Metal compound fine particle manufacturing device, metal compound fine particle manufacturing system

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 technology]

[0002] There is a demand for higher capacity and higher output in cathode materials for next-generation batteries, such as high-performance secondary batteries and all-solid-state batteries.

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

[0004] Coprecipitation is commonly used as a method for producing metal hydroxides, which are the raw material for cathode materials. The more the nickel content in the metal hydroxide is increased to increase the capacity of the cathode material, the larger the particle size of the metal hydroxide obtained by the coprecipitation method becomes, which is contrary to the need for fine particle size to obtain high output. In order to achieve both high capacity and high output, research is being conducted on technology that can increase the nickel content and produce fine particles.

[0005] Methods for increasing the nickel content and microparticulating the material include shortening the residence time of the crystals in the reaction tank and increasing the pH. Although it is possible to reduce the secondary particle size by these methods, excessive shortening of the residence time or high pH leads to a decrease in crystal quality, such as the miniaturization of primary particles and deterioration of the shape of secondary particles (decreased sphericity), and therefore the limit of maintaining crystal quality is the limit of adjustment using the above methods. Here, sphericity is defined as (diameter equivalent to the circle with the area of ​​the projected image of the particle) / (diameter of the smallest circumscribed circle of the projected image of the particle).

[0006] Research has been conducted into suppressing particle size growth by increasing the stirring and shearing forces in the reactor, but there is a need to transmit high stirring and shearing forces with high efficiency to the micro-reaction field of metal hydroxides, which have very short reaction times. In particular, when producing ultrafine particles with an average particle size of d50 = 3 μm or less from metal hydroxides with a high nickel content, the challenge is to transmit high stirring and shearing forces with high efficiency to the micro-reaction field in order to increase the sphericity.

[0007] Patent Document 1 discloses a production apparatus that is equipped with a pump and a propeller-type rotor stirrer, and that produces a positive electrode active material for a non-aqueous electrolyte secondary battery having an average particle size of 1.00 μm to 3.0 μm and a nickel content of up to 80%. Patent Document 2 discloses a production apparatus equipped with a turbine impeller as an agitator, for producing an oxide-based positive electrode active material for an all-solid-state lithium-ion battery having an average particle size d50 of 1.0 to 5.0 μm. Patent Document 3 discloses a production device for fine particles of a ternary oxide composed of cerium, zirconium, and yttrium, the primary particles having an average particle size of 0.5 to 100 nm and the secondary particles having an average particle size of 2 to 100 nm. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Republished WO2019 / 117027 [Patent Document 2] International Publication No. 2020 / 202602 Brochure [Patent Document 3] Patent No. 4784623 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made against this background, and aims to provide an apparatus for producing fine particles of a metal compound with a high nickel content, which can realize high capacity and high output to the extent that it can be used as a positive electrode material for next-generation batteries, and in which the average particle diameter d50 of the fine particles of the metal compound can be controlled mainly by adjusting the peripheral speed of the stirring blade. [Means for solving the problem]

[0010] In order to solve the above problems and achieve the above object, the present invention proposes the following means. A first aspect of the present invention is an apparatus for producing fine particles of a metal compound, comprising: an agitator having a plurality of holes penetrating radially and capable of rotatable around a central axis; a bottomed cylindrical reaction vessel capable of concentrically accommodating the agitator therein; a first liquid supply section provided in the reaction vessel and capable of supplying a first reaction liquid to the inside of the reaction vessel; a second liquid supply section provided in the agitator and capable of supplying a second reaction liquid to the inside of the reaction vessel; and a control section for controlling the peripheral speed of the agitator.

[0011] According to the first aspect of the present invention, it is possible to obtain a manufacturing device for metal compound fine particles, which is capable of controlling the average particle diameter d50 of a metal compound having high sphericity mainly by adjusting the peripheral speed of the stirring blade. That is, a control unit capable of controlling the peripheral speed of the stirring blade is provided, and the shear force and the circulation flow can be adjusted separately, so that the reaction vessel is specialized in transmitting the shear force. Mixing The main advantages of this improved mechanism are Mixing The advantage of this is that it is possible to control particle size by adjusting the peripheral speed of the blades. Conventionally, particle size control relied on adjusting the residence time and pH value, but the residence time and pH value settings remain constant under conditions that do not cause a decrease in product quality, and the particle size can be controlled mainly by adjusting the residence time and pH value. Mixing Since the particle size can be controlled by adjusting the peripheral speed of the blades, the controllability of the particle size is improved dramatically. This improvement in functionality makes it possible to control the particle size while maintaining the residence time and pH value that do not cause deterioration of the particle shape, and to obtain a high-quality metal hydroxide with a high nickel content and a small average particle size and high sphericity.

[0012] A second aspect of the present invention is an apparatus for producing fine particles of a metal compound, characterized in that in the first aspect, the agitator blade of the crystallization device comprises a cylindrical portion having a plurality of holes penetrating in the radial direction, a disk-shaped disk portion whose outer edge is fixed to the inner surface of the cylindrical portion, and a rotating shaft extending upward from the center of the disk portion along the central axis when viewed in a plane, the second reaction liquid can flow between the disk portion and the rotating shaft, and the second liquid supply portion is provided on the outer edge of the disk portion.

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

[0014] A third aspect of the present invention is the apparatus for producing fine particles of a metal compound according to the second aspect, characterized in that the second liquid supply section opens downward.

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

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

[0017] According to the fourth aspect of the present invention, it is possible to obtain an apparatus for producing fine particles of a metal compound, which can reduce the power required to rotate the stirring blade and control the average particle diameter d50 of a metal compound having high sphericity mainly by adjusting the peripheral speed of the stirring blade.

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

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

[0020] A sixth aspect of the present invention is an apparatus for producing 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 an apparatus for producing fine particles of a metal compound, which is capable of controlling the average particle size d50 of a metal compound having high sphericity mainly by adjusting the peripheral speed of the stirring blade.

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

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

[0024] An eighth aspect of the present invention is a system for producing fine particles of a metal compound, comprising: a manufacturing apparatus according to any one of the first to seventh aspects; a circulation pipeline for flowing a slurry containing the fine particles discharged from an outlet of the manufacturing apparatus and circulating the slurry from the first liquid supply section of the manufacturing apparatus into the manufacturing apparatus; and a circulation pump for circulating the slurry between the manufacturing apparatus and the circulation pipeline, wherein the circulation pipeline has a bent portion forming a serpentine shape.

[0025] According to the eighth aspect of the present invention, a system for producing fine particles of a metal compound can be obtained, which is capable of controlling the average particle size d50 of a metal compound having high sphericity mainly by adjusting the peripheral speed of the stirring blade.

[0026] A ninth aspect of the present invention is an apparatus for producing fine particles of a metal compound, characterized in that in the first aspect, the stirring blade comprises a 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 circumferential surface of the cylindrical portion, and a rotating shaft extending upward from the center of the disk portion along the central axis when viewed in a plane, and a through hole penetrating the disk portion in the direction of extension of the rotating shaft is provided on the radial outside of the disk portion, the second liquid supply portion is provided at two different locations in the direction of extension of the rotating shaft, the upper second liquid supply portion provided on the upper side is provided on the outer edge portion of the disk portion, and the lower second liquid supply portion provided on the lower side is provided on an extension portion extending radially outward from the lower part of the rotating shaft, and the second reaction liquid can flow through the rotating shaft, the disk portion, and the extension portion.

[0027] According to the ninth aspect of the present invention, the second liquid supplying section for supplying the second reaction liquid is provided at two different positions in the direction in which the rotation shaft extends, so that the first reaction liquid and the second reaction liquid are mixed more effectively. In addition, since a through hole penetrating the disk section is provided in the direction in which the rotation shaft extends, the flow of the mixed liquid flowing through the reaction tank becomes smooth, and pressure loss can be reduced. In other words, the flow resistance of the reaction tank to the flow of the mixed liquid can be reduced, so that pressure loss in the reaction tank can be reduced. Therefore, the power consumption of the pump can be suppressed when increasing the circulation flow rate.

[0028] A tenth aspect of the present invention is a manufacturing apparatus for metal compound microparticles, characterized in that, in the ninth aspect, the outlet of the reaction tank opens in the direction in which the rotation axis extends in the reaction tank.

[0029] According to a tenth aspect of the present invention, Mixing An increase in the peripheral speed of the impeller does not directly lead to an increase in the circulation flow rate of the mixed liquid from the first liquid supply section (inlet) to the outlet. In other words, Mixing The increase in the peripheral speed of the impeller increases only the shear force acting on the mixed liquid, and the increase in the circulation flow rate of the mixed liquid from the inlet to the outlet can be made to depend only on the flow rate of the pump installed outside the manufacturing apparatus. Mixing The increase or decrease in the shear force acting on the mixture due to the increase or decrease in the circumferential speed of the blades can be controlled individually with high precision, and therefore the properties of the generated particles can be controlled with high precision.

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

[0031] According to the eleventh aspect of the present invention, by providing a retention tank, it is possible to obtain desired fine particles by appropriately adjusting the reaction time and retention time required for producing fine particles.

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

[0033] According to the twelfth aspect of the present invention, since the retention tank is not included, the microparticle production system can have a completely sealed structure. Therefore, the production apparatus can be operated under pressure, Mixing The occurrence of cavitation caused by the mixed liquid falling below the saturated vapor pressure in the low-pressure region generated by the rotation of the blades can be suppressed, and the occurrence of cavitation can also be suppressed under high-temperature conditions where the saturated vapor pressure increases.

[0034] In a thirteenth aspect of the present invention, in the eleventh or twelfth aspect, the second liquid supply part capable of supplying the second reaction liquid to the inside of the reaction vessel is Mixing The system for producing fine particles of a metal compound is characterized in that a blade and the first liquid supply section are further provided above the blade and the first liquid supply section.

[0035] According to a thirteenth aspect of the present invention, Mixing The area above the wings and Mixing The shear forces acting on the mixed liquid in the region below the blades can be individually controlled. This allows for improved adjustment of not only the crystal particle size but also the crystal shape. Furthermore, the number of locations for supplying the second reaction liquid is increased, improving the dispersibility of the mixed liquid and improving the production capacity of fine particles. In addition, a system for supplying the second reaction liquid to the upper second liquid supply section and the lower second liquid supply section and a system for supplying the second reaction liquid to the upper second liquid supply section and the lower second liquid supply section are provided. MixingThe system can be divided into two parts, one for supplying the main raw material to the blade and the other for supplying a different additive that contributes to improving the quality of the crystal product, making it possible to shorten the process of adding the additive and to manufacture a product that contains the additive as an ingredient. Effect of the Invention

[0036] According to the present invention, it is possible to provide an apparatus for producing fine particles of a metal compound having a high nickel content, which can realize high capacity and high output sufficient for use as a positive electrode material for next-generation batteries, and in which the average particle diameter d50 of the fine particles of the metal compound can be controlled mainly by adjusting the peripheral speed of the stirring blade. [Brief description of the drawings]

[0037] [Figure 1] FIG. 1 is a schematic diagram of a crystallization system according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is an enlarged view of a main portion of a crystallization system according to a first embodiment of the present invention. [Diagram 3] 1 is a graph showing the relationship between the average particle size of fine particles produced using the crystallization system of the first embodiment according to the present invention and the peripheral speed of the stirring blade. [Figure 4] 1 is a photograph of fine particles produced using the crystallization system of the first embodiment according to the present invention. [Diagram 5] 1 is a photograph of microparticles produced using a prior art crystallization system. [Figure 6] 4 is a photograph of microparticles produced using the second or third modified example of the crystallization system of the first embodiment according to the present invention. [Figure 7] FIG. 1 is a schematic diagram of a crystallization system according to a first modified example of a first embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram of a crystallization system according to a second modified example of the first embodiment of the present invention. [Figure 9] FIG. 2 is a schematic diagram of a crystallization system according to a third modified example of the first embodiment of the present invention. [Figure 10]FIG. 2 is a schematic diagram of a crystallizer in a crystallization system according to a second embodiment of the present invention. [Figure 11] FIG. 11 is a schematic diagram of a modified example of a crystallizer in the crystallization system according to the second embodiment of the present invention. [Figure 12] FIG. 2 is a cross-sectional view of a crystallizer in a crystallization system according to a second embodiment of the present invention. [Figure 13] FIG. 2 is a schematic diagram of a crystallization system according to a second embodiment of the present invention. [Figure 14] FIG. 1 is a schematic diagram of a first modified example of a crystallization system according to a second embodiment of the present invention. [Figure 15] FIG. 1 is a schematic diagram of a second modified example of a crystallization system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] First Embodiment A crystallization system 10A according to a first embodiment of the present invention will be described below with reference to FIG.

[0039] The crystallization system 10A includes a crystallizer 4 that mixes a plurality of raw material solutions to generate particles derived from the raw materials in the plurality of raw material solutions, a circulation line Po that is provided downstream of the crystallizer 4 and circulates a slurry D1 discharged from an outlet 6 of the crystallizer 4 to an inlet (first liquid supply section) 5a of the crystallizer 4, and a circulation pump 30 that circulates the slurry D1 between the crystallizer 4 and the circulation line Po. In the following description, the particles may be referred to as fine particles or fine particles of a metal compound. Furthermore, the crystallization system 10A may be referred to as a manufacturing system for fine particles of a metal compound, and the crystallizer 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, which is a meandering pipeline. The circulation pipeline Po further includes a pipe 22 connecting the crystallizer 4 and the bent portion Pp, a pipe 23 connecting the circulation pump 30 and the bent portion Pp, and a pipe 24 connecting the circulation pump 30 and the crystallizer 4. The bent portion Pp is not limited to a meandering shape, and may be a spiral shape.

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

[0042] The crystallizer 4 includes a cylindrical reaction tank 1 with a bottom having a central axis O1 facing vertically, and a cylindrical agitator Wc. The agitator Wc can rotate around a hollow rotating shaft 3 extending upward along the central axis O1 from the center of the agitator Wc in a 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 a torque supplied through a belt B from a prime mover M provided outside the crystallizer 4. 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. The belt B that transmits the torque to the rotating shaft 3 is not particularly limited as long as it can transmit the torque, such as a chain or a gear. The bottom surface of the reaction tank 1 may be flat as shown in the figure, or may be a cone shape that is convex downward. An outlet 6 is provided at the top of the reaction tank 1, through which a slurry containing particles (crystals) generated in the reaction tank 1 can be discharged to the next process. A pressure indication controller that maintains or adjusts the pressure of the slurry D1 discharged from the discharge port 6 to the pipe 22 is provided on the pipe 22. The details of the mixing blade Wc will be described later.

[0043] The reaction tank 1 is provided at its bottom with an inlet 5a through which the first reaction liquid L1 and the slurry D1 flowing through the circulation pipe Po are supplied. A Or S BThe auxiliary material S is stored in a tank (not shown). A Or S B The auxiliary material S of the first reaction liquid L1 is supplied and mixed. A Or S B The flow rate of the first reaction liquid L1 is maintained or adjusted by flow indication controllers FIC2 and FIC3. A predetermined amount of the first reaction liquid L1 is supplied from the inlet 5a to the reaction tank 1. 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 necessary. In addition, a second reaction liquid L2 is supplied into the reaction tank 1 from a liquid supply section (second liquid supply section) 5b provided on the stirring blade Wc. The second reaction liquid L2 is a mixture of the main raw material S from the outside. M The flow rate of the second reaction liquid L2 is maintained or adjusted by a flow rate indicating controller FIC1. The first reaction liquid L1 and the second reaction liquid L2 supplied to the reaction vessel 1 react with each other to generate precipitated and crystallized fine particles of a metal compound. The slurry D1 is a fluid containing the fine particles of the metal compound.

[0044] The bent portion Pp is composed of a plurality of straight pipe sections (Po1, Po2, Po3, Po4, Po5, Po6) with an inner diameter r2 arranged to face substantially the same direction with a space between them, a plurality of curved pipe sections C (C1, C2, C3, C4, C5) with an inner diameter r3 that connect the adjacent straight pipe sections Po1, Po2, Po3, Po4, Po5, Po6 in a separable or detachable manner, and a fixing plate 21 that fixes the plurality of straight pipe sections. The fact that the plurality of curved pipe sections C are separable means that, for example, the curved pipe section C5 that is provided to connect the straight pipe section Po5 and the straight pipe section Po6 can be separated from the straight pipe section Po5 and the straight pipe section Po6. As a method of attaching and detaching the curved pipe section C5 to the straight pipe sections Po5 and Po6, flanges (not shown) are provided at both ends of the curved pipe section C5 and at the left ends of the straight pipe sections Po5 and Po6, and the curved pipe section C5 may be attached and detached to and from the straight pipe sections Po5 and Po6 by tightening and loosening the flanges using bolts, nuts, etc. The attachment and detachment method is not limited to this, and as long as it is freely attachable and detachable, it may be attached and detached by screwing both ends of the curved pipe section C5 to the left ends of the straight pipe sections Po5 and Po6, without being limited to a method using flanges. Although the fixed plate 21 has a rectangular shape in FIG. 1, the material and shape thereof are not particularly limited as long as the multiple straight pipe sections Po1, Po2, Po3, Po4, Po5, and Po6 can be held in a fixed state by the fixed plate 21. As described above, in the case of multiple separable straight pipe sections and multiple curved pipe sections C, the inner surfaces of the straight pipe sections and curved pipe sections C can be easily cleaned by separating them, thereby improving the maintainability of the crystallization system 10A.

[0045] In the example of Figure 1, the straight pipe section is composed of six straight pipe sections, namely straight pipe section Po1, straight pipe section Po2, straight pipe section Po3, straight pipe section Po4, straight pipe section Po5, and straight pipe section Po6, and the curved pipe section C is composed of five curved pipe sections, namely curved pipe section C1, curved pipe section C2, curved pipe section C3, curved pipe section C4, and curved pipe section C5, but is not limited to this example. The straight pipe section Po may be composed of six or more straight pipe sections Po, or six or less straight pipe sections Po. The number of curved pipe sections C increases or decreases according to the number of straight pipe sections Po. For example, in the example of FIG. 1, the second end of the curved pipe section C2, the first end of which is connected to the right end of the straight pipe section Po3, may be connected to the left end of the pipe 22. In this case, the curved pipe section C2 may be provided with a bellows section that is capable of expanding and contracting and bending, so that the curved pipe section C2 may be capable of expanding and contracting.

[0046] In this way, the pipeline length of the bent section Pp, i.e., the total length of the straight pipe sections and the curved pipe sections C (the number of straight pipe sections and curved pipe sections C), can be adjusted as desired to retain the slurry D1 for the desired retention time. That is, if a longer retention time is desired, it is desirable to increase the number of straight pipe sections and curved pipe sections C to lengthen the pipeline length of the bent section Pp, and if a shorter retention time is desired, it is desirable to decrease the number of straight pipe sections and curved pipe sections C to shorten the pipeline length of the bent section Pp.

[0047] Here, the flow rate of the slurry D1 is determined by the specific gravity and diameter of the particles constituting the slurry D1. That is, the settling speed of the particles constituting the slurry D1 is determined by the specific gravity and diameter of the particles constituting the slurry D1, so the flow rate of the slurry D1 is determined so that the slurry D1 flows in the piping without settling. Therefore, the pipe length of the bent portion Pp can be obtained from the desired residence time of the slurry D1 and the flow rate of the slurry D1 to prevent the slurry D1 from settling.

[0048] The crystallizer 4 and the bent portion Pp are connected by a pipe 22 having an inner diameter r1. The bent portion Pp and the circulation pump 30 are connected by a pipe 23 having an inner diameter r4. The circulation pump 30 and the crystallizer 4 are connected by a pipe 24 having an inner diameter r5. 1, the inner diameter of the circulation pipeline Po, i.e., the inner diameter r1 of the pipe 22, the inner diameter r2 of the straight pipe sections Po1, Po2, Po3, Po4, Po5, and Po6, the inner diameter r3 of the curved pipe sections C1, C2, C3, C4, and C5, the inner diameter r4 of the pipe 23, and the inner diameter r5 of the pipe 24 are all the same. In this case, the cross-sectional areas of the pipe 22, the straight pipe sections Po1, Po2, Po3, Po4, Po5, and Po6, the curved pipe sections C1, C2, C3, C4, and C5, the pipe 23, and the pipe 24 are constant, which makes it easy to perform a flow analysis of the slurry D1 flowing through the pipes. However, without being limited to the above example, the inner diameters of the circulation pipeline Po, i.e., the inner diameter r1 of the pipe 22, the inner diameter r2 of the straight pipe portions Po1, Po2, Po3, Po4, Po5, and Po6, the inner diameter r3 of the curved pipe portions C1, C2, C3, C4, and C5, the inner diameter r4 of the pipe 23, and the inner diameter r5 of the pipe 24 may be different from one another. In that case, the flow analysis may be performed taking into account the different inner diameters.

[0049] A pipeline connected to a slurry discharge pump 31 is connected to the pipe 23 through which the slurry D1 discharged from the bent portion Pp flows. This pipeline extracts the slurry D1 from the pipe 23 and accumulates it to become 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 extracted 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, the slurry discharge pump 31 is not necessarily limited to a slurry discharge pump as long as it has a function of extracting the slurry D1 from the pipe 23. For example, an impeller capable of controlling the rotation 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 necessary.

[0050] In the crystallization system 10A, at least a portion of the bent portion Pp is provided in the temperature adjustment 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 a 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, and 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, and Po6 of the bent portion Pp and the refrigerant CW via the members that constitute the straight pipe portions Po1, Po2, Po3, Po4, Po5, and Po6. Thus, the slurry D1 can be cooled or heated. 1, the straight pipe sections Po1, Po2, Po3, Po4, Po5, and Po6 are arranged substantially perpendicular to the flow direction of the refrigerant CW, but they do not necessarily have to be arranged substantially perpendicular to the flow direction of the refrigerant CW, and may be arranged at an angle other than perpendicular. Also, heat exchange with the refrigerant CW may occur in the curved pipe section C of the bent portion Pp, or heat exchange with the refrigerant CW may occur in both the straight pipe section and the curved pipe section C of the bent portion Pp.

[0051] Here, by adjusting the length of the straight pipe parts Po1, Po2, Po3, Po4, Po5, and Po6 or the number of the straight pipe parts Po1, Po2, Po3, Po4, Po5, and Po6 in the bent part Pp, the temperature adjustment ability for the slurry D1 can be adjusted. For example, if the heat amount Q1 is transferred from the slurry D1 having the heat amount Q flowing through the straight pipe part Po1 to the refrigerant CW by heat exchange, the heat amount Q2 is transferred from the slurry D1 having the heat amount (Q-Q1) flowing through the straight pipe part Po2 to the refrigerant CW by heat exchange. Furthermore, if the heat amount Q3 is transferred from the slurry D1 having the heat amount (Q-(Q1+Q2)) flowing through the straight pipe part Po3 to the refrigerant CW by heat exchange, the heat amount of the slurry D1 flowing through the straight pipe part Po4 becomes (Q-(Q1+Q2+Q3)). By repeating this a desired number of times, the heat amount of the slurry D1 can be reduced, so that the slurry D1 can be cooled by a desired amount. The same applies to the case where the slurry D1 is heated.

[0052] According to the crystallization system 10A equipped with the circulation pipe Po having such a bent portion Pp, the slurry D1 containing particles generated in the crystallizer 4 can be easily mixed completely and uniformly by controlling the flow rate of the circulation pump 30. Furthermore, the slurry D1 containing particles generated in the crystallizer 4 can be retained for a desired time by adjusting the pipe length of the bent portion Pp without requiring a retention tank. Therefore, the retention time of the slurry D1 in the bent portion Pp can be adjusted without performing a complex flow analysis of the slurry D1 required when a retention tank is used. A retention tank (not shown) may be added to the crystallization system 10A.

[0053] Furthermore, according to such a crystallization system 10A, the slurry D1 can be cooled or heated by a desired amount by adjusting the pipe length of the bent section Pp where heat exchange with the refrigerant CW takes place, i.e., the pipe length or number of the straight pipe sections Po1, Po2, Po3, Po4, Po5, and Po6.

[0054] Next, the stirring impeller Wc of the crystallization system 10A will be described in detail. The stirring impeller Wc includes a cylindrical portion 2, a disk-shaped disk portion 8 whose outer periphery is fixed to the inner periphery 2i of the cylindrical portion 2, and a second disk portion 15 whose outer periphery is fixed to the inner periphery 2i of the upper end of the cylindrical portion 2. The disk portion 8 is provided at a position where it is approximately half the height of the cylindrical portion 2, but is not limited to this example, and it may be provided below or above approximately half the height of the cylindrical portion 2. A rotating 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 rotating shaft 3 passes at the center when viewed from above. There are no holes passing through the second disk portion 15 in the direction of the central axis O1, except for the hole through which the rotating shaft 3 passes. Therefore, the first reaction liquid L1, the second reaction liquid L2, and a mixture thereof do not enter inside the second disk portion 15. The hollow interior of the rotating shaft 3 is a pipe line P1. A plurality of pipe lines P2 extend radially from the center toward the outer edge inside the disk portion 8. The pipe lines P1 of the rotating shaft 3 and the pipe lines P2 of the disk portion 8 are connected to each other. The rotating shaft 3 of the agitating blade Wc is connected to the main raw material S M The second reaction liquid L2 is supplied from a tank (not shown) that stores the second reaction liquid L2. The second reaction liquid L2 is supplied to a hollow pipe P1 of the rotating shaft 3 via a rotary joint R, and is then supplied to a pipe P2 of the disk unit 8. The tip of the pipe P2 on the radially outer side of the reaction tank 1 opens downward and serves as a liquid supply section (second liquid supply section) 5b from which the second reaction liquid L2 is discharged. Therefore, the disk unit 8 is provided with a plurality of liquid supply sections 5b spaced apart in the circumferential direction of the disk unit. For example, eight liquid supply sections 5b are provided. The number of liquid supply sections 5b is not limited, but it is desirable to provide them 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 impeller Wc and the center of the liquid supply portion 5b is 2 mm or less. As shown in FIG. 2, the distance (clearance) between the outer peripheral surface 2o of the cylindrical portion 2 of the impeller Wc and the inner peripheral surface 1i of the reaction vessel 1 is L3, and the height along the central axis O1 of the impeller Wc (cylindrical portion 2) is He. It is preferable that He / L3, which is the ratio of He to L3, is 10 or more. It is more preferable that He / L3 is 25 or more. Therefore, even if a device of a different size from this embodiment is used, a similar device can be manufactured based on this ratio. The impeller Wc rotates at a peripheral speed of 5 m / s or more and 50 m / s or less. The ratio of He / L3 may differ from the above ratio depending on the purpose. For example, if it is desired to suppress crystal crushing, the ratio may be lowered from the above value.

[0056] In the cylindrical portion 2 of the impeller Wc, a plurality of holes h penetrating the cylindrical portion 2 in the radial direction are provided below the disk portion 8. These holes h allow the first reaction liquid L1, the second reaction liquid L2, or a mixture thereof to flow. 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 impeller Wc, or from the outside to the inside of the impeller Wc, through the plurality of holes h. In this way, when the plurality of holes h penetrating the cylindrical portion 2 in the radial direction are provided below the disk portion 8, the impeller Wc can be rotated with less power than when the plurality of holes h are provided on both the lower and upper sides of the disk portion 8. Such a cylindrical portion 2 may be formed by processing the cylindrical portion 2 before processing, which has holes h evenly provided throughout the height direction of the cylindrical portion 2, so as to close the holes h above the disk portion 8, thereby forming a cylindrical portion 2 in which the holes h are provided only below the disk portion 8. Alternatively, the cylindrical portion 2 may be formed by processing the cylindrical portion 2 so as to provide the holes h only below the disk portion 8, and not processing the cylindrical portion 2 so as to provide the holes h above the disk portion 8.

[0057] In the crystallizer 4 equipped with such an agitator Wc, a predetermined amount of the first reaction liquid L1 is supplied to the reaction tank 1 from the inlet 5a. The amount of the first reaction liquid L1 supplied may be enough to fill the reaction tank 1 (full liquid state), or may be enough to press the first reaction liquid L1 against the inner circumferential surface 1i of the reaction tank 1 by the centrifugal force generated by the first reaction liquid L1 performing a circular motion around the central axis O1 of the reaction tank 1 when the agitator W rotates, and to form a liquid film of the first reaction liquid L1 on the inner circumferential surface 1i of the reaction tank 1. In the following, a description will be given assuming that the first reaction liquid L1 is supplied to the extent that the reaction tank 1 is full. In addition, the first reaction liquid L1 may be supplied to an extent that the above-mentioned liquid-filled state or liquid film formation state is achieved, and then the supply of the first reaction liquid L1 may be stopped and the reaction may be carried out in the reaction tank 1 (batch method described below), or the reaction in the reaction tank 1 may be carried out continuously while maintaining the first reaction liquid L1 at a flow rate sufficient to achieve the above-mentioned liquid-filled state or liquid film formation state (continuous method described below). For example, by providing an aperture adjustment valve (not shown) at the outlet 6 and adjusting the aperture of this aperture adjustment valve, the reaction tank 1 can be selected to be in either a liquid-filled state or a liquid film state in which a liquid film is formed.

[0058] In a state where the reaction vessel 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 part 5b along the inner circumferential surface 2i of the cylindrical part 2 of the stirring blade Wc, thereby supplying the second reaction liquid L2 into the reaction vessel 1. In this way, the second reaction liquid L2 discharged from the liquid supply part 5b along the inner circumferential surface 2i of the cylindrical part 2 of the stirring blade Wc comes into contact with the first reaction liquid L1 rotating with the rotation of the stirring blade Wc in the vicinity of the inner circumferential surface 2i of the cylindrical part 2 of the stirring blade Wc in the reaction vessel 1 filled with the first reaction liquid L1. In this way, the first reaction liquid L1 and the second reaction liquid L2 come into contact with each other, causing a reaction to occur and generating particles.

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

[0060] Here, due to the centrifugal force generated in the mixture of the first reaction liquid L1 rotating with the rotation of the impeller Wc, the second reaction liquid L2 discharged from the liquid supply part 5b of the impeller Wc rotating at a peripheral speed of 5 m / s to 50 m / s, and the first reaction liquid L1, the second reaction liquid L2, and the mixture (hereinafter, sometimes collectively referred to as the mixture) move radially outward from the cylindrical part 2 of the impeller Wc, collide with the inner circumferential surface 1i of the reaction vessel 1 through a plurality of holes h provided in the cylindrical part 2 of the impeller Wc, and then move vertically along the inner circumferential surface 1i of the reaction vessel 1. The mixture that mainly moves downward is attracted by the flow toward the radial outward direction caused by the centrifugal force generated by the rotation of the impeller Wc, and again passes through a plurality of holes h provided in the cylindrical part 2 of the impeller Wc, collide with the inner circumferential surface 1i of the reaction vessel 1, and then moves vertically along the inner circumferential surface 1i of the reaction vessel 1, thereby generating convection. Here, when the mixed liquid passes through the multiple holes h, the mixed liquid is accelerated radially outward due to the effect of the throttle flow path, so the radially outward flow velocity of the mixed liquid is the highest in the vicinity of the multiple holes h. Furthermore, a shear force is applied in the circumferential direction to the mixed liquid present between the outer peripheral surface 2o and inner peripheral surface 2i of the cylindrical part 2 of the stirring impeller Wc rotating at a peripheral speed of 5 m / s to 50 m / s and the inner peripheral surface 1i of the fixed reaction vessel 1. The shear force applied to the mixed liquid is larger the closer it is to the inner peripheral surface 2i and outer peripheral surface 2o of the cylindrical part 2 of the stirring impeller Wc. The shear force applied to the mixed liquid is a major factor that determines the particle size and uniformity of the obtained particles. In particular, the larger the applied shear force, the finer the particle size of the particles that can be obtained.

[0061] In the crystallizer 4 of this embodiment, the liquid supply section 5b is provided on the outer edge of the disk section 8. Specifically, as described above, the distance between the inner circumferential surface 2i of the cylindrical section 2 of the impeller Wc and the center of the liquid supply section 5b is set to 2 mm or less. Therefore, at the reaction initiation point where the second reaction liquid L2 discharged from the liquid supply section 5b along the inner circumferential surface 2i of the cylindrical section 2 of the impeller Wc and the first reaction liquid L1 rotating with the rotation of the impeller Wc near the inner circumferential surface 2i of the cylindrical section 2 of the impeller Wc come into contact for the first time and start the reaction, a maximum shear force is applied in addition to the flow toward the radial outside due to the centrifugal force and the effect of the throttle flow path. Therefore, the region where the applied shear force is the largest can be set as the reaction initiation point. Specifically, the reaction initiation point can be formed in a region close to the inner circumferential surface 2i and the outer circumferential surface 2o of the cylindrical section 2 of the impeller Wc, for example, within 2 mm. Here, the mixed liquid can move from the inner circumferential side to the outer circumferential side of the cylindrical section 2 through the above-mentioned multiple holes h. Therefore, the mixing of the first reaction liquid L1 and the second reaction liquid L2 at the reaction initiation point is promoted by the shear force. Therefore, more uniform mixing of the first reaction liquid L1 and the second reaction liquid L2 is started from the reaction initiation point, and the mixing and reaction are carried out in the reaction field where the reaction occurs along the flow of the mixed liquid, thereby producing fine particles with a uniform diameter. Here, the reaction initiation point refers to the area where the reaction starts, and the reaction field refers to the entire field where the reaction occurs. Therefore, the reaction initiation point is included in the reaction field. A baffle (baffle plate) 7 shown in Fig. 2 may be provided on the inner peripheral surface of the reaction vessel 1 corresponding to the upper part of the stirring blade Wc. When the reaction vessel 1 is filled with liquid, the baffle 7 has the effect of suppressing the generation of vortexes and promoting the stirring of the mixed liquid. On the other hand, when the reaction vessel 1 is not filled with liquid 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, if a mechanical seal (not shown) is provided at the location in the reaction vessel 1 where the rotating shaft 3 is inserted, and a completely liquid-filled state with no gas phase is achieved, the generation of vortexes is suppressed, and therefore the baffle 7 may not be provided. If the baffle 7 is not provided, the flow path resistance is reduced, and the power of the prime mover M can be reduced.

[0062] In addition, even in a state where a liquid film is formed instead of a liquid-filled state, the same effect as in the liquid-filled state can be obtained.

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

[0064] The crystallizer 4 of such a crystallization system 10A is further provided with a control unit CON capable of controlling the rotation speed of the prime mover M. Therefore, by controlling the rotation speed of the prime mover M with the control unit CON, the rotation speed (circumferential speed) of the stirring blade Wc can be controlled. The control unit CON is a computer that controls the rotation speed of the prime mover M based on the operation by the operator of the crystallization system 10A. That is, the control unit CON may be a known computer including a CPU, RAM, ROM, etc. that can perform the above-mentioned 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 FIG. 1 and FIG. 2, the control unit CON is electrically or electronically connected to the prime mover M. The control unit CON may also include a rotation speed sensor that measures the rotation speed of the stirring blade Wc (rotating 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 corresponds 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 amount of fuel supplied to the engine.

[0065] Using this crystallization system 10A, the residence time of the crystals in the reaction tank 1 and the pH in the reaction tank 1 were fixed at constant conditions, and the average particle diameter d50 of the fine particles obtained was measured when the peripheral speed of the stirring blade Wc was changed. 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] A graph obtained by interpolating the obtained measurement points a, b, and c using a known method is shown in Figure 3. It was confirmed from Figure 3 that as the peripheral speed of the stirring blade Wc increases, fine particles with a smaller average particle diameter d50 are obtained. It was also confirmed from Figure 3 that when the peripheral speed is approximately 25 m / s or more, the obtained average particle diameter d50 is 3 μm or less. Here, a peripheral speed of approximately 25 m / s or more refers to a peripheral speed between 23 m / s and 25 m / s or more when the average particle diameter d50 is 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 impeller Wc to approximately 25 m / s or more, fine particles with an average particle size d50 of 3 μm or less can be obtained. It was also confirmed that by increasing the peripheral speed of the impeller Wc, fine particles with a smaller average particle size d50 can be obtained. This is thought to be due to the fact that, since a shear force is generated in a fluid due to a speed difference, the greater the peripheral speed of the impeller Wc is, the greater the speed difference between the mixed liquid rotating with the impeller Wc and the mixed liquid stationary in the reaction tank 1 becomes, and a greater shear force is applied to the mixed liquid. Therefore, the control unit CON, which controls the peripheral speed of the impeller Wc by controlling the rotation speed of the prime mover M, controls the shear force applied to the mixed liquid, and further controls the average particle size d50 of the fine particles produced.

[0068] The microparticles 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 microparticles, the substance amount ratio of nickel is 90% or more. Here, a substance amount ratio of 90% or more means that, when the total substance amount of nickel, cobalt, and manganese is taken as 100, the substance amount of nickel is 90% or more. Therefore, it was confirmed that, despite the high nickel content, minute microparticles with an average particle size d50 of 3 μm or less were obtained. The fine particles are not necessarily limited to fine particles of a ternary metal hydroxide composed of nickel, cobalt, and manganese, but may be fine particles of a metal compound composed of nickel, cobalt, and aluminum.

[0069] The results shown in FIG. 3 were obtained when the crystallization system 10A was operated in a continuous mode. The continuous mode is when the main raw material S M and auxiliary material S A Or S B is continuously supplied, and the slurry D1 containing the generated fine particles is continuously discharged from the crystallization system 10A to the outside. Since the nickel mass ratio of the ternary metal hydroxide composed of nickel, cobalt, and manganese produced in the crystallization system 10A is 90% or more, the nickel mass ratio of the metal-based raw material input to the crystallization system 10A is also 90% or more. In addition to the continuous operation, there is also a batch operation. During the operation of the crystallization system 10A, the main raw material S M and auxiliary material S A Or S B Before starting the operation of the crystallization system 10A, a predetermined amount of the main raw material S is supplied without supplying M and auxiliary material S A Or S B to the crystallization system 10A, the crystallization system 10A is operated, and the operation of the crystallization system 10A is stopped, and then the slurry D1 containing the generated fine particles is discharged to the outside.

[0070] FIG. 4 is an electron microscope photograph of fine particles obtained by operating the crystallization system 10A in such a continuous manner so that the peripheral speed of the impeller Wc is approximately 25 m / s or more. It can be seen that the sphericity of the particles is high, being 0.85 or more on average. In this case, the average particle diameter d50 was 1.32 μm. FIG. 5 is an electron microscope photograph of fine particles obtained by a conventional technique that does not use an impeller shaped like the impeller Wc of the crystallization system 10A. It can be seen that the sphericity of the fine particles is clearly lower than that of the fine particles in FIG. 4. In this case, the average particle diameter d50 was 1.37 μm.

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

[0072] Therefore, according to the crystallization system 10A including the crystallizer 4 equipped with the control unit CON capable of controlling the circumferential speed of the stirring blade Wc, it is possible to obtain fine particles of ternary metal hydroxide composed of nickel, cobalt, and manganese, which have high sphericity, a high nickel content of 90% or more in terms of substance amount ratio, and a minute average particle diameter d50 of 3 μm or less. Furthermore, by adjusting mainly the circumferential speed of the stirring blade Wc under the control of the control unit CON, it is possible to control the average particle diameter d50 of the obtained metal compound fine particles. In other words, by providing the control unit CON capable of controlling the circumferential speed of the stirring blade and making it possible to adjust the shear force and the circulation flow separately, the reaction tank 1 has a function specialized in transmitting the shear force. Mixing That is, the shear force applied to the mixed liquid in the reaction vessel 1 is adjusted by adjusting the peripheral speed of the stirring blades Wc, and the circulation flow is adjusted by adjusting the rotation speed of the circulation pump 30 in FIG. 1. The main advantages of this improvement in the mechanism are MixingThe advantage of this is that it is possible to control particle size by adjusting the peripheral speed of the blade Wc. Conventionally, particle size control relied on adjusting the residence time and pH value, but the residence time and pH value settings remain constant under conditions that do not cause a decrease in product quality, and the particle size can be controlled mainly by adjusting the residence time and pH value. Mixing Since the particle size can be controlled by adjusting the peripheral speed of the blades Wc, the controllability of the particle size is improved dramatically. This improvement in functionality makes it possible to control the particle size while maintaining the residence time and pH value that do not cause deterioration of the particle shape, and to obtain a high-quality metal hydroxide with a high nickel content and a small average particle size d50 and high sphericity.

[0073] <First Modification of First Embodiment> 7 is a schematic diagram showing a crystallization system 10B according to a first modified 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.

[0074] The crystallization system 10B differs 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 in that the bent portion Pp is not provided inside the temperature adjustment tank 13.

[0075] As shown in FIG. 7, the impeller Wd is different from the impeller Wc in that the disk portion 8 is provided at the upper end of the cylindrical portion 2. In addition, the height of the cylindrical portion 2 is about half the height of the cylindrical portion 2 of the impeller Wc. By using a crystallizer 4d equipped with such an impeller Wd, the same effect as the crystallizer 4 equipped with the impeller Wc can be achieved. In addition, since the cylindrical portion 2 is not provided above the disk portion 8, the impeller Wd can be made lighter than the impeller Wc. In addition, since the impeller Wd can be made to have a simple structure, the impeller Wd can be operated with less power than the impeller Wc, and energy saving of the crystallizer 4d and simplification of the manufacture of the impeller Wd can be expected. Furthermore, since the height of the cylindrical portion 2 is kept short, the crystallizer 4d can be made compact.

[0076] The use of the crystallization system 10B according to the first modified example including such a crystallizer 4d can produce fine particles of a ternary metal hydroxide composed of nickel, cobalt, and manganese, which has high sphericity, a high nickel content of 90% or more in terms of substance amount ratio, and a very small average particle diameter d50 of 3 μm or less. This can be achieved in the same manner as the use of the crystallization system 10A. The crystallization system 10B may be provided with the temperature adjustment 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 of First Embodiment> 8 is a schematic diagram showing a crystallization system 10C according to a second modified 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 differs 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] While the crystallization system 10A and the crystallization system 10B are configured to be used when operating in a continuous manner, the crystallization system 10C is configured to be used when operating in a batch manner. In this case, a larger device capacity can be secured than when the bent portion Pp is used, so that in a batch manner in which the system forming the crystallization system 10C during operation is closed to the outside, more fine particles can be produced in one operation. Therefore, fine particles can be produced efficiently. Even when such a crystallization system 10C is operated in a batch manner, fine particles having a high sphericity, a high nickel content of 90% or more in terms of substance amount ratio, and an average particle diameter d50 of 3 μm or less can be produced, as shown in FIG. 6. Furthermore, when fine particles are produced in a batch manner, the uniformity of the particle size distribution is significantly improved compared to the continuous manner, and a span: (d90-d10) / d50=0.7 or less can be achieved. The retention tank 10 of the crystallization system 10C may be provided with an agitator (not shown). As the agitator, for example, a known screw type agitator may be provided. In this case, the fluidity in the retention tank 10 can be further improved, and the dispersibility when raw materials and additives are added to the retention tank 10 can be improved.

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

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

[0082] By combining the crystallization system 10D with a concentrator 11, it is possible to increase the slurry concentration in the device and improve the production volume per unit volume. In principle, the slurry has fluidity and the slurry concentration can be increased to a concentration that allows it to be pumped. A filter, a centrifuge, a thickener, or the like can be applied to the concentrator 11. When such a crystallization system 10D is used, it is possible to produce fine particles with high sphericity, a high nickel content of 90% or more in terms of substance amount ratio, and an average particle diameter d50 of 3 μm or less, as shown in FIG. 6. The retention tank 10 of the crystallization system 10D may be provided with an agitator (not shown). As the agitator, for example, a known screw type agitator may be provided. In this case, the fluidity in the retention tank 10 can be further improved, and the dispersibility when raw materials and additives are added to the retention tank 10 can be improved.

[0083] Here, the advantages of using the stirring blade Wc or the stirring blade Wd will be described from a different perspective. Compared with the case of using a flat disk turbine as disclosed in Patent Document 3, when operated 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 the stirring blade Wc or the stirring blade Wd is used, a larger shear force can be applied to the micro-reaction field of the metal hydroxide than in the conventional technology. This is considered to be because the resistance received from the water when the stirring blade Wc or the stirring blade Wd is rotated is smaller than that of the flat disk turbine. Therefore, since the stirring blade Wc or the stirring blade Wd can be rotated at a higher speed, it is considered that a larger shear force can be applied to the micro-reaction field of the metal hydroxide.

[0084] <Second embodiment> Fig. 10 is a schematic diagram of a crystallizer 40 of a crystallization system 20A according to a 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 explanation, the differences from the crystallization system 10B according to the first modified example of the first embodiment shown in Fig. 7 will be mainly described.

[0085] The crystallizer 40 of the crystallization system 20A has a discharge port 6a that opens in the direction in which the rotating shaft 3 extends in the reaction tank 1A, and Mixing The blade Ws is the same as that of the crystallization system 10B of the first modified example of the first embodiment. Mixing It differs from wing Wd in that it has a different shape.

[0086] In the reaction tank 1A in the crystallization apparatus 40 of the crystallization system 20A of the second embodiment of the present invention, an inlet (first liquid supply part) 5a1 through which a first reaction liquid L1 is supplied is provided in the upper part of the reaction tank 1A, MixingThe outlet 6a is provided above the blade Ws. In the reaction tank 1A in the crystallizer 40 of the crystallization system 20A of the second embodiment of the present invention, the outlet 6a opens in the direction in which the rotation shaft 3 extends. In the example of FIG. 10, the outlet 6a is provided at the bottom of the reaction tank 1A. The bottom of the reaction tank 1A is not limited to a 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 in Fig. 10. As shown in Fig. 12(a), the inlet 5a1 is connected to the reaction tank 1A so that the reaction liquid L1 that flows from the inlet 5a1 into the reaction tank 1A forms a vortex. The inlet 5a1 may be connected in the tangential direction of the reaction tank 1A so that a vortex is easily formed.

[0088] As shown in Figure 10 Mixing The blade Ws is the same as that of the crystallizer 4d shown in FIG. Mixing In the impeller Wd, the pipe P2 opens from the outer edge of the disk portion 8 toward the radially outward direction, and a liquid supply portion (upper second liquid supply portion) 5b1 is provided on the outer circumferential surface 2o of the cylindrical portion 2, which penetrates the cylindrical portion 2 in the radial direction and supplies the second reaction liquid L2 toward the radially outward direction of the cylindrical portion 2 into the reaction tank 1A. Mixing In the impeller Wd, the rotating shaft 3 extends further downward from the disk portion 8, and a liquid supply section (lower second liquid supply section) 5b2 that supplies the second reaction liquid L2 radially outward from the lower end of the rotating shaft 3 into the reaction tank 1A radially outward from the cylindrical portion 2 opens at the tip of an extension section 9 that extends radially outward from the lower end of the rotating shaft 3. A further difference is that a plurality of through holes h1 are provided that penetrate the disk portion 8 in the direction in which the rotating shaft 3 extends. Here, the clearance between the inner circumferential surface 2i of the cylindrical portion 2 and the rotating shaft 3 is set to the inner circumferential surface 1i of the reaction tank 1A. Mixing The clearance is set to be larger than the clearance between the blades Ws. In addition, the tip of the extension 9 is provided radially inward of the inner circumferential surface 2i of the cylindrical portion 2.

[0089] below, MixingThe structure of the blade Ws will be described in more detail. (b) of FIG. 12 shows a BB cross-sectional view of FIG. 10. The duct P2 branches from the duct P1 provided inside the rotating shaft 3 toward the radially outer side of the rotating shaft 3. In the example of (b) of FIG. 12, four ducts P2 are provided and are provided at equal intervals in the circumferential direction. The number of ducts P2 is not necessarily limited to four, but may be less than four or more than four as long as they are provided at equal intervals in the circumferential direction around the rotating shaft 3. In the example of (b) of FIG. 12, the through holes h1 are slit-shaped extending in the circumferential direction of the cylindrical portion 2, and four of them are provided at equal intervals in the circumferential direction. The number of the through holes h1 is not limited to four as long as they are provided at equal intervals in the circumferential direction.

[0090] Fig. 12(c) shows a cross-sectional view taken along line CC in Fig. 10. The conduit P3 branches out from the conduit P1 provided inside the rotating shaft 3 toward the radially outer side of the rotating shaft 3. In the example of Fig. 12(c), four conduits P3 are provided at equal intervals in the circumferential direction. The number of conduits P3 is not necessarily limited to four, but may be less than four or more than four as long as they are provided at equal intervals in the circumferential direction around the rotating shaft 3. The number of conduits P2 and the number of conduits P3 (the number of extensions) may be equal or different.

[0091] 10, an expanded diameter portion 3a may be provided at the bottom of the rotating shaft 3, and the extension portions 9 may extend radially outward from the expanded diameter portion 3a. Alternatively, the expanded diameter portion 3a may be provided detachably on the rotating shaft 3, and a nut N may be used to fasten the expanded diameter portion 3a to the rotating shaft 3 from its lower end. With this structure, the expanded diameter portion 3a can be easily replaced with another expanded diameter portion 3a having a different number of extension portions 9.

[0092] Such a reactor 1A and Mixing In the crystallizer 40 equipped with the impeller Ws, the first reaction liquid L1 supplied from the inlet (first liquid supply part) 5a1 flows in the reaction tank 1A toward the outlet 6a. Mixing The first reaction liquid L1 rotates in accordance with the rotation of the blade Ws. MixingThe second reaction liquid L2 is supplied radially outward from the upper second liquid supply section 5b1 and the lower second liquid supply section 5b2 provided on the blade Ws, that is, from two different locations in the direction in which the rotating shaft 3 extends (up and down direction) into the reaction tank 1A. Therefore, the first reaction liquid L1 and the second reaction liquid L2 are mixed better than in the crystallizer 4d and the crystallizer 4. Furthermore, since a plurality of through holes h1 are provided penetrating the disk portion 8 in the direction in which the rotating shaft 3 extends, the flow of the mixed liquid from the inlet 5a1 toward the outlet 6a is smoother than in the crystallizer 4d and the crystallizer 4, and pressure loss can be reduced. In other words, the flow resistance of the reaction tank 1A to the flow of the mixed liquid from the inlet 5a1 toward the outlet 6a can be reduced, so that the pressure loss in the reaction tank 1A can be reduced. Therefore, the power consumption of the pump can be suppressed when increasing the circulation flow rate. In addition, the upper second liquid supply part 5b1 and the lower second liquid supply part 5b2 open radially outward, but the inner peripheral surface 1i of the reaction tank 1A is present radially outward of the upper second liquid supply part 5b1 and the lower second liquid supply part 5b2, and the discharge port 6a opens in the direction in which the rotation shaft 3 extends. Mixing The peripheral speed of the blade Ws increases, and the increased peripheral speed Mixing Around the wing Ws Mixing Even if the centrifugal force acting on the mixed liquid rotating together with the impeller Ws increases, the increase in the flow of the mixed liquid toward the outside in the radial direction due to the increase in centrifugal force is countered by the inner peripheral surface 1i of the reaction vessel 1A. Mixing Wing Wd or Mixing Unlike the case of the wing Wc, Mixing An increase in the peripheral speed of the blade Ws does not directly lead to an increase in the circulation flow rate of the mixed liquid from the inlet 5a1 to the outlet 6a. Mixing An increase in the peripheral speed of the impeller Ws increases only the shear force acting on the mixed liquid, and an increase in the circulation flow rate of the mixed liquid from the inlet 5a1 toward the outlet 6a can be made to 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 Mixing The increase or decrease in the shear force acting on the mixed liquid due to the increase or decrease in the peripheral speed of the blade Ws can be individually controlled with high precision, and therefore the properties of the generated particles can be controlled with high precision.

[0093] 13 is a schematic diagram of a crystallization system 20A according to a second embodiment of the present invention. The slurry D1 discharged from the outlet 6a of the crystallizer 40 flows into the retention tank 10 through the pipe 22. After being retained in the retention tank 10, the slurry D1 is discharged from an outlet 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 from a pipe (not shown) provided in the pipe 23 using a slurry discharge pump or the like. Here, the inside of the retention tank 10 is at atmospheric pressure. <Modification of the second embodiment>

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

[0095] The crystallizer 41 according to a modified example of the crystallization system 20A of the second embodiment shown in FIG. 11 is different from the crystallizer 40 in that 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 an outlet 6b is provided at the top of the reaction tank 1B. Mixing The blade Ws is used in the crystallizer 40. Mixing Even in this case, the outlet 6b opens in the direction in which the rotating shaft 3 extends in the reaction tank 1B, as in the crystallizer 40. Therefore, the same effects as those of the crystallizer 40 can be achieved. <First Modification of the Crystallization System of the Second Embodiment>

[0096] FIG. 14 is a schematic diagram of a crystallization system 20B according to a first modified example of the second embodiment of the present invention. The crystallization system 20B differs from the crystallization system 20A in that it is not provided with a retention tank 10. When a short reaction time or retention time is acceptable, the retention tank 10 may not be provided. By not providing the retention tank 10, the crystallization system 20B can be made smaller. Furthermore, by not providing the retention tank 10, the crystallization system 20B can have a completely sealed structure. Therefore, it becomes possible to operate the crystallization system 20B under pressure. In this case, Mixing With the rotation of the wing Ws Mixing Since the low pressure region generated around the blade Ws is prevented from falling below the saturated vapor pressure, the occurrence of cavitation can be suppressed, and the quality of the particles can be stabilized. <Second Modification of Crystallization System of Second Embodiment>

[0097] FIG. 15 is a schematic diagram of a crystallization system 20C according to a second modified example of the second embodiment of the present invention. The crystallization system 20C is different from the crystallization system 20A in the configuration of the crystallizer 42. That is, in the crystallization system 20C, the second reaction liquid L2 is Mixing The crystallization system 20A differs from the crystallization system 20A in that liquid is supplied into the reaction tank 1C from a fixed-side second liquid supply part 5b3 provided in the reaction tank 1C in addition to an upper-side second liquid supply part 5b1 and a lower-side second liquid supply part 5b2 provided in the impeller Ws. Furthermore, an inlet (first liquid supply part) 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 parts 5b3 are provided near the inner circumferential surface 1i of the reaction tank 1C, and supply 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 parts 5b3 are provided at equal intervals in the circumferential direction of the reaction tank 1C. The number of the fixed-side second liquid supply parts 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 crystallizer 42 of such a crystallization system 20C, an upper reaction region is formed in region A shown by a dashed line in FIG. 15, and a lower reaction region B is formed in region B shown by a dashed line. In the upper reaction region A, a reaction occurs when a second reaction liquid L2 is supplied from the fixed side second liquid supply section 5b3 to a first reaction liquid L1, which is supplied in the tangential direction of the reaction tank 1C and forms a vortex. Meanwhile, in the lower reaction region B, similar to the crystallizer 40, the first reaction liquid L1 supplied from the inlet (first liquid supply section) 5a1 and Mixing A reaction takes place between the second reaction liquid L2 supplied from the blade Ws.

[0100] Here, the shear force acting on the mixed liquid in the upper reaction area A is generated in the circumferential direction between the mixed liquid stationary on the inner circumferential surface 1i of the reaction tank 1C in the upper reaction area A and the mixed liquid that is located radially inside the inner circumferential surface 1i of the reaction tank 1C and rotates around the rotation axis 3 together with the first reaction liquid L1 supplied from the inlet 5a1. Since a shear force is generated in a fluid due to a speed difference, the shear force acting on the mixed liquid in the upper reaction area A depends on the circumferential speed of the mixed liquid in the upper reaction area A. In other words, 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 area B, a shear force is generated in the circumferential direction of the mixed liquid that exists between the outer circumferential surface 2o and inner circumferential surface 2i of the cylindrical part 2 of the rotating stirring impeller Ws and the inner circumferential surface 1i of the fixed reaction tank 1C. In other words, the shear force acting on the mixed liquid in the lower reaction area B is Mixing It depends on the peripheral speed of the impeller Ws. Therefore, it is possible to individually control the shear force acting on the mixed liquid in the upper reaction region A and the lower reaction region B. Therefore, in the crystallizer 42, it is possible to improve the adjustment function of not only the crystal particle size but also the crystal shape.

[0101] Furthermore, in the crystallizer 42, the number of points to which the second reaction liquid L2 is supplied is increased, improving the dispersibility of the mixed liquid, and therefore the production capacity of the fine particles can be improved. Also, the second reaction liquid L2 can be divided into a system that supplies the upper second liquid supply part 5b1 and the lower second liquid supply part 5b2, and a system that supplies the fixed side second liquid supply part 5b3. Therefore, the main raw material S is supplied to one system, and the second reaction liquid L2 is supplied to the other system. MBy supplying one system with a different additive X that contributes to improving the quality of the crystal product to the other system, it becomes possible to shorten the process of adding the additive and to manufacture a product that contains the additive as an ingredient.

[0102] The above describes in detail an embodiment of the present invention and its modified examples with reference to the drawings. However, the specific configurations are not limited to the embodiment and its modified examples, and also include designs and the like that do not deviate from the gist of the present invention and mutual combinations of the embodiment and modified examples. [Explanation of symbols]

[0103] 1, 1A, 1B, 1C Reactors 2 Cylindrical section 3 Rotation Axis 4, 4d, 40, 41, 42 crystallizer 5a Inlet (1st liquid supply part) 5b Liquid supply part (2nd liquid supply part) 6 Outlet 8 Disc Section h hole 10A, 10B, 10C, 10D, 20A, 20B, 20C Crystallization Systems 22, 23, 24 Piping 30 Circulation Pump 31 Second Circulation Pump Po circulation pipe Pp bent part Po1, Po2, Po3, Po4, Po5, Po6 straight pipe section C, C1, C2, C3, C4, C5 bent pipe section Wc, Wd, Ws Agitator blades

Claims

1. A stirring blade having a plurality of holes penetrating in a radial direction and rotatable around a central axis; a cylindrical reaction vessel having a bottom, capable of concentrically accommodating the stirring blade therein; A first liquid supply unit provided in the reaction tank and capable of supplying a first reaction liquid to the inside of the reaction tank; A second liquid supply part provided on the stirring blade and capable of supplying a second reaction liquid to the inside of the reaction tank; A control unit for controlling the peripheral speed of the stirring blade; An apparatus for producing fine particles of a metal compound, comprising:

2. The stirring blade is A cylindrical portion having the plurality of holes penetrating in the radial direction; a disk-shaped portion having an outer peripheral portion fixed to an inner peripheral surface of the cylindrical portion; a rotation axis extending upward from the center of the disk portion in a plan view along the central axis, The apparatus for producing metal compound microparticles as described in claim 1, characterized in that the second reaction liquid can flow through the interior of the disk portion and the rotating shaft, and the second liquid supply portion is provided on the outer edge of the disk portion.

3. 3. The apparatus for producing fine particles of a metal compound according to claim 2, wherein the second liquid supply section opens downward.

4. The apparatus for producing metal compound microparticles as described in claim 3, characterized in that in the cylindrical portion above the disk portion, the multiple holes penetrating in the radial direction are blocked, and a disk-shaped second disk portion whose outer edge is fixed to the inner surface of the cylindrical portion is provided at the upper end of the cylindrical portion.

5. 4. The apparatus for producing fine particles of a metal compound according to claim 3, wherein the disk portion is provided at an upper end of the cylindrical portion.

6. An apparatus for producing metal compound microparticles described in any one of claims 2 to 5, characterized in that 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.

7. 6. The apparatus for producing fine particles of a metal compound according to claim 1, wherein a plurality of the second liquid supply parts are provided.

8. The manufacturing apparatus according to any one of claims 1 to 5; a circulation pipe for flowing the slurry containing the fine particles discharged from an outlet of the manufacturing apparatus and circulating the slurry from the first liquid supply unit of the manufacturing apparatus into the manufacturing apparatus; a circulation pump that circulates the slurry between the manufacturing apparatus and the circulation line; 2. A system for producing fine particles of a metal compound, wherein the circulation pipeline has a meandering bent portion.

9. The stirring blade is A cylindrical portion having the plurality of holes penetrating in the radial direction; a disk-shaped portion having an outer peripheral portion fixed to an inner peripheral surface of the cylindrical portion; a rotation axis extending upward from the center of the disk portion in a plan view along the central axis, a through hole penetrating the disk portion in a direction in which the rotation shaft extends, the through hole being provided on a radially outer side of the disk portion; The second liquid supply portion is provided at two different positions in a direction in which the rotation shaft extends, the upper second liquid supply portion provided on the upper side is provided on the outer edge portion of the disk portion, The lower second liquid supply portion is provided on an extension portion extending radially outward from a lower portion of the rotating shaft, 2. The apparatus for producing fine particles of a metal compound according to claim 1, wherein the second reaction liquid is capable of flowing through the interior of the rotating shaft, the disk portion, and the extension portion.

10. 10. The apparatus for producing fine particles of a metal compound according to claim 9, wherein the outlet of the reaction vessel is open in the direction in which the rotation shaft extends in the reaction vessel.

11. The manufacturing apparatus according to claim 10; a circulation pipe for flowing the slurry containing the fine particles discharged from the discharge port of the manufacturing apparatus and circulating the slurry from the first liquid supply unit of the manufacturing apparatus into the manufacturing apparatus; a circulation pump that circulates the slurry between the manufacturing apparatus and the circulation line; A system for producing fine particles of a metal compound, wherein the circulation pipeline includes a retention tank.

12. The manufacturing apparatus according to claim 10; a circulation pipe for flowing the slurry containing the fine particles discharged from the discharge port of the manufacturing apparatus and circulating the slurry from the first liquid supply unit of the manufacturing apparatus into the manufacturing apparatus; a circulation pump that circulates the slurry between the manufacturing apparatus and the circulation line; 2. A system for producing fine particles of a metal compound, wherein the circulation pipeline does not include a retention tank.

13. A system for producing fine particles of a metal compound as described in claim 11 or 12, characterized in that a second liquid supply part capable of supplying the second reaction liquid into the inside of the reaction tank is further provided in the reaction tank above the stirring blade and the first liquid supply part.

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