JP2019104657A - Production method of nickel-containing hydroxide - Google Patents

Abstract

To provide a production method of a nickel-containing hydroxide, by which particles having decreased roughness on outer surfaces thereof can be produced while suppressing increase in agitation power.SOLUTION: A production method of a nickel-containing hydroxide is provided, in which particles of a nickel-containing hydroxide are obtained by neutralization crystallization in a reaction aqueous solution prepared by mixing a metal salt containing at least nickel salt, a complexing agent to be coupled with a metal ion of the metal salt to form a complex, and a neutralizer that reacts with the metal salt and the complex to produce a metal hydroxide. The method includes a recovery step of, after the particles of the nickel-containing hydroxide are produced, adding a neutralizer to the reaction aqueous solution to increase the pH value of the reaction aqueous solution to crystallize the nickel-containing hydroxide and recovering metal ions remaining in the reaction aqueous solution as a solid-phase nickel-containing hydroxide. In the recovery step, the neutralizer is added through an addition port disposed in a region where a value of uK of the reaction aqueous solution is 30% or more with respect to a maximum value uKof the uK.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a nickel-containing hydroxide used as a precursor of a positive electrode active material of a lithium ion secondary battery.

  2. Description of the Related Art In recent years, with the spread of portable electronic devices such as mobile phones and notebook personal computers, development of small and lightweight secondary batteries having high energy density has been required. In addition, development of a high output secondary battery is also required as a battery for electric vehicles including hybrid vehicles. There is a lithium ion secondary battery as a non-aqueous electrolyte secondary battery satisfying such a demand. The lithium ion secondary battery is composed of a negative electrode, a positive electrode, an electrolytic solution and the like, and a material capable of desorbing and inserting lithium is used as the active material of the negative electrode and the positive electrode.

  A lithium ion secondary battery using a lithium composite oxide, particularly a lithium cobalt composite oxide which is relatively easy to synthesize, as a positive electrode material is expected as a battery having a high energy density since a high voltage of 4 V is obtained. Practical application is in progress. In a battery using lithium cobalt composite oxide, many developments for obtaining excellent initial capacity characteristics and cycle characteristics have been carried out so far, and various results have already been obtained.

  However, since lithium cobalt composite oxide uses an expensive cobalt compound as a raw material, the unit cost per capacity of a battery using this lithium cobalt composite oxide is much higher than that of a nickel hydrogen battery, and the applicable application is considerable. It is limited. Therefore, the cost of the positive electrode material can be reduced not only for small secondary batteries for portable devices but also for large secondary batteries for electric power storage, electric vehicles, etc., and cheaper lithium ion secondary batteries can be manufactured. Expectations are high for making it possible, and it can be said that its realization has great industrial significance.

  As a new material of the active material for lithium ion secondary batteries, lithium nickel complex oxide using nickel cheaper than cobalt can be mentioned. The lithium nickel composite oxide exhibits a lower electrochemical potential than the lithium cobalt composite oxide, so decomposition by the oxidation of the electrolytic solution is less likely to be a problem, higher capacity can be expected, and battery voltage as high as cobalt type. Development is actively conducted. However, when a lithium ion secondary battery is manufactured using a lithium-nickel composite oxide synthesized purely with only nickel as a positive electrode material, the relative cycle characteristics are inferior to cobalt-based batteries, and the battery is relatively used by using or storing under high temperature environment. It has the disadvantage of being easily impaired in performance. Therefore, lithium nickel composite oxides in which a part of nickel is replaced by cobalt or aluminum are generally known.

  The general production method of the positive electrode active material is as follows: (1) First, a nickel composite hydroxide which is a precursor of a lithium nickel composite oxide is produced by a neutralization crystallization method, and (2) the precursor is a lithium compound There is known a method of mixing with and baking. Among these, as a method of producing particles of nickel composite hydroxide by the neutralization crystallization method of (1), a typical embodiment is a process using a stirring tank.

  In Patent Document 1, a mixed aqueous solution containing nickel salt and cobalt salt, an aqueous solution containing an ammonium ion supplier, and an aqueous caustic aqueous solution are supplied and reacted in a stirring vessel to obtain particles of nickel-cobalt composite hydroxide. It is deposited. By setting the ratio of the amount of reaction to the amount of reaction aqueous solution per supply port of the mixed aqueous solution to 0.04 volume% / min or less, it is described that particles having a large particle size, high crystallinity and substantially spherical shape can be obtained. ing.

JP, 2011-201764, A

  Heretofore, various studies have been made to obtain nickel-containing hydroxide particles of desired properties.

  However, when the device structure such as the type and the blade diameter of the stirring blade and the volume of the stirring tank changes, it is necessary to set conditions each time.

  When producing particles of nickel composite hydroxide by the neutralization crystallization method, metal salts such as nickel salt and cobalt salt supplied in the stirring tank react with the alkaline aqueous solution to be neutralized to the nickel composite hydroxide By this, a nucleus is generated. In addition, a part of the metal salt such as nickel salt or cobalt salt reacts with an aqueous solution containing an ammonium ion supplier to form a metal complex, and then this complex and an aqueous alkali solution react with each other to form a nickel composite hydroxide. And the nucleus is generated. The generated nuclei are grown by the metal salt supplied into the stirring vessel to obtain particles of nickel composite hydroxide. At this time, if the diffusion of the caustic aqueous solution supplied into the stirring tank is insufficient, a region of extremely high pH is locally formed near the addition port of the caustic aqueous solution, and nickel complex hydroxide is formed. It is easy to form a region where the concentration of substances is high. In the region where the concentration of the nickel composite hydroxide is high, new nucleation is likely to occur. The newly formed nuclei may adhere to the particles of the nickel composite hydroxide or may not grow sufficiently and remain in the stirring vessel as fine particles.

  Therefore, there is a method of sufficiently diffusing the added caustic aqueous solution in order to reduce the volume of the region where the concentration of the nickel composite hydroxide formed in the vicinity of the addition port of the caustic aqueous solution is high. As a method of diffusing a caustic aqueous solution, there is, for example, a method of increasing the number of rotations of a stirring blade.

  However, when the rotational speed of the stirring blade is increased, the power for rotating the stirring blade (hereinafter, referred to as “stirring power”) is increased accordingly.

  This invention is made in view of the said subject, Comprising: The main purpose of provision of the manufacturing method of the nickel containing hydroxide which can manufacture the particle | grains which reduced the unevenness of the outer surface, suppressing increase of stirring power. I assume.

According to one aspect of the present invention, in order to solve the above problems,
A metal salt containing at least a nickel salt, a complexing agent which forms a complex by binding to the metal ion of the metal salt, and a neutralizing agent which reacts with the metal salt and the complex to form a metal hydroxide A method for producing a nickel-containing hydroxide, wherein particles of a nickel-containing hydroxide are obtained by neutralization crystallization in a mixed reaction aqueous solution,
After the particles of the nickel-containing hydroxide are formed, the neutralizing agent is added to the reaction aqueous solution to raise the pH value of the reaction aqueous solution to precipitate the nickel-containing hydroxide, which is contained in the reaction aqueous solution. A recovery step of recovering the metal ion remaining in the solid phase as the nickel-containing hydroxide,
In the recovery step, the neutralizing agent is provided from an addition port provided in a region where the value of the product uK of the flow velocity u of the reaction aqueous solution and the turbulent diffusion coefficient K is 30% or more with respect to the maximum value uK _max of the uK. There is provided a method of producing a nickel-containing hydroxide, wherein

  According to one aspect of the present invention, there is provided a method for producing a nickel-containing hydroxide that can produce particles with reduced unevenness on the outer surface while suppressing increase in stirring power.

5 is a flow chart of a method of manufacturing a nickel-containing hydroxide according to one embodiment. It is a top view which shows the chemical reactor used for the manufacturing method of the nickel containing hydroxide by one Embodiment. FIG. 3 is a cross-sectional view of the chemical reaction device taken along line II of FIG. 2; FIG. 5 is a diagram showing a highly supersaturated region in a reaction aqueous solution in a recovery process according to one embodiment. It is a figure which shows an example of the flow of reaction aqueous solution. It is a figure which shows an example of distribution of uK of the reaction aqueous solution in a stirring tank. 5 is a SEM photograph of particles of the nickel composite hydroxide obtained in Example 1. FIG. 6 is a graph showing measurement results of particle size distribution of particles of the nickel composite hydroxide obtained in Example 1. 6 is a SEM photograph of particles of the nickel composite hydroxide obtained in Comparative Example 1. It is a figure which shows the measurement result of the particle size distribution of the particle | grains of the nickel compound hydroxide obtained by the comparative example 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and the description thereof will be omitted.

  FIG. 1 is a flow chart of a method of producing a nickel-containing hydroxide according to one embodiment. As shown in FIG. 1, the method for producing a nickel-containing hydroxide is to obtain particles of the nickel-containing hydroxide by neutralization crystallization, and a nucleation step for producing a nucleus composed of the nickel-containing hydroxide S11, a particle growth step S12 for growing a nucleus, and a recovery step S13 for recovering metal ions remaining in the reaction aqueous solution as a nickel-containing hydroxide. Hereinafter, although each process is demonstrated, before that, the nickel containing hydroxide obtained is demonstrated.

<Nickel-containing hydroxide>
A nickel containing hydroxide is used as a precursor of the positive electrode active material of a lithium ion secondary battery. The nickel-containing hydroxide includes, for example, (1) nickel (Ni), cobalt (Co) and aluminum (Al), and the substance mass ratio (molar ratio) is Ni: Co: Al = 1-x-y: x Or a nickel composite hydroxide containing y so as to satisfy 0 ≦ x ≦ 0.3 and 0.005 ≦ y ≦ 0.15, or (2) nickel (Ni) and cobalt (Co) Substance ratio (molar ratio) of manganese, manganese (Mn) and M (M is at least one additive element selected from Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, and W) Is Ni: Co: Mn: M = x: y: z: t (where, x + y + z + t = 1, 0.1 ≦ x ≦ 0.7, 0.1 ≦ y ≦ 0.5, 0.1 ≦ z ≦ 0 .8, 0 ≦ t ≦ 0.02).

  The amount of hydroxide ions contained in the nickel-containing hydroxide according to one embodiment generally has a stoichiometric ratio, but may be excessive to the extent that it does not affect the present embodiment or may be deficient. . In addition, a part of the hydroxide ions may be replaced with an anion (for example, a carbonate ion, a sulfate ion, or the like) to an extent not affecting the present embodiment.

  In addition, the nickel containing hydroxide by one Embodiment should just be a single phase (or main component is nickel containing hydroxide) of a nickel containing hydroxide by X-ray diffraction (XRD) measurement.

  The nickel-containing hydroxide contains nickel and preferably further contains a metal other than nickel. Hydroxides further containing metals other than nickel are referred to as nickel composite hydroxides. Since the metal composition ratio of nickel composite hydroxide (for example, Ni: Co: Mn: M) is also maintained in the obtained positive electrode active material, it should be consistent with the metal composition ratio required for the positive electrode active material Adjusted to

<Method of producing nickel-containing hydroxide>
The method for producing the nickel-containing hydroxide, as described above, includes the nucleation step S11, the particle growth step S12, and the recovery step S13. In the present embodiment, each step may use either a batch-type stirring tank or a continuous stirring tank. Each process may be performed in the same stirring tank, and may be performed in a different stirring tank. The nucleation step S11 and the particle growth step S12 may be performed simultaneously. In this case, the recovery step S13 is performed after the nucleation step S11 and the particle growth step S12 are simultaneously performed.

  Hereinafter, the nucleation step S11, the particle growth step S12, and the recovery step S13 will be described.

(Nucleation process, particle growth process)
In the nucleation step S11, in the stirring vessel, the raw material liquid containing a nickel salt, the complexing agent, the neutralizing agent, and water (reaction aqueous solution) are mixed while being stirred and reacted. From the nucleation step S11 to the particle growth step S12, the raw material liquid, the complexing agent and the neutralizing agent are reacted while being continuously supplied into the stirring tank.

  The raw material liquid contains at least a nickel salt, and preferably further contains a metal salt other than the nickel salt. As metal salts, sulfates, nitrates, hydrochlorides and the like are used. More specifically, for example, nickel sulfate, nickel nitrate, nickel chloride, manganese sulfate, cobalt sulfate, aluminum sulfate, titanium sulfate, ammonium peroxotitanate, potassium titanium oxalate, vanadium sulfate, ammonium vanadate, chromium sulfate, chromium Potassium acid, zirconium sulfate, zirconium nitrate, niobium oxalate, ammonium molybdate, hafnium sulfate, sodium tantalate, sodium tungstate, or ammonium tungstate are used. In addition, since the metal composition ratio (for example, Ni: Co: Mn: M) of the raw material liquid is also maintained in the obtained nickel composite hydroxide, it corresponds to the composition ratio required for the nickel composite hydroxide To be adjusted.

The complexing agent may be any one that can form a complex by binding to a metal ion such as nickel ion in an aqueous solution in a stirring tank. As the complexing agent, an aqueous solution containing an ammonium ion donor is used. As the ammonium ion supplier, one that forms a nickel ammine complex ([Ni (NH ₃ ) ₆ ] ²⁺ ) in an aqueous solution in a stirring tank is used. As the ammonium ion supplier, for example, ammonia, ammonium sulfate, ammonium chloride, ammonium carbonate or ammonium fluoride can be used. In the present embodiment, an aqueous solution containing an ammonium ion donor is used as the complexing agent, but ethylenediaminetetraacetic acid, nitrite triacetic acid, uracildiacetic acid, glycine or the like may be used. Among them, it is preferable to use an aqueous solution containing ammonia (ammonia water) as the complexing agent from the viewpoint of ease of handling and the like.

  The neutralizing agent may be any one that reacts with the metal salt and the complex formed from the metal salt to form a metal hydroxide. The neutralizing agent is also used as a pH adjuster to adjust the pH of the aqueous solution. As the neutralizing agent, one containing an alkaline aqueous solution is used. As the aqueous alkali solution, for example, one containing an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is used. The alkali metal hydroxide may be supplied as a solid, but is preferably supplied as an aqueous solution.

In the nucleation step S11 and the particle growth step S12, a nickel-containing hydroxide is produced through the following two routes. In the first route, a metal salt containing a nickel salt contained in the raw material solution is reacted with an aqueous alkali solution as a neutralizer to form a nickel-containing hydroxide. For example, nickel ions contained in the raw material solution react with hydroxyl groups of sodium hydroxide as shown in the following formula (1) to form nickel hydroxide. In the second route, first, an ion such as nickel of a nickel salt contained in the raw material solution or a metal ion of a metal salt is combined with ammonia or the like of a complexing agent to form a complex. Thereafter, the complex reacts with an aqueous alkaline solution, which is a neutralizing agent, to form a nickel-containing hydroxide. For example, nickel ions contained in the raw material solution react with ammonia in the reaction aqueous solution as shown in the following formula (2-1) to form a nickel ammine complex ([Ni (NH ₃ ) ₆ ] ²⁺ ). Thereafter, the nickel ammine complex reacts with the hydroxyl group of sodium hydroxide as in the following formula (2-2) to form nickel hydroxide.
Ni ²⁺ + 2OH ⁻ → Ni (OH) ₂ (1)
Ni ²⁺ +6 NH ₃ → [Ni (NH ₃ ) ₆ ] ²⁺ (2-1)
_{[Ni (NH 3) 6]} 2+ + 2OH - → Ni (OH) 2 + 6NH 3 ··· (2-2)

  In the nucleation step S11 and the particle growth step S12, fine nuclei consisting of a nickel-containing hydroxide are precipitated by neutralization crystallization, and the nuclei grow (particle growth), thereby particles of the nickel-containing hydroxide Is obtained. The particle size of the particles of the nickel-containing hydroxide can be estimated from the amount of metal salt supplied in each of the nucleation step S11 and the particle growth step S12.

(Recovery process)
After completion of the particle growth step S12, in the recovery step S13, while continuing the stirring of the reaction aqueous solution, the supply of the raw material liquid and the complexing agent into the stirring tank is stopped, and the supply of the neutralizing agent is continued. In the recovery step S13, the pH value of the reaction aqueous solution in the stirring tank is increased as compared to the particle growth step S12. As a result, the solubility of the nickel-containing hydroxide is reduced, and particles of the nickel-containing hydroxide are easily precipitated. Therefore, metal ions such as nickel ions dissolved in the reaction aqueous solution can be recovered. Specifically, the pH value of the reaction aqueous solution is adjusted to be within the range of 12.0-14.0, preferably 12.3-13.5, on the basis of a liquid temperature of 25 ° C. The pH value of the reaction aqueous solution can be measured using a known pH meter or the like.

  In the recovery step S13, the neutralizing agent is first added to the reaction aqueous solution to increase the pH value of the reaction aqueous solution, thereby facilitating precipitation of the nickel-containing hydroxide particles. In particular, the pH value in the reaction aqueous solution is the highest in the vicinity of the addition port 63 (see FIGS. 2 and 3) of the neutralizing agent supply pipe 62 (see FIGS. 2 and 3) to which the neutralizing agent is supplied. The solubility of the contained hydroxide is further lowered, and particles of the nickel-containing hydroxide are easily precipitated.

  The temperature of the reaction aqueous solution is preferably adjusted within the range of 20 to 60 ° C, more preferably 35 to 60 ° C. The temperature of the reaction aqueous solution can be measured using a known thermometer or the like.

  After adjusting the pH value of the reaction aqueous solution, the supply of the neutralizing agent into the stirring tank is stopped. Then, while maintaining the temperature of the reaction aqueous solution, the reaction aqueous solution is continuously stirred for 60 minutes, preferably 15 minutes to 30 minutes. Thereby, by the particle growth step S12, the metal ion of the complex formed by the reaction with the complexing agent reacts with the neutralizing agent to precipitate the nickel-containing hydroxide in the reaction aqueous solution. Thereby, the metal ion of the complex is recovered as the solid phase nickel-containing hydroxide.

  Here, an example of the chemical reaction apparatus used for the manufacturing method of the nickel containing hydroxide by one Embodiment is demonstrated. FIG. 2 is a top view showing a chemical reaction apparatus used in the method for producing a nickel-containing hydroxide according to one embodiment. FIG. 3 is a cross-sectional view of the chemical reaction device taken along line II of FIG. As shown in FIGS. 2 and 3, the chemical reaction device 10 has a stirring tank 20, a stirring blade 30, a stirring shaft 40 and a baffle 50. The stirring tank 20 accommodates the reaction aqueous solution in a cylindrical internal space. The stirring blade 30 stirs the reaction aqueous solution in the stirring tank 20. The stirring blade 30 is attached to the lower end of the stirring shaft 40. The stirring blade 30 is rotated by rotating the stirring shaft 40 by a motor or the like. The center line of the stirring tank 20, the center line of the stirring blade 30, and the center line of the stirring shaft 40 may coincide with each other and be vertical. The baffles 50 are also called baffles. The baffles 50 protrude from the inner circumferential surface of the stirring tank 20, and generate an upward flow or a downward flow by interrupting the rotational flow to improve the stirring efficiency of the reaction aqueous solution.

  The chemical reaction device 10 further includes a raw material liquid supply pipe 60, a neutralizing agent supply pipe 62, and a complexing agent supply pipe 64. The raw material liquid supply pipe 60 supplies the raw material liquid into the stirring tank 20 from the addition port 61. The neutralizing agent supply pipe 62 supplies the neutralizing agent into the stirring tank 20 from the addition port 63. The complexing agent supply pipe 64 supplies the complexing agent into the stirring tank 20.

  The inventor of the present invention focused on the following two points as a result of studying conditions that can reduce unevenness of the outer surface of the particles obtained at the completion of neutralization crystallization, universally, with chemical reactors of various structures. The first point is that, in the recovery step S13, the complex formed in the particle growth step S12 is dissolved and remains in the reaction aqueous solution. The second point is that a neutralizing agent is added to the reaction aqueous solution in the stirring tank 20 through the addition port 63 of the neutralizing agent supply pipe 62, whereby a high pH region is formed in the reaction aqueous solution through the addition port 63. Is Rukoto. When the complex reacts with the neutralizing agent through the high pH region of the reaction aqueous solution where the complex is formed in the vicinity of the addition port 63, a nickel-containing hydroxide is formed to form a highly supersaturated region 12 (see FIG. 4). , A new nucleus is generated. When the generated nuclei adhere to the surface of the nickel-containing hydroxide particles, the unevenness of the outer surface of the nickel-containing hydroxide particles becomes large. Also, newly generated nuclei do not grow sufficiently and become fine particles.

  Therefore, in the recovery step S13, the volume ratio of the high supersaturation region 12 (see FIG. 4) formed in the reaction aqueous solution from the addition port 63 of the neutralizing agent supply pipe 62 in the reaction aqueous solution is newly adjusted. It has been found that the generation of nuclei can be suppressed.

  FIG. 4 is a view showing a high supersaturation region in the reaction aqueous solution in the recovery step S13 according to one embodiment. In FIG. 4, the arrow direction represents the flow direction in the vicinity of the addition port 63 of the neutralizing agent supply pipe 62. When the neutralizing agent is added to the reaction aqueous solution in the stirring tank 20 from the addition port 63 of the neutralizing agent supply pipe 62, the pH value of the reaction aqueous solution in the vicinity of the addition port 63 locally increases. In particular, the pH value is increased. Therefore, in the vicinity of the addition port 63, the complex reacts with the neutralizing agent to form a nickel-containing hydroxide, and when the highly supersaturated region 12 is formed, nuclei are easily generated in the reaction aqueous solution. Therefore, if the high supersaturation region 12 occupied in the reaction aqueous solution is wide in the recovery step S13, the possibility that more nuclei will be generated in the reaction aqueous solution will be high. In addition, the probability of generation of fine particles for which the particle growth of the nucleus is not sufficient increases.

The high supersaturated region 12 means a region in which the molar concentration of the nickel-containing hydroxide dissolved in the reaction aqueous solution is 5.0 mol / m ³ or more. In the high supersaturation region 12, nucleation occurs at a significant rate, as the molar concentration of the nickel-containing hydroxide is sufficiently higher than the solubility.

Here, the solubility means limit amount of nickel hydroxide containing soluble in water 100g of _{(g / 100g-H 2 O} ). The solubility of nickel hydroxide (Ni (OH) ₂ ) is, for example, 10 ⁻⁷ (g / 100 g—H ₂ O). Thus, since the solubility of the nickel-containing hydroxide is close to zero, it is negligible compared to the lower limit value 5.0 mol / m ³ of the molar concentration of the high supersaturated region 12.

  The highly supersaturated region 12 is formed in the aqueous reaction solution from the addition port 63 of the neutralizing agent supply pipe 62, as shown in FIG. Since the addition port 63 is disposed in the flow field of the reaction aqueous solution, the volume and the like of the high supersaturation region 12 are affected by the flow field. The flow field changes according to the type and diameter of the stirring blade 30, the volume of the stirring tank 20, and the like, in addition to the rotation speed of the stirring blade 30. The conditions that affect the flow field in the stirring tank 20 are referred to as stirring conditions.

  In FIGS. 2 to 4, the number of the addition ports 63 is one, but may be more than one, and the number of the high supersaturation regions 12 may be more than one. When the number of high supersaturation regions 12 is more than one, the volume of the high supersaturation region 12 means the total volume.

  In the recovery step S13, the alkaline aqueous solution is supplied to the reaction aqueous solution from the addition port 63 of the neutralizing agent supply pipe 62, whereby a region of high pH is formed in the reaction aqueous solution present near the addition port 63. When the complex passes through the high pH region of the reaction aqueous solution present near the addition port 63, the complex reacts with a neutralizing agent such as an aqueous alkali solution to form a nickel-containing hydroxide. Thus, a highly supersaturated region 12 (see FIG. 4) in which the molar concentration of the nickel-containing hydroxide is high is formed in the reaction aqueous solution from the addition port 63. By setting the volume ratio of the highly supersaturated region 12 (see FIG. 4) to less than 0.100% with respect to the whole of the reaction aqueous solution, it is produced by the particle growth step without newly generating nuclei in the reaction aqueous solution Can be deposited on the surface of the nickel-containing hydroxide particles. As a result, it is possible to suppress adhesion of the generated nuclei to the surface of the particles of the nickel-containing hydroxide, thereby reducing the unevenness of the outer surface of the particles of the nickel-containing hydroxide which is finally obtained. be able to. In addition, generation of fine particles can be suppressed by suppressing the generation of new nuclei.

  From the viewpoint of reducing unevenness of the outer surface of the particles obtained upon completion of the neutralization crystallization, the smaller the volume ratio of the high supersaturation region 12 in the reaction aqueous solution in the recovery step S13, the better. The volume ratio is preferably 0.070% or less, more preferably 0.050% or less, and still more preferably 0.030% or less. However, the volume ratio is preferably 0.004% or more. This depends on the flow velocity u of the reaction aqueous solution near the addition port 63 and the turbulent diffusion coefficient K as described later, and the flow velocity u of the reaction aqueous solution and the turbulent diffusion coefficient K rotate the stirring shaft 40 as described later. This is because the motor capacity is limited.

By the way, the reaction aqueous solution is stirred by the stirring blade 30 in the stirring tank 20, but even if the stirring conditions are the same, the flow field of the reaction aqueous solution differs depending on the location of the reaction aqueous solution. The volume ratio of the highly supersaturated region 12 (see FIG. 4) in the reaction aqueous solution is affected by the flow field of the reaction aqueous solution, so the above volume ratio fluctuates depending on the flow field of the reaction aqueous solution near the addition port 63 of the neutralizing agent. Do. The inventor focused on the flow velocity (flow rate) u (unit: m / s) of the reaction aqueous solution and the turbulent diffusion coefficient K (unit: m ² / s) as parameters of the flow field of the reaction aqueous solution. Then, it was noted that the product uK of the flow velocity u of the reaction aqueous solution and the turbulent diffusion coefficient K in the region to which the neutralizing agent is added affects the above-mentioned volume ratio. When the neutralizing agent is added to a region where the value of uK is small, the volume ratio becomes large, and therefore, a nucleus of a nickel-containing hydroxide is likely to be newly generated in the reaction aqueous solution. When the generated nuclei adhere to the surface of the nickel-containing hydroxide particles, the unevenness of the outer surface of the nickel-containing hydroxide particles becomes large. Also, newly generated nuclei do not grow sufficiently and become fine particles.

  Therefore, in the recovery step S13, the addition port 63 is disposed in a region where the value of uK is large, and the neutralizing agent is added to the reaction aqueous solution from the addition port 63 to form a highly supersaturated region 12 formed near the addition port 63. It has been found that the volume ratio of (see FIG. 6) can be reduced.

  The relationship between the magnitude of the uK value of the reaction aqueous solution and the size of the high supersaturation region 12 will be described. The uK value of the reaction aqueous solution and the volume of the high supersaturation region 12 (see FIG. 4) can be determined by carrying out a simulation as described later.

Tables 1 to 3 show the relationship between the value of uK near the addition port 63 and the volume of the high supersaturation region 12 when the addition port 63 is provided at a predetermined position of the reaction aqueous solution. Table 1 shows the values of uK near the addition port 63 and the volume V of the high supersaturation region 12 (see FIG. 4) when the turbulent diffusion coefficient K of the reaction aqueous solution is the same and the flow velocity u is different. Show the relationship between Table 2 shows the value of uK near the addition port 63 and the volume V of the high supersaturation region 12 (see FIG. 4) when the flow velocity u of the reaction aqueous solution is the same and the turbulent diffusion coefficient K is different. Show the relationship between Table 3 shows uK near the addition port 63 and the high supersaturation region 12 (see FIG. 4) when the flow velocity u of the reaction solution and the turbulent diffusion coefficient K are different but the value of uK becomes the same value. The relationship between the volume V and the In Tables 1 to 3, Examples 1 to 10 are the positions of predetermined flow fields of the reaction aqueous solution in the stirring tank 20. The flow velocity u of the reaction aqueous solution of Example 1, the turbulent diffusion coefficient K, uK, and the volume V of the high supersaturated region 12 (see FIG. 6) are respectively the flow velocity u ₀ , the turbulent diffusion coefficient K ₀ , u ₀ K ₀ , and a volume _{V 0,} as the reference value (1.0). The flow velocity u of the reaction aqueous solution of Examples 2 to 10, the turbulent diffusion coefficient K, uK, and the volume V of the high supersaturated region 12 (see FIG. 6) are respectively the flow velocity u ₀ , the turbulent diffusion coefficient K ₀ , u ₀ K _0, and represents standardized by volume _{V 0.}

  As apparent from Tables 1 to 3, the larger the value of uK in the region near the additive addition port 63 of the neutralizing agent, the smaller the volume V of the high supersaturation region 12 (see FIG. 6) near the addition port 63 tends to be smaller. Can be seen. When the value of uK in the region near the addition port 63 of the neutralizing agent is the same, the volume V of the highly supersaturated region 12 (see FIG. 6) in the vicinity of the addition port 63 tends to be almost the same value. More specifically, the volume V of the high supersaturation region 12 (see FIG. 6) is inversely proportional to uK of the region near the addition port 63 within an error of ± 5%. In addition, this tendency is also seen even if the flow velocity u of the reaction aqueous solution or the turbulent diffusion coefficient K is changed.

In the present embodiment, the addition port 63 is provided in a region where the value of uK of the reaction aqueous solution is 30% or more with respect to the maximum value uK _max of uK of the reaction aqueous solution. value of uK is added to 30% or more regions with respect to the maximum value uK _max of uK reaction solution. Thus, the volume ratio of the high supersaturation region 12 (see FIG. 4) formed near the addition port 63 can be reduced without increasing the stirring power.

Addition port 63, preferably a value of uK a region comprising 35% or more relative to the maximum value uK _max of uK, more preferably 40% or more values of uK is the maximum value uK _max of uK region, more preferably provided in a region which the value of uK is 50% or more of the maximum value uK _max of uK, adding a neutralizing agent. Thereby, the volume ratio of the highly supersaturated region 12 occupied in the reaction aqueous solution can be further reduced.

area value of uK is 30% or more of the maximum value uK _max of uK differs depending on the direction of water flow of the reaction solution circulating in the stirred tank 20. By the reaction aqueous solution in the stirring tank 20 being stirred by the rotation of the stirring blade 30, a downflow is generated along the stirring shaft 40 from the upper surface of the reaction aqueous solution toward the stirring blade 30 as shown in FIG. It is assumed that a rising flow occurs from the bottom of the stirring tank 20 along the baffle 50 to the top side of the reaction aqueous solution.

An example of the distribution of uK of the reaction aqueous solution in this case is shown in FIG. In FIG. 6, the uK ratio refers to a value of uK to maximum uK _max of uK. The distribution of uK of the reaction aqueous solution in the stirring tank 20 is determined by simulation. In this simulation, the volume of the stirring tank 20 is 2 L, the type of the stirring blade 30 is a disk turbine blade, the number of the blades of the stirring blade 30 is six, the blade diameter of the stirring blade 30 is 80 mm, the stirring blade 30 and the stirring tank 20 The vertical distance to the bottom is 5 mm, and the rotational speed of the stirring blade 30 is 850 rpm.

In this case, a region where the value of uK is 30% or more of the maximum value uK _max of uK, for example, as shown in FIG. 6, the vicinity of the upper and lower stirring blades 30 or the stirring blade 30, It is formed on the radially outer side or the like. Therefore, it is preferable that the addition port 63 be disposed in the downward flow and in the vicinity above the stirring blade 30. Thereby, the neutralizing agent added from the addition port 63 can be efficiently stirred in the reaction aqueous solution, so the volume ratio of the high supersaturation region (see FIG. 4) formed in the vicinity of the addition port 63 can be reduced. Can.

  The value of uK in the stirring tank 20 varies depending on the location, and tends to be particularly large in the vicinity of the upper side or the lower side of the stirring blade 30, or radially outside of the stirring blade 30, or the like. Further, even if the stirring conditions such as the type and the blade diameter of the stirring blade 30 and the volume of the stirring tank 20 are changed, the same tendency is seen in the distribution of uK of the reaction aqueous solution in the stirring tank 20.

Thus, in the recovery step S13, the neutralizing agent is added to the reaction aqueous solution from the addition port 63 provided in the region where the value of uK of the reaction aqueous solution is 30% or more with respect to the maximum value uK _max of uK. As a result, the volume ratio of the highly supersaturated region 12 (see FIG. 4) formed in the vicinity of the addition port 63 can be reduced without increasing the stirring power of the reaction aqueous solution. As a result, since newly generated nuclei can be made to grow into particles of the nickel-containing hydroxide in the reaction aqueous solution, generation of new nuclei in the reaction aqueous solution is suppressed, and newly generated nuclei are generated. Can be prevented from adhering to the surface of the nickel-containing hydroxide particles. Therefore, it is possible to produce nickel-containing hydroxide particles in which the unevenness of the outer surface is reduced while suppressing the increase in the stirring power required to stir the reaction aqueous solution. In addition, generation of fine particles can be suppressed by suppressing the generation of new nuclei.

Moreover, although the addition port 61 of the raw material liquid supply pipe 60 may be provided anywhere in the reaction aqueous solution, like the addition port 63 of the neutralizing agent supply pipe 62, the uK value of the reaction aqueous solution is the maximum of uK it is preferably provided in a region of 30% or more of the values uK _max. In the recovery step S13, since the supply of the raw material liquid is stopped, the raw material liquid supply pipe 60 is not in use. Therefore, when the addition port 61 is provided in the above region, the addition port 61 used for supplying the raw material liquid to the reaction aqueous solution in the nucleation step S11 and the particle growth step S12 is middle in the recovery step S13. It can be used for supplying Japanese medicine. Providing the addition port 61 in the above area is effective, for example, when the addition port 63 is not provided in the above area or when the addition port 63 is deviated from the above area. Even in such a case, by using the addition port 61 for supplying the neutralizing agent, the neutralizing agent can be stably added to the above region. When both the addition port 61 and the addition port 63 are provided in the above region, the neutralizing agent may be added to the above area from both the addition port 61 and the addition port 63.

The position of the addition port 61 is designed in accordance with the flow of the reaction aqueous solution, similarly to the addition port 63 of the neutralizing agent supply pipe 62. For example, as shown in FIG. 5, when the downflow of the reaction aqueous solution is generated along the stirring shaft 40 in the stirring tank 20, the addition port 61 is similar to the addition port 63 of the neutralizing agent supply pipe 62. , a upper vicinity of the stirring blade 30 is provided in a region where the value of uK is more than 30% of the maximum value uK _max of uK.

  The uK in the stirring tank 20 and the volume of the high supersaturation region 12 can be determined by simulation using general-purpose fluid analysis software.

  Hereinafter, steady state fluid analysis in the case of producing nickel hydroxide by reacting sodium hydroxide with a nickel ammine complex in a continuous stirring tank will be mainly described. As fluid analysis software, ANSYS CFX Ver 15.0 (trade name) manufactured by ANSYS, Inc. is used. The analysis conditions etc. are shown below.

<Coordinate system>
-In the region where fluid analysis is performed (hereinafter, also referred to as "analysis region"), the stirring shaft and the surroundings of the stirring blade are handled in a rotational coordinate system that rotates with the stirring shaft and the stirring blade. The area handled in the rotational coordinate system is cylindrical, and its center line is superimposed on the stirring axis or the center line of the stirring blade, its diameter is set to 115% of the blade diameter of the stirring blade, and the range in the vertical direction is stirred From the inner bottom of the tank to the liquid level.
-Other areas in the analysis area are handled in the static coordinate system.
Connect the rotating coordinate system and the stationary coordinate system using the interface function of fluid analysis software. As an interface function, an optional "Frozen Rotor" is used.

Turbulence model
The flow in the stirred tank is not laminar but turbulent. As the turbulent flow model, the SST (Shear Stress Transport) model is used.

<Chemical reaction>
The formula of the chemical reaction that occurs in the stirred tank is shown below.
2NaOH + NiSO ₄ → Ni (OH) ₂ + Na ₂ SO ₄
The focusing of the chemical reactions of the actual phenomenon, shown in the above formula (2-2), nickel ammine complex with an alkaline aqueous solution of hydroxide ions (OH ^-) by reaction with, for generating a nickel hydroxide reaction It is. On the other hand, in the simulation model, the nickel ammine complex and the simple nickel ion are not distinguished, and are treated as being identical as the nickel ion. That is, assuming that a single nickel ion having the same concentration as that of the nickel ion present as a nickel ammine complex is dispersed in the stirring tank, the single nickel ion is hydroxylated in the alkaline aqueous solution based on the above formula (1). It objects ions (OH ^-) react with, treated as nickel hydroxide is generated.
To advance the chemical reaction in the actual crystallization stirred tank, first by turbulent mixing, a hydroxide ion nickel ions and an aqueous alkali solution (OH ^-) and it is necessary to contact the. The transport rate of ions depending on this turbulent mixing is considered to be sufficiently slow as compared to the chemical reaction rate by the collisional combination of nickel ions and hydroxide ions, which occurs as the subsequent reaction process. Therefore, the actual chemical reaction rate can be regarded as the rate-limiting turbulent mixing of nickel ions and hydroxide ions. This turbulent mixing velocity can be considered to be almost identical between a single nickel ion and a nickel ion of a nickel ammine complex. Therefore, in the simulation model, the reaction rate between the nickel ammine complex and the hydroxide ion is considered to be the same as the reaction rate between the single nickel ion and the hydroxide ion, and the nickel ammine complex and the single nickel ion The nickel hydroxide is treated as being generated based on the above formula (1), without distinction.
-In fluid analysis, it deals with single-phase multi-component fluids containing the following five components.
1) Reaction component A: NaOH
2) Reaction component B: NiSO ₄
3) Produced component C: Ni (OH) ₂
4) Product component D: Na ₂ SO ₄
5) The magnitude of the velocity of water and chemical reaction is calculated by the vortex dissipation model. The vortex dissipation model is a reaction model on the assumption that the above-mentioned chemical reaction occurs when the reaction component A and the reaction component B are mixed to the molecular level by turbulent dispersion. The settings of the vortex dissipation model are the default settings of the fluid analysis software.

<Calculation method of mass fraction of each component>
The mass fraction of the sum of the five components is 1 at any position and any point in the analysis region. Therefore, the mass fraction of each of the four components excluding water among the above five components is a value obtained by solving the transport equation by CFX, and the mass fraction of water is the total mass fraction of the four components from 1 to It is the value obtained by subtracting.

<Boundary condition>
・ Wall boundary (boundary where there is no flow of fluid)
There is no slip at boundaries with solids such as stirring tanks, stirring shafts, stirring blades, baffles, etc. On the other hand, it is assumed that there is slippage at the boundary with the outside air (liquid level). In addition, a liquid level shall not be deform | transformed by stirring, and let it be a plane whose height is constant.

・ Inflow boundary (boundary of fluid)
The fluid in the stirring tank is provided with an inflow boundary into which an aqueous solution containing the reaction component A (hereinafter, referred to as “aqueous solution A”) flows. The inflow rate of the aqueous solution A and the ratio of the reaction component A in the aqueous solution A are constant. The inflow boundary is set so that the aqueous solution B is uniformly generated from the entire tank so that the concentration of the reaction component B of the aqueous solution in the stirring tank is maintained at a predetermined value (for example, 1 g / L).

・ Outflow boundary (boundary where fluid flows out)
An outflow boundary from which the fluid in the stirring tank flows out is provided on a part of the inner peripheral surface of the stirring tank. Effluent liquids are those containing product components C and D, unreacted reaction components A and B, and water. The outflow amount is set so that the pressure difference between the analysis region and the outside of the system is zero. In the case of the overflow type continuous type, the liquid level is the outflow boundary.

Thermal condition
-The temperature of the fluid in the stirring tank is kept constant at 25 ° C. It is assumed that there is no heat generation due to the chemical reaction and no heat in / out at the inflow boundary or the outflow boundary.

<Initial condition>
The fluid in the stirring tank is homogeneous in the initial state, and contains only the two components of the reaction component B and water among the above five components. Specifically, among the fluid in the stirring vessel, the initial mass fraction of the reaction component A, the initial mass fraction of the generation component C, and the initial mass fraction of the generation component D are zero, and the initial mass fraction of the reaction component B Is set so that the concentration of the reaction component B of the aqueous solution in the stirring tank becomes the above-mentioned predetermined value.

  Here, although the initial mass fraction of the formation component C and the initial mass fraction of the formation component D are set to zero here, in order to reduce the number of iterations for finding a steady solution (that is, calculation time) It may be set to an average value over the entire analysis area that is predicted to reach in the state. The average value in the whole analysis area is the inflow rate of the aqueous solution A, the ratio of the reaction component A occupying the aqueous solution A, the inflow flow rate of the aqueous solution B, the ratio of the reactive component B occupying the aqueous solution B, quantitative It can be calculated based on the relationship etc.

<Convergence judgment>
Iteration calculation for obtaining a steady solution is performed at any position within the analysis region, for the flow velocity component (m / s) and pressure (Pa) of the flow, and the root mean square of the mass fraction of each of the four components. Perform until the residual is less than 10 ^-4 .

<How to calculate uK>
uK is the product of the flow velocity u of the reaction aqueous solution and the turbulent diffusion coefficient K. u and K can be obtained by performing simulation of the flow field of the stirring tank.

<Method of calculating volume in high supersaturation region>
The high supersaturation region is a region where the concentration of the generated component C dissolved in the aqueous solution in the stirring tank is 5.0 mol / m ³ or more. A high supersaturation region is formed around the inflow boundary of the aqueous solution A.
By the way, in the fluid analysis, as described above, in order to treat the above five components as a single-phase multi-component fluid, all of the generated components C are treated as a liquid. On the other hand, in practice, most of the product component C precipitates and becomes solid, and only the remaining part of the product component C is dissolved in the aqueous solution as a liquid.
・ Therefore, the volume of the high supersaturation region is calculated by correcting the concentration distribution of the generated component C obtained by the fluid analysis. In the correction, the concentration of the generated component C is uniformly lowered in the entire fluid in the stirring tank so that the concentration of the generated component C becomes equivalent to the solubility at the outflow boundary sufficiently separated from the inflow boundary of the aqueous solution A.
・ In addition, when the stirring tank is not continuous type but batch type, there is no outflow boundary. In this case, in the concentration distribution correction, the concentration of the generated component C is uniformly lowered in the entire fluid in the stirring tank so that the concentration of the generated component C becomes equivalent to the solubility on the liquid surface of the aqueous solution in the stirring tank. Just do it. Incidentally, in the case of the overflow type continuous type, the liquid level is the outflow boundary.

Although the analysis conditions in the case of obtaining nickel hydroxide were shown in the above-mentioned explanation, the analysis conditions in the case of obtaining nickel compound hydroxide can be set up similarly. For example, when nickel sulfate or manganese sulfate is reacted with sodium hydroxide to obtain a nickel-manganese composite hydroxide, fluid analysis deals with a single-phase multi-component fluid containing the following seven components.
In the simulation model, the complex generated in the reaction aqueous solution is calculated on the assumption that ions of nickel sulfate or manganese sulfate corresponding to the complex concentration are dispersed in the stirring tank.
1) Reaction component A: NaOH
2) Reactive component B1: NiSO ₄
3) Reactive component B2: MnSO ₄
4) Produced component C1: Ni (OH) ₂
5) Produced component C2: Mn (OH) ₂
6) Product component D: Na ₂ SO ₄
7) Water Here, two chemical reactions “2A + B1 → C1 + D” and “2A + B2 → C2 + D” occur in the stirring tank, and a vortex dissipation model corresponding to each chemical reaction is used as a reaction model. The reaction component B1 and the reaction component B2 are dispersed in water in a state of being uniformly dissolved in water. An aqueous solution A containing the reaction component A is supplied from the inflow boundary. A high supersaturation region is formed around the inflow boundary of the aqueous solution A. The high supersaturation region means that the total molar concentration of all metal hydroxides (here, the component C1 and the component C2) of the product components dissolved in the aqueous solution in the stirring tank is 5.0 mol / m ^3. It is the above area.

  The reason for summing the molar concentrations of all the metal hydroxides of the produced components will be described below. First, as described above, the reaction component B1 and the reaction component B2 are dispersed in water uniformly dissolved in water. At this time, reaction component B1 and reaction component B2 react rapidly with reaction component A in the vicinity of the addition port of reaction component A to produce product component C1 and product component C2. Therefore, the produced component C1 and the produced component C2 exist in a sufficiently mixed state at the time of production. As a result, the generated component C1 and the generated component C2 do not separate out as separate hydroxides, but separate out as a solid solution of the composite hydroxide of the respective components.

When nickel sulfate, cobalt sulfate and aluminum sulfate are used to obtain a nickel composite hydroxide containing nickel, cobalt and aluminum, the fluid analysis deals with a single-phase multi-component fluid containing the following nine components.
In the simulation model, the complex generated in the reaction aqueous solution is calculated on the assumption that ions of nickel sulfate, cobalt sulfate and aluminum sulfate corresponding to the complex concentration are dispersed in the stirring tank.
1) Reaction component A: NaOH
2) Reactive component B1: NiSO ₄
3) Reactive component B2: CoSO ₄
4) Reactive component B3: Al ₂ (SO ₄ ) ₃
5) Produced component C1: Ni (OH) ₂
6) Produced component C2: Co (OH) ₂
7) Produced component C3: Al (OH) ₃
8) Product component D: Na ₂ SO ₄
9) Water Here, it is assumed that three chemical reactions “2A + B1 → C1 + D”, “2A + B2 → C2 + D”, and “3A + 1⁄2B3 → C3 + 3 / 2D” occur in the stirring tank, and the vortex dissipation corresponding to each chemical reaction A model is used as a reaction model. The reaction component B1, the reaction component B2 and the reaction component B3 are dispersed in water uniformly dissolved in water. An aqueous solution A containing the reaction component A is supplied from the inflow boundary. A high supersaturation region is formed around the inflow boundary of the aqueous solution A. In the high supersaturation region, the total molar concentration of all metal hydroxides (here, product component C1, product component C2 and product component C3) of the product components dissolved in the aqueous solution in the stirring tank is 5. It is a region of 0 mol / m ³ or more.

  The reason for summing the molar concentrations of all the metal hydroxides of the produced components will be described below. First, as described above, the reaction component B1, the reaction component B2 and the reaction component B3 are dispersed uniformly in water. At this time, reaction component B1, reaction component B2 and reaction component B3 react rapidly with reaction component A in the vicinity of the addition port of reaction component A to produce product component C1, product component C2 and product component C3. Therefore, the produced component C1, the produced component C2 and the produced component C3 are present in a sufficiently mixed state at the time of production. As a result, the generated component C1, the generated component C2 and the generated component C3 are not precipitated as individual hydroxides, but are precipitated as solid solutions of hydroxides in which the respective components are complexed.

Furthermore, in the case of obtaining nickel-cobalt-manganese composite hydroxide using nickel sulfate, manganese sulfate and cobalt sulfate, fluid analysis deals with a single-phase multi-component fluid including the following nine components.
In the simulation model, the complex generated in the reaction aqueous solution is calculated assuming that ions of nickel sulfate, manganese sulfate and cobalt sulfate corresponding to the complex concentration are dispersed in the stirring tank.
1) Reaction component A: NaOH
2) Reactive component B1: NiSO ₄
3) Reactive component B2: MnSO ₄
4) Reaction component B3: CoSO ₄
5) Produced component C1: Ni (OH) ₂
6) Produced component C2: Mn (OH) ₂
7) Produced component C3: Co (OH) ₂
8) Product component D: Na ₂ SO ₄
9) Water Here, it is assumed that three chemical reactions “2A + B1 → C1 + D”, “2A + B2 → C2 + D”, and “3A + 1⁄2B3 → C3 + 3 / 2D” occur in the stirring tank, and the vortex dissipation corresponding to each chemical reaction A model is used as a reaction model. The reaction component B1, the reaction component B2 and the reaction component B3 are dispersed in water uniformly dissolved in water. An aqueous solution A containing the reaction component A is supplied from the inflow boundary. A high supersaturation region is formed around the inflow boundary of the aqueous solution A. In the high supersaturation region, the total molar concentration of all metal hydroxides of the product components dissolved in the aqueous solution in the stirring tank (here, product component C1, product component C2, and product component C3) is 5. It is a region of 0 mol / m ³ or more.

  As to the reason for summing the molar concentrations of all metal hydroxides among the produced components, in the case of obtaining a nickel composite hydroxide containing nickel, cobalt and aluminum as described above, The description is omitted because it is the same as the case of summing the molar concentrations.

  The number of inflow boundaries of the aqueous solution A may be more than one, and the number of high supersaturation regions may be more than one. When the number of high supersaturation regions is more than one, the volume of the high supersaturation region means the total volume.

The method for producing a nickel-containing hydroxide simulates that an addition port is provided in a region where the value of uK is 30% or more with respect to the maximum value uK _{max of} uK in the nucleation step or the particle growth step. It may have the process of confirming by. This confirmation may be made each time the manufacturing conditions change. The change of the manufacturing conditions includes, for example, the capacity and shape of the stirring tank, the number, shape, size or location of the stirring blades, the number of rotations of the stirring blades, the flow rate and concentration of the neutralizing agent, or the neutralizing agent. The shape, number or arrangement of the nozzles may be mentioned. For example, when a stirring tank is a batch type, while manufacturing conditions are the same, confirmation may be performed once, and each confirmation is unnecessary.

Example 1
In Example 1, using an overflow-type continuous stirring tank, a nucleation step of forming nuclei of particles of nickel composite hydroxide by neutralization crystallization and a particle growth step of growing particles are simultaneously performed. The The capacity of the stirring tank is 200 L, the type of stirring blade is disk turbine blade, the number of blades of the stirring blade is 6, the diameter of the stirring blade is 250 mm, the vertical distance between the stirring blade and the inner bottom of the stirring tank is The rotational speed of the stirring blade was set to 280 rpm. The liquid volume of the reaction aqueous solution in the stirring tank was 200 L, the ammonium ion concentration of the reaction aqueous solution was 12 g / L, and the temperature of the reaction aqueous solution was maintained at 50 ° C. The atmosphere around the reaction aqueous solution was an air atmosphere.

The raw material liquid was prepared so as to obtain Ni _0.82 Co _0.15 Al _0.03 (OH) ₂ as a nickel composite hydroxide. The number of raw material liquid supply pipes was one, and the supply amount from one raw material liquid supply pipe was 400 ml / min.

  During the nucleation step and particle growth step, in addition to the raw material liquid, an aqueous solution of sodium hydroxide as a neutralizing agent and aqueous ammonia as a complexing agent are supplied to the stirring tank to maintain the ammonium ion concentration of the reaction aqueous solution. did.

  After the nucleation step and the particle growth step, a recovery step of recovering metal ions (nickel ions, cobalt ions and aluminum ions) of the raw material liquid remaining in the reaction aqueous solution in the reaction aqueous solution was performed. In the recovery step, stopping the supply of the raw material liquid and the ammonia water into the stirring tank, and continuing the sodium hydroxide aqueous solution at a rate of 200 ml / min until the pH value of the reaction aqueous solution reaches 12.6. Supplied. At this time, an aqueous solution of sodium hydroxide was added to a place where uK at the addition site of sodium hydroxide was 40% with respect to the maximum value uKmax of uK of the reaction aqueous solution.

The volume ratio of the highly supersaturated region in which the molar concentration of the nickel-containing hydroxide in the vicinity of the addition site of the sodium hydroxide aqueous solution is 5.0 mol / m ³ or more in the reaction aqueous solution is 0.075% as calculated by simulation. Met. The analysis conditions were set in the same manner as the above-mentioned analysis conditions.

  The particles of the obtained nickel composite hydroxide were observed with a scanning electron microscope (SEM). In FIG. 7, the SEM photograph of the particle | grains of the nickel compound hydroxide obtained in Example 1 is shown. As shown in FIG. 7, the outer surface of the particles obtained at the completion of the neutralization crystallization was smooth, and almost no unevenness was observed.

  The particle size distribution of the particles of the obtained nickel composite hydroxide was measured. The measurement result of the particle size distribution of the particle | grains of the nickel compound hydroxide obtained in Example 1 is shown in FIG. As shown in FIG. 8, the particle size distribution of the obtained particles had a single peak.

Example 2
Example 2 is the same as Example 1 except that the aqueous sodium hydroxide solution is added to a place where the uK at the sodium hydroxide addition site is 33% of the maximum uK of the reaction aqueous solution. The particles of nickel composite hydroxide were produced.

The volume ratio of the highly supersaturated region in which the molar concentration of the nickel-containing hydroxide in the vicinity of the addition site of the sodium hydroxide aqueous solution is 5.0 mol / m ³ or more in the reaction aqueous solution at this time is simulated as in Example The calculated value was 0.091%.

  The particles of the obtained nickel composite hydroxide, like the particles of the nickel composite hydroxide obtained in Example 1, were smooth on the outer surface of the particles, and almost no unevenness was observed. Further, the particle size distribution of the particles of the obtained nickel composite hydroxide also had one peak as in the particles of Example 1 shown in FIG.

[Example 3]
In Example 3, particles of a nickel composite hydroxide were prepared in the same manner as in Example 1 except that the raw material liquid was prepared so as to obtain Ni _0.88 Co _0.09 Al _0.03 (OH) ₂ as a nickel composite hydroxide. Manufactured.

The volume ratio of the highly supersaturated region in which the molar concentration of the nickel-containing hydroxide in the vicinity of the addition site of the sodium hydroxide aqueous solution is 5.0 mol / m ³ or more in the reaction aqueous solution at this time is simulated as in Example 1. It was 0.075% when calculated by.

  The particles of the obtained nickel composite hydroxide, like the particles of the nickel composite hydroxide obtained in Example 1, were smooth on the outer surface of the particles, and almost no unevenness was observed. Further, the particle size distribution of the particles of the obtained nickel composite hydroxide also had one peak as in the particles of Example 1 shown in FIG.

Example 4
In Example 4, particles of nickel composite hydroxide were prepared in the same manner as in Example 1 except that the raw material liquid was prepared so as to obtain Ni _0.34 Mn _0.33 Co _0.33 (OH) ₂ as a nickel composite hydroxide. Manufactured.

The volume ratio of the highly supersaturated region in which the molar concentration of the nickel-containing hydroxide in the vicinity of the addition site of the sodium hydroxide aqueous solution is 5.0 mol / m ³ or more in the reaction aqueous solution at this time is simulated as in Example 1. It was 0.075% when calculated by.

  Similar to the particles of the nickel composite hydroxide obtained in Example 1, the outer surface of the particles of the particle image of the obtained nickel composite hydroxide was smooth, and almost no unevenness was observed. Further, the particle size distribution of the particles of the obtained nickel composite hydroxide also had one peak as in the particles of Example 1 shown in FIG.

[Example 5]
In Example 5, particles of a nickel composite hydroxide were prepared in the same manner as in Example 1 except that the raw material liquid was prepared so as to obtain Ni _0.40 Mn _0.30 Co _0.30 (OH) ₂ as a nickel composite hydroxide. Manufactured.

The volume ratio of the highly supersaturated region in which the molar concentration of the nickel-containing hydroxide in the vicinity of the addition site of the sodium hydroxide aqueous solution is 5.0 mol / m ³ or more in the reaction aqueous solution at this time is simulated as in Example 1. It was 0.075% when calculated by.

  The particles of the obtained nickel composite hydroxide, like the particles of the nickel composite hydroxide obtained in Example 1, were smooth on the outer surface of the particles, and almost no unevenness was observed. Further, the particle size distribution of the particles of the obtained nickel composite hydroxide also had one peak as in the particles of Example 1 shown in FIG.

Comparative Example 1
In Comparative Example 1, the addition site of the aqueous sodium hydroxide solution is changed to a place where the value of uK of the reaction aqueous solution is 20% of the maximum uK _max of the reaction aqueous solution in the stirring tank. In the same manner as in Example 1, particles of nickel composite hydroxide were produced. The volume ratio of the high supersaturation region in the reaction aqueous solution was 0.150% as calculated by simulation in the same manner as in Example 1.

  The result of having observed the particle | grains of the nickel compound hydroxide obtained by the comparative example 1 in FIG. 9 by SEM is shown. As shown in FIG. 9, remarkable unevenness was observed on the outer surface of the particles obtained at the completion of the neutralization crystallization. It is considered that this is because nucleation could not be suppressed in the vicinity of the place where the neutralizing agent was added, so that the particles became finer and remarkable unevenness was formed on the outer surface of the particles.

  The particle size distribution of the particles of the obtained nickel composite hydroxide was measured. In FIG. 10, the measurement result of the particle size distribution of the particle | grains of the nickel compound hydroxide obtained in Example 1 is shown. As shown in FIG. 10, the particle size distribution of the obtained particles had two large and small peaks.

Comparative Example 2
Comparative Example 2 is the same as Example 1 except that the aqueous sodium hydroxide solution is added to a place where the uK at the addition site of sodium hydroxide is 27% with respect to the maximum uK _max of the reaction aqueous solution. Similarly, particles of nickel composite hydroxide were produced.

The volume ratio of the highly supersaturated region in which the molar concentration of the nickel-containing hydroxide in the vicinity of the addition site of the sodium hydroxide aqueous solution is 5.0 mol / m ³ or more in the reaction aqueous solution at this time is simulated as in Example 1. It was 0.012% when calculated by.

  Also in the particles of the nickel composite hydroxide obtained in Comparative Example 2, similar to the particles of Comparative Example 1 shown in FIG. 9, remarkable unevenness was observed on the outer surface of the nickel composite hydroxide. Further, the particle size distribution of the particles of the obtained nickel composite hydroxide also had two peaks as in the particles of Comparative Example 1 shown in FIG.

[Summary]
From this example and comparative examples, if adding a neutralizing agent to 30% or more regions with respect to the maximum value uK _max of uK values uK is aqueous reaction solution, the stirring blade type and blade diameter, of the stirred tank It can be seen that even if the volume changes, it is possible to produce particles with reduced unevenness on the outer surface of the particles while suppressing an increase in stirring power.

  As mentioned above, although the embodiment etc. of the manufacturing method of nickel content hydroxide were explained, the present invention is not limited to the above-mentioned embodiment etc., within the range of the gist of the present invention indicated in the claim. Various modifications and improvements are possible.

DESCRIPTION OF SYMBOLS 10 Chemical reaction apparatus 12 High super saturated area | region 20 stirring tank 30 stirring blade 40 stirring shaft 50 baffle 60 raw material liquid supply pipe 61, 63 addition port 62 neutralizing agent supply pipe 64 complexing agent supply pipe

Claims (3)

A metal salt containing at least a nickel salt, a complexing agent which forms a complex by binding to the metal ion of the metal salt, and a neutralizing agent which reacts with the metal salt and the complex to form a metal hydroxide A method for producing a nickel-containing hydroxide, wherein particles of a nickel-containing hydroxide are obtained by neutralization crystallization in a mixed reaction aqueous solution,
After the particles of the nickel-containing hydroxide are formed, the neutralizing agent is added to the reaction aqueous solution to raise the pH value of the reaction aqueous solution to precipitate the nickel-containing hydroxide, which is contained in the reaction aqueous solution. A recovery step of recovering the metal ion remaining in the solid phase as the nickel-containing hydroxide,
In the recovery step, the neutralizing agent is provided from an addition port provided in a region where the value of the product uK of the flow velocity u of the reaction aqueous solution and the turbulent diffusion coefficient K is 30% or more with respect to the maximum value uK _max of the uK. A method of producing a nickel-containing hydroxide, wherein   The nickel-containing hydroxide contains Ni, Co, and Al at a mass ratio of Ni: Co: Al = 1-x-y: x: y (where 0 ≦ x ≦ 0.3, 0.005 ≦ The method for producing a nickel-containing hydroxide according to claim 1, wherein y ≦ 0.15).   The nickel-containing hydroxide comprises Ni, Co, Mn and M (M is at least one additive element selected from Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, and W) The substance mass ratio is Ni: Co: Mn: M = x: y: z: t (where x + y + z + t = 1, 0.1 ≦ x ≦ 0.7, 0.1 ≦ y ≦ 0.5, 0.1) The manufacturing method of the nickel containing hydroxide of Claim 1 containing so that it may become <= z <= 0.8 and 0 <= t <= 0.02).