Device and method for producing fine particles of metal compound

Abstract

To provide a device for producing fine particles of a metal compound high in sphericity, 90% or higher in nickel content by a physical mass ratio, and 3 μm or less in average particle diameter d50.SOLUTION: The device for producing fine particles of the metal compound comprises: a stirring blade provided with a plurality of holes formed through in a radial direction and rotatable about a center axis; a bottomed cylindrical reaction tank that can concentrically store the stirring blade; a first liquid supply unit provided in the reaction tank and capable of supplying a first reaction liquid into the reaction tank; a second liquid supply unit provided in the stirring blade and capable of supplying a second reaction liquid into the reaction tank; and a control unit that controls the peripheral speed of the stirring blade.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an apparatus for producing fine particles of a metal compound and a system for producing fine particles of a metal compound.

Background Art

[0002] In positive electrode materials for next-generation batteries such as high-performance secondary batteries and all-solid-state batteries, high capacity and high output are required.

[0003] In order to achieve high capacity and high output, research is being carried out on increasing the nickel content in the positive electrode material and reducing the particle size (secondary particle size).

[0004] The coprecipitation method is generally used as a method for producing metal hydroxides, which are raw materials for positive electrode materials. As the nickel content in the metal hydroxide is increased for higher capacity of the positive electrode material, the particle size of the metal hydroxide obtained by the coprecipitation method tends to increase, which is contrary to the reduction in particle size for obtaining high output. In order to achieve both high capacity and high output, research is being carried out on technologies with a high nickel content and fine particle size.

[0005] As methods for having a high nickel content and fine particle size, there are methods such as shortening the residence time of crystals in the reaction tank and increasing the pH. By this, it is possible to reduce the secondary particle size, but excessive shortening of the residence time and high pH lead to a decrease in crystal quality such as refinement of primary particles and deterioration of the shape of secondary particles (decrease in sphericity). Therefore, the limit of maintaining crystal quality becomes the limit of adjustment by the above methods. Here, the sphericity is defined by (equivalent diameter of the area circle of the particle projection image) / (diameter of the smallest circumscribed circle of the particle projection image).

[0006] Although research has been conducted on suppressing particle size growth by increasing the stirring force and shear force in a reaction apparatus, it is required to efficiently transmit a high stirring force and shear force to a minute reaction field of metal hydroxide with a very short reaction time. Particularly, in the case of manufacturing ultrafine particles with an average particle diameter d50 of 3 μm or less of metal hydroxide with a high nickel content, in order to increase the sphericity, it is an issue to efficiently transmit a high stirring force and shear force to the minute reaction field.

[0007] Patent Document 1 discloses a manufacturing apparatus including a pump and a stirrer with a propeller-type rotating blade for manufacturing a positive electrode active material for a non-aqueous electrolyte secondary battery having an average particle diameter of 1.00 μm to 3.0 μm and a maximum nickel content of 80%. Patent Document 2 discloses a manufacturing apparatus including a turbine blade as a stirring blade for manufacturing an oxide-based positive electrode active material for an all-solid-state lithium-ion battery having an average particle diameter d50 of 1.0 to 5.0 μm. Patent Document 3 discloses a manufacturing apparatus for ternary oxide fine particles composed of cerium, zirconium, and yttrium, having an average primary particle diameter of 0.5 to 100 nm and an average secondary particle diameter of 2 to 100 nm.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention has been made under such a background, and aims to provide a manufacturing apparatus for fine particles of a metal compound with a high nickel content, which can achieve a high capacity and high output to such an extent that it can be used as a cathode material for next-generation batteries, and can control the average particle diameter d50 of the fine particles of the metal compound mainly by adjusting the peripheral speed of the stirring blade.

Means for Solving the Problems

[0010] In order to solve the above problems and achieve such an object, the present invention proposes the following means. A first aspect of the present invention includes a stirring blade having a plurality of holes penetrating in the radial direction and rotatable around a central axis, a bottomed cylindrical reaction tank capable of concentrically accommodating the stirring blade inside, a first liquid supply section provided in the reaction tank and capable of supplying a first reaction liquid to the inside of the reaction tank, a second liquid supply section provided in the stirring blade and capable of supplying a second reaction liquid to the inside of the reaction tank, and a control section for controlling the peripheral speed of the stirring blade, and is characterized in being a manufacturing apparatus for fine particles of a metal compound.

[0011] According to the first aspect of the present invention, a manufacturing apparatus for fine particles of a metal compound can be obtained, in which the average particle diameter d50 of the metal compound having a high sphericity can be mainly controlled by adjusting the peripheral speed of the stirring blade. That is, a control section capable of controlling the peripheral speed of the stirring blade is provided, and by enabling the individual adjustment of the shear force and the circulation flow, stirring specialized for the transmission of the shear force can be performed in the reaction tank. The great merit of this mechanism improvement is that the particle diameter can be mainly controlled by adjusting the peripheral speed of the stirring blade. From the conventional particle diameter control relying on the adjustment of the residence time and pH value, the set values of the residence time and pH value remain constant under the condition of no deterioration of the product quality, and since the particle diameter can be mainly controlled by adjusting the peripheral speed of the stirring blade, the particle diameter control performance is improved dramatically. Due to this improvement in functionality, the particle diameter can be controlled while maintaining the residence time and pH value that do not cause deterioration of the particle shape, and a high-quality metal hydroxide with a high nickel content, a small average particle diameter, and a high sphericity can be obtained.

[0012] In a second aspect of the present invention, in the first aspect, the stirring blade of the crystallization apparatus includes a cylindrical cylindrical portion having a plurality of holes penetrating in the radial direction, a disk-shaped disk portion having an outer edge portion fixed to the inner peripheral surface of the cylindrical portion, and a rotation axis extending upward along the central axis from the center of the disk portion in plan view. The second reaction liquid can flow through the inside of the disk portion and the rotation axis, and the second liquid supply portion is provided at the outer edge portion of the disk portion. A manufacturing apparatus for fine particles of a metal compound, characterized in that it is provided.

[0013] According to the second aspect of the present invention, a manufacturing apparatus for fine particles of a metal compound can be obtained in which the second reaction liquid can be supplied to a range in the immediate vicinity from the inner and outer circumferences of the stirring blade having a high shearing force, and the average particle diameter d50 of the metal compound having a high sphericity can be controlled mainly by adjusting the peripheral speed of the stirring blade.

[0014] In a third aspect of the present invention, in the second aspect, the second liquid supply portion is a manufacturing apparatus for fine particles of a metal compound, characterized in that it opens downward.

[0015] According to the third aspect of the present invention, a manufacturing apparatus for fine particles of a metal compound can be obtained in which the second reaction liquid can be supplied to a range in the immediate vicinity from the inner and outer circumferences of the stirring blade having a high shearing force, and the average particle diameter d50 of the metal compound having a high sphericity can be controlled mainly by adjusting the peripheral speed of the stirring blade.

[0016] In a fourth aspect of the present invention, in the third aspect, in the cylindrical portion above the disk portion, a plurality of holes penetrating in the radial direction are closed, and a disk-shaped second disk portion having an outer edge portion fixed to the inner peripheral surface of the cylindrical portion is provided at the upper end portion of the cylindrical portion. A manufacturing apparatus for fine particles of a metal compound, characterized in that it is provided.

[0017] According to the fourth aspect of the present invention, a manufacturing apparatus for fine particles of a metal compound can be obtained in which the power for rotating the stirring blade is suppressed, and the average particle diameter d50 of the metal compound having a high sphericity can be controlled mainly by adjusting the peripheral speed of the stirring blade.

[0018] The fifth aspect of the present invention is a manufacturing apparatus for fine particles of a metal compound, characterized in that, in the third aspect, the disk portion is provided at the upper end portion of the cylindrical portion.

[0019] According to the fifth aspect of the present invention, it is possible to obtain a manufacturing apparatus for fine particles of a metal compound that suppresses the power for rotating the stirring blade and can control the average particle diameter d50 of the metal compound having a high sphericity mainly by adjusting the peripheral speed of the stirring blade.

[0020] The sixth aspect of the present invention is a manufacturing apparatus for fine particles of a metal compound, characterized in that, in any one of the second to fifth aspects, when the clearance between the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the reaction tank is L3 and the height of the cylindrical portion is He, He / L3 is 10 or more.

[0021] According to the sixth aspect of the present invention, it is possible to obtain a manufacturing apparatus for fine particles of a metal compound that can control the average particle diameter d50 of the metal compound having a high sphericity mainly by adjusting the peripheral speed of the stirring blade.

[0022] The seventh aspect of the present invention is a manufacturing apparatus for fine particles of a metal compound, characterized in that, in any one of the first to sixth aspects, a plurality of second liquid supply portions are provided.

[0023] According to the seventh aspect of the present invention, it is possible to uniformly supply the second reaction liquid in the circumferential direction of the disk portion, and to obtain a manufacturing apparatus for fine particles of a metal compound that can control the average particle diameter d50 of the metal compound having a high sphericity mainly by adjusting the peripheral speed of the stirring blade.

[0024] The eighth aspect of the present invention is a manufacturing system for fine particles of a metal compound, comprising the manufacturing apparatus according to any one of the first to seventh aspects, a circulation pipeline that circulates the slurry containing the fine particles discharged from the discharge port of the manufacturing apparatus into the manufacturing apparatus from the first liquid supply portion of the manufacturing apparatus, and a circulation pump that circulates the slurry between the manufacturing apparatus and the circulation pipeline, wherein the circulation pipeline has a bent portion having a meandering shape.

[0025] According to the eighth aspect of the present invention, it is possible to obtain a production system for fine particles of a metal compound in which the average particle diameter d50 of the metal compound having a high sphericity can be controlled mainly by adjusting the peripheral speed of the stirring blade.

[0026] According to the ninth aspect of the present invention, in the first aspect, the stirring blade includes a cylindrical cylindrical portion having the plurality of holes penetrating in the radial direction, a disk-shaped disk portion having an outer edge portion fixed to the inner peripheral surface of the cylindrical portion, and a rotating shaft extending upward along the central axis from the center of the disk portion in a plan view. A through hole penetrating the disk portion in the extending direction of the rotating shaft is provided outside the radial direction of the disk portion, and the second liquid supply portion is provided at two different positions in the extending direction of the rotating shaft. The upper second liquid supply portion provided on the upper side is provided at the outer edge portion of the disk portion, and the lower second liquid supply portion provided on the lower side is provided at an extending portion extending radially outward from the lower portion of the rotating shaft. The second reaction liquid can flow through the inside of the rotating shaft, the disk portion, and the extending portion. It is a production apparatus for fine particles of a metal compound.

[0027] According to the ninth aspect of the present invention, since the second liquid supply portion for supplying the second reaction liquid is provided at two different positions in the extending direction of the rotating shaft, the mixing of the first reaction liquid and the second reaction liquid is performed better. Further, since a through hole penetrating the disk portion in the extending direction of the rotating shaft is provided, the flow of the mixed liquid flowing through the reaction tank becomes smooth and the pressure loss can be reduced. That is, since the flow path resistance of the reaction tank can be reduced with respect to the flow of the mixed liquid, the pressure loss in the reaction tank can be reduced. Therefore, it is possible to suppress the power consumption of the pump when increasing the circulation flow rate.

[0028] According to the tenth aspect of the present invention, in the ninth aspect, the discharge port of the reaction tank is an apparatus for producing fine particles of a metal compound, characterized in that it opens in the direction in which the rotating shaft extends in the reaction tank.

[0029] According to the tenth aspect of the present invention, an increase in the peripheral speed of the stirring blade is not directly linked to an increase in the circulation flow rate of the mixed liquid from the first liquid supply section (inlet) toward the discharge port. That is, an increase in the peripheral speed of the stirring blade only increases the shearing force acting on the mixed liquid, and an increase in the circulation flow rate of the mixed liquid from the inlet toward the discharge port can be made to depend only on the flow rate of the pump provided outside the manufacturing apparatus. Therefore, the circulation flow rate of the mixed liquid in the manufacturing apparatus and the increase and decrease of the shearing force acting on the mixed liquid due to the increase and decrease of the peripheral speed of the stirring blade can be controlled individually with higher precision. Thus, the characteristics of the generated particles can be controlled with higher precision.

[0030] The eleventh aspect of the present invention is a manufacturing system for fine particles of a metal compound, comprising the manufacturing apparatus according to the tenth aspect, a circulation pipe for flowing the slurry containing the fine particles discharged from the discharge port of the manufacturing apparatus and circulating the slurry into the manufacturing apparatus from the first liquid supply section of the manufacturing apparatus, and a circulation pump for circulating the slurry between the manufacturing apparatus and the circulation pipe, wherein the circulation pipe includes a retention tank.

[0031] According to the eleventh aspect of the present invention, by providing a retention tank, desired fine particles can be obtained by appropriately adjusting the reaction time and retention time required for the generation of the fine particles.

[0032] The twelfth aspect of the present invention is a manufacturing system for fine particles of a metal compound, comprising the manufacturing apparatus according to the tenth aspect, a circulation pipe for flowing the slurry containing the fine particles discharged from the discharge port of the manufacturing apparatus and circulating the slurry into the manufacturing apparatus from the first liquid supply section of the manufacturing apparatus, and a circulation pump for circulating the slurry between the manufacturing apparatus and the circulation pipe, wherein the circulation pipe does not include a retention tank.

[0033] According to the twelfth aspect of the present invention, by not including a retention tank, the particulate manufacturing system can be made into a completely sealed structure. Therefore, since the manufacturing apparatus can be operated under pressure, it is possible to suppress the occurrence of cavitation caused by the mixed liquid becoming below the saturated vapor pressure in the low-pressure region generated as the stirring blade rotates, and it is possible to suppress the occurrence of cavitation even under high-temperature conditions where the saturated vapor pressure rises.

[0034] A thirteenth aspect of the present invention is a system for manufacturing fine particles of a metal compound according to the eleventh or twelfth aspect, wherein the second liquid supply section capable of supplying the second reaction liquid into the reaction tank is further provided above the stirring blade and the first liquid supply section in the reaction tank.

[0035] According to the thirteenth aspect of the present invention, the shearing force acting on the mixed liquid in the region above the stirring blade and the region below the stirring blade can be individually controlled. Therefore, not only the crystal particle size but also the function of adjusting the crystal shape can be improved. Furthermore, since the number of locations for supplying the second reaction liquid increases, the dispersibility of the mixed liquid is improved, and the production capacity of the fine particles can be improved. Also, the system for supplying the second reaction liquid to the upper second liquid supply section and the lower second liquid supply section can be separated from the system for supplying the second reaction liquid above the stirring blade and the first liquid supply section in the reaction tank. Therefore, by supplying the main raw material to one system and different additives that contribute to improving the quality of the crystal product to the other system, it becomes possible to shorten the additive addition process and manufacture products containing the additive as a component.

Effects of the Invention

[0036] According to the present invention, it is possible to provide a manufacturing apparatus for fine particles of a metal compound having a high nickel content, in which the average particle diameter d50 of the fine particles can be mainly controlled by adjusting the peripheral speed of the stirring blade so as to achieve a high capacity and a high output that can be used for a cathode material for next-generation batteries.

Brief Description of the Drawings

[0037]

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Embodiments for Carrying Out the Invention

[0038] <First Embodiment> Hereinafter, the crystallization system 10A according to the first embodiment of the present invention will be described with reference to FIG. 1.

[0039] The crystallization system 10A includes a crystallization device 4 that mixes a plurality of raw material solutions to generate particles derived from the raw materials in these plurality of raw material solutions, a circulation pipeline Po provided downstream of the crystallization device 4 that circulates the slurry D1 discharged from the discharge port 6 of the crystallization device 4 to the inlet (first liquid supply section) 5a of the crystallization device 4, and a circulation pump 30 that circulates the slurry D1 between the crystallization device 4 and the circulation pipeline Po. In the following description, the particles may be referred to as fine particles or fine particles of a metal compound. Further, the crystallization system 10A may be referred to as a manufacturing system for fine particles of a metal compound, and the crystallization device 4 may be referred to as a manufacturing device for fine particles of a metal compound.

[0040] The circulation pipeline Po includes a bent portion Pp that is a meandering pipeline. Further, the circulation pipeline Po includes a pipe 22 that connects the crystallization device 4 and the bent portion Pp, a pipe 23 that connects the circulation pump 30 and the bent portion Pp, and a pipe 24 that connects the circulation pump 30 and the crystallization device 4. Note that the bent portion Pp is not limited to a meandering shape and may have a spiral shape.

[0041] The circulation pump 30 is a circulation pump having a function of circulating the slurry D1 between the crystallization device 4 and the bent portion Pp while being able to adjust the flow rate. However, as long as it is a device having a similar function, it is not necessarily limited to a circulation pump. For example, an impeller with a controllable rotational speed may be provided in the pipe 23 or the pipe 24.

[0042] The crystallization device 4 includes a bottomed cylindrical reaction tank 1 having a central axis O1 oriented in the vertical direction, and a cylindrical stirring blade Wc. The stirring blade Wc is rotatable about a hollow rotating shaft 3 that extends upward along the central axis O1 from the center of the stirring blade Wc in plan view, and is housed inside the reaction tank 1 with the central axis O1 as the same central axis. The rotating shaft 3 rotates by the rotational force supplied via a belt B from a prime mover M provided outside the crystallization device 4. Note that the prime mover M is not particularly limited as long as it is a device that generates rotational power such as a motor or an engine. Also, the belt B that transmits the rotational force to the rotating shaft 3 is not particularly limited as long as it can transmit the rotational force such as a chain or a gear. Note that the bottom surface of the reaction tank 1 may be in a conical shape that bulges downward in addition to being planar as shown in the figure. An outlet 6 is provided at the upper part of the reaction tank 1 through which the slurry containing the particles (crystals) generated in the reaction tank 1 can be discharged to the next process. A pressure indication controller is provided in the pipe 22 to maintain or adjust the pressure of the slurry D1 discharged from the outlet 6 to the pipe 22. Details of the stirring blade Wc will be described later.

[0043] An inlet 5a through which the first reaction liquid L1 and the slurry D1 flowing through the circulation pipeline Po are supplied is provided at the lower part of the reaction tank 1. The first reaction liquid L1 is generated by supplying and mixing the external auxiliary raw materials S A and S B from a tank (not shown) that stores the auxiliary raw materials S A and S B . The flow rates of the auxiliary raw materials S A and S B in the first reaction liquid L1 are maintained or adjusted by flow indication controllers FIC2 and FIC3. The first reaction liquid L1 is supplied to the reaction tank 1 from the inlet 5a in a predetermined amount. The supply amount of the first reaction liquid L1 from the inlet 5a can be adjusted to a predetermined amount, for example, by adjusting the rotation speed of the circulation pump 30. A pressure indicator PI1 is provided in the pipe 24 through which the first reaction liquid L1 flows as needed. Further, the second reaction liquid L2 is supplied into the reaction tank 1 from a liquid supply part (second liquid supply part) 5b provided on the stirring blade Wc. The second reaction liquid L2 is supplied from a tank (not shown) that stores the external main raw material S M The flow rate of the second reaction liquid L2 is maintained or adjusted by a flow rate indicating controller FIC1. By reacting the first reaction liquid L1 and the second reaction liquid L2 supplied into the reaction tank 1, fine particles of the precipitated and crystallized metal compound are generated. The slurry D1 is a fluid containing the fine particles of this metal compound.

[0044] The bent part Pp is composed of a plurality of straight pipe parts (Po1, Po2, Po3, Po4, Po5, Po6) with an inner diameter r2 arranged at intervals in substantially the same direction, a plurality of curved pipe parts C (C1, C2, C3, C4, C5) with an inner diameter r3 that can separate or detachably connect adjacent straight pipe parts Po1, Po2, Po3, Po4, Po5, Po6, and a fixing plate 21 that fixes the plurality of straight pipe parts. The fact that the plurality of curved pipe parts C are separable means, for example, that the curved pipe part C5 provided to connect the straight pipe part Po5 and the straight pipe part Po6 can be separated from the straight pipe part Po5 and the straight pipe part Po6. As a method of attaching and detaching the curved pipe part C5 to and from the straight pipe part Po5 and the straight pipe part Po6, flange parts (not shown) are provided at both ends of the curved pipe part C5 and at the left ends of the straight pipe part Po5 and the straight pipe part Po6, and by tightening or loosening the flange parts using bolts, nuts, etc., the curved pipe part C5 may be attached to and detached from the straight pipe part Po5 and the straight pipe part Po6. The attachment and detachment method is not limited to this, and as long as it is detachable, for example, it is not limited to the method using flange parts, and the curved pipe part C5 may be attached and detached by screwing both ends of the curved pipe part C5 to the left ends of the straight pipe part Po5 and the straight pipe part Po6. The fixing plate 21 is rectangular in FIG. 1, but its material and shape are not particularly limited as long as the plurality of straight pipe parts Po1, Po2, Po3, Po4, Po5, Po6 can be held in a fixed state on the fixing plate 21. As described above, in the plurality of straight pipe portions and the plurality of bent pipe portions C that can be separated, the inner peripheral surfaces of the straight pipe portions and the bent pipe portions C can be easily cleaned by separating them, so that the maintainability of the crystallization system 10A can be improved.

[0045] In the example of FIG. 1, the straight pipe portions are composed of six straight pipe portions, namely, straight pipe portion Po1, straight pipe portion Po2, straight pipe portion Po3, straight pipe portion Po4, straight pipe portion Po5, and straight pipe portion Po6, and the bent pipe portion C is composed of five bent pipe portions, namely, bent pipe portion C1, bent pipe portion C2, bent pipe portion C3, bent pipe portion C4, and bent pipe portion C5, but it is not limited to this example. The straight pipe portion Po may be composed of six or more straight pipe portions Po, or may be composed of six or less straight pipe portions Po. The number of the bent pipe portions C also increases or decreases according to the number of the straight pipe portions Po. For example, in the example of FIG. 1, the second end of the bent pipe portion C2 whose first end is connected to the right end portion of the straight pipe portion Po3 may be connected to the left end portion of the pipe 22. In this case, since the bellows portion that can expand, contract, and bend is provided in the bent pipe portion C2, the bent pipe portion C2 may be able to expand and contract.

[0046] In this way, the pipeline length of the bent portion Pp, that is, the total length of the straight pipe portion and the bent pipe portion C (the number of the straight pipe portion and the bent pipe portion C) can be adjusted according to the requirement for the purpose of retaining the slurry D1 for a desired residence time. That is, when a longer residence time is desired, it is desirable to increase the number of the straight pipe portion and the bent pipe portion C to increase the pipeline length of the bent portion Pp, and when a shorter residence time is desired, it is desirable to decrease the number of the straight pipe portion and the bent pipe portion C to shorten the pipeline length of the bent portion Pp.

[0047] Here, the flow velocity of the slurry D1 is determined by the specific gravity and diameter of the particles constituting the slurry D1. That is, since the sedimentation velocity of the particles constituting the slurry D1 is determined by the specific gravity and diameter of the particles constituting the slurry D1, the flow velocity of the slurry D1 is determined so that the slurry D1 flows without sedimenting in the pipe. Therefore, the pipeline length of the bent portion Pp can be obtained from the desired residence time of the slurry D1 and the flow velocity of the slurry D1 for preventing the slurry D1 from sedimenting.

[0048] The crystallization device 4 and the bent portion Pp are connected by a pipe 22 with an inner diameter r1. The bent portion Pp and the circulation pump 30 are connected by a pipe 23 with an inner diameter r4. The circulation pump 30 and the crystallization device 4 are connected by a pipe 24 with an inner diameter r5. In the example of FIG. 1, the inner diameter of the circulation pipeline Po, that is, the inner diameter r1 of the pipe 22, the inner diameters r2 of the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6, the inner diameters r3 of the curved pipe portions C1, C2, C3, C4, C5, the inner diameter r4 of the pipe 23, and the inner diameter r5 of the pipe 24 are the same. In this case, since the cross-sectional areas of the pipe 22, the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6, the curved pipe portions C1, C2, C3, C4, C5, the pipe 23, and the pipe 24 are constant, the fluid analysis of the slurry D1 flowing through the pipeline becomes easy. However, it is not limited to the above example, and the inner diameter of the circulation pipeline Po, that is, the inner diameter r1 of the pipe 22, the inner diameters r2 of the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6, the inner diameters r3 of the curved pipe portions C1, C2, C3, C4, C5, the inner diameter r4 of the pipe 23, and the inner diameter r5 of the pipe 24 may be different from each other. In that case, the fluid analysis may be performed in consideration of the different inner diameters.

[0049] A pipeline connected to the slurry discharge pump 31 is connected to the pipe 23 through which the slurry D1 discharged from the bent portion Pp flows. This pipeline draws out the slurry D1 from the pipe 23 and accumulates it to form a product. A flow indication controller FIC4 is provided near the slurry discharge pump 31 to maintain or adjust the flow rate of the slurry D1 drawn out to the outside of the crystallization system 10A. The slurry discharge pump 31 is a slurry discharge pump having a function of adjusting the flow rate, similar to the circulation pump 30. However, it is not necessarily limited to the slurry discharge pump as long as it is a device having a function of drawing out the slurry D1 from the pipe 23. For example, an impeller with a controllable rotational speed may be provided in the pipeline. The pressure of the slurry D1 in the pipe 23 immediately after the slurry D1 is drawn out to the outside is monitored by a pressure indicator PI2 as needed.

[0050] In the crystallization system 10A, at least a part of the bent portion Pp is provided in the temperature control tank 13. The temperature control tank 13 is a member that maintains a state in which a refrigerant CW such as cold water flows in one direction inside the temperature control tank 13 by a pump or the like (not shown). When at least a part of the bent portion Pp is provided in such a temperature control tank 13, the refrigerant collides with the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6 of the bent portion Pp. In this case, heat exchange is performed between the slurry D1 flowing through the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6 of the bent portion Pp and the refrigerant CW through the members constituting the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6. Therefore, the slurry D1 can be cooled or heated. Here, in the case of FIG. 1, the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6 are provided substantially perpendicular to the flow direction of the refrigerant CW, but the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6 do not necessarily have to be provided substantially perpendicular to the flow direction of the refrigerant CW, and they may be provided at an angle that is not perpendicular. Further, heat exchange with the refrigerant CW may be performed in the curved pipe portion C of the bent portion Pp, or heat exchange with the refrigerant CW may be performed in both the straight pipe portion and the curved pipe portion C of the bent portion Pp.

[0051] Here, by adjusting the length of the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6 or the number of the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6 among the bent portion Pp, the temperature adjustment ability for the slurry D1 can be adjusted. For example, assuming that a heat quantity Q1 is transferred from the slurry D1 having a heat quantity Q flowing through the straight pipe portion Po1 to the refrigerant CW by heat exchange, a heat quantity Q2 is transferred from the slurry D1 having a heat quantity (Q - Q1) flowing through the straight pipe portion Po2 to the refrigerant CW by heat exchange. Further, assuming that a heat quantity Q3 is transferred from the slurry D1 having a heat quantity (Q - (Q1 + Q2)) flowing through the straight pipe portion Po3 to the refrigerant CW by heat exchange, the heat quantity of the slurry D1 flowing through the straight pipe portion Po4 is (Q - (Q1 + Q2 + Q3)). By repeating this a desired number of times, the heat quantity of the slurry D1 can be reduced, so that the slurry D1 can be cooled by a desired amount. The same applies when heating the slurry D1.

[0052] According to the crystallization system 10A including the circulation pipeline Po having such a bent portion Pp, the slurry D1 containing the particles generated in the crystallization device 4 can be easily and completely uniformly mixed by controlling the flow rate of the circulation pump 30. Further, by adjusting the pipeline length of the bent portion Pp, the slurry D1 containing the particles generated in the crystallization device 4 can be retained for a desired time without requiring a retention tank. Therefore, the retention time of the slurry D1 in the bent portion Pp can be adjusted without performing a complicated flow analysis of the slurry D1 required when using a retention tank. Note that a retention tank (not shown) may be added to the crystallization system 10A.

[0053] Also, according to such a crystallization system 10A, by adjusting the pipeline length of the bent portion Pp where heat exchange is performed with the refrigerant CW, that is, the pipeline lengths or numbers of the straight pipe portions Po1, Po2, Po3, Po4, Po5, Po6, the slurry D1 can be cooled or heated by a desired amount.

[0054] Next, the stirring blade Wc of the crystallization system 10A will be described in detail. The stirring blade Wc includes a cylindrical portion 2, a disk-shaped disk portion 8 whose outer edge portion is fixed to the inner peripheral surface 2i of the cylindrical portion 2, and a second disk portion 15 whose outer edge portion is fixed to the inner peripheral surface 2i of the upper end portion of the cylindrical portion 2. The disk portion 8 is provided at a position where the height of the cylindrical portion 2 is approximately halved, but is not limited to this example, and may be provided below or above approximately half of the height of the cylindrical portion 2. The rotation shaft 3 is fixed to the center of the disk portion 8 in a plan view. The second disk portion 15 is a disk-shaped member provided above the disk portion 8 and has a hole through which the rotation shaft 3 passes at the center in a plan view. Except for the hole through which the rotation shaft 3 passes, there is no hole penetrating the second disk portion 15 in the direction of the central axis O1. Therefore, the first reaction liquid L1, the second reaction liquid L2, and their mixed liquid do not enter the inside of the second disk portion 15. The hollow interior of the rotating shaft 3 serves as the pipeline P1. Inside the disk portion 8, a plurality of pipelines P2 extend radially from the center toward the outer edge. The pipeline P1 of the rotating shaft 3 communicates with the pipelines P2 of the disk portion 8. To the rotating shaft 3 of the stirring blade Wc, there is supplied the main raw material S M from a tank (not shown) for storing the main raw material S provided outside the crystallization device 4. The second reaction liquid L2 is supplied to the hollow pipeline P1 of the rotating shaft 3 via the rotary joint R, and then supplied to the pipeline P2 of the disk portion 8. The tip of the pipeline P2 on the radially outer side of the reaction tank 1 opens downward and serves as a liquid supply portion (second liquid supply portion) 5b from which the second reaction liquid L2 is discharged. Therefore, a plurality of liquid supply portions 5b are provided at intervals in the circumferential direction of the disk portion 8. For example, eight liquid supply portions 5b are provided. The number of the liquid supply portions 5b is not limited, but it is preferably provided symmetrically with respect to the central axis O1.

[0055] In this embodiment, the distance between the inner peripheral surface 2i of the cylindrical portion 2 of the stirring blade Wc and the center of the liquid supply portion 5b is set to 2 mm or less. Also, as shown in FIG. 2, when the distance (clearance) between the outer peripheral surface 2o of the cylindrical portion 2 of the stirring blade Wc and the inner peripheral surface 1i of the reaction tank 1 is L3, and the height along the central axis O1 of the stirring blade Wc (cylindrical portion 2) is He, it is preferable that He / L3, which is the ratio of He to L3, is 10 or more. More preferably, He / L3 is 25 or more. Therefore, even when using a device of a size different from this embodiment, a similar device can be manufactured based on this ratio. The stirring blade Wc rotates at a circumferential speed of 5 m / s or more and 50 m / s or less. Note that the ratio of He / L3 may be different from the above ratio depending on the purpose. For example, when it is desired to suppress crystal crushing, the ratio may be lowered from the above value.

[0056] In the cylindrical portion 2 of the stirring blade Wc, a plurality of holes h penetrating in the radial direction of the cylindrical portion 2 are provided below the disk portion 8. These holes h are allowed to pass through the first reaction liquid L1, the second reaction liquid L2, or a mixture thereof. Therefore, the first reaction liquid L1, the second reaction liquid L2, or a mixture thereof can move from the inside to the outside of the stirring blade Wc or from the outside to the inside of the stirring blade W through the plurality of holes h. Thus, when a plurality of holes h penetrating in the radial direction of the cylindrical portion 2 are provided below the disk portion 8, the stirring blade Wc can be rotated with less power as compared with the case where the plurality of holes h are provided on both the lower side and the upper side of the disk portion 8. Such a cylindrical portion 2 may be formed by processing the cylindrical portion 2 before processing in which the holes h are evenly provided in the height direction of the cylindrical portion 2 so as to block the holes h above the disk portion 8, so that the holes h are provided only below the disk portion 8. Alternatively, in the cylindrical portion 2, processing may be performed to provide the holes h only below the disk portion 8, and the cylindrical portion 2 may be formed so as not to perform processing to provide the holes h above the disk portion 8.

[0057] In the crystallization apparatus 4 including such a stirring blade Wc, a predetermined amount of the first reaction liquid L1 is supplied from the inlet 5a to the reaction tank 1. The amount of the first reaction liquid L1 supplied may be such that the reaction tank 1 is filled (full liquid state), or when the stirring blade W rotates, the first reaction liquid L1 performs circular motion around the central axis O1 of the reaction tank 1, and the first reaction liquid L1 is pressed against the inner peripheral surface 1i of the reaction tank 1 by the centrifugal force generated in the first reaction liquid L1, and the first reaction liquid L1 may be supplied to such an extent that a liquid film of the first reaction liquid L1 is formed on the inner peripheral surface 1i of the reaction tank 1. Hereinafter, the case where the first reaction liquid L1 is supplied to such an extent that it becomes a full liquid state will be assumed for explanation. Further, after the first reaction liquid L1 is supplied to the above-described full liquid state or liquid film forming state, the supply of the first reaction liquid L1 may be stopped and then the reaction may be carried out in the reaction tank 1 (batch method described later), or the reaction in the reaction tank 1 may be continuously carried out while maintaining the first reaction liquid L1 at a flow rate that becomes the above-described full liquid state or liquid film forming state (continuous method described later). For example, an opening adjustment valve (not shown) is provided at the discharge port 6, and by adjusting the opening of this opening adjustment valve, the reaction tank 1 can be selected to be either in a full liquid state or a liquid film state in which a liquid film is formed.

[0058] In a state where the reaction tank 1 is filled with the first reaction liquid L1, the stirring blade Wc is rotated, and the second reaction liquid L2 is discharged from the liquid supply section 5b along the inner peripheral surface 2i of the cylindrical portion 2 of the stirring blade Wc, thereby supplying the second reaction liquid L2 into the reaction tank 1. By doing so, the second reaction liquid L2 discharged from the liquid supply section 5b along the inner peripheral surface 2i of the cylindrical portion 2 of the stirring blade Wc comes into contact with the first reaction liquid L1 that is rotating along with the rotation of the stirring blade Wc in the vicinity of the inner peripheral surface 2i of the cylindrical portion 2 of the stirring blade Wc in the reaction tank 1 filled with the first reaction liquid L1. Thus, when the first reaction liquid L1 and the second reaction liquid L2 come into contact with each other, a reaction occurs and particles are generated.

[0059] At this time, by supplying the second reaction liquid L2 from the liquid supply section 5b of the stirring blade Wc that is rotating at a circumferential speed of 5 m / s or more and 50 m / s or less to the first reaction liquid L1, the second reaction liquid L2 can be uniformly mixed with the first reaction liquid L1.

[0060] Here, the first reaction liquid L1 rotating with the rotation of the stirring blade Wc, the second reaction liquid L2 discharged from the liquid supply part 5b of the stirring blade Wc rotating at a circumferential speed of 5 m / s or more and 50 m / s or less, and the centrifugal force generated in these mixed liquids cause the first reaction liquid L1, the second reaction liquid L2, and the mixed liquid (hereinafter, may be collectively referred to as the mixed liquid) to move to the outside in the radial direction of the cylindrical part 2 of the stirring blade Wc, collide with the inner peripheral surface 1i of the reaction tank 1 through a plurality of holes h provided in the cylindrical part 2 of the stirring blade Wc, and then move in the vertical direction along the inner peripheral surface 1i of the reaction tank 1. The mixed liquid that has mainly moved downward is attracted by the flow toward the outside in the radial direction caused by the centrifugal force generated by the rotation of the stirring blade Wc, collides again with the inner peripheral surface 1i of the reaction tank 1 through a plurality of holes h provided in the cylindrical part 2 of the stirring blade Wc, and then moves in the vertical direction along the inner peripheral surface 1i of the reaction tank 1, thereby generating convection. Here, when the mixed liquid passes through the plurality of holes h, due to the effect of the throttle flow path, the mixed liquid is accelerated to the outside in the radial direction, so the flow velocity of the mixed liquid in the outward radial direction is the highest in the vicinity of the plurality of holes h. Further, a shearing force in the circumferential direction is applied to the mixed liquid existing between the outer peripheral surface 2o and the inner peripheral surface 2i of the cylindrical part 2 of the stirring blade Wc rotating at a circumferential speed of 5 m / s or more and 50 m / s or less and the inner peripheral surface 1i of the reaction tank 1 fixed thereto. The shearing force applied to the mixed liquid is greater the closer it is to the inner peripheral surface 2i and the outer peripheral surface 2o of the cylindrical part 2 of the stirring blade Wc. The shearing force applied to the mixed liquid is a major factor determining the particle diameter and uniformity of the obtained particles. In particular, the greater the applied shearing force, the finer the particles that can be obtained.

[0061] In the crystallization apparatus 4 of the present embodiment, the liquid supply section 5b is provided at the outer edge of the disk section 8. Specifically, as described above, the distance between the inner peripheral surface 2i of the cylindrical section 2 of the stirring blade Wc and the center of the liquid supply section 5b is set to 2 mm or less. Therefore, at the reaction start point where the second reaction liquid L2 discharged from the liquid supply section 5b along the inner peripheral surface 2i of the cylindrical section 2 of the stirring blade Wc and the first reaction liquid L1 rotating along with the rotation of the stirring blade Wc in the vicinity of the inner peripheral surface 2i of the cylindrical section 2 of the stirring blade Wc first come into contact and start the reaction, in addition to the centrifugal force and the flow toward the outer side in the radial direction due to the effect of the throttle flow path, the shear force is applied to the maximum extent. Therefore, the region where the applied shear force is the largest can be set as the reaction start point. Specifically, the reaction start point can be formed in the region at the closest distance, for example, within 2 mm, from the inner peripheral surface 2i to the outer peripheral surface 2o of the cylindrical section 2 of the stirring blade Wc. Here, the mixed liquid can move from the inner peripheral side to the outer peripheral side of the cylindrical section 2 through the plurality of holes h described above. Therefore, the stirring of the first reaction liquid L1 and the second reaction liquid L2 at the reaction start point is promoted by the shear force. Therefore, more uniform mixing of the first reaction liquid L1 and the second reaction liquid L2 starts from the reaction start point, and mixing and reaction are performed in the reaction field, which is the place where the reaction occurs along the flow of the mixed liquid, so that particles having a fine and uniform diameter can be generated. Here, the reaction start point refers to the region where the reaction is started, and the reaction field refers to the entire place where the reaction occurs. Therefore, the reaction start point is included in the reaction field. Note that a baffle (baffle plate) 7 shown in FIG. 2 may be provided on the inner peripheral surface of the reaction tank 1 corresponding to the upper part of the stirring blade Wc. The baffle 7 has the effect of suppressing the generation of vortices and promoting the stirring of the mixed liquid when the reaction tank 1 is in a full liquid state. On the other hand, when the reaction tank 1 is not full and a liquid film of the mixed liquid is formed, it is not necessary to provide the baffle 7. Note that the baffle 7 is not an essential component and may not be provided. For example, when a mechanical seal (not shown) is provided at the location where the rotating shaft 3 in the reaction tank 1 is inserted to achieve a complete full liquid state without a gas phase part, the generation of vortices is suppressed, so the baffle 7 does not need to be provided. When the baffle 7 is not provided, the flow path resistance is reduced, and the power of the prime mover M can be reduced.

[0062] Even in a state where a liquid film is formed instead of a full liquid state, the same effects as in the case of the full liquid state can be obtained.

[0063] According to such a crystallization system 10A including the crystallization apparatus 4, the shearing force, the circulation amount of the first reaction liquid L1, and the residence time of the slurry that affect the particle quality such as the particle diameter, particle size distribution, and sphericity of the reaction product in the crystallization apparatus 4 can be individually adjusted, and the control performance of the particle quality can be further improved.

[0064] Such a crystallization apparatus 4 of the crystallization system 10A is further provided with a control unit CON capable of controlling the rotational speed of the prime mover M. Therefore, by controlling the rotational speed of the prime mover M by the control unit CON, the rotational speed (peripheral speed) of the stirring blade Wc can be controlled. The control unit CON is a computer that controls the rotational speed of the prime mover M based on operations by the operator of the crystallization system 10A or the like. That is, the control unit CON may be a known computer including a CPU, RAM, ROM, etc. capable of performing the above-described control. The details of the control by the control unit CON may be defined by software that can be arbitrarily changed or updated by the user. As shown in FIGS. 1 and 2, the control unit CON is electrically or electronically connected to the prime mover M. Further, the control unit CON may include a rotation speed sensor that measures the rotation speed of the stirring blade Wc (rotation shaft 3), and the control unit CON may control the rotation speed of the prime mover M so that the rotation speed signal received from the rotation speed sensor becomes the rotation speed corresponding to the desired peripheral speed. For example, when the prime mover M is a motor, the control unit CON may control the rotation speed of the motor by controlling the drive voltage of the motor. When the prime mover M is an engine, the control unit CON may control the rotation speed of the engine by controlling the fuel supply amount to the engine.

[0065] Using such a crystallization system 10A, the residence time of crystals in the reaction tank 1 and the pH in the reaction tank 1 were fixed under certain conditions, and the average particle diameter d50 of the fine particles obtained when the peripheral speed of the stirring blade Wc was changed was measured. As a result, the average particle diameter d50 of the fine particles obtained when the peripheral speed of the stirring blade Wc was 20 m / s was 3.79 μm (measurement point a). The average particle diameter d50 of the fine particles obtained when the peripheral speed of the stirring blade Wc was 40 m / s was 1.71 μm (measurement point b). The average particle diameter d50 of the fine particles obtained when the peripheral speed of the stirring blade Wc was 50 m / s was 1.32 μm (measurement point c).

[0066] The graph obtained by interpolating the obtained measurement points a, b, and c by a known method is shown in FIG. 3. From FIG. 3, it was confirmed that as the peripheral speed of the stirring blade Wc increases, fine particles with a smaller average particle diameter d50 can be obtained. Also, from FIG. 3, it was confirmed that when the peripheral speed is approximately 25 m / s or more, the obtained average particle diameter d50 is 3 μm or less. Here, the peripheral speed of approximately 25 m / s or more refers to the range between 23 m / s and 25 m / s or more of the peripheral speed when the average particle diameter d50 becomes 3 μm or less.

[0067] From the results of FIG. 3, it was confirmed that by using the crystallization system 10A and setting the peripheral speed of the stirring blade Wc to approximately 25 m / s or more, fine particles with an average particle diameter d50 of 3 μm or less can be obtained. And it was confirmed that as the peripheral speed of the stirring blade Wc increases, fine particles with a smaller average particle diameter d50 can be obtained. This is presumably because a shear force is generated in the fluid due to the velocity difference. The greater the increase in the peripheral speed of the stirring blade Wc, the greater the velocity difference between the mixed liquid rotating with the stirring blade Wc and the mixed liquid stationary in the reaction tank 1, and a greater shear force is applied to the mixed liquid. Therefore, the control unit CON that controls the peripheral speed of the stirring blade Wc by controlling the rotational speed of the prime mover M controls the shear force applied to the mixed liquid, and further controls the average particle diameter d50 of the fine particles to be manufactured.

[0068] The fine particles obtained in FIG. 3 are metal compounds containing nickel, cobalt, and manganese. More specifically, they are ternary metal hydroxides composed of nickel, cobalt, and manganese. In these fine particles, the molar ratio of nickel is 90% or more. The molar ratio of 90% or more here means that when the total molar amount of nickel, cobalt, and manganese is 100, the molar amount of nickel is 90 or more. Therefore, it was confirmed that fine particles with an average particle diameter d50 of 3 μm or less were obtained despite the high nickel content. Note that the fine particles are not necessarily limited to fine particles of ternary metal hydroxides composed of nickel, cobalt, and manganese, and may be fine particles of metal compounds composed of nickel, cobalt, and aluminum.

[0069] Here, the results in FIG. 3 were obtained when the crystallization system 10A was operated in a continuous mode. The continuous mode means that during the operation of the crystallization system 10A shown in FIG. 1, the main raw material S M and the auxiliary raw materials S A and S B are continuously supplied, and the slurry D1 containing the generated fine particles is continuously discharged from the crystallization system 10A to the outside. Since the molar ratio of nickel in the ternary metal hydroxide composed of nickel, cobalt, and manganese produced by the crystallization system 10A is 90% or more, the molar ratio of nickel in the metal-based raw materials input into the crystallization system 10A is also 90% or more. Note that in addition to the continuous mode of operation, there is also a batch mode of operation. This is an operation mode in which, during the operation of the crystallization system 10A, the main raw material S M and the auxiliary raw materials S A and S B are not supplied, and a predetermined amount of the main raw material S M and the auxiliary raw materials S A and S B are supplied to the crystallization system 10A before starting the operation of the crystallization system 10A, then the crystallization system 10A is operated, and after stopping the operation of the crystallization system 10A, the slurry D1 containing the generated fine particles is discharged to the outside.

[0070] Fig. 4 is an electron micrograph of fine particles obtained by operating the crystallization system 10A in such a continuous mode that the peripheral speed of the stirring blade Wc is 25 m / s or more. It can be seen that the sphericity of the particles is 0.85 or more on average, which is high. The average particle diameter d50 in this case was 1.32 μm. Fig. 5 is an electron micrograph of fine particles obtained by a conventional technique that does not use a stirring blade having a shape like the stirring blade Wc of the crystallization system 10A. Comparing with the fine particles in Fig. 4, it can be seen that the sphericity of the fine particles is clearly low. The average particle diameter d50 in this case was 1.37 μm.

[0071] Fig. 6 is an electron micrograph of fine particles obtained by operating the crystallization system 10C or crystallization system 10D described later in a batch mode. Similar to the fine particles obtained by the continuous mode shown in Fig. 4, it can be seen that even when operating in a batch mode, the sphericity of the particles is 0.9 or more on average, and fine particles with a high sphericity can be obtained. Furthermore, compared with the continuous mode, the uniformity of the particle size distribution is significantly improved, achieving a span: (d90 - d10) / d50 = 0.7 or less. The average particle diameter d50 in this case was 1.40 μm.

[0072] Therefore, according to the crystallization system 10A including the crystallization apparatus 4 provided with the control unit CON capable of controlling the peripheral speed of the stirring blade Wc, fine particles of a ternary metal hydroxide composed of nickel, cobalt, and manganese can be obtained, which have a high sphericity, a high nickel content of 90% or more in terms of the amount of substance, and a small average particle diameter d50 of 3 μm or less. Further, by mainly adjusting the peripheral speed of the stirring blade Wc under the control of the control unit CON, the average particle diameter d50 of the obtained fine particles of the metal compound can be controlled. That is, since the control unit CON capable of controlling the peripheral speed of the stirring blade is provided and the shearing force and the circulation flow can be adjusted individually, stirring specialized for the transmission of the shearing force is possible in the reaction tank 1. That is, the shearing force applied to the mixed liquid in the reaction tank 1 is adjusted by adjusting the peripheral speed of the stirring blade Wc, and the circulation flow is adjusted by adjusting the rotation speed of the circulation pump 30 in FIG. 1. The great merit of this mechanism improvement is that the particle diameter can be controlled mainly by adjusting the peripheral speed of the stirring blade Wc. From the conventional particle diameter control relying on the adjustment of the residence time and the pH value, the set values of the residence time and the pH value remain constant under the condition that the product quality does not deteriorate, and the particle diameter can be controlled mainly by adjusting the peripheral speed of the stirring blade Wc. Therefore, the particle diameter control performance is improved dramatically. Due to this improvement in functionality, the particle diameter can be controlled while maintaining the residence time and the pH value that do not cause deterioration of the particle shape, and high-quality metal hydroxide with a high nickel content, a small average particle diameter d50, and a high sphericity can be obtained.

[0073] <First Modification of the First Embodiment> FIG. 7 is a schematic view showing a crystallization system 10B according to the first modification of the first embodiment of the present invention. In the following description, only the differences from the crystallization system 10A according to the first embodiment will be described.

[0074] The crystallization system 10B is different from the crystallization system 10A in that the shape of the stirring blade Wd is different from that of the stirring blade Wc of the crystallization system 10A, and the bent portion Pp is not provided in the temperature control tank 13.

[0075] As shown in Fig. 7, the stirring blade Wd is different from the stirring blade Wc in that the disk portion 8 is provided at the upper end portion of the cylindrical portion 2. Also, the height of the cylindrical portion 2 is about half of the height of the cylindrical portion 2 of the stirring blade Wc. By using the crystallization apparatus 4d provided with such a stirring blade Wd, the same effects as those of the crystallization apparatus 4 provided with the stirring blade Wc can be achieved. Further, since the cylindrical portion 2 is not provided above the disk portion 8, the stirring blade Wd can be made lighter than the stirring blade Wc. Also, since the stirring blade Wd can have a simple structure, the stirring blade Wd can be operated with less power than the stirring blade Wc, and energy saving of the crystallization apparatus 4d and ease of manufacturing of the stirring blade Wd can be expected. Furthermore, since the height of the cylindrical portion 2 is suppressed to be short, the crystallization apparatus 4d can be miniaturized.

[0076] Even when using the crystallization system 10B according to the first modification example including such a crystallization apparatus 4d, similar to the case of using the crystallization system 10A, fine particles of a ternary metal hydroxide composed of nickel, cobalt, and manganese, which have a high sphericity, a high nickel content of 90% or more in terms of molar ratio, and a small average particle diameter d50 of 3 μm or less, can be produced. Note that the crystallization system 10B may be provided with the temperature control tank 13 used in the crystallization system 10A. In that case, the slurry D1 can be cooled or heated by a desired amount in the same manner as in the crystallization system 10A.

[0077] <Second Modification Example of the First Embodiment> Fig. 8 is a schematic view showing a crystallization system 10C according to the second modification example of the first embodiment of the present invention. In the following description, only the differences from the crystallization system 10A according to the first embodiment will be described.

[0078] The crystallization system 10C is different from the crystallization system 10A in that a retention tank 10 is provided instead of the bent portion Pp of the crystallization system 10A.

[0079] In contrast to the configuration adopted when the crystallization system 10A and the crystallization system 10B operate in a continuous mode, the crystallization system 10C is a configuration adopted when operating in a batch mode. In this case, since more apparatus capacity can be secured than when using the bent portion Pp, in the batch mode where the system forming the crystallization system 10C is closed to the outside during operation, more fine particles can be produced in one operation. Therefore, efficient production of fine particles can be achieved. Even when such a crystallization system 10C is operated in a batch mode, fine particles with a high sphericity, a high nickel content of 90% or more in terms of the molar ratio, and an average particle diameter d50 of 3 μm or less, as shown in FIG. 6, can be produced. Furthermore, when producing fine particles in a batch mode, the uniformity of the particle size distribution is significantly improved compared to the continuous mode, and a span: (d90 - d10) / d50 = 0.7 or less can be achieved. Note that a stirrer (not shown) may be provided in the retention tank 10 of the crystallization system 10C. As the stirrer, for example, a known screw-type stirrer may be provided. In this case, further improvement in fluidity in the retention tank 10 and improvement in dispersibility when adding a raw material or an additive to the retention tank 10 can be achieved.

[0080] <The third modification of the first embodiment> FIG. 9 is a schematic diagram showing a crystallization system 10D according to the third modification of the first embodiment of the present invention. In the following description, only the differences from the crystallization system 10C according to the second modification of the first embodiment will be described.

[0081] The crystallization system 10D is different from the crystallization system 10C in that a concentrator 11 is connected to the retention tank 10 of the crystallization system 10C.

[0082] When combined with a concentrator 11, like the crystallization system 10D, it is possible to increase the slurry concentration within the apparatus and improve the production amount per unit volume. In principle, since the slurry has fluidity, the slurry concentration can be increased to a concentration that can be pumped. As the concentrator 11, a filter, a centrifuge, a thickener, etc. can be applied. Even when using such a crystallization system 10D, it is possible to produce fine particles with a high sphericity, a high nickel content of 90% or more in terms of the molar ratio, and an average particle diameter d50 of 3 μm or less, as shown in FIG. 6. Note that a stirrer (not shown) may be provided in the retention tank 10 of the crystallization system 10D. As the stirrer, for example, a known screw-type stirrer may be provided. In this case, it is possible to further improve the fluidity in the retention tank 10 and the dispersibility when adding raw materials and additives to the retention tank 10.

[0083] Here, the advantages of using the stirring blade Wc or the stirring blade Wd will be explained from different viewpoints. Compared with the case of using a flat disk turbine as disclosed in Patent Document 3, when operating with the same power, the stirring blade Wc or the stirring blade Wd having a blade diameter 1.25 times that of the flat disk turbine can be operated at a peripheral speed 3.3 times that of the flat disk turbine. Therefore, when using the stirring blade Wc or the stirring blade Wd, a larger shearing force can be applied to the micro reaction field of the metal hydroxide than in the prior art. This is presumably because, compared with the flat disk turbine, there is less resistance received from the water when rotating the stirring blade Wc or the stirring blade Wd. Therefore, since the stirring blade Wc or the stirring blade Wd can be rotated at a higher speed, it is considered that a larger shearing force can be applied to the micro reaction field of the metal hydroxide.

[0084] <Second Embodiment> FIG. 10 is a schematic view of the crystallization apparatus 40 of the crystallization system 20A according to the second embodiment of the present invention. The crystallization system 20A according to the second embodiment of the present invention is shown in FIG. 13. In the following description, the differences from the crystallization apparatus 4d of the crystallization system 10B, which is the first modification of the first embodiment shown in FIG. 7, will be mainly described.

[0085] In the crystallization apparatus 40 of the crystallization system 20A, the discharge port 6a opens in the direction in which the rotating shaft 3 extends in the reaction tank 1A, and the stirring blade Ws of the crystallization apparatus 40 has a different shape from the stirring blade Wd of the crystallization system 10B of the first modification of the first embodiment.

[0086] In the reaction tank 1A of the crystallization apparatus 40 of the crystallization system 20A according to the second embodiment of the present invention, the inlet (first liquid supply section) 5a1 for supplying the first reaction liquid L1 is located above the reaction tank 1A and is provided above the stirring blade Ws. Also, in the reaction tank 1A of the crystallization apparatus 40 of the crystallization system 20A according to the second embodiment of the present invention, the discharge port 6a opens in the direction in which the rotating shaft 3 extends. In the example of FIG. 10, the discharge port 6a is provided at the bottom of the reaction tank 1A. Note that the bottom of the reaction tank 1A is not limited to the downwardly convex shape as shown in FIG. 10 and may be flat.

[0087] FIG. 12(a) shows a cross-sectional view taken along line AA of FIG. 10. As shown in FIG. 12(a), the inlet 5a1 is connected to the reaction tank 1A such that the reaction liquid L1 flowing into the reaction tank 1A from the inlet 5a1 forms a vortex. The inlet 5a1 may be connected to the reaction tank 1A in a tangential direction so that a vortex is easily formed.

[0088] The stirring blade Ws shown in Fig. 10 is different from the stirring blade Wd of the crystallization device 4d shown in Fig. 7 in that in the stirring blade Wd, the pipeline P2 opens radially outward from the outer edge of the disk portion 8, penetrates the cylindrical portion 2 in the radial direction, and a liquid supply portion (upper second liquid supply portion) 5b1 for supplying the second reaction liquid L2 into the reaction tank 1A toward the radially outer side of the cylindrical portion 2 is provided on the outer peripheral surface 2o of the cylindrical portion 2. Further, in the stirring blade Wd of the crystallization device 4d shown in Fig. 7, the rotating shaft 3 extends further downward from the disk portion 8, and a liquid supply portion (lower second liquid supply portion) 5b2 for supplying the second reaction liquid L2 into the reaction tank 1A toward the radially outer side of the cylindrical portion 2 extends radially outward from the lower end portion of the rotating shaft 3 and opens at the tip of the extending portion 9 extending radially outward from the lower end portion of the rotating shaft 3. Furthermore, it is different in that a plurality of through holes h1 penetrating the disk portion 8 in the extending direction of the rotating shaft 3 are provided. Here, the clearance between the inner peripheral surface 2i of the cylindrical portion 2 and the rotating shaft 3 is set larger than the clearance between the inner peripheral surface 1i of the reaction tank 1A and the stirring blade Ws. Also, the tip of the extending portion 9 is provided radially inward of the inner peripheral surface 2i of the cylindrical portion 2.

[0089] Hereinafter, the structure of the stirring blade Ws will be described in more detail. Fig. 12(b) shows a cross-sectional view taken along line BB of Fig. 10. The pipeline P2 branches from the pipeline P1 provided inside the rotating shaft 3 toward the radially outer side of the rotating shaft 3. In the example of Fig. 12(b), four pipelines P2 are provided and are equally spaced in the circumferential direction. The number of pipelines P2 is not necessarily limited to four, but may be less than or more than four as long as they are equally spaced in the circumferential direction around the rotating shaft 3. Also, in the example of Fig. 12(b), the through hole h1 is in the shape of a slit extending in the circumferential direction of the cylindrical portion 2, and four are provided at equal intervals in the circumferential direction. The through holes h1 only need to be equally spaced in the circumferential direction, and the number is not limited to four.

[0090] (c) of Fig. 12 shows a CC cross-sectional view of Fig. 10. The pipeline P3 branches out from the pipeline P1 provided inside the rotating shaft 3 toward the outside in the radial direction of the rotating shaft 3. In the example of (c) of Fig. 12, four pipelines P3 are provided and are equally spaced in the circumferential direction. The number of pipelines P3 is not necessarily limited to four, but may be less than or more than four as long as they are equally spaced in the circumferential direction around the rotating shaft 3. Note that the number of pipelines P2 and the number of pipelines P3 (the number of extending portions) may be the same or different.

[0091] Also, as shown in Fig. 10, a diameter-expanded portion 3a may be provided at the lower part of the rotating shaft 3, and the extending portion 9 may extend radially outward from the diameter-expanded portion 3a. Further, the diameter-expanded portion 3a may be detachably provided with respect to the rotating shaft 3, and may be configured to be fastened and fixed to the rotating shaft 3 with a nut N from the lower end of the diameter-expanded portion 3a. With such a structure, the extending portion 9 can be easily replaced with another diameter-expanded portion 3a provided with a different number.

[0092] In the crystallization apparatus 40 including such a reaction tank 1A and the stirring blade Ws, the first reaction liquid L1 supplied from the inlet (first liquid supply section) 5a1 flows through the reaction tank 1A toward the outlet 6a. At this time, along with the rotation of the stirring blade Ws, the first reaction liquid L1 performs a rotational motion. At this time, the upper second liquid supply section 5b1 and the lower second liquid supply section 5b2 provided on the rotating stirring blade Ws, that is, the second reaction liquid L2 is supplied into the reaction tank 1A radially outward from two different positions in the extending direction (vertical direction) of the rotation shaft 3. Therefore, the mixing of the first reaction liquid L1 and the second reaction liquid L2 is performed better than in the case of the crystallization apparatus 4d or the crystallization apparatus 4. Further, since a plurality of through holes h1 penetrating in the extending direction of the rotation shaft 3 are provided in the disk portion 8, the flow of the mixed liquid from the inlet 5a1 toward the outlet 6a becomes smoother and the pressure loss can be reduced compared to the case of the crystallization apparatus 4d or the crystallization apparatus 4. That is, the flow resistance of the reaction tank 1A can be reduced with respect to the flow of the mixed liquid from the inlet 5a1 toward the outlet 6a, so that the pressure loss in the reaction tank 1A can be reduced. Therefore, when increasing the circulation flow rate, the power consumption of the pump can be suppressed. Further, although the upper second liquid supply section 5b1 and the lower second liquid supply section 5b2 are open radially outward, the inner peripheral surface 1i of the reaction tank 1A exists on the radially outer sides of the upper second liquid supply section 5b1 and the lower second liquid supply section 5b2, and further the outlet 6a is open in the extending direction of the rotation shaft 3. Therefore, even if the peripheral speed of the stirring blade Ws increases and the centrifugal force acting on the mixed liquid rotating together with the stirring blade Ws around the stirring blade Ws having the increased peripheral speed increases, the increase in the flow of the mixed liquid toward the radially outer side due to the increase in the centrifugal force is canceled by the inner peripheral surface 1i of the reaction tank 1A. Therefore, unlike the case of the stirring blade Wd or the stirring blade Wc in the crystallization apparatus 4d or the crystallization apparatus 4 in which the outlet 6 opens radially outward of the reaction tank 1, the increase in the peripheral speed of the stirring blade Ws is not directly connected to the increase in the circulation flow rate of the mixed liquid from the inlet 5a1 toward the outlet 6a. That is, the increase in the peripheral speed of the stirring blade Ws can increase only the shearing force acting on the mixed liquid, and the increase in the circulation flow rate of the mixed liquid from the inlet 5a1 toward the outlet 6a can depend only on the flow rate of the pump 30. Therefore, the circulation flow rate of the mixed liquid in the crystallization system 20A and the increase and decrease in the shearing force acting on the mixed liquid due to the increase and decrease in the peripheral speed of the stirring blade Ws can be controlled individually with higher accuracy.Therefore, the characteristics of the generated particles can be controlled with higher precision.

[0093] Note that FIG. 13 is a schematic diagram of the crystallization system 20A according to the second embodiment of the present invention. The slurry D1 discharged from the discharge port 6a of the crystallization apparatus 40 flows into the retention tank 10 through the pipe 22. After staying in the retention tank 10, the slurry D1 is discharged from the discharge port provided at the bottom of the retention tank 10, flows into the pump 30 through the pipe 23, and is supplied to the reaction tank 1A from the inlet 5a1 through the pipe 24. The slurry D1 can be taken out to the outside using a slurry discharge pump or the like from a pipe (not shown) provided in the pipe line 23. Here, the inside of the retention tank 10 is at atmospheric pressure. <Modification Example of the Second Embodiment>

[0094] FIG. 11 is a schematic diagram of a crystallization apparatus 41 according to a modification example of the crystallization system 20A of the second embodiment of the present invention. In the following description, only the differences from the crystallization apparatus 40 of the crystallization system 20A of the second embodiment shown in FIG. 10 will be described.

[0095] In the crystallization apparatus 41 according to the modification example of the crystallization system 20A of the second embodiment shown in FIG. 11, an inlet (first liquid supply section) 5a2 for supplying the first reaction liquid L1 to the reaction tank 1B is provided at the bottom of the reaction tank 1B, and the discharge port 6b is provided at the upper part of the reaction tank 1B, which is different from the crystallization apparatus 40. The stirring blade Ws used in the crystallization apparatus 41 is the same as the stirring blade Ws used in the crystallization apparatus 40. Even in this case, similar to the crystallization apparatus 40, the discharge port 6b opens in the direction in which the rotation shaft 3 extends in the reaction tank 1B. Therefore, the same effects as those of the crystallization apparatus 40 can be achieved. <First Modification Example of the Crystallization System of the Second Embodiment>

[0096] FIG. 14 is a schematic diagram of a crystallization system 20B according to a first modification of the second embodiment of the present invention. The crystallization system 20B is different from the crystallization system 20A in that the retention tank 10 is not provided. When the reaction time and the residence time may be short, the configuration may be such that the retention tank 10 is not provided. By not providing the retention tank 10, the crystallization system 20B can be miniaturized. Further, by not providing the retention tank 10, the crystallization system 20B can be made into a completely sealed structure. Therefore, the crystallization system 20B can be operated under pressure. In this case, since the generation of a low-pressure region generated around the stirring blade Ws due to the rotation of the stirring blade Ws is suppressed to be below the saturated vapor pressure, the generation of cavitation can be suppressed, and the quality of the particles can be stabilized. <Second Modification of the Crystallization System of the Second Embodiment>

[0097] FIG. 15 is a schematic diagram of a crystallization system 20C according to a second modification of the second embodiment of the present invention. The crystallization system 20C is different from the crystallization system 20A in the configuration of the crystallization device 42. That is, in the crystallization system 20C, the second reaction liquid L2 is supplied into the reaction tank 1C not only from the upper second liquid supply portion 5b1 and the lower second liquid supply portion 5b2 provided on the stirring blade Ws but also from the fixed-side second liquid supply portion 5b3 provided in the reaction tank 1C, which is different from the crystallization system 20A. Further, the inlet (first liquid supply portion) 5a1 for supplying the first reaction liquid L1 to the reaction tank 1C is provided so as to supply the first reaction liquid L1 in the tangential direction of the reaction tank 1C.

[0098] The fixed-side second supply portion 5b3 is provided near the inner peripheral surface 1i of the reaction tank 1C and supplies the second reaction liquid L2 toward the bottom of the reaction tank 1C in the direction in which the rotation shaft 3 extends. Here, the fixed-side second liquid supply portions 5b3 are provided at equal intervals in the circumferential direction of the reaction tank 1C. The number of the fixed-side second liquid supply portions 5b3 is not limited as long as they are provided at equal intervals in the circumferential direction of the reaction tank 1C.

[0099] In the crystallization device 42 of such a crystallization system 20C, an upper reaction region is formed in the region A indicated by the broken line in FIG. 15, and a lower reaction region B is formed in the region B indicated by the broken line. In the upper reaction region A, the second reaction liquid L2 is supplied from the fixed-side second liquid supply section 5b3 to the first reaction liquid L1 that is supplied in the tangential direction of the reaction tank 1C to form a vortex, and a reaction occurs. On the other hand, in the lower reaction region B, similar to the crystallization device 40, a reaction occurs between the first reaction liquid L1 supplied from the inlet (first liquid supply section) 5a1 and the second reaction liquid L2 supplied from the stirring blade Ws.

[0100] Here, the shearing force acting on the mixed liquid in the upper reaction region A is generated in the circumferential direction between the mixed liquid stationary on the inner peripheral surface 1i of the reaction tank 1C in the upper reaction region A and the mixed liquid located radially inside the inner peripheral surface 1i of the reaction tank 1C and rotating about the rotation axis 3 together with the first reaction liquid L1 supplied from the inlet 5a1. Since a shearing force is generated in the fluid due to the velocity difference, the shearing force acting on the mixed liquid in the upper reaction region A depends on the circumferential velocity of the mixed liquid in the upper reaction region A. That is, it can be said that it depends on the circulation flow rate of the mixed liquid or the discharge amount of the pump 30. On the other hand, in the lower reaction region B, a shearing force is generated in the circumferential direction of the mixed liquid existing between the outer peripheral surface 2o and the inner peripheral surface 2i of the cylindrical portion 2 of the rotating stirring blade Ws and the inner peripheral surface 1i of the fixed reaction tank 1C. That is, the shearing force acting on the mixed liquid in the lower reaction region B depends on the circumferential velocity of the stirring blade Ws. Therefore, the shearing force acting on the mixed liquid in the upper reaction region A and the lower reaction region B can be controlled individually. Therefore, in the crystallization device 42, not only the crystal particle size but also the function of adjusting the crystal shape can be improved.

[0101] Furthermore, in the crystallization device 42, since the number of locations for supplying the second reaction liquid L2 increases, the dispersibility of the mixed liquid is improved, and based on this, the production capacity of fine particles can be improved. Also, the second reaction liquid L2 can be divided into a system for supplying it to the upper second liquid supply section 5b1 and the lower second liquid supply section 5b2 and a system for supplying it to the fixed-side second liquid supply section 5b3. Therefore, in one system, the main raw material S MBy supplying to one system and supplying different additives X that contribute to improving the quality of the crystalline product to the other system, it becomes possible to shorten the additive addition process and manufacture products containing the additive as a component.

[0102] As described above, the embodiments of the present invention and their modifications have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments and their modifications, and designs within the scope not departing from the gist of the present invention, etc., and combinations of the embodiments and modifications are also included.

Explanation of Reference Numerals

[0103] 1, 1A, 1B, 1C Reaction tank 2 Cylindrical part 3 Rotating shaft 4, 4d, 40, 41, 42 Crystallization device 5a Inlet (first liquid supply part) 5b Liquid supply part (second liquid supply part) 6 Outlet 8 Disk part h Hole 10A, 10B, 10C, 10D, 20A, 20B, 20C Crystallization system 22, 23, 24 Pipe 30 Circulation pump 31 Second circulation pump Po Circulation pipeline Pp Bending part Po1, Po2, Po3, Po4, Po5, Po6 Straight pipe part C, C1, C2, C3, C4, C5 Curved pipe part Wc, Wd, Ws Stirring blade

Claims

1. A stirring blade having a plurality of holes penetrating in the radial direction and rotatable around a central axis, A bottomed cylindrical reaction tank capable of concentrically accommodating the stirring blade therein, A first liquid supply section provided in the reaction tank and capable of supplying a first reaction liquid into the reaction tank, A second liquid supply section provided on the stirring blade and capable of supplying a second reaction liquid into the reaction tank, A control section for controlling the peripheral speed of the stirring blade, Comprising, The stirring blade includes a hollow rotating shaft extending upward along the central axis from the center of the stirring blade in a plan view, A manufacturing apparatus for fine particles of a metal compound, characterized in that a discharge port of the reaction tank opens in a direction in which the rotating shaft extends in the reaction tank.

2. The manufacturing apparatus for fine particles of a metal compound according to claim 1, characterized in that a baffle plate is provided in the reaction tank.

3. The manufacturing apparatus for fine particles of a metal compound according to claim 1, characterized in that the first liquid supply section is provided above the stirring blade.

4. The stirring blade includes a cylindrical portion having the plurality of holes penetrating in the radial direction, When a clearance between an outer peripheral surface of the cylindrical portion and an inner peripheral surface of the reaction tank is L3 and a height of the cylindrical portion is He, He / L3 is 10 or more. The manufacturing apparatus for fine particles of a metal compound according to any one of claims 1 to 3.

5. The manufacturing apparatus for fine particles of a metal compound according to any one of claims 1 to 3, characterized in that a plurality of the second liquid supply sections are provided.

6. The manufacturing apparatus according to claim 5, A circulation pipeline for flowing a slurry containing the fine particles discharged from the discharge port of the manufacturing apparatus and circulating the slurry into the manufacturing apparatus from the first liquid supply section of the manufacturing apparatus, A circulation pump for circulating the slurry between the manufacturing apparatus and the circulation pipeline. A manufacturing system for fine particles of a metal compound, characterized in that the circulation pipeline includes a retention tank.

7. The manufacturing apparatus according to claim 5, A circulation pipeline for flowing a slurry containing the fine particles discharged from the discharge port of the manufacturing apparatus and circulating the slurry into the manufacturing apparatus from the first liquid supply section of the manufacturing apparatus, A circulation pump for circulating the slurry between the manufacturing apparatus and the circulation pipeline. A manufacturing system for fine particles of a metal compound, characterized in that the circulation pipeline does not include a retention tank. Comprising,

8. The manufacturing system for fine particles of a metal compound according to claim 7, characterized in that the circulation pipeline includes a flowmeter for measuring a flow rate of the slurry flowing through the circulation pipeline.

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