Thickening system in synthesis crystallization kettle

Abstract

The utility model discloses a thickening system in a synthesis crystallization kettle. Comprising a synthesis crystallization kettle, a suction filtration device and a mother liquor collecting device, a filter element module is arranged in the synthesis crystallization kettle and comprises a filter element and a filter element back flushing unit, the filter element back flushing unit comprises a nozzle, the nozzle faces the surface of the filter element, the suction filtration device is connected with one end of the filter element, and the mother liquor collecting device is connected with the other end of the filter element. The mother liquor collecting device is connected with the suction filtration device. According to the utility model, the filter element is arranged in the synthesis crystallization kettle and is directly connected with the suction filtration device, so that the synthesis mother liquor in the synthesis crystallization kettle can be extracted from the synthesis crystallization kettle under the separation action of the filter element, and the solid-liquid ratio in the synthesis crystallization kettle is increased; separation of precipitated crystal particles and synthetic mother liquor is achieved in the synthetic crystallization kettle, the growth time of coprecipitated synthetic particles in the synthetic crystallization kettle with the determined volume is prolonged, the production efficiency is improved, and the consistency of physical and chemical properties of the crystal particles in the synthetic crystallization kettle is higher.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of stirred tank production equipment, especially suitable for lithium ion battery positive material precursor, nickel cobalt manganese hydroxide synthesis crystallization kettle in the field of thickening, especially relates to a kind of synthesis crystallization kettle in thickening system. BACKGROUND

[0002] Lithium ion battery is generally composed of positive electrode, diaphragm, negative electrode, organic electrolyte and shell. The active material of the positive electrode is generally composed of lithium manganate, lithium ferrophosphite, lithium cobaltate, lithium nickel cobalt manganese oxide and other materials or their composite materials.

[0003] Lithium nickel cobalt manganese oxide is a key ternary positive material of lithium ion battery, and its chemical formula is LiNi x CoyMn 1-x-y O2. It has higher specific capacity than single positive material and lower cost. Lithium nickel cobalt manganese oxide replaces more than two-thirds of cobalt in lithium cobaltate with relatively cheap nickel and manganese, and has obvious advantages in cost. Compared with other lithium ion battery positive materials lithium manganate and lithium ferrophosphite, lithium nickel cobalt manganese oxide material and lithium cobaltate are very close in electrochemical performance and processing performance, making lithium nickel cobalt manganese oxide material become a new battery material and gradually replace lithium cobaltate.

[0004] Lithium nickel cobalt manganese oxide positive material is usually made by mixing nickel cobalt manganese hydroxide with lithium salt and sintering at high temperature, and is usually called ternary positive material. Nickel cobalt manganese hydroxide is a precursor of lithium nickel cobalt manganese oxide, and the final performance of the positive material inherits the morphology structure characteristics of the precursor. The quality of the precursor (morphology, particle size, particle size distribution, specific surface area, impurity content, tap density, etc.) directly determines the physical and chemical indexes of the positive sintering product, which is usually called ternary precursor material.

[0005] Nickel cobalt manganese hydroxide is usually made of nickel salt, cobalt salt and manganese salt as raw material. The ratio of nickel, cobalt and manganese (x:y:z) can be adjusted according to actual needs. Crystal salt is dissolved in pure water, and sodium hydroxide solution and ammonia solution are used as precipitator and complexing agent respectively. Under nitrogen atmosphere and at a certain temperature, nickel cobalt manganese hydroxide is prepared by chemical co-precipitation method in synthesis crystallization kettle. Nickel cobalt manganese hydroxide is a key intermediate product connecting upstream resources and downstream materials in battery industry chain. The upstream resources are nickel, cobalt, manganese and aluminum, and the downstream materials are lithium ion battery positive materials, which are mainly used in power battery, and gradually replace energy storage and consumer battery, so that the global shipment volume of ternary lithium ion battery is steadily increasing, and the global shipment volume of nickel cobalt manganese hydroxide is also steadily increasing. According to statistics, the total output of nickel cobalt manganese hydroxide in the world was 100.62 million tons in 2022, with a year-on-year growth of 34.6%.

[0006] In order to improve the particle size, sphericity and tap density of the secondary agglomerated particles, the reaction time of the coprecipitation is usually lengthened to allow the crystal particles to grow for a certain time when the nickel-cobalt-manganese hydroxide is prepared by using the chemical coprecipitation method. Generally, the volume of the synthesis crystallizer is fixed, and the volume of the synthesis crystallizer is far less than the total volume of the solution added in the time period required for the particles to reach the target requirement while maintaining the flow of the raw material solution and the precipitant solution to ensure a certain production efficiency. In order to reduce the increase in investment on the volume of the synthesis crystallizer, the mother liquor generated in the reaction process needs to be continuously discharged, and a thickener provided with a filter core is generally connected to the synthesis crystallizer. The slurry in the synthesis crystallizer is pressed into the thickener by a pump, and the mother liquor is discharged from the discharge port of the thickener through the filter core due to the solid-liquid separation function of the filter core. The precipitate crystal particles are intercepted by the surface of the filter core, and when the crystal particles intercepted by the surface of the filter core reach a certain amount, the crystal particles are blown back into the original synthesis crystallizer through the back flushing device of the thickener, so that the reaction time of the coprecipitation is lengthened in the fixed volume synthesis crystallizer. The lengthened time can be adjusted according to the production task requirements, that is, the reaction time can be adjusted to obtain nickel-cobalt-manganese hydroxide crystals with different particle sizes.

[0007] However, the ordinary nickel-cobalt-manganese hydroxide synthesis thickening device has fatal defects in production practice. Before the back flushing operation of the crystal particles pumped into the thickener by the delivery pump, the crystal particles do not continue to participate in the synthesis reaction, and the environment of the crystal particles is inconsistent with that of other crystal particles in the synthesis crystallizer. The inconsistency will be reflected in the inconsistency of the morphology and physical properties of the crystal particles after the reaction is completed, and the inconsistent distribution of the proportions of nickel, cobalt and manganese elements in different particles.

[0008] The above content is only used to assist in understanding the technical scheme of the utility model, and does not mean that the above content is prior art. Utility model content

[0009] The main purpose of the utility model is to solve the technical problems in the background art.

[0010] In order to achieve the above purpose, the utility model provides a synthesis crystallizer in-cylinder thickening system, the synthesis crystallizer in-cylinder thickening system includes a synthesis crystallizer, a suction filter device and a mother liquor collecting device, the synthesis crystallizer is provided with a filter core module, the filter core module includes a filter core and a filter core back flushing unit, the filter core back flushing unit includes a nozzle, the nozzle faces the surface of the filter core, the suction filter device is connected with one end of the filter core, and the mother liquor collecting device is connected with the suction filter device.

[0011] In one of the embodiments, the filter core module further comprises a filter core fixing unit, which fixes the filter core in the synthetic crystallization kettle.

[0012] In one of the embodiments, the filter core fixing unit is liftable.

[0013] In one of the embodiments, the filter core module further comprises a filter core replacing unit, which is installed on the synthetic crystallization kettle and connected with the filter core.

[0014] In one of the embodiments, the suction filter device comprises a vacuum suction filter buffer tank, a vacuum pump and a vacuum buffer tank liquid discharge pump, the vacuum suction filter buffer tank is connected with the filter core, the vacuum pump is connected with the vacuum suction filter buffer tank, and the suction filter device is connected with the mother liquor collecting device through the vacuum buffer tank liquid discharge pump.

[0015] In one of the embodiments, the vacuum suction filter buffer tank is connected with the filter core through a vacuum pipe, and a suction filter control valve is arranged at the connection.

[0016] In one of the embodiments, the mother liquor collecting device comprises a mother liquor collecting stirring tank, a mother liquor collecting stirring tank liquid discharge pump, a mother liquor precision filter, a mother liquor final discharge tank and a mother liquor final discharge tank pump connected in sequence, and the mother liquor collecting stirring tank is connected with the suction filter device.

[0017] In one of the embodiments, the synthetic crystallization kettle in-kettle thickening system further comprises an automatic control module, the automatic control module comprises a self-control instrument, a self-control valve and a programmable logic control unit, the self-control valve is arranged at the connection between the filter core and the suction filter device, and the self-control instrument and the programmable logic control unit are connected with the self-control valve.

[0018] In one of the embodiments, the filter core replacing unit is connected with the programmable logic control unit.

[0019] In one of the embodiments, the filter core back-flushing unit is connected with the programmable logic control unit.

[0020] The filter core is arranged in the synthetic crystallization kettle, and the filter core is directly connected with the suction filter device, so that the synthetic mother liquor in the synthetic crystallization kettle can be extracted from the synthetic crystallization kettle through the separation effect of the filter core, the separation of the precipitated crystal particles and the mother liquor is realized in the synthetic crystallization kettle, the solid-liquid ratio in the synthetic crystallization kettle is improved, and the consistency of the synthesized crystal in the synthetic crystallization kettle is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0022] Figure 1 Assembling schematic view of the dense system in the synthetic crystallization kettle in an embodiment of the present application;

[0023] Main element symbol explanation:

[0024] 1-filter core back flushing unit; 2-filter core fixing unit; 3-synthetic crystallization kettle; 4-filtering control valve; 5-filtering filter core; 6-vacuum filtering buffer tank; 7-vacuum pump; 8-vacuum buffer tank liquid discharge pump; 9-mother liquor collecting stirring tank; 10-mother liquor collecting stirring tank liquid discharge pump; 11-mother liquor precision filter; 12-mother liquor final discharge groove; 13-mother liquor final discharge groove pump. DETAILED DESCRIPTION

[0025] In order to better understand the above technical solutions, the exemplary embodiments of the present application will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0026] It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0027] It should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the coordinate system shown in the drawings, and are only used for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0028] In the utility model, unless another definite provision and limitation, the terms "mount", "link", "connect", "fix" and so on should do the broad sense understanding, for example, can be fixed connection, also can be detachable connection, or be integrated;Can be mechanical connection, also can be electrical connection;Can be direct connection, also can pass through the indirect connection of intermediate medium, can be the communication or mutual action relation of two elements inside two elements.For the ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0029] In the utility model, unless another definite provision and limitation, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0030] The utility model provides a kind of synthetic crystallizer in-vessel thickening system, refer to Figure 1 In an embodiment, the synthetic crystallizer in-vessel thickening system includes a synthetic crystallizer 3, a suction filtration device, and a mother liquor collection device. The synthetic crystallizer 3 is provided with a filter core module, the filter core module includes a filter core 5 and a filter core backflushing unit 1, the filter core backflushing unit 1 includes a nozzle, the nozzle faces the surface of the filter core 5, the suction filtration device is connected with one end of the filter core 5, and the mother liquor collection device is connected with the suction filtration device.

[0031] In the embodiment, refer to Figure 1 The filter core backflushing unit 1 is a prior art, and the filter core backflushing unit 1 further includes a pneumatic control valve (i.e., the filter core backflushing unit includes a pneumatic control valve and a nozzle). The nozzle can flush or blow air to the filter core 5 through liquid or gas. The filter core 5 is a hollow cylinder, and the other end of the filter core 5 is in a closed state. The filter precision of the filter core 5 is 0.1 μm-1 μm. The material of the filter core 5 can be polyethylene (PE), polyamide fiber (PA), ceramic material, metal material, etc. Different materials can be selected according to actual needs. The number of filter cores 5 fixed in the synthetic crystallizer 3 can also be selected according to needs, such as one, two, three, four, etc.

[0032] Specifically, when the system is working normally, the suction filtration device is turned on, the filter element 5 is connected with the suction filtration device, the inside of the filter element 5 is in a vacuum state, the water molecules in the mixed solution outside the filter element 5 are attracted by the suction of the vacuum inside the filter element 5, pass through the filter element membrane wall, enter the inside of the filter element, enter the suction filtration device along the inside space of the filter element and the outside pipeline, and enter the next step, while the solid particles in the mixed solution cannot normally pass through the filter element wall due to the particle size being greater than the filter element gap, and are intercepted outside the filter element.

[0033] In the embodiment, by embedding the filter element 5 in the synthetic crystallization kettle 3 and directly connecting the filter element with the suction filtration device, the synthetic mother liquor in the synthetic crystallization kettle 3 can be extracted from the synthetic crystallization kettle 3 through the separation of the filter element, while the solid particles in the mixed solution are intercepted outside the filter element, so that the solid-liquid ratio in the synthetic crystallization kettle 3 is improved, and the consistency of the synthetic crystals in the synthetic crystallization kettle 3 is achieved.

[0034] In one of the embodiments, referring to Figure 1 , the filter element module further comprises a filter element fixing unit 2, and the filter element fixing unit 2 fixes the filter element 5 in the synthetic crystallization kettle 3.

[0035] In the embodiment, referring to Figure 1 , the filter element fixing unit 2 is a control pipeline movable support.

[0036] Specifically, the in-kettle thickening system of the synthetic crystallization kettle comprises a synthetic crystallization kettle 3, a suction filtration device and a mother liquor collecting device, the synthetic crystallization kettle 3 is provided with a filter element module, the filter element module comprises a filter element 5, a filter element backflushing unit 1 and a filter element fixing unit 2, the filter element backflushing unit 1 comprises a nozzle, the nozzle faces the surface of the filter element 5, the suction filtration device is connected with one end of the filter element 5, the mother liquor collecting device is connected with the suction filtration device, and the filter element fixing unit 2 fixes the filter element 5 in the synthetic crystallization kettle 3.

[0037] In the embodiment, by arranging the filter element fixing unit 2 to fix the filter element 5 in the synthetic crystallization kettle 3, the stability of the in-kettle thickening system of the synthetic crystallization kettle is improved.

[0038] In one of the embodiments, referring to Figure 1 , the filter element fixing unit 2 is liftable.

[0039] Specifically, the in-kettle thickening system of the synthetic crystallization kettle comprises a synthetic crystallization kettle 3, a suction filtration device and a mother liquor collecting device, the synthetic crystallization kettle 3 is provided with a filter core module, the filter core module comprises a filter core 5, a filter core back flushing unit 1 and a filter core fixing unit 2, the filter core back flushing unit 1 comprises a nozzle, the nozzle faces the surface of the filter core 5, the suction filtration device is connected with one end of the filter core 5, the mother liquor collecting device is connected with the suction filtration device, the filter core fixing unit 2 fixes the filter core 5 in the synthetic crystallization kettle 3, and the filter core fixing unit 2 is liftable.

[0040] In the embodiment, the filter core fixing unit 2 is liftable, so that the filter core 5 is more convenient to replace.

[0041] In one of the embodiments, referring to Figure 1 , the filter core module further comprises a filter core replacing unit, the filter core replacing unit is installed on the synthetic crystallization kettle 3 and connected with the filter core 5.

[0042] Specifically, the in-kettle thickening system of the synthetic crystallization kettle comprises a synthetic crystallization kettle 3, a suction filtration device and a mother liquor collecting device, the synthetic crystallization kettle 3 is provided with a filter core module, the filter core module comprises a filter core 5, a filter core back flushing unit 1 and a filter core replacing unit, the filter core back flushing unit 1 comprises a nozzle, the nozzle faces the surface of the filter core 5, the suction filtration device is connected with one end of the filter core 5, the mother liquor collecting device is connected with the suction filtration device, the filter core replacing unit is installed on the synthetic crystallization kettle 3 and connected with the filter core 5.

[0043] In the embodiment, the filter core replacing unit is installed on the synthetic crystallization kettle 3, the filter core 5 can be replaced through the filter core replacing unit, and the efficiency of replacing the filter core 5 is higher than that of manual replacement.

[0044] In one of the embodiments, referring to Figure 1 , the suction filtration device comprises a vacuum suction filtration buffer tank 6, a vacuum pump 7 and a vacuum buffer tank liquid discharge pump 8, the vacuum suction filtration buffer tank 6 is connected with the filter core, the vacuum pump 7 is connected with the vacuum suction filtration buffer tank 6, and the suction filtration device is connected with the mother liquor collecting device through the vacuum buffer tank liquid discharge pump 8.

[0045] In the embodiment, the vacuum suction filtration buffer tank 6 is a stainless steel vacuum buffer tank, the vacuum pump 7 is a water ring vacuum pump 7, the vacuum buffer tank liquid discharge pump 8 is a centrifugal pump, and the vacuum degree of the vacuum suction filtration buffer tank 6 is -0.01Mpa~ -0.1Mpa.

[0046] Specifically, the in-cylinder thickening system of the synthetic crystallization kettle comprises a synthetic crystallization kettle 3, a filtration device and a mother liquor collecting device. The synthetic crystallization kettle 3 is provided with a filter core module, the filter core module comprises a filter core 5 and a filter core back flushing unit 1, the filter core back flushing unit 1 comprises a nozzle, the nozzle faces the surface of the filter core 5, the filtration device is connected with one end of the filter core 5, the mother liquor collecting device is connected with the filtration device, the filtration device comprises a vacuum filtration buffer tank 6, a vacuum pump 7 and a vacuum buffer tank liquid discharge pump 8, the vacuum filtration buffer tank 6 is connected with the filter core, the vacuum pump 7 is connected with the vacuum filtration buffer tank 6, and the filtration device is connected with the mother liquor collecting device through the vacuum buffer tank liquid discharge pump 8.

[0047] In the embodiment, the water ring vacuum pump 7 works to generate vacuum in the system. The vacuum degree of the system is measured by a vacuum degree table on the stainless steel vacuum buffer tank. The stainless steel vacuum buffer tank is connected with the filter core in the synthetic crystallization kettle 3 to generate vacuum in the filter core to suck water molecules in the synthetic crystallization kettle 3. The system can adjust the vacuum degree of the system by adjusting the running frequency of the vacuum pump 7 and the vent valve arranged on the vacuum buffer tank to control the speed of the filter core to suck the solution. When the volume of the solution collected in the stainless steel vacuum buffer tank reaches a certain value, the buffer tank conveying pump is started to discharge the solution in the vacuum buffer tank to the next process.

[0048] In one of the embodiments, referring to Figure 1 The vacuum filtration buffer tank 6 is connected with the filter core through a vacuum pipe, and a filtration control valve 4 is arranged at the connection.

[0049] In the embodiment, the filtration control valve 4 is a pneumatic control valve.

[0050] Specifically, the in-cylinder thickening system of the synthetic crystallization kettle comprises a synthetic crystallization kettle 3, a filtration device and a mother liquor collecting device. The synthetic crystallization kettle 3 is provided with a filter core module, the filter core module comprises a filter core 5 and a filter core back flushing unit 1, the filter core back flushing unit 1 comprises a nozzle, the nozzle faces the surface of the filter core 5, the filtration device is connected with one end of the filter core 5, the mother liquor collecting device is connected with the filtration device, the filtration device comprises a vacuum filtration buffer tank 6, a vacuum pump 7 and a vacuum buffer tank liquid discharge pump 8, the vacuum filtration buffer tank 6 is connected with the filter core, the vacuum pump 7 is connected with the vacuum filtration buffer tank 6, and the filtration device is connected with the mother liquor collecting device through the vacuum buffer tank liquid discharge pump 8, the vacuum filtration buffer tank 6 is connected with the filter core through a vacuum pipe, and a filtration control valve 4 is arranged at the connection.

[0051] In one of the embodiments, referring to Figure 1The mother liquor collecting device is connected with the filter device, and comprises a mother liquor collecting stirring tank 9, a mother liquor collecting stirring tank discharge pump 10, a mother liquor precision filter 11, a mother liquor final discharge tank 12 and a mother liquor final discharge tank pump 13 connected in sequence, wherein the mother liquor collecting stirring tank 9 is connected with the filter device.

[0052] In the embodiment, the mother liquor collecting stirring tank 9 is a polypropylene (PPH) stirring tank, the mother liquor collecting stirring tank discharge pump 10 is a centrifugal pump, the mother liquor precision filter 11 is a high-precision microporous filter, the mother liquor final discharge tank 12 is a polypropylene (PPH) storage tank, and the mother liquor final discharge tank pump 13 is a magnetic drive pump. The filter core in the mother liquor precision filter 11 has a filtering precision of 0.05-0.3 μm. The filtering core 5 can be made of polyethylene (PE), polyamide fiber (PA), ceramic material, metal material or the like, and the number of the filtering core 5 can be one, two, three or four according to actual needs.

[0053] Specifically, the in-cylinder thickening system of the synthesis crystallization kettle comprises a synthesis crystallization kettle 3, a filter device and a mother liquor collecting device. The synthesis crystallization kettle 3 is provided with a filter core module, the filter core module comprises a filtering core 5 and a filter core backflushing unit 1, the filter core backflushing unit 1 comprises a nozzle, the nozzle faces the surface of the filtering core 5, the filter device is connected with one end of the filtering core 5, the mother liquor collecting device is connected with the filter device, and the mother liquor collecting device comprises a mother liquor collecting stirring tank 9, a mother liquor collecting stirring tank discharge pump 10, a mother liquor precision filter 11, a mother liquor final discharge tank 12 and a mother liquor final discharge tank pump 13 connected in sequence, wherein the mother liquor collecting stirring tank 9 is connected with the filter device.

[0054] In the embodiment, the mother liquor collecting device collects the small particles filtered out from the filtering core during the synthesis, thereby saving the material and improving the yield.

[0055] In one of the embodiments, referring to Figure 1 The in-cylinder thickening system of the synthesis crystallization kettle further comprises an automatic control module, the automatic control module comprises a self-control instrument, a self-control valve and a programmable logic control unit, the self-control valve is arranged at the connection between the filter core and the filter device, and the self-control instrument and the programmable logic control unit are connected with the self-control valve.

[0056] The programmable logic control unit is a PLC control unit, which is a prior art and can be set according to actual needs by those skilled in the art.

[0057] Specifically, the thickening system in the synthesis crystallization kettle comprises a synthesis crystallization kettle 3, a suction filtration device and a mother liquor collecting device. The synthesis crystallization kettle 3 is provided with a filter core module, the filter core module comprises a filter core 5, a filter core back flushing unit 1, a filter core fixing unit 2 and a filter core replacing unit. The filter core back flushing unit 1 comprises a nozzle, the nozzle faces the surface of the filter core 5. The suction filtration device is connected with one end of the filter core 5. The filter core fixing unit 2 fixes the filter core 5 in the synthesis crystallization kettle 3. The filter core fixing unit 2 is liftable. The filter core replacing unit is installed on the synthesis crystallization kettle 3 and connected with the filter core 5. The suction filtration device comprises a vacuum suction filtration buffer tank 6, a vacuum pump 7 and a vacuum buffer tank liquid discharge pump 8. The vacuum suction filtration buffer tank 6 is connected with the filter core. The vacuum pump 7 is connected with the vacuum suction filtration buffer tank 6. The suction filtration device is connected with the mother liquor collecting device through the vacuum buffer tank liquid discharge pump 8. The vacuum suction filtration buffer tank 6 is connected with the filter core through a vacuum pipe. The connection is provided with a suction filtration control valve 4. The mother liquor collecting device comprises a mother liquor collecting stirring tank 9, a mother liquor collecting stirring tank liquid discharge pump 10, a mother liquor precision filter 11, a mother liquor final discharge tank 12 and a mother liquor final discharge tank pump 13 which are connected in sequence. The mother liquor collecting stirring tank 9 is connected with the suction filtration device.

[0058] In the embodiment, the vacuum degree is adjusted by the automatic control module, so that the slurry concentration in the synthesis crystallization kettle 3 reaches a balance or a range required by the process. After the system, the material yield in the reaction process reaches 99.85%~99.95%. By using the thickening production system, the consistency of the synthesized crystals in the synthesis crystallization kettle 3 can be maintained to achieve the thickening effect. At the same time, there is no waste water discharge in the production process, and the energy consumption in the production process is relatively small. The system has high automation degree, is suitable for industrial production, has high economic benefit and popularization value.

[0059] In one of the embodiments, referring to Figure 1 The filter core replacing unit is connected with the programmable logic control unit.

[0060] Specifically, the thickening system in the synthesis crystallization kettle includes a synthesis crystallization kettle 3, a suction filtration device, and a mother liquor collecting device. The synthesis crystallization kettle 3 is provided with a filter core module, which includes a filter core 5, a filter core backflushing unit 1, a filter core fixing unit 2, and a filter core replacing unit. The filter core backflushing unit 1 includes a nozzle, which faces the surface of the filter core 5. The suction filtration device is connected with one end of the filter core 5. The filter core fixing unit 2 fixes the filter core 5 in the synthesis crystallization kettle 3. The filter core fixing unit 2 is liftable. The filter core replacing unit is installed on the synthesis crystallization kettle 3 and connected with the filter core 5. The suction filtration device includes a vacuum suction filtration buffer tank 6, a vacuum pump 7, and a vacuum buffer tank liquid discharge pump 8. The vacuum suction filtration buffer tank 6 is connected with the filter core. The vacuum pump 7 is connected with the vacuum suction filtration buffer tank 6. The suction filtration device is connected with the mother liquor collecting device through the vacuum buffer tank liquid discharge pump 8. The vacuum suction filtration buffer tank 6 is connected with the filter core through a vacuum pipe, and a suction filtration control valve 4 is arranged at the connection position. The mother liquor collecting device includes a mother liquor collecting stirring tank 9, a mother liquor collecting stirring tank liquid discharge pump 10, a mother liquor precision filter 11, a mother liquor final discharge tank 12, and a mother liquor final discharge tank pump 13, which are connected in sequence. The mother liquor collecting stirring tank 9 is connected with the suction filtration device. The filter core replacing unit is connected with the programmable logic control unit.

[0061] In the embodiment, the filter core replacing unit is connected with the programmable logic control unit. The filter core 5 can be adjusted up, down, left, and right through the programmable logic control unit, so that the filter core can be replaced conveniently.

[0062] In one of the embodiments, referring to Figure 1 , the filter core backflushing unit 1 is connected with the programmable logic control unit.

[0063] Specifically, the in-cylinder thickening system of the synthesis crystallization kettle comprises a synthesis crystallization kettle 3, a suction filtration device and a mother liquor collecting device. The synthesis crystallization kettle 3 is provided with a filter core module. The filter core module comprises a filter core 5, a filter core backflushing unit 1, a filter core fixing unit 2 and a filter core replacing unit. The filter core backflushing unit 1 comprises a nozzle, which faces the surface of the filter core 5. The suction filtration device is connected with one end of the filter core 5. The filter core fixing unit 2 fixes the filter core 5 in the synthesis crystallization kettle 3. The filter core fixing unit 2 is liftable. The filter core replacing unit is installed on the synthesis crystallization kettle 3 and connected with the filter core 5. The suction filtration device comprises a vacuum suction filtration buffer tank 6, a vacuum pump 7 and a vacuum buffer tank liquid discharge pump 8. The vacuum suction filtration buffer tank 6 is connected with the filter core. The vacuum pump 7 is connected with the vacuum suction filtration buffer tank 6. The suction filtration device is connected with the mother liquor collecting device through the vacuum buffer tank liquid discharge pump 8. The vacuum suction filtration buffer tank 6 is connected with the filter core through a vacuum pipe. The connection is provided with a suction filtration control valve 4. The mother liquor collecting device comprises a mother liquor collecting stirring tank 9, a mother liquor collecting stirring tank liquid discharge pump 10, a mother liquor precision filter 11, a mother liquor final discharge tank 12 and a mother liquor final discharge tank pump 13, which are connected in sequence. The mother liquor collecting stirring tank 9 is connected with the suction filtration device. The filter core backflushing unit 1 is connected with the programmable logic control unit.

[0064] In the embodiment, the filter core backflushing unit 1 is connected with the programmable logic control unit. Clean compressed air or clean nitrogen can be blown into the filter core through the programmable logic control unit to regenerate the filter core.

[0065] In one of the embodiments, the suction filtration device and the mother liquor collecting device are both connected with the automatic control module. Through the automatic control module, the vacuum degree in the system can be automatically adjusted, measured and displayed. The filtration speed of the solution in the synthesis crystallization kettle 3 can be automatically adjusted to meet the process requirement of adjusting the slurry concentration in the synthesis crystallization kettle 3.

[0066] For example, a synthesis crystallization kettle with a total volume of 6m³ is used to produce 1000kg of nickel-cobalt-manganese hydroxide with a particle size D50 of 10μm (the molar ratio of nickel-cobalt-manganese elements is 8:1:1). According to the calculation, the nickel metal content in the nickel-cobalt-manganese hydroxide is 50.8%, the cobalt metal content is 6.35% and the manganese metal content is 5.95%.

[0067] Embodiment conditions:

[0068] The raw materials were NiSO4*6H2O (nickel content 22.2%) 2299.8 kg, CoSO4*7H2O (cobalt content 20.5%) 311.31 kg, and MnSO4*H2O (manganese content 31.5%) 189.84 kg, which were dissolved in pure water to prepare a mixed solution (nickel-cobalt-manganese mixed metal salt solution) 6342 liters with a metal content of 100 g / L, and the average nickel-cobalt-manganese metal molar concentration was 1.71 mol / L.

[0069] The auxiliary material sodium hydroxide solution (32%) was 2853 kg, and the density was 1.35 g / cm 3 The sodium hydroxide solution was prepared to 2113 liters.

[0070] At the initial stage of synthesis in the synthesis crystallization kettle, pure water bottom liquid needs to be added to the synthesis crystallization kettle to submerge the stirring paddle. In this example, 1000 liters of bottom liquid pure water was added.

[0071] The auxiliary material ammonia solution (27.5%) was prepared to a total of 520 liters.

[0072] The nickel-cobalt-manganese mixed metal salt solution was added at a flow rate of 200 L / h, and the liquid alkali solution (sodium hydroxide solution) was calculated to be added at a flow rate of 200 L / h*1.71 mol / L*2 / 10.83 mol / L*1.05=66.51 L / h. The addition flow rate of ammonia water was adjusted according to the pH during the reaction process, and the average flow rate was 16.4 L / h.

[0073] The total volume of the synthesis crystallization kettle in this example was 6 m³, and the effective volume was taken as the loading coefficient 0.85, so the effective volume was 5.1 m³, which was the upper limit of the liquid level.

[0074] Implementation process:

[0075] First, 1 m³ of pure water was pumped into the synthesis crystallization kettle, a small amount of ammonia solution was added, the pH value and ammonia concentration of the solution were adjusted, the pH value was adjusted to 10.5-11.5, and the ammonia concentration was adjusted to 1.5-3 g / L in this example, and the temperature was raised to the process required temperature, which was 50°-60° in this example. After the pH value, temperature, and ammonia concentration reached the process requirements, the nickel-cobalt-manganese mixed metal salt solution was added at a flow rate of 200 L / h, the liquid alkali solution was added at a flow rate of 66.51 L / h, and the ammonia solution was added at a flow rate of 16.4 L / h. The total flow rate was 282.9 L / h, which was added into the synthesis crystallization kettle. This process was a coprecipitation method for preparing nickel-cobalt-manganese hydroxide. At the initial stage of the reaction, the median particle size D50 of the nickel-cobalt-manganese hydroxide particles formed was about 2 μm.

[0076] The second step, according to the above process parameters, when the liquid surface reaches the upper limit of the synthesis crystallization kettle, the reaction time is (5.1*1000-1000) L / 282.9 L / h=14.49 h. At this time, the in-kettle thickening system of the synthesis crystallization kettle is started, the synthesis mother liquor in the synthesis crystallization kettle is filtered through the in-kettle filter element of the synthesis crystallization kettle, and then is discharged from the synthesis crystallization kettle, and at the same time, the vacuum degree of the filter device is adjusted to adjust the discharge speed of the synthesis mother liquor, which is basically consistent with the total flow rate of the feed. According to the co-precipitation process, the growth rate of the median particle size of the nickel-cobalt-manganese hydroxide particles is about 0.25 μm / h.

[0077] The third step, according to the above process and the flow rates of various solutions, the reaction is continuously continued for (6342 L-200 L / h*14.49 h) / 200 L / h=17.22 h, that is, the end point. During the reaction process, the in-kettle thickening system of the synthesis crystallization kettle is continuously operated to keep the liquid surface in the synthesis crystallization kettle stable. At the end point of the reaction, the total volume of the synthesis mother liquor discharged is 4875 L, and the total reaction time is 31.71 h. According to the process conditions, the median particle size of the nickel-cobalt-manganese hydroxide crystal particles grows to 2 μm+0.25 μm / h*31.71 h=9.93 μm.

[0078] The fourth step, the synthesized nickel-cobalt-manganese hydroxide slurry is subjected to aging, centrifugation, washing, drying, batching, magnetic removal, sieving and packaging to become 1000 kg of nickel-cobalt-manganese hydroxide product with a particle size D50=10 μm.

[0079] As can be seen from the above embodiment, to produce 1000 kg of nickel-cobalt-manganese hydroxide product with a particle size D50=10 μm, the total volume of the synthesis crystallization kettle required is 9975 L, and in the embodiment, a 6 m³ synthesis crystallization kettle is used, which saves a volume of 39.8% of the total volume of the synthesis crystallization kettle, and at the same time, an out-kettle thickener is not needed, and accordingly, more than 50% of the investment in the synthesis crystallization kettle and the thickener can be saved.

[0080] The same as the utility model can be applied to the production of any liquid-phase chemical synthesis reaction to generate crystal precipitate product, and has high technical promotion and economic value.

[0081] The above is only a preferred embodiment of the utility model, and does not limit the patent range of the utility model, and any equivalent structure or equivalent process conversion using the contents of the utility model specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection range of the utility model.

Claims

1. A system for thickening in a synthesis crystallizer, characterized in that The in-cylinder thickening system of the synthetic crystallization kettle comprises a synthetic crystallization kettle, a suction filtration device and a mother liquor collecting device, the synthetic crystallization kettle is provided with a filter core module, the filter core module comprises a filter core and a filter core back flushing unit, the filter core back flushing unit comprises a nozzle, the nozzle faces the surface of the filter core, the suction filtration device is connected with one end of the filter core, and the mother liquor collecting device is connected with the suction filtration device.

2. The in-drum thickener system of claim 1, wherein, The filter core module further comprises a filter core fixing unit, and the filter core fixing unit fixes the filter core in the synthetic crystallization kettle.

3. The in-drum thickener system of claim 2, wherein, The filter core fixing unit is liftable.

4. The in-drum thickener system of claim 1, wherein, The filter core module further comprises a filter core replacing unit, and the filter core replacing unit is installed on the synthetic crystallization kettle and connected with the filter core.

5. The in-drum thickener system of claim 1, wherein, The suction filtration device comprises a vacuum suction filtration buffer tank, a vacuum pump and a vacuum buffer tank liquid discharge pump, the vacuum suction filtration buffer tank is connected with the filter core, the vacuum pump is connected with the vacuum suction filtration buffer tank, and the suction filtration device is connected with the mother liquor collecting device through the vacuum buffer tank liquid discharge pump.

6. The in-drum thickener system of claim 5, wherein, The vacuum suction filtration buffer tank is connected with the filter core through a vacuum pipe, and a suction filtration control valve is arranged at the connection position.

7. The in-drum thickener system of claim 1, wherein, The mother liquor collecting device comprises a mother liquor collecting stirring tank, a mother liquor collecting stirring tank liquid discharge pump, a mother liquor precision filter, a mother liquor final discharge tank and a mother liquor final discharge tank pump which are connected in sequence, and the mother liquor collecting stirring tank is connected with the suction filtration device.

8. The in-drum thickener system of any one of claims 1-7, wherein, The in-cylinder thickening system of the synthetic crystallization kettle further comprises an automatic control module, the automatic control module comprises a self-control instrument, a self-control valve and a programmable logic control unit, the self-control valve is arranged at the connection position of the filter core and the suction filtration device, and the self-control instrument and the programmable logic control unit are connected with the self-control valve.

9. The in-drum thickener system of claim 8, wherein, The filter core back flushing unit is connected with the programmable logic control unit. The filter core back flushing unit is connected with the programmable logic control unit.

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