet is prepared by using the above-mentioned ternary positive electrode material.

[0035] A lithium-ion battery comprises the above-mentioned positive electrode sheet.

[0036] Compared with the prior art, the present invention has at least the following advantages:

[0037] 1. In the above-mentioned washing method of the ternary precursor, since the material after the solid-liquid separation is washed with butanone and butylamine aqueous solution, the carbonyl group of butanone is more likely to combine with the OH of the ternary precursor, destroying the interaction between the OH and OH in the ternary precursor, that is, destroying the interaction between the hydrogen bonds of the OH of the ternary precursor, and the intercalation of the methyl and ethyl groups of butanone increases the interlayer spacing, making it easier for the inside of the crystal to be washed by water; at the same time, butylamine combines with H+ of water, and the remaining OH- makes the aqueous solution alkaline, and OH- takes advantage of the wide open interlayer to more easily replace SO42- inside the lattice, thereby reducing the Na content and S content of the ternary precursor;

[0038] 2. The material after alkali washing, i.e., the ternary precursor, is stirred and soaked once in low-salt wastewater for a first preset time, and then the slurry after stirring and soaking is subjected to the initial solid-liquid separation, and then the material after the initial solid-liquid separation, i.e., the ternary precursor, is stirred and soaked in low-salt wastewater for a second preset time, so that the ternary precursor is subsequently more fully in contact with water, and the material after the second solid-liquid separation is washed with butanone and butylamine aqueous solutions, which not only reduces the Na content and S content of the ternary precursor, but also reduces the amount of pure water used, thereby reducing the production cost of the ternary precursor. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 A flow chart of the steps of a method for washing a ternary precursor according to an embodiment;

[0041] Figure 2 Schematic diagram of the process flow of washing a ternary precursor according to an embodiment. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly understood. It should be noted that when an element is referred to as "fixed to" another element, it can be directly on another element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present application. The terms used in the specification of the present application are only for the purpose of describing specific implementation methods and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0043] Please also read Figure 1 and Figure 2, the present application provides a method for washing a ternary precursor. In order to better understand the method for washing a ternary precursor of the present application, the following further explains the method for washing a ternary precursor of the present application:

[0044] The washing method of the ternary precursor of one embodiment is used to wash the ternary precursor to remove most of the Na + and SO4 2- .like Figure 1 As shown, further, the washing method of the ternary precursor includes part or all of the following steps:

[0045] S101, performing solid-liquid separation on the ternary precursor slurry.

[0046] Among them, the ternary precursor slurry is subjected to solid-liquid separation to separate the material and waste liquid of the ternary precursor slurry from each other. Furthermore, the step of solid-liquid separation of the ternary precursor slurry is specifically as follows: the ternary precursor slurry prepared by the co-precipitation method in the reactor is subjected to solid-liquid separation by a filter press, and the separated high-salt wastewater is discharged into a high-salt wastewater tank. The present application does not limit the specific model of the ternary precursor slurry, and the ternary precursor slurry can be NCM811 ternary precursor.

[0047] S103, using a dilute alkaline solution to perform alkaline washing on the material after solid-liquid separation.

[0048] Among them, a dilute alkaline solution is used to wash the solid-liquid separated material to remove most of the SO4 in the material. 2- . Further, the step of using a dilute alkali solution to perform alkali washing on the material after solid-liquid separation is specifically: using a dilute alkali solution to perform alkali washing on the material after solid-liquid separation; discharging the high-salt wastewater after alkali washing into a high-salt wastewater tank. Further, the dilute alkali solution is at least one of a sodium hydroxide solution, a sodium carbonate solution, or an ammonia solution. In this embodiment, the dilute alkali solution is a sodium hydroxide solution. Specifically, the dilute alkali solution is a 2% to 5% sodium hydroxide solution.

[0049] S105, stirring and soaking the low-salt wastewater and the material after alkali washing.

[0050] The low-salt wastewater and the alkali-washed material are stirred and soaked once, so that the low-salt wastewater and the alkali-washed material are fully mixed and reliably soaked through the stirring and soaking operation. In this embodiment, the time of the stirring and soaking operation is the first preset time. Further, the first preset time is 15min to 90min, so that the low-salt wastewater and the alkali-washed material are well mixed, and the low-salt wastewater can well soak the alkali-washed material.

[0051] Furthermore, the step of stirring and soaking the low-salt wastewater and the alkali-washed material once is specifically as follows: first, unloading the alkali-washed material into a pulping tank; then adding the low-salt wastewater into the low-salt wastewater tank and stirring and soaking it once. In this embodiment, the step of adding the low-salt wastewater into the low-salt wastewater tank and stirring and soaking it once includes: first, adding the low-salt wastewater into the low-salt wastewater tank, so that the low-salt wastewater is immersed in the solid material in the pulping tank; then stirring and soaking the low-salt wastewater and the solid material in the low-salt wastewater tank.

[0052] S107, subjecting the slurry after the first stirring and soaking to a first soaking solid-liquid separation, and then subjecting the solid-liquid separated material to a second stirring and soaking operation with low-salt wastewater.

[0053] Among them, the slurry after stirring and soaking is subjected to a first soaking solid-liquid separation, so that the material and waste liquid of the slurry after stirring and soaking are separated from each other, and then the material after solid-liquid separation and low-salt wastewater are subjected to a second stirring and soaking operation, so that the low-salt wastewater and the material after solid-liquid separation are fully mixed and reliably soaked through the second stirring and soaking operation. In this embodiment, the time of the second stirring and soaking operation is the second preset time. Furthermore, the second preset time is 15min~90min, so that the low-salt wastewater and the material after solid-liquid separation are fully mixed and reliably soaked through the second stirring and soaking operation.

[0054] Furthermore, the steps of soaking the stirred and soaked slurry once for solid-liquid separation, and then stirring and soaking the material after solid-liquid separation with low-salt wastewater for a second time include: first, soaking the stirred and soaked slurry once for solid-liquid separation, so that the waste liquid of the slurry and the material are initially separated; then, stirring and soaking the material after solid-liquid separation with low-salt wastewater for a second time, so that the material and the low-salt wastewater are fully mixed and soaked, so that the low-salt wastewater can better soak the ternary precursor, so that the ternary precursor can be better contacted with water later. In this embodiment, the step of soaking the stirred and soaked slurry once for solid-liquid separation is specifically: soaking the stirred and soaked slurry once for solid-liquid separation through the filter press 1.

[0055] S109, subjecting the slurry after the secondary stirring and soaking operation to secondary soaking for solid-liquid separation.

[0056] The slurry after the secondary stirring and soaking operation is subjected to secondary soaking solid-liquid separation, so that the material and the waste liquid of the soaked slurry are separated into solid and liquid. Specifically, the step of subjecting the slurry after the secondary stirring and soaking operation to secondary soaking solid-liquid separation is as follows: subjecting the slurry after the secondary stirring and soaking operation to secondary soaking solid-liquid separation through a filter press 2.

[0057] S111, using butanone and butylamine aqueous solution to rinse the material after the second immersion solid-liquid separation.

[0058] Wherein, the material after the second soaking solid-liquid separation is rinsed with butanone and butylamine aqueous solution, and the washed solution becomes butanone and butylamine waste liquid. In one embodiment, after step S111 of rinsing the material after the second soaking solid-liquid separation with butanone and butylamine aqueous solution, the washing method further includes: discharging the butanone and butylamine waste liquid generated by the washing into a butanone and butylamine waste liquid tank.

[0059] S113, washing the material after the rinsing operation with pure water, and drying the washed material to obtain a dry sample of the ternary precursor.

[0060] Wherein, the material after the rinsing operation is washed with pure water, and the washed material is dried to obtain a dry sample of the ternary precursor. In this embodiment, the material after the rinsing operation is washed with pure water, and the pure water after washing becomes low-salt wastewater. The washed material is the material to be dried. Specifically, the step of drying the washed material is as follows: the washed material is dried with a disk dryer to obtain a dry sample of the ternary precursor.

[0061] In the above-mentioned washing method of the ternary precursor, since the material after soaking solid-liquid separation is washed with butanone and butylamine aqueous solution, the carbonyl group of butanone is more likely to combine with the OH of the ternary precursor, destroying the interaction between OH and OH in the ternary precursor, that is, destroying the interaction between the hydrogen bonds of OH in the ternary precursor, and the intercalation of the methyl and ethyl groups of butanone increases the interlayer spacing, making it easier for the interior of the crystal to be washed by water; at the same time, the H + Combined, the remaining OH - The aqueous solution becomes alkaline, OH - Taking advantage of the wide open interlayer, it is easier to move SO4 2- replaced, thus reducing the Na and S contents of the ternary precursor.

[0062] Furthermore, the material after alkali washing, i.e., the ternary precursor, is stirred and soaked once in low-salt wastewater for a first preset time, and the slurry after stirring and soaking is then soaked once for solid-liquid separation, and then the material after the solid-liquid separation, i.e., the ternary precursor, is stirred and soaked twice with low-salt wastewater for a second preset time, so that the ternary precursor is more fully contacted with water later, and the material after the second soaking and solid-liquid separation is washed with butanone and butylamine aqueous solutions, which not only reduces the Na content and S content of the ternary precursor, but also reduces the amount of pure water used, thereby reducing the production cost of the ternary precursor.

[0063] In one of the embodiments, in order to better illustrate the advantages of the above-mentioned ternary precursor washing method, the present application is further described below in conjunction with a specific embodiment:

[0064] For the washing sequence, the following three experiments were designed:

[0065] The first method: first separate the solid and liquid, then wash with a dilute alkali solution, then soak with low-salt wastewater, then separate the solid and liquid, then wash with butanone and butylamine aqueous solution, and finally wash with pure water;

[0066] The second method: first separate the solid and liquid, then wash with a dilute alkali solution, then wash with a butanone and butylamine aqueous solution, then soak with low-salt wastewater, then separate the solid and liquid, and finally wash with pure water;

[0067] The third method: first separate the solid and liquid, then wash with butanone and butylamine aqueous solution, then wash with dilute alkali solution, then soak with low-salt waste water, then separate the solid and liquid, and finally wash with pure water.

[0068] The three tests above differ only in the washing order, and other factors such as the concentration of dilute alkali, temperature, time, water volume, concentration of butanone aqueous solution, etc. are the same. The three tests above are all dried at the end to detect the Na content and S content. The specific results are shown in Table 1 below.

[0069]

[0070] From the results in Table 1, it can be seen that the first washing sequence, i.e., solid-liquid separation first, alkaline washing with a dilute alkaline solution, then soaking with low-salt wastewater, solid-liquid separation again, then washing with butanone and butylamine aqueous solutions, and finally washing with pure water, has the best result.

[0071] In one of the embodiments, the above-mentioned washing method of the ternary precursor effectively reduces the Na content and S content in the nickel-cobalt-manganese ternary precursor. Through multiple experiments, it is found that after washing treatment with the above-mentioned washing method of the ternary precursor, the Na content can be lower than 170ppm, and the S content can be lower than 1600ppm, so that the Na content and S content of the washed ternary precursor are lower than the national standard of the product.

[0072] In one of the embodiments, the step of performing solid-liquid separation on the slurry after stirring and soaking, and then performing a secondary stirring and soaking operation on the material after solid-liquid separation and low-salt wastewater is repeated more than twice. In this embodiment, the step of performing solid-liquid separation on the slurry after stirring and soaking, and then performing a secondary stirring and soaking operation on the material after solid-liquid separation and low-salt wastewater is repeated more than twice, so that the material of the ternary precursor is soaked in low-salt wastewater more than twice, so that the subsequent ternary precursor is more fully in contact with water, which not only reduces the Na content and S content of the ternary precursor, but also reduces the amount of pure water used, thereby reducing the production cost of the ternary precursor.

[0073] Furthermore, the step of washing the material after the flushing operation with pure water includes: washing the material after the flushing operation with pure water, and discharging the washed low-salt wastewater into a low-salt wastewater tank.

[0074] In one embodiment, after the step of drying the washed material, the washing method further comprises: distilling the butanone and butylamine waste liquids generated by the flushing operation to obtain butanone, butylamine and water respectively, so as to recover the butanone and butylamine waste liquids. Specifically, the step of distilling the butanone and butylamine waste liquids generated by the flushing operation is specifically: distilling the butanone and butylamine waste liquids generated by the flushing operation through a distillation tower. It should be noted that in addition to butanone, butylamine and water, the substances obtained by distillation through the distillation tower also include sodium sulfate products.

[0075] In one embodiment, after the step of distilling the butanone and butylamine waste liquid generated by the flushing operation, the washing method further comprises: reconstituting butanone, butylamine and water to obtain a butanone and butylamine aqueous solution, thereby achieving regeneration of the butanone and butylamine aqueous solution and avoiding the problem of environmental pollution caused by direct discharge of butanone and butylamine waste liquid. Specifically, the step of reconstituting butanone, butylamine and water to obtain a butanone and butylamine aqueous solution is specifically: reconstituting butanone, butylamine and water to obtain a butanone and butylamine aqueous solution through a butanone and butylamine aqueous solution preparation tank.

[0076] In one embodiment, after the step of reconstituting butanone, butylamine and water to obtain the butanone and butylamine aqueous solution, the washing method further comprises: using the configured butanone and butylamine aqueous solution in the rinsing operation, thereby realizing the recycling of the butanone and butylamine aqueous solution and reducing the use cost of the butanone and butylamine aqueous solution required for washing.

[0077] In one embodiment, the low-salt wastewater of the first stirring and soaking operation and the low-salt wastewater of the second stirring and soaking operation come from the same low-salt wastewater source, so as to flexibly allocate according to the use of the low-salt wastewater of the first stirring and soaking operation and the second stirring and soaking operation, while reducing the number of low-salt wastewater sources. In this embodiment, the low-salt wastewater of the first stirring and soaking operation and the low-salt wastewater of the second stirring and soaking operation come from the same low-salt wastewater tank.

[0078] In one embodiment, the low-salt wastewater of the first stirring and soaking operation and the low-salt wastewater of the second stirring and soaking operation are generated by the washing operation. Specifically, the low-salt wastewater of the first stirring and soaking operation and the low-salt wastewater of the second stirring and soaking operation are generated by the washing operation, i.e., step S113.

[0079] In one embodiment, the high-salt wastewater generated by the secondary immersion solid-liquid separation is collected together with the high-salt wastewater generated by the primary immersion solid-liquid separation so as to centrally treat the high-salt wastewater. Specifically, the step of collecting the high-salt wastewater generated by the secondary immersion solid-liquid separation and the high-salt wastewater generated by the primary immersion solid-liquid separation is as follows: the high-salt wastewater generated by the secondary immersion solid-liquid separation and the high-salt wastewater generated by the primary immersion solid-liquid separation are collected in the same high-salt wastewater tank.

[0080] In one embodiment, after the stirred and soaked slurry is subjected to a solid-liquid separation step, the washing method further includes: treating the high-salt wastewater to avoid the problem of environmental pollution caused by direct discharge of the high-salt wastewater. Furthermore, the step of treating the high-salt wastewater is specifically: treating the high-salt wastewater by a deammoniation treatment method to obtain ammonia water, evaporated condensed water and sodium sulfate, wherein the evaporated condensed water can be directly reused, and the sodium sulfate is then crystallized to obtain a sodium sulfate product.

[0081] Further, the butanone concentration of the butanone and butylamine aqueous solution used in step S111 is 1% to 8%. And / or, further, the butanone concentration of the butanone and butylamine aqueous solution used in step S111 is 1% to 8%, so that the butanone and butylamine aqueous solution have a better washing effect on the material after the second soaking solid-liquid separation. In this embodiment, the butanone concentration and butylamine concentration of the butanone and butylamine aqueous solution used in step S111 are both 5%, so that the butanone and butylamine aqueous solution have the best effect on washing the material after the second soaking solid-liquid separation.

[0082] In order to better illustrate the effect of washing the material after the second immersion solid-liquid separation for the concentration of butanone and butylamine in the butanone and butylamine aqueous solutions under the same other conditions, further, the butanone concentration of 1%, 3%, 5%, 8% and the butylamine concentration of 1%, 3%, 5%, 8% were mixed to obtain 16 different mixed concentrations of butanone and butylamine aqueous solutions. Finally, the precursor was dried and the Na content and S content were detected. The results are shown in Table 2:

[0083]

[0084] It can be seen from Table 2 that, when other conditions are the same, the washing effect is best when the concentration of butanone in the butanone and butylamine aqueous solution is 5% and the concentration of butylamine is also 5%.

[0085] The present application also provides a ternary precursor, which is obtained by washing using the ternary precursor washing method described in any of the above embodiments.

[0086] The present application also provides a ternary positive electrode material, which is prepared using the above-mentioned ternary precursor.

[0087] The present application also provides a positive electrode sheet, which is prepared using the above-mentioned ternary positive electrode material.

[0088] The present application also provides a lithium-ion battery, comprising the above-mentioned positive electrode sheet.

[0089] Some specific examples are given below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0090] Example 1

[0091] S1: The NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm newly produced from the reactor overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. Figure 2 , and then use a pump to press the slurry into the filter press 1 for solid-liquid separation, and the high-salt wastewater enters the high-salt wastewater tank, and the material is purged with compressed air to remove the residual mother liquor;

[0092] S2: Use 3% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0093] S3: Open the filter plate of filter press 1, unload the material into the pulping tank below filter press 1, then add 4m³ of low-salt wastewater in the low-salt wastewater tank to immerse the solid material in the pulping tank, and then start the stirring of the pulping tank for 30 minutes;

[0094] S4: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 30 minutes;

[0095] S5: After sufficient stirring, the slurry in the slurry making tank is pressed into the filter press 2 above the disk dryer for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank, and then 6m³ of a mixed aqueous solution of 5% butanone and 5% butylamine in the butanone and butylamine preparation tank is pumped into the filter press 2 to wash the material. The butanone and butylamine waste liquid enters the butanone and butylamine waste liquid tank, and then the material is purged with compressed air;

[0096] S6: Then, the material washed with butanone and butylamine aqueous solution is washed with 12m³ pure water, and the low-salt wastewater after washing enters the low-salt wastewater tank. The material is purged with compressed air to remove the residual low-salt wastewater, and then the filter plate of the filter press 2 is opened, and the material is unloaded into the disk dryer below for drying to obtain a ternary precursor dry sample, which is sent for inspection of Na content and S content;

[0097] S7: pumping the butanone and butylamine waste liquid in the butanone and butylamine waste liquid tank into a distillation tower, heating the distillation tower for distillation, and distilling the butanone, butylamine and water directly into the butanone and butylamine preparation tank, and using the distilled crystallized salt for other purposes;

[0098] S8: Add butanone, butylamine and pure water to the butanone and butylamine preparation tank to prepare 40m³ of 5% butanone and 5% butylamine aqueous solutions.

[0099] Example 2

[0100] S1: The NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm newly produced from the reactor overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. Figure 2 , and then use a pump to press the slurry into the filter press 1 for solid-liquid separation, and the high-salt wastewater enters the high-salt wastewater tank, and the material is purged with compressed air to remove the residual mother liquor;

[0101] S2: Use 3% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0102] S3: Open the filter plate of filter press 1, unload the material into the pulping tank below filter press 1, then add 4m³ of low-salt wastewater in the low-salt wastewater tank to immerse the solid material in the pulping tank, and then start the stirring of the pulping tank for 30 minutes;

[0103] S4: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 30 minutes;

[0104] S5: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 30 minutes;

[0105] S6: After sufficient stirring, the slurry in the slurry making tank is pressed into the filter press 2 above the disk dryer for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank, and then 6m³ of a mixed aqueous solution of 5% butanone and 5% butylamine in the butanone and butylamine preparation tank is pumped into the filter press 2 to wash the material. The butanone and butylamine waste liquid enters the butanone and butylamine waste liquid tank, and then the material is purged with compressed air;

[0106] S7: Then, the material washed with butanone and butylamine aqueous solution is washed with 12m³ pure water, and the low-salt wastewater after washing enters the low-salt wastewater tank. The material is purged with compressed air to remove the residual low-salt wastewater, and then the filter plate of the filter press 2 is opened, and the material is unloaded into the disk dryer below for drying to obtain a ternary precursor dry sample, which is sent for inspection of Na content and S content;

[0107] S8: pumping the butanone and butylamine waste liquid in the butanone and butylamine waste liquid tank into a distillation tower, heating the distillation tower for distillation, distilling the butanone, butylamine and water directly into the butanone and butylamine preparation tank, and using the distilled crystallized salt for other purposes;

[0108] S9: Add butanone, butylamine and pure water to the butanone and butylamine preparation tank to prepare 40m³ of 5% butanone and 5% butylamine aqueous solutions.

[0109] Example 3

[0110] S1: The NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm newly produced from the reactor overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. Figure 2 , and then use a pump to press the slurry into the filter press 1 for solid-liquid separation, and the high-salt wastewater enters the high-salt wastewater tank, and the material is purged with compressed air to remove the residual mother liquor;

[0111] S2: Use 3% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0112] S3: Open the filter plate of filter press 1, unload the material into the pulping tank below filter press 1, then add 4m³ of low-salt wastewater in the low-salt wastewater tank to immerse the solid material in the pulping tank, and then start the stirring of the pulping tank for 30 minutes;

[0113] S4: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 30 minutes;

[0114] S5: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 30 minutes;

[0115] S6: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 30 minutes;

[0116] S7: After sufficient stirring, the slurry in the slurry making tank is pressed into the filter press 2 above the disk dryer for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank, and then 6m³ of a mixed aqueous solution of 5% butanone and 5% butylamine in the butanone and butylamine preparation tank is pumped into the filter press 2 to wash the material. The butanone and butylamine waste liquid enters the butanone and butylamine waste liquid tank, and then the material is purged with compressed air;

[0117] S8: Then, the material washed with butanone and butylamine aqueous solution is washed with 12m³ pure water, and the low-salt wastewater after washing enters the low-salt wastewater tank. The material is purged with compressed air to remove the residual low-salt wastewater, and then the filter plate of the filter press 2 is opened, and the material is unloaded into the disk dryer below for drying to obtain a ternary precursor dry sample, which is sent for inspection of Na content and S content;

[0118] S9: pumping the butanone and butylamine waste liquid in the butanone and butylamine waste liquid tank into a distillation tower, heating the distillation tower for distillation, and distilling the butanone, butylamine and water directly into the butanone and butylamine preparation tank, and using the distilled crystallized salt for other purposes;

[0119] S10: Add butanone, butylamine and pure water into the butanone and butylamine preparation tank to prepare 40m³ of 5% butanone and 5% butylamine aqueous solutions.

[0120] Example 4

[0121] S1: The NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm newly produced from the reactor overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. Figure 2 , and then use a pump to press the slurry into the filter press 1 for solid-liquid separation, and the high-salt wastewater enters the high-salt wastewater tank, and the material is purged with compressed air to remove the residual mother liquor;

[0122] S2: Use 3% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0123] S3: Open the filter plate of filter press 1, unload the material into the pulping tank below filter press 1, then add 4m³ of low-salt wastewater in the low-salt wastewater tank to immerse the solid material in the pulping tank, and then start the stirring of the pulping tank for 60 minutes;

[0124] S4: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 60 minutes;

[0125] S5: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 60 minutes;

[0126] S6: After sufficient stirring, the slurry in the slurry making tank is pressed into the filter press 2 above the disk dryer for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank, and then 6m³ of a mixed aqueous solution of 5% butanone and 5% butylamine in the butanone and butylamine preparation tank is pumped into the filter press 2 to wash the material. The butanone and butylamine waste liquid enters the butanone and butylamine waste liquid tank, and then the material is purged with compressed air;

[0127] S7: Then, the material washed with butanone and butylamine aqueous solution is washed with 12m³ pure water, and the low-salt wastewater after washing enters the low-salt wastewater tank. The material is purged with compressed air to remove the residual low-salt wastewater, and then the filter plate of the filter press 2 is opened, and the material is unloaded into the disk dryer below for drying to obtain a ternary precursor dry sample, which is sent for inspection of Na content and S content;

[0128] S8: pumping the butanone and butylamine waste liquid in the butanone and butylamine waste liquid tank into a distillation tower, heating the distillation tower for distillation, distilling the butanone, butylamine and water directly into the butanone and butylamine preparation tank, and using the distilled crystallized salt for other purposes;

[0129] S9: Add butanone, butylamine and pure water to the butanone and butylamine preparation tank to prepare 40m³ of 5% butanone and 5% butylamine aqueous solutions.

[0130] Example 5

[0131] S1: The NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm newly produced from the reactor overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. Figure 2 , and then use a pump to press the slurry into the filter press 1 for solid-liquid separation, and the high-salt wastewater enters the high-salt wastewater tank, and the material is purged with compressed air to remove the residual mother liquor;

[0132] S2: Use 3% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0133] S3: Open the filter plate of filter press 1, unload the material into the pulping tank below filter press 1, then add 4m³ of low-salt wastewater from the low-salt wastewater tank to immerse the solid material in the pulping tank, and then start the stirring of the pulping tank for 90 minutes;

[0134] S4: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 90 minutes;

[0135] S5: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 90 minutes;

[0136] S6: After sufficient stirring, the slurry in the slurry making tank is pressed into the filter press 2 above the disk dryer for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank, and then 6m³ of a mixed aqueous solution of 5% butanone and 5% butylamine in the butanone and butylamine preparation tank is pumped into the filter press 2 to wash the material. The butanone and butylamine waste liquid enters the butanone and butylamine waste liquid tank, and then the material is purged with compressed air;

[0137] S7: Then, the material washed with butanone and butylamine aqueous solution is washed with 12m³ pure water, and the low-salt wastewater after washing enters the low-salt wastewater tank. The material is purged with compressed air to remove the residual low-salt wastewater, and then the filter plate of the filter press 2 is opened, and the material is unloaded into the disk dryer below for drying to obtain a ternary precursor dry sample, which is sent for inspection of Na content and S content;

[0138] S8: pumping the butanone and butylamine waste liquid in the butanone and butylamine waste liquid tank into a distillation tower, heating the distillation tower for distillation, distilling the butanone, butylamine and water directly into the butanone and butylamine preparation tank, and using the distilled crystallized salt for other purposes;

[0139] S9: Add butanone, butylamine and pure water to the butanone and butylamine preparation tank to prepare 40m³ of 5% butanone and 5% butylamine aqueous solutions.

[0140] Example 6

[0141] S1: The NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm newly produced from the reactor overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. Figure 2 , and then use a pump to press the slurry into the filter press 1 for solid-liquid separation, and the high-salt wastewater enters the high-salt wastewater tank, and the material is purged with compressed air to remove the residual mother liquor;

[0142] S2: Use 2% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0143] S3: Open the filter plate of filter press 1, unload the material into the pulping tank below filter press 1, then add 4m³ of low-salt wastewater in the low-salt wastewater tank to immerse the solid material in the pulping tank, and then start the stirring of the pulping tank for 60 minutes;

[0144] S4: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 60 minutes;

[0145] S5: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 60 minutes;

[0146] S6: After sufficient stirring, the slurry in the slurry making tank is pressed into the filter press 2 above the disk dryer for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank, and then 6m³ of a mixed aqueous solution of 5% butanone and 5% butylamine in the butanone and butylamine preparation tank is pumped into the filter press 2 to wash the material. The butanone and butylamine waste liquid enters the butanone and butylamine waste liquid tank, and then the material is purged with compressed air;

[0147] S7: Then, the material washed with butanone and butylamine aqueous solution is washed with 12m³ pure water, and the low-salt wastewater after washing enters the low-salt wastewater tank. The material is purged with compressed air to remove the residual low-salt wastewater, and then the filter plate of the filter press 2 is opened, and the material is unloaded into the disk dryer below for drying to obtain a ternary precursor dry sample, which is sent for inspection of Na content and S content;

[0148] S8: pumping the butanone and butylamine waste liquid in the butanone and butylamine waste liquid tank into a distillation tower, heating the distillation tower for distillation, distilling the butanone, butylamine and water directly into the butanone and butylamine preparation tank, and using the distilled crystallized salt for other purposes;

[0149] S9: Add butanone, butylamine and pure water to the butanone and butylamine preparation tank to prepare 40m³ of 5% butanone and 5% butylamine aqueous solutions.

[0150] Example 7

[0151] S1: The NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm newly produced from the reactor overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. Figure 2 , and then use a pump to press the slurry into the filter press 1 for solid-liquid separation, and the high-salt wastewater enters the high-salt wastewater tank, and the material is purged with compressed air to remove the residual mother liquor;

[0152] S2: Use 4% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0153] S3: Open the filter plate of filter press 1, unload the material into the pulping tank below filter press 1, then add 4m³ of low-salt wastewater in the low-salt wastewater tank to immerse the solid material in the pulping tank, and then start the stirring of the pulping tank for 60 minutes;

[0154] S4: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 60 minutes;

[0155] S5: After sufficient stirring, the slurry in the pulping tank is pressed into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then 4m³ of low-salt wastewater in the low-salt wastewater tank is added to immerse the solid materials in the pulping tank, and then the stirring of the pulping tank is turned on for 60 minutes;

[0156] S6: After sufficient stirring, the slurry in the slurry making tank is pressed into the filter press 2 above the disk dryer for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank, and then 6m³ of a mixed aqueous solution of 5% butanone and 5% butylamine in the butanone and butylamine preparation tank is pumped into the filter press 2 to wash the material. The butanone and butylamine waste liquid enters the butanone and butylamine waste liquid tank, and then the material is purged with compressed air;

[0157] S7: Then, the material washed with butanone and butylamine aqueous solution is washed with 12m³ pure water, and the low-salt wastewater after washing enters the low-salt wastewater tank. The material is purged with compressed air to remove the residual low-salt wastewater, and then the filter plate of the filter press 2 is opened, and the material is unloaded into the disk dryer below for drying to obtain a ternary precursor dry sample, which is sent for inspection of Na content and S content;

[0158] S8: pumping the butanone and butylamine waste liquid in the butanone and butylamine waste liquid tank into a distillation tower, heating the distillation tower for distillation, distilling the butanone, butylamine and water directly into the butanone and butylamine preparation tank, and using the distilled crystallized salt for other purposes;

[0159] S9: Add butanone, butylamine and pure water to the butanone and butylamine preparation tank to prepare 40m³ of 5% butanone and 5% butylamine aqueous solutions.

[0160] Comparative Example 1

[0161] S1: The newly produced NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. The slurry is then pumped into the filter press for solid-liquid separation. The high-salt wastewater enters the high-salt wastewater tank. The material is purged with compressed air to remove the residual mother liquor.

[0162] S2: Use 3% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0163] S3: Use 30m³ of pure water to wash the material after solid-liquid separation. The low-salt wastewater after washing enters the low-salt wastewater tank. Use compressed air to blow the material to remove the residual low-salt wastewater. Then open the filter plate of the filter press and unload the material into the disk dryer below for drying to obtain a dry sample of the ternary precursor and send it for Na content testing.

[0164] Comparative Example 2

[0165] S1: The newly produced NCM811 ternary precursor slurry with a D50 of 9.5μm~11μm overflows into the aging tank. When the liquid level in the aging tank reaches 3m, the stirring of the aging tank is turned on for 30min. The slurry is then pumped into the filter press 1 for solid-liquid separation. The high-salt wastewater enters the high-salt wastewater tank. The material is purged with compressed air to remove the residual mother liquor.

[0166] S2: Use 3% dilute alkali solution to wash the material. After washing, use compressed air to purge the material to remove the residual dilute alkali solution;

[0167] S3: Open the filter plate of filter press 1, unload the material into the pulping tank below filter press 1, then add 5m³ of low-salt wastewater in the low-salt wastewater tank to immerse the solid material in the pulping tank, and then start the stirring of the pulping tank for 30 minutes;

[0168] S4: After sufficient stirring, start pump 2 to press the slurry in the pulping tank into the filter press 1 above the pulping tank for solid-liquid separation. The high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank. The material after solid-liquid separation is unloaded into the pulping tank below the filter press 1, and then add 5m³ of low-salt wastewater in the low-salt wastewater tank to immerse the solid materials in the pulping tank, and then start the stirring of the pulping tank for 30 minutes;

[0169] S5: After sufficient stirring, the slurry in the slurry making tank is pressed into the filter press 2 above the disk dryer for solid-liquid separation, and the high-salt wastewater after solid-liquid separation enters the high-salt wastewater tank;

[0170] S6: Use 18 m³ of pure water to wash the material after solid-liquid separation. The low-salt wastewater after washing enters the low-salt wastewater tank. Use compressed air to blow the material to remove the residual low-salt wastewater. Then open the filter plate of filter press 2 and unload the material into the disk dryer below for drying to obtain a dry sample of the ternary precursor, which is then sent for testing of Na content and S content.

[0171] The Na content and pure water consumption before and after washing in each example are shown in Table 3, and the S content is shown in Table 4. Among them, the above-mentioned comparative example 1 is a technical solution currently on the market.

[0172]

[0173]

[0174] From the data in Table 3 and Table 4, it can be seen that the ternary precursor is first washed with a 3% dilute alkali solution, and then soaked three times with low-salt wastewater from the washing, with each soaking and stirring time of 60 minutes, and then washed with 5% butanone and 5% butylamine aqueous solution, and then washed with a small amount of pure water, which has a good sodium and sulfur removal effect. In the washing process, a large amount of SO4 on the surface of the material is removed by the dilute alkali solution. 2- ; The second is to use low-salt wastewater to soak, so that water and ternary precursors can be more fully contacted; the third is that the carbonyl group of butanone is more likely to combine with the OH of the ternary precursor, destroying the interaction force (hydrogen bond) between the OH and OH of the ternary precursor, and the intercalation of the methyl and ethyl groups of butanone increases the interlayer spacing, making the interior of the crystal easier to be washed by water; the fourth is that while the interlayer spacing is opened, the H bond between butylamine and water + Combined, the remaining OH - The aqueous solution becomes alkaline, OH - Taking advantage of the wide open interlayer, it is easier to move SO4 2- It can be replaced to reduce the S content, while saving a certain amount of pure water usage and reducing the production cost of the ternary precursor.

[0175] Compared with the prior art, this application has at least the following advantages:

[0176] 1) In the above-mentioned washing method of the ternary precursor, since the material after soaking solid-liquid separation is washed with butanone and butylamine aqueous solution, the carbonyl group of butanone is more likely to combine with the OH of the ternary precursor, destroying the interaction between OH and OH in the ternary precursor, that is, destroying the interaction between the hydrogen bonds of OH in the ternary precursor. In addition, the intercalation of the methyl and ethyl groups of butanone increases the interlayer spacing, making it easier for the interior of the crystal to be washed by water; at the same time, the H + Combined, the remaining OH - The aqueous solution becomes alkaline, OH -Taking advantage of the wide open interlayer, it is easier to move SO4 2- The ternary precursor is replaced by the alkali-washed material, i.e., the ternary precursor, by stirring and soaking it for a first preset time in low-salt wastewater, and then the slurry after stirring and soaking is soaked for solid-liquid separation, and then the material after the solid-liquid separation is soaked once, i.e., the ternary precursor, and the low-salt wastewater are stirred and soaked for a second preset time, so that the ternary precursor is more fully contacted with water later, and the material after the second soaking solid-liquid separation is washed with butanone and butylamine aqueous solution, which not only reduces the Na and S contents of the ternary precursor, but also reduces the amount of pure water used, thereby reducing the production cost of the ternary precursor.

[0177] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-described embodiments only express several implementation methods of the present application, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several deformations and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of this application shall be based on the attached claims.

Claims

1. A method for washing a ternary precursor, characterized in that: include: Performing solid-liquid separation on the ternary precursor slurry; Using a dilute alkaline solution to perform alkaline washing on the material after solid-liquid separation; Performing a stirring and soaking operation on the low-salt wastewater and the material after alkali washing, wherein the time of the stirring and soaking operation is a first preset time; The slurry after the first stirring and soaking is subjected to a first soaking solid-liquid separation, and then the solid-liquid separated material and low-salt wastewater are subjected to a second stirring and soaking operation, wherein the time of the second stirring and soaking operation is a second preset time; The slurry after the secondary stirring and soaking operation is subjected to secondary soaking solid-liquid separation; The material after the second soaking solid-liquid separation is rinsed with butanone and butylamine aqueous solution; The material after the flushing operation is washed with pure water, and the washed material is dried to obtain a dry sample of the ternary precursor; wherein, the material after the flushing operation is washed with pure water, and the pure water after washing becomes the low-salt wastewater.

2. The method for washing a ternary precursor according to claim 1, characterized in that: The steps of performing solid-liquid separation on the slurry after the first stirring and soaking, and then performing a second stirring and soaking operation on the material after the solid-liquid separation and the low-salt wastewater are repeated more than twice.

3. The washing method of the ternary precursor according to claim 1, characterized in that: After the step of drying the washed material, the washing method further comprises: The butanone and butylamine waste liquids produced by the flushing operation are distilled to obtain butanone, butylamine and water respectively.

4. The method for washing a ternary precursor according to claim 3, characterized in that: After the step of distilling the butanone and butylamine waste liquids produced by the flushing operation, the washing method further comprises: The butanone, butylamine and water are reconstituted to obtain a butanone and butylamine aqueous solution.

5. The method for washing a ternary precursor according to claim 4, characterized in that: After the step of re-formulating butanone, butylamine and water to obtain an aqueous solution of butanone and butylamine, the washing method further comprises: The prepared butanone and butylamine aqueous solution is used in the flushing operation.

6. The method for washing a ternary precursor according to claim 1, characterized in that: The low-salt wastewater from the first stirring and soaking operation and the low-salt wastewater from the second stirring and soaking operation come from the same low-salt wastewater source.

7. The method for washing a ternary precursor according to claim 1, characterized in that: The low-salt wastewater from the first stirring and soaking operation and the low-salt wastewater from the second stirring and soaking operation are generated by the washing operation.

8. The method for washing a ternary precursor according to claim 1, characterized in that: The first preset time is 15 minutes to 90 minutes.

9. The method for washing a ternary precursor according to claim 1, characterized in that: The second preset time is 15 minutes to 90 minutes.

10. The method for washing a ternary precursor according to claim 1, characterized in that: The high-salt wastewater generated by the secondary immersion solid-liquid separation is combined with the high-salt wastewater generated by the primary immersion solid-liquid separation.

11. The method for washing a ternary precursor according to claim 10, characterized in that: After the stirred and soaked slurry is subjected to a step of soaking solid-liquid separation, the washing method further comprises: Treatment operations for high-salinity wastewater.

12. The method for washing a ternary precursor according to claim 1, characterized in that: The steps of performing a first soaking solid-liquid separation on the stirred and soaked slurry, and then performing a second stirring soaking operation on the solid-liquid separated material and low-salt wastewater include: The stirred and soaked slurry is subjected to a soaking solid-liquid separation; The material after solid-liquid separation is subjected to secondary stirring and soaking operation with low-salt wastewater.

13. The method for washing a ternary precursor according to claim 1, characterized in that: The dilute alkali solution is a 2% to 5% sodium hydroxide solution.

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