Inorganic compound particle manufacturing device

Abstract

The present invention provides an inorganic compound particle manufacturing apparatus capable of producing inorganic compound particles with a particle size in the nanometer range. [Solution] The inorganic compound particle manufacturing apparatus comprises a first raw material supply unit that supplies a first solution and a second solution; a first mixing unit having a first mixer that mixes the first solution and the second solution supplied from the first raw material supply unit; a stirring tank located downstream of the first mixing unit that stores and stirs the mixed solution of the first solution and the second solution; and a second raw material supply unit that supplies the first solution and the second solution to the stirring tank.

Description

Technical Field

[0001] The present disclosure relates to an inorganic compound particle manufacturing apparatus using a microchannel.

Background Art

[0002] Conventionally, inorganic compound particles have been used for various applications, and in order to obtain inorganic compound particles having a desired particle size according to the application, they have been produced by various manufacturing methods. For example, a crystal manufacturing apparatus including a reaction vessel for crystallizing a crystalline compound, a sedimentation separator for classifying by sedimentation separation into crystals on the large particle size side and crystals on the small particle size side, and a filter for filtering and concentrating is known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above crystal manufacturing apparatus, it is difficult to classify particles having a particle size in the order of several μm, and it is substantially limited to particles having a particle size of 10 μm or more, and it is impossible to obtain inorganic compound particles having a smaller particle size in the order of nm.

[0005] Therefore, an object of the present disclosure is to provide an inorganic compound particle manufacturing apparatus capable of manufacturing inorganic compound particles having a particle size in the order of nm.

Means for Solving the Problems

[0006] The inorganic compound particle manufacturing apparatus according to this disclosure comprises: a first raw material supply unit that supplies a first solution and a second solution; a first mixing unit having a first mixer that mixes the first solution and the second solution supplied from the first raw material supply unit; a stirring tank located downstream of the first mixing unit that stores and stirs the mixed solution of the first solution and the second solution; and a second raw material supply unit that supplies the first solution and the second solution to the stirring tank. [Effects of the Invention]

[0007] The inorganic compound particle manufacturing apparatus described herein can produce inorganic compound particles with a particle size in the nanometer range. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a schematic diagram showing the configuration of the inorganic compound particle manufacturing apparatus according to Embodiment 1. [Figure 1B] This is a schematic diagram showing the particle size distribution and particle size control range of inorganic compound particles obtained by the inorganic compound particle manufacturing apparatus according to Embodiment 1. [Figure 2] Table 1 shows the manufacturing conditions for inorganic compound particles and the characteristics of the obtained inorganic compound particles for Examples 1 to 6 and Comparative Examples 1 to 3 using the inorganic compound particle manufacturing apparatus shown in Figure 1A. [Figure 3] This is a schematic diagram showing the configuration of the inorganic compound particle manufacturing apparatus according to Embodiment 2. [Figure 4] Table 2 shows the manufacturing conditions for inorganic compound particles and the characteristics of the obtained inorganic compound particles for Examples 7 to 10 and Comparative Examples 4 to 5, using the inorganic compound particle manufacturing apparatus shown in Figure 3. [Modes for carrying out the invention]

[0009] The inorganic compound particle manufacturing apparatus according to the first embodiment comprises: a first raw material supply unit that supplies a first solution and a second solution; a first mixing unit having a first mixer that mixes the first solution and the second solution supplied from the first raw material supply unit; a stirring tank located downstream of the first mixing unit that stores and stirs the mixed solution of the first solution and the second solution; and a second raw material supply unit that supplies the first solution and the second solution to the stirring tank.

[0010] In the second embodiment of the inorganic compound particle manufacturing apparatus, the second raw material supply unit may supply the first solution and the second solution separately to the stirring tank, as described in the first embodiment.

[0011] In the third embodiment of the inorganic compound particle manufacturing apparatus, the second raw material supply unit may supply a mixed solution, obtained by mixing the first solution and the second solution to a concentration below saturation, to the stirring tank.

[0012] The inorganic compound manufacturing apparatus according to the fourth embodiment may further include, in the first to third embodiments described above, a detection and evaluation unit that detects the average particle size of inorganic compound particles generated and precipitated by the reaction of the first solution and the second solution downstream of the stirring tank, and a control unit that changes the concentration or supply amount of the first solution and / or the second solution supplied from the first raw material supply unit and / or the second raw material supply unit based on the average particle size of the inorganic compound particles detected by the detection and evaluation unit.

[0013] The inorganic compound manufacturing apparatus according to the fifth embodiment is, in the first to third embodiments described above, a first solution is a first solution in which a first compound containing fluorine and an alkali metal element is dissolved, a second solution is a second solution in which a second compound containing at least one metal element selected from the group consisting of alkaline earth metal elements, aluminum, gallium, indium, zinc, and yttrium is dissolved, and the inorganic compound particles may be polyfluoride composite particles.

[0014] The inorganic compound particle manufacturing apparatus according to the embodiments of this disclosure will be described below with reference to the attached drawings. However, unless otherwise specified, the components, types, combinations, shapes, and relative positions described in this embodiment are not intended to limit the scope of this disclosure to these specific examples, but are merely illustrative examples.

[0015] (Embodiment 1) Figure 1A is a schematic diagram showing the configuration of the inorganic compound particle manufacturing apparatus 100 according to Embodiment 1. The inorganic compound particle manufacturing apparatus 100 according to Embodiment 1 includes a first raw material supply unit 10 that supplies a first solution and a second solution, a first mixing unit (first mixer) 20 that mixes the first solution and the second solution, a stirring tank 40 that stores and stirs the mixed solution of the first solution and the second solution on the downstream side of the first mixing unit 20, and a second raw material supply unit 30 that supplies the first solution and the second solution to the stirring tank. According to this inorganic compound particle manufacturing apparatus 100, on the downstream side of the first mixing unit 20, it includes a stirring tank 40 and a second raw material supply unit 30 that supplies the first solution and the second solution to the stirring tank. Thereby, the inorganic compound particles generated in the first mixing unit 20 can be grown in the stirring tank 40, and by supplying the first solution and the second solution to the stirring tank, the average particle size can be increased, and the particle size can be controlled from the nm size to the μm size.

[0016] Hereinafter, each member constituting this inorganic compound particle manufacturing apparatus 100 will be described.

[0017] <First raw material supply unit> The first raw material supply unit 10 supplies the first solution 12 and the second solution 13 to the first mixing unit 20. The first solution 12 and the second solution 13 are respectively supplied, for example, from the first liquid feeding unit 14 and the second liquid feeding unit 15 through the first flow path 1 and the second flow path 2. Note that the first solution 12 and the second solution 13 supplied by the first raw material supply unit 10 may be collectively referred to as the first raw material group 11. <Liquid feeding unit> The first liquid feeding unit 14 and the second liquid feeding unit 15 only need to be able to feed the first solution 12 and the second solution 13 respectively, and are, for example, composed of liquid feeding devices such as syringe pumps, plunger pumps, diaphragm pumps, tube pumps, mono pumps, and piezo pumps.

[0018] <Flow path> The materials of the first flow path 1 and the second flow path 2 are not particularly limited, and for example, inorganic materials such as glass, quartz, ceramics, silicon, etc., or resin materials such as thermoplastic resins and thermosetting resins can be used. The inner diameters of the first flow path 1 and the second flow path 2 are, for example, 0.1 mm or more and 1.59 mm or less, but are not limited thereto. In FIG. 1A, the first solution 12 and the second solution 13 are respectively fed into the first flow path 1 and the second flow path 2 that communicate from the first liquid feeding section 14 and the second liquid feeding section 15. For example, the first solution 12 of the first compound which is an alkali metal fluoride is fed into the first flow path 1, and the second solution 13 of the second compound having a metal element different from the alkali metal fluoride is fed into the second flow path 2.

[0019] <First solution> The first solution 12 is, for example, a solution of the first compound which is an alkali metal fluoride. Examples of the alkali metal element contained in the first compound include lithium, sodium, potassium, rubidium, and cesium. Specifically, the first compound may contain at least one alkali metal element selected from the group consisting of lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, and cesium fluoride. In the first flow path 1, the first solution 12 is fed at a concentration that does not reach the supersaturated state. Thereby, the first compound contained in the first solution 12 does not precipitate in the first flow path. Also, the concentration of the first solution is set to a concentration at which the mixed solution of the first solution and the second solution becomes supersaturated when mixed with the second solution 13 in the first mixing section 20. Specifically, for example, it is set so that the concentration of the first compound becomes 40 mM or more and 640 mM or less after mixing the first solution and the second solution. In the figure, the first solution 12 is stored in a tank, but this is an example and is not limited thereto.

[0020] <Second solution> The second solution 13 is a solution of a second compound having a different metal element than the alkali metal fluoride. The second compound is at least one selected from the group consisting of metal chlorides, metal nitrates, metal sulfates, and metal organic acid salts, and may include metal salts other than metal fluorides. The metal element contained in the second compound may be at least one selected from the group consisting of alkaline earth metal elements, aluminum, gallium, indium, zinc, and yttrium. The second compound may include, for example, aluminum chloride. In the second channel 2, the second solution 13 is delivered at a concentration that does not cause supersaturation. This prevents the second compound contained in the second solution 13 from precipitating within the second channel 2. Furthermore, the concentration of the second solution 13 is set so that when it is mixed with the first solution 12 in the first mixing unit 20, the mixed solution of the first solution 12 and the second solution 13 becomes supersaturated. Specifically, for example, the concentration of the second compound is set so that after mixing the first and second solutions, the concentration of the second compound is 1 / 20th or less of the concentration of the first compound. The concentrations of the first solution and the second solution mixed in the first mixing unit 20 may be set in stoichiometric ratios with respect to the inorganic compound particles produced, but are not limited to this. For example, the concentration of either the first solution or the second solution may be set to be either an excess or a deficiency of the stoichiometric ratio. Note that in the diagram, the second solution 13 is shown stored in the tank, but this is an example and not the only way to proceed.

[0021] <1st mixing section (1st mixer)> The first mixing unit 20 consists of a first mixer that mixes the first solution 12 and the second solution 13 of the first raw material group 11. The first solution 12, which is delivered through the first channel 1, and the second solution 13, which is delivered through the second channel 2, are mixed in the first mixer 20 to form a mixed solution, which is then delivered to the third channel 3. The mixed solution is in a supersaturated state, and inorganic compound particles are generated and precipitate in the mixed solution. The first mixing section (first mixer) 20 only needs to be capable of mixing multiple liquids, and is composed of flow path connecting members such as union tees or manifolds for pipe fittings, or flat plates with grooves or through holes, which are made by bonding or laminating multiple flat plates and fixing them together. Specifically, it may be constructed using, for example, a T-mixer or a three-way joint.

[0022] <Second raw material supply section> The second raw material supply unit 30 supplies the first solution 32 and the second solution 33 to the stirring tank 40 downstream of the first mixing unit 20. In Embodiment 1, as shown in Figure 1A, the first solution 32 and the second solution 33 are supplied separately to the stirring tank 40. The first solution 32 and the second solution 33 are supplied, for example, from the third liquid delivery unit 34 and the fourth liquid delivery unit 35 via the fourth flow path 4 and the fifth flow path 5, respectively. The first solution 32 and the second solution 33 supplied by the second raw material supply unit 30 are sometimes collectively referred to as the second raw material group 31. The second raw material supply unit 30, like the first raw material supply unit 10, can set the concentrations of the first solution 32 and the second solution 33, or supply pure water to lower the concentration.

[0023] The detection and evaluation unit 50 and control unit 60, described later, detect the average particle size of the obtained inorganic compound particles. If feedback control is performed based on the detected average particle size, the concentration or supply amount of the first solution 12 and second solution 13 of the first raw material group 11 and / or the first solution 32 and second solution 33 of the second raw material group 31 may be changed. For example, if inorganic compound particles with a particle size of a desired size or larger have already been generated, the concentration and / or flow rate of the first solution 12 and / or second solution 13 of the first raw material group 11 may be controlled. If the particle size of the generated inorganic compound particles has not reached the desired particle size, the third liquid delivery unit 34 and / or fourth liquid delivery unit 35 may be controlled to change the concentration and / or flow rate of the first solution 32 and / or second solution 33 of the second raw material group 31.

[0024] <Stirring tank> Figure 1B is a schematic diagram showing the particle size distribution and particle size control range of inorganic compound particles obtained by the inorganic compound particle manufacturing apparatus 100 according to Embodiment 1. The stirring tank 40 is located downstream of the first mixing unit 20 and stores a mixed solution of the first and second solutions of the first raw material group 11. Furthermore, the first solution 32 and second solution 33 of the second raw material group 31, supplied from the second raw material supply unit 30, are mixed into the mixed solution. In the stirring tank 40, inorganic compound particles that have been mixed and precipitated in the first mixer 20 are supplied, and further particle growth occurs with the first solution 32 and second solution 33 of the second raw material group 31, which are supplied separately from the second raw material supply unit 30. This allows for control of the average particle size over a wide range, from nanometers to micrometers. In addition, by using the stirring tank 40, the amount of inorganic compound particles that can be processed at one time can be increased compared to when the inorganic compound particle manufacturing apparatus is composed only of microchannels.

[0025] <Detection and Evaluation Department> The system may include a detection and evaluation unit 50 for detecting the average particle size of inorganic compound particles generated and precipitated by the reaction between the first solution and the second solution. The average particle size may be represented, for example, by the median diameter D50, which is the particle size with a cumulative frequency of 50% in the particle size distribution obtained from the particle size histogram. In this case, the detection and evaluation unit 50 may obtain a histogram of the particle sizes of the inorganic compound particles.

[0026] <Department Head> The system may also include a control unit 60 that changes the supply conditions of the concentration and / or supply amount of the first solution and / or second solution supplied from the first raw material supply unit 10 and / or the second raw material supply unit 30 based on the average particle size of inorganic compound particles detected by the detection and evaluation unit 50. For example, if inorganic compound particles of a size greater than or equal to the desired particle size have already been generated, the flow rates of the first solution 12 and the second solution 13 in the first raw material group 11 may be controlled, since particle growth is performed in two stages. Alternatively, if inorganic compound particles of a size greater than or equal to the desired particle size have not been generated, the flow rate of the second raw material group 31 may be controlled.

[0027] <Recovery and Separation Section> A recovery and separation unit (not shown) for recovering the obtained inorganic compound particles may be provided downstream of the stirring tank 40 and the detection and evaluation unit 50, which may be provided as needed. The inorganic compound particles generated by the recovery and separation unit are separated and recovered. The separation of the inorganic compound particles is performed, for example, by a solid-liquid separation method from the solution. The solid-liquid separation method is not particularly limited, and for example, filtration or centrifugation can be used.

[0028] When the second compound is a metal chloride, metal nitrate, metal sulfate, or metal organic acid salt, alkali metal chlorides, nitrates, sulfates, or metal organic acid salts are produced as by-products in addition to inorganic compound particles when the first and second compounds are mixed. Therefore, a washing operation may be performed to remove the by-products. Alkali metal compounds may be removed, for example, by washing with a solvent such as water during filtration or centrifugation.

[0029] According to the inorganic compound particle manufacturing apparatus of Embodiment 1, inorganic compound particles with particle sizes in the nanometer range can be manufactured, classification operations are unnecessary, and an inorganic compound particle manufacturing apparatus that is easy to operate and manage can be provided.

[0030] Next, we will provide an example of the resulting inorganic compound particles.

[0031] <Inorganic compound particles> The inorganic compound particles according to this embodiment 1 may be, for example, polyfluoride composite particles. The polyfluoride composite may contain alkali metal elements. The polyfluoride may contain, for example, at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium. The polyfluoride composite may contain fluorine, alkali metal elements, and additional metal elements other than alkali metal elements as its main components. The additional metal elements may include at least one metal selected from the group consisting of alkaline earth metals, aluminum, gallium, indium, zinc, and yttrium. Specifically, the additional metal elements may include at least one metal selected from the group consisting of magnesium, calcium, strontium, barium, aluminum, gallium, indium, zinc, and yttrium. Polyfluorides containing these metal elements can be easily manufactured into molded bodies, for example, by a pressurized heating method. The term "main components" here means that the total content of fluorine, alkali metal elements, and additional metal elements in the polyfluoride is 80% or more in molar ratio. The above total content may be 85% or more, 90% or more, 95% or more, or 100%.

[0032] The polyfluoride complex may specifically contain at least one of A3AlF6 and ABF3 (wherein the above compositional formula, A represents one or more alkali metal elements as described above, and B represents one or more alkaline earth metal elements as described above). A3AlF6 may contain, for example, at least one selected from the group consisting of Li3AlF6, Li2NaAlF6, Li2KAlF6, Na3AlF6, Na2LiAlF6, Na2KAlF6, K3AlF6, K2LiAlF6, and K2NaAlF6. ABF3 may contain, for example, at least one selected from the group consisting of LiMgF3, NaMgF3, KMgF3, LiCaF3, NaCaF3, and KCaF3. More specifically, the polyfluoride complex may contain at least one selected from the group consisting of Na3AlF6 and NaMgF3.

[0033] The polyfluoride composite may contain fluorine, alkali metal elements, and aluminum as its main components. Here, "main components" means that the total content of fluorine, alkali metal elements, and aluminum in the polyfluoride is 80% or more in molar ratio. This total content may be 85% or more, 90% or more, 95% or more, or 100%.

[0034] The polyfluoride complex may have some of its constituent anions substituted with hydroxide ions and oxide ions. For example, in the case of polyfluorides synthesized in the liquid phase, some of the polyfluoride ions may be substituted with at least one of hydroxide ions and oxide ions.

[0035] (Examples 1-6, Comparative Examples 1-3) The following describes examples and comparative examples of producing sodium hexafluoroaluminate (Na3AlF6), a polyfluoride, as inorganic compound particles using the inorganic compound particle production apparatus according to Embodiment 1.

[0036] (Example 1) In this embodiment 1, two plunger pumps were used as the liquid delivery units for the first and second solutions in the first raw material supply unit, respectively, to deliver two types of compound solutions. Here, as compound solutions for synthesizing Na3AlF6 as inorganic compound particles, a first solution was prepared by dissolving sodium fluoride, the first compound, in ultrapure water at 48 mM, and a second solution was prepared by dissolving aluminum chloride hexahydrate, the second compound, in ultrapure water at 40 mM. The flow rate ratio of the second solution to the first solution was set to 1 / 5, and the flow rates of each plunger pump were adjusted so that the flow rate of the mixed solution was 10 mL / min (flow rate of the first solution: flow rate of the second solution = 5:1). At the above flow rates, the concentration of the first compound after mixing the two solutions is 40 mM. A T-shaped mixer (made of SUS316 stainless steel, with an inner diameter of 0.5 mm) was used as the first mixer for the first and second solutions.

[0037] Two plunger pumps were also used in the liquid transfer section of the second raw material supply unit. The second raw material group consisted of a first solution, in which sodium fluoride (the first compound) was dissolved in ultrapure water at 48 mM, and a second solution, in which aluminum chloride hexahydrate (the second compound) was dissolved at 40 mM. In this case, the flow rate ratio of the second solution to the first solution was 1 / 5 (flow rate of the first solution:flow rate of the second solution = 5:1). If only the second raw material group were mixed, the flow rate would be 10 mL / min, and the concentration of the first compound in that solution would be 40 mM. The first group of raw materials, mixed in a T-type mixer, and the second group of raw materials, delivered by a plunger pump, were further mixed in a stirring tank. The solution mixed in the stirring tank passed through a particle detection unit (particle size evaluation unit) located downstream, and the particle size was evaluated. In Example 1, the target particle size was set to 10 μm, and the liquid flow rate was adjusted using feedback control in the control unit.

[0038] (Example 2) In Example 2, inorganic compound particles were prepared under the same manufacturing conditions as in Example 1, except that a first solution was prepared by dissolving the first compound from the first raw material group in ultrapure water at 768 mM, and a second solution was prepared by dissolving the second compound in ultrapure water at 640 mM. The concentration of the first compound in the solution mixed with the first raw material group was 640 mM. In Example 2, the target particle size was set to 250 nm.

[0039] (Example 3) In Example 3, inorganic compound particles were prepared under the same manufacturing conditions as in Example 1, except that feedback control was not performed.

[0040] (Example 4) In Example 4, inorganic compound particles were prepared under the same manufacturing conditions as in Example 2, except that feedback control was not performed.

[0041] (Example 5) In Example 5, inorganic compound particles were prepared under the same manufacturing conditions as in Example 1, except that a first solution was prepared by dissolving the first compound of the first raw material group in ultrapure water at 192 mM, and a second solution was prepared by dissolving the second compound in ultrapure water at 160 mM. The concentration of the first compound in the solution mixed with the first raw material group was 160 mM. In Example 5, the target particle size was set to 500 nm.

[0042] (Example 6) In Example 6, inorganic compound particles were prepared under the same manufacturing conditions as in Example 5, except that feedback control was not performed.

[0043] (Comparative Example 1) In Comparative Example 1, inorganic compound particles were produced under the same manufacturing conditions as in Example 1, except that feedback control was not performed and the second raw material group was not used.

[0044] (Comparative Example 2) In Comparative Example 2, inorganic compound particles were produced under the same manufacturing conditions as in Example 2, except that feedback control was not performed and the second raw material group was not used.

[0045] (Comparative Example 3) In Comparative Example 3, inorganic compound particles were produced under the same manufacturing conditions as in Example 5, except that feedback control was not performed and the second raw material group was not used.

[0046] (evaluation) If the particle size evaluation value (average particle size) was within 10% of the target particle size, it was marked with ◎; if it was between 10% and 20%, it was marked with ○; and otherwise, it was marked with ×.

[0047] Figure 2 is Table 1, which shows the manufacturing conditions for inorganic compound particles and the characteristics of the obtained inorganic compound particles for Examples 1 to 6 and Comparative Examples 1 to 3 using the inorganic compound particle manufacturing apparatus shown in Figure 1A.

[0048] As shown in Table 1 of Figure 2, in Examples 1 to 6, which used an inorganic compound particle manufacturing apparatus having a second raw material supply unit in addition to a first mixing unit and a stirring tank, it was possible to reach the target average particle size within the error range. In contrast, in Comparative Examples 1 to 3, which used an inorganic compound particle manufacturing apparatus without a second raw material supply unit, it was not possible to reach the target average particle size within the error range.

[0049] Furthermore, comparing Examples 1, 2, and 5 with Examples 3, 4, and 6, it can be seen that when feedback control is performed using the detection and evaluation unit and the control unit, the average particle size obtained is closer to the target average particle size, even considering the error.

[0050] (Embodiment 2) Figure 3 is a schematic diagram showing the configuration of the inorganic compound particle manufacturing apparatus 100a according to Embodiment 2. The inorganic compound particle manufacturing apparatus 100a according to Embodiment 2 differs from the inorganic compound particle manufacturing apparatus according to Embodiment 1 in that, as shown in Figure 3, the first solution and the second solution of the second raw material group 31 are mixed and supplied as a mixed solution 36 via the fifth liquid delivery unit 37 and the eighth flow path 8 in the second raw material supply unit 30. The other configurations are substantially the same as those of the inorganic compound particle manufacturing apparatus according to Embodiment 1. In this case, the concentrations of the first solution and the second solution are set so that the concentration of the mixed solution 36 is below the saturation concentration so that inorganic compound particles do not precipitate before being supplied to the stirring tank 40. This allows for the simplification of the second raw material supply unit 30, enabling miniaturization. Furthermore, it reduces manufacturing instability caused by pulsation in the liquid delivery unit.

[0051] (Examples 7-10 and Comparative Examples 4-5) Below, we describe examples and comparative examples in which sodium hexafluoroaluminate (Na3AlF6), a polyfluoride, was produced as inorganic compound particles using the inorganic compound particle manufacturing apparatus according to Embodiment 2.

[0052] (Example 7) In this embodiment 7, two plunger pumps were used as the liquid delivery section of the first raw material supply unit to deliver two types of compound solutions. Here, as compound solutions for synthesizing Na3AlF6 as inorganic compound particles, a first solution was prepared by dissolving sodium fluoride, the first compound, in ultrapure water at 48 mM, and a second solution was prepared by dissolving aluminum chloride hexahydrate, the second compound, in ultrapure water at 40 mM. The flow rate ratio of the second solution to the first solution was set to 1 / 5, and the flow rates of each plunger pump were adjusted so that the flow rate of the mixed solution was 10 mL / min (flow rate of the first solution: flow rate of the second solution = 5:1). At the above flow rates, the concentration of the first compound after mixing the two solutions is 40 mM. A T-shaped mixer (made of SUS316 stainless steel, with an inner diameter of 0.5 mm) was used as the first mixer for the first and second solutions.

[0053] A plunger pump was also used in the liquid delivery section of the second raw material supply unit. The second raw material group used a pre-mixed solution consisting of a first solution, which was obtained by dissolving sodium fluoride (the first compound) in ultrapure water at 24 mM, and a second solution, which was obtained by dissolving aluminum chloride hexahydrate (the second compound) at 20 mM. At this time, the volume ratio of the second solution to the first solution was 1 / 5 (volume of first solution:volume of second solution = 5:1), and the concentration of the first compound after mixing the two solutions was 20 mM. This solution was delivered at a rate of 10 mL / min. The first group of raw materials, mixed in a T-type mixer, and the second group of raw materials, delivered by a plunger pump, were further mixed in a stirring tank. The solution mixed in the stirring tank passed through a particle detection unit (particle size evaluation unit) located downstream, and the particle size was evaluated. In Example 1, the target particle size was set to 10 μm, and the liquid flow rate was adjusted by feedback control in the control unit.

[0054] (Example 8) In Example 8, inorganic compound particles were produced under the same manufacturing conditions as in Example 1, except that in the first raw material supply unit, a first solution was used, which consisted of the first compound dissolved in ultrapure water at 768 mM, and a second solution was used, which consisted of the second compound dissolved in ultrapure water at 640 mM. The concentration of the first compound in the mixed solution obtained by mixing the first raw material group was 640 mM. In Example 2, the target particle size was set to 250 nm.

[0055] (Example 9) In Example 9, inorganic compound particles were prepared under the same manufacturing conditions as in Example 7, except that feedback control was not performed.

[0056] (Example 10) In Example 10, inorganic compound particles were prepared under the same manufacturing conditions as in Example 8, except that feedback control was not performed.

[0057] (Comparative Example 4) In Comparative Example 4, inorganic compound particles were produced under the same manufacturing conditions as in Example 7, except that feedback control was not performed and the second raw material group was not used.

[0058] (Comparative Example 5) In Comparative Example 5, inorganic compound particles were produced under the same manufacturing conditions as in Example 8, except that feedback control was not performed and the second raw material group was not used.

[0059] (evaluation) If the particle size evaluation value (average particle size) was within 10% of the target particle size, it was marked with ◎; if it was between 10% and 20%, it was marked with ○; and otherwise, it was marked with ×.

[0060] Figure 4 is shown in Table 2, which illustrates the manufacturing conditions for inorganic compound particles in Examples 7 to 10 and Comparative Examples 4 to 5 using the inorganic compound particle manufacturing apparatus shown in Figure 3, as well as the characteristics of the obtained inorganic compound particles.

[0061] As shown in Table 2 of Figure 4, in Examples 7 to 10, which used an inorganic compound particle manufacturing apparatus having a second raw material supply unit that supplies a second raw material group in addition to a first raw material supply unit that supplies a first raw material group, it was possible to reach the target average particle size within the error range. In contrast, in Comparative Examples 4 and 5, which used an inorganic compound particle manufacturing apparatus without a second raw material supply unit, it was not possible to reach the target average particle size within the error range.

[0062] Furthermore, comparing Examples 7 and 8 with Examples 9 and 10, it can be seen that when feedback control is performed using the detection and evaluation unit and the control unit, the average particle size obtained is closer to the target average particle size, even considering the error. [Industrial applicability]

[0063] The inorganic compound particle manufacturing apparatus described herein can produce inorganic compound particles with a particle size in the nanometer range. [Explanation of Symbols]

[0064] 1. First channel 2. Second channel 3. Third channel 4. Fourth channel 5. Fifth channel 6. Sixth channel 7. The seventh channel 8. Channel 8 10 1st raw material supply section 11 First raw material group 12 First solution 13 Second solution 14. First liquid delivery section 15. Second liquid delivery section 20 1st mixing section (1st mixer) 30 2nd raw material supply section 31 Second raw material group 32 First solution 33 Second solution 34 Third liquid delivery section 35. Fourth liquid delivery section 36 Mixed solution 37. Fifth liquid delivery section 40 Stirring tank 50 Detection and Evaluation Unit 60 Control Unit 100, 100a inorganic compound particle manufacturing equipment

Claims

1. A first raw material supply unit that supplies the first solution and the second solution, A first mixing unit having a first mixer for mixing a first solution and a second solution supplied from the first raw material supply unit, Downstream of the first mixing section, there is a stirring tank for storing and stirring the mixed solution of the first solution and the second solution, A second raw material supply unit that supplies the first solution and the second solution to the stirring tank, An inorganic compound particle manufacturing apparatus equipped with the following features.

2. The inorganic compound particle manufacturing apparatus according to claim 1, wherein the second raw material supply unit supplies the first solution and the second solution separately to the stirring tank.

3. The inorganic compound particle manufacturing apparatus according to claim 1, wherein the second raw material supply unit supplies a mixed solution, obtained by mixing the first solution and the second solution to the stirring tank at a concentration below saturation.

4. A detection and evaluation unit located downstream of the stirring tank is provided to detect the average particle size of inorganic compound particles generated and precipitated by the reaction between the first solution and the second solution. A control unit that changes the concentration or supply amount of the first solution and / or the second solution supplied from the first raw material supply unit and / or the second solution supply unit based on the average particle size of the inorganic compound particles detected by the detection and evaluation unit, The inorganic compound particle manufacturing apparatus according to claims 1 to 3, further comprising:

5. The first solution is a first solution in which a first compound containing fluorine and an alkali metal element is dissolved, The second solution is a second solution in which a second compound containing at least one metal element selected from the group consisting of alkaline earth metal elements, aluminum, gallium, indium, zinc, and yttrium is dissolved. The inorganic compound particle manufacturing apparatus according to claims 1 to 3, wherein the inorganic compound particles are complex fluoride particles.

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