JP2805098B2 - Method for producing nickel hydroxide - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel method for producing spherical nickel hydroxide particles or spherical nickel hydroxide particles containing cobalt and cadmium.

In the following, the term “nickel hydroxide particles or powder” includes “nickel hydroxide particles or powder containing cobalt and cadmium” unless otherwise specified.

2. Related Art and its Problems Nickel hydroxide powder used for non-sintered nickel positive electrodes for alkaline batteries is required to have a spherical particle shape and a high bulk density. This is because (a) when such a nickel hydroxide powder is filled into a metallic pocket or the like as an active material of a nickel positive electrode, it can be densely filled. When used in paste form, the properties of the paste such as fluidity are stabilized, so that the filling properties and the filling rate are improved. (C) Therefore, in either case (a) or (b) This is also because the utilization factor of the active material is improved and an electrode having excellent performance can be obtained.

However, in the conventional method for producing nickel hydroxide, it has been difficult to obtain a powder having the above characteristics.

One of the inventors of the present application has conducted intensive studies in view of the current state of such technology, and as a result, "(a) nickel salt aqueous solution,
(B) In producing nickel hydroxide by reacting an aqueous solution of an alkali metal hydroxide and (c) an ammonium ion donor, the above three steps (a), (b) and (c) are continuously and simultaneously performed. To the reaction system, and raise the temperature of the reaction system to 20-80.
The reaction proceeds while maintaining the pH at a constant value in the range of 9 ° C. and a constant value in the range of 9 to 12 to produce spherical nickel hydroxide particles having an average particle diameter of 2 to 50 μm, and continuously taking out the particles. And a patent application has been filed by the present applicant.
No. 6340; this method is hereinafter referred to as a prior invention).

Although the prior invention is an excellent method as compared with the prior art, the number of fine particles becomes insufficient as the nickel hydroxide particles grow as a whole with the progress of the reaction.
Therefore, when filling a metallic pocket or the like as the active material of the nickel positive electrode, the product tends to have a large porosity, that is, a product having a large tapping density. An increase in the tapping density leads to a decrease in the utilization factor as a positive electrode of an alkaline battery. Therefore, improvement in this point is desired.

Means for Solving the Problems The present inventor has conducted further studies in view of the current state of the art as described above, and as a result, in the continuous production process of nickel hydroxide according to the prior invention, When the pH of the reaction system is periodically fluctuated or the supply of the ammonium ion donor is stopped or reduced at the time when the growth of nickel particles has progressed, fine particles serving as nuclei of nickel hydroxide particles are included in the reaction system. By returning the pH of the reaction system to the initial value, a cycle consisting of particle growth and generation of particle nuclei is repeated, and as a result, nickel hydroxide having a stable tapping density is obtained. Was found to be.

Further, after repeating a cycle consisting of particle growth and generation of particle nuclei in the same manner as described above under different conditions in a plurality of reaction systems, by mixing the obtained particle groups having different particle diameters, It has also been found that nickel hydroxide mixed particles having a more precisely controlled particle size distribution can be easily obtained.

That is, the present invention provides the following method for producing nickel hydroxide: (a) an aqueous solution of a nickel salt or an aqueous solution containing a nickel salt, a cobalt salt and a cadmium salt, (b) an aqueous solution of an alkali metal hydroxide, and (C) The ammonium ion supplier is continuously supplied to the reaction system, and the temperature of the reaction system is 20 to 80 ° C.
The reaction is allowed to proceed while maintaining the pH at a constant value in the range and a pH in the range from 9 to 12 to produce nickel hydroxide particles or nickel hydroxide particles containing cobalt and cadmium. In the continuous extraction method, nickel hydroxide fine particles that serve as nuclei are generated intermittently by adjusting the pH of the reaction system by increasing the supply amount of the alkali metal hydroxide aqueous solution over a certain period of time. A method for producing spherical nickel hydroxide particles or spherical nickel hydroxide particles containing cobalt and cadmium.

(A) an aqueous solution of a nickel salt or an aqueous solution containing a nickel salt, a cobalt salt and a cadmium salt, (b) an aqueous solution of an alkali metal hydroxide and (c) an ammonium ion donor are continuously supplied to the reaction system. 20 ~ 80 ℃
The reaction is allowed to proceed while maintaining the pH at a constant value in the range and a pH in the range from 9 to 12 to produce nickel hydroxide particles or nickel hydroxide particles containing cobalt and cadmium. In this method, the supply of the ammonium ion donor to the reaction system is intermittently stopped for a certain period of time, or the supply amount is reduced to generate nickel hydroxide fine particles serving as nuclei. A method for producing spherical nickel hydroxide particles or spherical nickel hydroxide particles containing cobalt and cadmium.

(A) an aqueous solution of a nickel salt or an aqueous solution containing a nickel salt, a cobalt salt and a cadmium salt, (b) an aqueous solution of an alkali metal hydroxide and (c) an ammonium ion donor are continuously supplied to the reaction system. 20 ~ 80 ℃
The reaction is allowed to proceed while maintaining the pH at a constant value in the range and a pH in the range from 9 to 12 to produce nickel hydroxide particles or nickel hydroxide particles containing cobalt and cadmium. In the continuous extraction method, a plurality of reaction systems are allowed to react under different conditions to form particles having different particle diameters, and each reaction system is intermittently supplied with an alkali metal hydroxide aqueous solution for a certain period of time. By adjusting the pH of the reaction system by increasing the amount,
By generating nickel hydroxide fine particles serving as a nucleus and mixing the particle groups having different particle diameters obtained above, spherical nickel hydroxide particles characterized by obtaining mixed particles having a predetermined particle size distribution or A method for producing spherical nickel hydroxide particles containing cobalt and cadmium.

(A) an aqueous solution of a nickel salt or an aqueous solution containing a nickel salt, a cobalt salt and a cadmium salt, (b) an aqueous solution of an alkali metal hydroxide and (c) an ammonium ion donor are continuously supplied to the reaction system. 20 ~ 80 ℃
The reaction is allowed to proceed while maintaining the pH at a constant value in the range and a pH in the range from 9 to 12 to produce nickel hydroxide particles or nickel hydroxide particles containing cobalt and cadmium. In the continuous extraction method, a plurality of reaction systems are allowed to react under different conditions to form particles having different particle diameters, and ammonium ion is supplied to the reaction system intermittently for a certain period of time in each reaction system. By stopping the supply of the body or reducing the supply amount, nickel hydroxide fine particles serving as a nucleus are generated, and by mixing the particle groups having different particle diameters obtained above, a predetermined particle size distribution is obtained. A method for producing spherical nickel hydroxide particles or spherical nickel hydroxide particles containing cobalt and cadmium, characterized by obtaining mixed particles having the same.

Hereinafter, the invention described in claim 1 of the present application will be referred to as the first invention of the present application, the invention described in claim 2 of the present application will be referred to as the second invention of the present application, and the invention described in claim 3 of the present application will be described. The invention described in (1) is the third invention of the present application, and the invention described in claim 4 of the present application is the fourth invention of the present application. Also,
If the inventions are not particularly distinguished, they are collectively referred to simply as the invention.

Salts forming the nickel salt aqueous solution used in the method of the present invention include nickel nitrate, nickel sulfate,
And water-soluble nickel salts such as nickel chloride. The concentration of the nickel salt aqueous solution is usually about 0.5 to 3.5 mol /. When a cobalt salt and a cadmium salt are contained together with a nickel salt in an aqueous solution, a water-soluble cobalt salt such as cobalt sulfate, cobalt nitrate, and cobalt chloride and a water-soluble cadmium salt such as cadmium sulfate, cadmium nitrate, and cadmium chloride are used. You. The concentration of cobalt in the aqueous solution is about 0.01 to 0.5 mol / about as cobalt ions, and the concentration of cadmium is about 0.01 to 0.5 mol / about as cadmium ions.

Examples of the aqueous solution of the alkali metal hydroxide used in the method of the present invention include sodium hydroxide and potassium hydroxide. The concentration of the alkali metal hydroxide aqueous solution is usually about 1.25 to 10 mol /.

As the (c) ammonium ion donor used in the present invention, ammonium nitrate, ammonium sulfate,
Aqueous solution of ammonium salt such as ammonium chloride (usually 3 to 7.5 mol / about), aqueous ammonia (usually 10 to 2
8%), ammonia gas and the like.

In the method of the present invention, the above three kinds of raw materials (hereinafter simply referred to as an aqueous solution) of (a), (b) and (c) are continuously supplied to a reaction system. The supply ratio of the three aqueous solutions is (a)
Alkali metal hydroxide per mole of nickel salt
About 1.8 to 2.2 mol, ammonium ion donor 0.1 to 1.5
It is in the mole range. The three types of aqueous solutions are supplied to the reaction system while being sufficiently stirred. The supply amount of these aqueous solutions depends on the volume and shape of the reaction tank, the concentration of each aqueous solution,
The residence time in the reaction system may be usually about 1 to 10 hours, depending on the desired particle size of the nickel hydroxide.

Hereinafter, the first to fourth inventions of the present application will be described in detail with reference to the accompanying drawings.

I. First Invention of the Present Application and II. Second Invention of the Present Invention FIG. 1 shows an outline of an example of a reaction apparatus used in carrying out the first invention and the second invention of the present application.

In a reaction tank (1) equipped with a stirrer (17), an aqueous solution of nickel salt is supplied from line (3), an ammonium ion donor is supplied from line (5), and an aqueous solution of alkali metal hydroxide is supplied from line (7). Each is continuously supplied via a metering pump (9). (11) is a pH controller, and (13) is a temperature controller. The liquid containing the generated nickel hydroxide particles is continuously taken out from the line (15). This liquid is filtered by a known means to obtain desired nickel hydroxide particles.

When the reaction is carried out under the conditions shown in FIG. 1, if the other conditions of the reaction system are kept constant, the relationship between the pH of the reaction solution and the ammonium ion concentration in the reaction solution is determined by the growth rate of the nickel hydroxide particles. Has a great effect on That is, as the pH of the reaction solution increases, it is necessary to increase the ammonium ion concentration in the reaction solution. For example, if the pH of the reaction solution is 1
Comparing the case of 1.0 with the case of 11.5, in the latter case, the ammonium ion concentration needs to be about 1.5 times. In this pH range, a proportional relationship is almost established between the pH value and the required ammonium ion concentration. Under these circumstances, by continuing the reaction while keeping the ammonium ion concentration constant and the pH of the reaction solution constant (11.0), the nickel hydroxide particles are grown for a certain period of time. Assuming that the pH is increased to 11.5, in order to further grow the nickel hydroxide particles, it is necessary to increase the concentration of ammonium ions so as to correspond to the increased pH value of the reaction solution. At this time, if the initial pH of the reaction solution is
If you continue to supply the ammonium ion supplier at a concentration corresponding to (11.0), the amount of ammonium ions will be insufficient,
It has been found that the growth of the nickel hydroxide particles generated so far almost stops, and instead, nickel hydroxide fine particles serving as new nickel hydroxide particle nuclei are generated.

Also, when the supply of the ammonium ion supplier is stopped or the supply is significantly reduced while maintaining the pH of the reaction solution constant, the amount of ammonium ions is insufficient, and It was also found that the growth of nickel oxide particles almost stopped, and instead nickel hydroxide fine particles serving as new nickel hydroxide particle nuclei were generated.

The first invention and the second invention of the present application have been completed based on such findings on the correlation between the pH of the reaction solution and the ammonium ion concentration in the reaction solution.

The first invention of the present application is implemented, for example, as follows.

First, the reaction is carried out in a steady state while maintaining the conditions such as the supply amount of the nickel salt aqueous solution and the ammonium ion donor to the reaction system, the temperature of the reaction system, etc. An operation in which the pH of the reaction system is rapidly increased by increasing the supply amount, and after maintaining the state for a certain period of time, the supply amount of the alkali metal hydroxide aqueous solution is reduced to a steady amount and returned to the original pH again. Perform For example, as shown in FIG. 2, after performing the reaction for 1 hour at a pH of the reaction system of 11.0, the supply amount of the alkali metal hydroxide aqueous solution is rapidly increased at a point A to raise the pH of the reaction system to 11.5. Enhance
This state is continued for Y time until point B. In this case, at point A, the average particle diameter of the nickel hydroxide particles shows the maximum value,
From point B to point B, the amount of nickel hydroxide fine particles gradually increases, and at point B, the amount of nickel hydroxide fine particles shows a maximum value. Subsequently, from the point B to the point D through the point C, the pH of the reaction system is again set to 11.0 and the reaction is carried out for X hours.
At this point, the supply amount of the alkali metal hydroxide aqueous solution is rapidly increased to raise the pH of the reaction system to 11.5, and the same operation is repeated thereafter. The reaction system temperature, steady-state pH value, steady-state holding time of pH (X), rising pH value, pH rising time (Y), etc.
It can vary depending on the concentrations of the three aqueous solutions (a), (b) and (c), the desired average particle size and particle size distribution of nickel hydroxide, etc., but usually a constant value within a temperature range of 20 to 80 ° C. The steady pH value and the rising pH value are constant values in the range of 9 to 12, X is about 5 to 30 hours, and Y is about 0.5 to 3 hours. Thus, it has a certain particle size distribution and an average particle size of 2
Approximately 50 μm, and a product in which almost all of the particles of nickel hydroxide are spherical or nearly spherical.

In the second invention of the present application, the supply amount of the aqueous nickel salt solution and the aqueous alkali metal hydroxide solution to the reaction system,
While maintaining constant conditions such as pH and temperature of the reaction system,
By intermittently stopping the supply of the ammonium ion supplier or greatly reducing the supply amount, the concentration of the ammonium ion in the reaction system is rapidly reduced, and after maintaining the state for a certain period of time, the supply amount of the ammonium ion supplier is reduced. To return to a steady amount. For example, as shown in FIG. 3, after the X'-hour reaction is performed for the steady supply of the ammonium ion supplier to the reaction system, the supply of the ammonium ion supplier is stopped at point A 'or the supply amount is greatly reduced. This state is continued for Y 'time until point B'. In this case, the average particle size of the nickel hydroxide particles at the point A 'shows the maximum value, and A'
The amount of the nickel hydroxide fine particles gradually increases from the point to the point B ′, and the amount of the nickel hydroxide fine particles shows the maximum value at the point B ′. Subsequently, after a steady supply of the ammonium ion supplier to the reaction system from the point B 'to the point D' via the point C 'to the point D' for X 'hours, the supply of the ammonium ion supplier is stopped again at the point D'. Greatly reduce the supply,
Hereinafter, the same operation is repeated. The temperature and pH value of the reaction system, the steady-state supply time (X ') of the ammonium ion supplier, the supply stoppage of the ammonium ion supplier or the supply decrease time (Y'), and the like are (A), (B) and (C) ) Can vary depending on the concentrations of the three aqueous solutions, the desired average particle size and particle size distribution of nickel hydroxide, etc.
Constant value in the range of ° C., pH value = constant value in the range of 9 to 12,
X '= about 5 to 30 hours, Y' = about 0.5 to 3 hours. Thus, it has a certain particle size distribution and an average particle size of 2
Approximately 50 μm, and a product in which almost all of the particles of nickel hydroxide are spherical or nearly spherical.

III. Third Invention of the Present Application and IV. Fourth Invention of the Present Application FIG. 4 shows an outline of an example of an apparatus used in carrying out the third invention and the fourth invention of the present application. This device basically has a structure in which two reactors shown in FIG. 1 are combined and one mixing device is further added. In FIG. 4, each element of the reactor shown at the upper left is shown by 100 numbers, and each element of the reactor shown at the upper right is shown by 200 numbers. For example, (101) and (201) both indicate a reaction tank having the same function as the reaction tank (1) in FIG.

In the third and fourth inventions of the present application, the reaction tank (10
By producing nickel hydroxide particles under different reaction conditions in 1) and the reaction tank (201), products having different average particle diameters and particle size distributions can be obtained in the respective tanks. That is, in the two reaction vessels, nickel hydroxide nuclei may be formed by changing the pH, or nickel hydroxide nuclei may be formed by stopping or decreasing the supply of the ammonium ion donor, or In the above-mentioned reaction vessel, nickel hydroxide nuclei may be formed by pH change, and in the other reaction tank, nickel hydroxide nuclei may be formed by stopping or decreasing the supply of the ammonium ion donor. The two kinds of nickel hydroxide particle-containing liquids thus obtained are sent from respective product take-out lines (115) and (215) to the mixing tank (301), and are uniformly stirred by the stirrer (303). After that, it is taken out from the final product take-out line (305). The obtained nickel hydroxide particle-containing liquid is subjected to a filtration treatment according to a conventional method to obtain desired nickel hydroxide particles.

According to the third and fourth inventions of the present application, the reaction tank (10
By adjusting the reaction conditions in 1) and the reaction tank (201) separately, spherical or nearly spherical nickel hydroxide particles having an arbitrary average particle size and particle size distribution within an average particle size of about 2 to 50 μm. Can be manufactured.

FIG. 4 shows an embodiment in which two reaction vessels are used, but in the third and fourth inventions of the present application,
It is also possible to control the average particle size and particle size distribution of nickel hydroxide particles more precisely by producing particles having different average particle sizes and particle size distributions by using three or more reaction vessels and mixing them. Is possible.

Nickel hydroxide particles obtained by the method of the present invention, a non-sintered type nickel positive electrode material for alkaline batteries, a material for surface treatment of a steel sheet, a material for nickel plating, etc.
Useful.

In addition, nickel hydroxide particles containing particularly cobalt and cadmium are used as non-sintered nickel positive electrode materials for alkaline batteries, such as for suppressing self-discharge of alkaline secondary batteries and improving the charging efficiency of alkaline secondary batteries. It is effective.

According to the method of the present invention, the following remarkable effects are achieved.

(A) Spherical to spherical nickel hydroxide particles are obtained.

(B) Since the obtained nickel hydroxide particles are spherical or almost spherical, they are excellent in filterability during production, easy to remove impurities during production, easy to handle as powder,
High tapping density.

(C) It is easy to control the average particle size and particle size distribution of the nickel hydroxide particles.

EXAMPLES Examples are shown below to further clarify features of the present invention.

Example 1 Continuous production of nickel hydroxide particles was carried out with stirring using a reactor of the type shown in FIG.

The used aqueous solutions, reaction conditions, and the like are as follows. The capacity of the reaction tank (1) was 100.

(A) Nickel salt aqueous solution: concentration: 2.2 mol of nickel sulfate / supply amount: 15.9 / hr (b) Alkali metal hydroxide aqueous solution: concentration: 6.0 mol of sodium hydroxide / supply amount: pH of the steady-state reaction system is 11.0 (Average supply amount 9 / hr) (C) Ammonium ion supplier: Concentration: 25% ammonia water Supply amount: 1.7 / hr (d) Conditions in the reaction tank at steady state: pH: 11.0 Temperature: 50 After removing the initial product for 20 hours until the reaction reaches a stable state, and continuing the reaction for 14 hours under the same conditions (X = 14 hours in FIG. 2), supply of aqueous sodium hydroxide solution The amount was increased and only the pH of the reaction system was changed to 11.5, and the reaction was carried out under these conditions for 1 hour (Y = 1 hour in FIG. 2). Next, the pH of the reaction system was returned to 11.0, and the reaction was carried out in a steady state for 14 hours. Thereafter, the reaction was repeated in the same cycle.

Scanning electron micrographs (approximately 500 times) of the nickel hydroxide particles at the respective times corresponding to A to D in FIG. 2 are shown in FIGS. 5 to 8, respectively.

First, it is clear that the nickel hydroxide particles obtained at the time corresponding to A (FIG. 5) have a substantially spherical particle shape.

Further, it is clear that the nickel hydroxide particles (FIG. 6) obtained at the time corresponding to B contain fine particles which are to be nuclei for subsequent particle growth.

Further, in the nickel hydroxide particles obtained at the time corresponding to C (FIG. 7), particles having an intermediate particle diameter indicating that the fine particles are growing are recognized.

The nickel hydroxide particles obtained at the time corresponding to D (FIG. 8) have the same particle shape and particle size distribution as the nickel hydroxide particles obtained at the time corresponding to A (FIG. 5). It is clear that you are.

This corresponds to one cycle of the reaction from A to D above.
The average particle size of the product obtained by filtering the nickel hydroxide particles obtained during the time, washing with water and drying according to a conventional method, is 7.
1 μm and the tapping density was 2.02 g / ml.

Since the obtained nickel hydroxide particles were spherical or almost spherical, filtration was easy and handling as a powder was easy.

Example 2 Cobalt and cadmium-containing nickel hydroxide particles were obtained in the same manner as in Example 1 except that the following aqueous solution was used instead of the nickel salt aqueous solution used in Example 1.

(A ') Cobalt / cadmium-containing nickel salt aqueous solution: concentration: 2.1 mol of nickel sulfate / 0.03 mol of cobalt sulfate / 0.07 mol of cadmium sulfate / corresponding to one cycle of the reaction from A to D in FIG.
The cobalt-cadmium-containing nickel hydroxide particles obtained during 15 hours are filtered according to a conventional method, washed with water, and dried.The average particle diameter of the obtained product is 6.8 μm, and the tapping density is 2.04 g / ml.

Further, the obtained cobalt / cadmium-containing nickel hydroxide particles were also spherical or almost spherical, easy to filter, and easy to handle as powder.

Example 3 Continuous production of nickel hydroxide particles was carried out with stirring using a reactor of the type shown in FIG.

The used aqueous solutions, reaction conditions, and the like are as follows.

(B) Nickel salt aqueous solution: concentration: 2.2 mol of nickel sulfate / supply amount: 15.9 / hr (b) Alkali metal hydroxide aqueous solution: concentration: 6.0 mol of sodium hydroxide / supply amount: Maintain the pH of the reaction system at 11.0 Quantity (average supply 9
(c) Ammonium ion supplier: Concentration: 25% ammonia water Supply: 1.7 / hr (steady state) (d) Conditions in the reactor at steady state: pH: 11.0 Temperature: 50 ° C Reaction is stable After 20 hours of the initial product until reaching pH, the reaction was continued for 14 hours under the same conditions (X '= 14 hours in FIG. 3), and ammonium ions were added while maintaining the pH at 11.0. The supply of the feeder was stopped, and the reaction was carried out under these conditions for 1 hour (in FIG. 3,
Y '= 1 hour). Next, the supply of the ammonium ion donor was restarted, the reaction was carried out in a steady state for 14 hours, and the reaction was repeated in the same cycle thereafter.

The concentration of ammonium ion in the reaction solution at the time corresponding to A ′ (FIG. 3) was 0.7%, and B ′ (FIG. 3)
The concentration of ammonium ion in the reaction solution at the time point corresponding to was 0.40%.

The nickel hydroxide particles obtained at each time point corresponding to A ′, B ′, C ′ and D ′ in FIG.
The nickel hydroxide particles obtained at each time point corresponding to B, C and D were almost spherical or almost spherical.

The average particle size of the product obtained by filtering, washing with water and drying the nickel hydroxide particles obtained during 15 hours corresponding to one cycle of the reaction from A 'to D' is as follows: 5.8 μm and the tapping density was 2.03 g / ml.

Since the obtained nickel hydroxide particles were spherical or almost spherical, filtration was easy and handling as a powder was easy.

Example 4 Cobalt and cadmium-containing nickel hydroxide particles were obtained in the same manner as in Example 3, except that the following aqueous solution was used instead of the nickel salt aqueous solution used in Example 3.

(A ') Cobalt / cadmium-containing nickel salt aqueous solution: concentration: 2.1 mol of nickel sulfate / 0.03 mol of cobalt sulfate / 0.07 mol of cadmium sulfate / 15 hours corresponding to one cycle of the reaction from A' to D 'in FIG. The cobalt-cadmium-containing nickel hydroxide particles obtained in the meantime were filtered, washed with water and dried in a conventional manner, and the product obtained had an average particle diameter of 6.0 μm and a tapping density of 2.04 g / ml. Was.

Further, the obtained cobalt / cadmium-containing nickel hydroxide particles were also spherical or almost spherical, easy to filter, and easy to handle as powder.

Example 5 Continuous production of nickel hydroxide particles was carried out with stirring using a reactor of the type shown in FIG.

A. Reaction in reaction tank (101): The used aqueous solutions, reaction conditions, etc. are as follows. The reactor volume was 100.

(A) Aqueous nickel salt solution: concentration: 2.2 mol of nickel sulfate / supply amount: 8.0 / hr (b) Aqueous alkali metal hydroxide solution: concentration: 6.0 mol of sodium hydroxide / supply amount: pH of the reaction system during steady-state reaction Amount to be maintained at 11.0 (average supply amount 4.5 / hr) (c) Ammonium ion supplier: Concentration: 25% ammonia water Supply amount: 0.9 / hr (steady state) (d) Conditions in reaction tank at steady state: pH … 11.0 Temperature… 50 ° C Excluding the initial product for 20 hours until the reaction reaches a stable state, and continuing the reaction for 15 hours under the same conditions (X = 15 hours in FIG. 2), water The pH of the reaction system alone was changed to 11.5 by increasing the supply amount of the aqueous sodium oxide solution, and the reaction was carried out under these conditions for 1 hour (Y = 1 hour in FIG. 2). Next, the pH of the reaction system was returned to 11.0, and the reaction was carried out in a steady state for 15 hours. Thereafter, the reaction was repeated in the same cycle.

B. Reaction in reaction tank (201): The used aqueous solutions, reaction conditions and the like are as follows. The reactor volume was 50.

(A) Aqueous nickel salt solution: concentration: 1.1 mol of nickel sulfate / supply amount: 4.0 / hr (b) Aqueous alkali metal hydroxide solution: concentration: 3.0 mol of sodium hydroxide / supply amount: pH of the reaction system during steady-state reaction Amount to be maintained at 11.0 (average supply amount 2.25 / hr) (c) Ammonium ion supplier: Concentration: 12.5% ammonia water Supply amount: 0.45 / hr (steady state) (d) Reaction tank conditions in steady state: pH … 11.0 Temperature… 50 ° C Excluding the initial product for 20 hours until the reaction reaches a stable state, and continuing the reaction for 15 hours under the same conditions (X = 15 hours in FIG. 2), water The pH of the reaction system alone was changed to 11.5 by increasing the supply amount of the aqueous sodium oxide solution, and the reaction was carried out under these conditions for 1 hour (Y = 1 hour in FIG. 2). Next, the pH of the reaction system was returned to 11.0, and the reaction was carried out in a steady state for 15 hours. Thereafter, the reaction was repeated in the same cycle.

C. Mixing operation in the mixing tank (301): The nickel hydroxide particle-containing liquid obtained in each of the reaction tanks (101) and (201) is continuously mixed through the lines (115) and (215). After thoroughly mixing the mixture, the mixture was filtered according to a conventional method, washed with water, and dried. The obtained nickel hydroxide particles were spherical or almost spherical, regardless of the size of the particle size, were easy to filter, and were easy to handle as powder. The average particle size was 7.5 μm, and the tapping density was 2.12 g / ml.

Example 6 (A) A cobalt- and cadmium-containing hydroxide was prepared in the same manner as in the step A of Example 5, except that the following aqueous solution was used instead of the aqueous nickel salt solution used in the step A of Example 5. Nickel particles were obtained.

Concentration: 2.1 mol of nickel sulfate / 0.03 mol of cobalt sulfate / 0.07 mol of cadmium sulfate / (B) Step B of Example 5 except that the following aqueous solution was used instead of the aqueous nickel salt solution used in Step B of Example 5 The same operation as described above was performed to obtain nickel hydroxide particles containing cobalt and cadmium.

Concentration: Nickel sulfate 1.05 mol / Cobalt sulfate 0.015 mol / Cadmium sulfate 0.035 mol / (C) The nickel hydroxide particle-containing liquid obtained in the above steps (A) and (B) is continuously subjected to lines (115) and (215). After passing through to a mixing tank (301), and thoroughly mixed, the mixture was filtered according to a conventional method, washed with water, and dried.

The obtained nickel hydroxide particles were spherical or almost spherical, regardless of the size of the particle size, were easy to filter, and were easy to handle as powder. The particle size and particle size distribution of the nickel hydroxide particles were almost the same as in Example 5.

[Brief description of the drawings]

FIG. 1 is a flow chart showing an example of a reaction apparatus used in carrying out the method of the present invention. FIG. 2 is a diagram showing an example of pH adjustment performed when carrying out the method of the present invention. FIG. 3 is a diagram showing an example of the adjustment of the addition of an ammonium ion donor when the method of the present invention is carried out. FIG. 4 is a flowchart showing another example of the reaction apparatus used in carrying out the method of the present invention. FIG. 5 is a scanning electron micrograph showing the particle structure of nickel hydroxide obtained at a time corresponding to A of FIG. FIG. 6 is a scanning electron micrograph showing the particle structure of nickel hydroxide obtained at a time corresponding to B of FIG. FIG. 7 is a scanning electron micrograph showing the particle structure of nickel hydroxide obtained at a time corresponding to C of FIG. FIG. 8 is a scanning electron micrograph showing the particle structure of nickel hydroxide obtained at a time corresponding to D in FIG. (1) ... reaction tank (3) ... nickel salt aqueous solution supply line (5) ... ammonium ion supplier supply line (7) ... alkali metal hydroxide aqueous solution supply line (9) ... metering pump (11) ) PH controller (13) Temperature controller (15) Nickel hydroxide particle-containing liquid removal line (17) Stirrer (101) Reaction tank (103) Nickel salt aqueous solution supply line (105) ) ... Supply line of ammonium ion supplier (107) ... Supply line of alkali metal hydroxide aqueous solution (109) Metering pump (111) ... pH controller (113) ... Temperature controller (115) ... Nickel hydroxide particles Liquid removal line (117) Stirrer (201) Reaction tank (203) Nickel salt aqueous solution supply line (205) Ammonium ion supply line (207) Alkaline metal hydroxide aqueous solution supply line (209)… Measuring pump (211)… pH controller (213)… Temperature controller (215)… Removal line of nickel hydroxide particle-containing liquid (217)… Stirrer (301) )… Mixing tank (303)… Stirrer

Claims (4)

(57) [Claims] 1. An aqueous nickel salt solution or an aqueous solution containing a nickel salt, a cobalt salt and a cadmium salt.
(B) The aqueous alkali metal hydroxide solution and (c) the ammonium ion donor are continuously supplied to the reaction system, and the temperature of the reaction system is kept at a constant value in the range of 20 to 80 ° C. and the pH is adjusted to 9 to 12. In a method in which nickel hydroxide particles or nickel hydroxide particles containing cobalt and cadmium are produced by advancing the reaction while maintaining a constant value within the range, and the product is continuously taken out, intermittently over a certain period of time. Includes spherical nickel hydroxide particles or cobalt and cadmium characterized by generating nickel hydroxide fine particles as nuclei by increasing the supply amount of alkali metal hydroxide aqueous solution and adjusting the pH of the reaction system A method for producing spherical nickel hydroxide particles. 2. An aqueous nickel salt solution or an aqueous solution containing a nickel salt, a cobalt salt and a cadmium salt.
(B) The aqueous alkali metal hydroxide solution and (c) the ammonium ion donor are continuously supplied to the reaction system, and the temperature of the reaction system is kept at a constant value in the range of 20 to 80 ° C. and the pH is adjusted to 9 to 12. In a method in which nickel hydroxide particles or nickel hydroxide particles containing cobalt and cadmium are produced by advancing the reaction while maintaining a constant value within the range, and the product is continuously taken out, intermittently over a certain period of time. By stopping or reducing the supply of the ammonium ion donor to the reaction system, spherical nickel hydroxide particles or cobalt and cadmium characterized by generating nickel hydroxide fine particles serving as nuclei. For producing spherical nickel hydroxide particles containing the same. 3. An aqueous nickel salt solution or an aqueous solution containing a nickel salt, a cobalt salt and a cadmium salt.
(B) The aqueous alkali metal hydroxide solution and (c) the ammonium ion donor are continuously supplied to the reaction system, and the temperature of the reaction system is kept at a constant value in the range of 20 to 80 ° C. and the pH is adjusted to 9 to 12. In a method in which nickel hydroxide particles or nickel hydroxide particles containing cobalt and cadmium are produced by allowing the reaction to proceed while maintaining a constant value within the range, and the product is continuously taken out, different conditions are used in a plurality of reaction systems. The reaction is carried out below to form a group of particles having different particle diameters, and in each reaction system, the pH of the reaction system is adjusted by increasing the supply amount of the aqueous alkali metal hydroxide solution for a certain period of time intermittently. By generating nickel hydroxide fine particles serving as a nucleus and mixing the particle groups having different particle diameters obtained above, a mixed particle having a predetermined particle size distribution is obtained. A method for producing nickel hydroxide particles or spherical nickel hydroxide particles containing cobalt and cadmium. 4. An aqueous nickel salt solution or an aqueous solution containing a nickel salt, a cobalt salt and a cadmium salt.
(B) The aqueous alkali metal hydroxide solution and (c) the ammonium ion donor are continuously supplied to the reaction system, and the temperature of the reaction system is kept at a constant value in the range of 20 to 80 ° C. and the pH is adjusted to 9 to 12. In a method in which nickel hydroxide particles or nickel hydroxide particles containing cobalt and cadmium are produced by allowing the reaction to proceed while maintaining a constant value within the range, and the product is continuously taken out, different conditions are used in a plurality of reaction systems. The reaction is performed below to form a group of particles having different particle sizes, and in each reaction system, the supply of the ammonium ion donor to the reaction system is intermittently stopped for a certain period of time or the supply amount is reduced. Thereby, nickel hydroxide fine particles serving as a nucleus are generated, and by mixing the particle groups having different particle diameters obtained above, mixed particles having a predetermined particle size distribution are obtained. Method for producing spherical nickel hydroxide particles comprising spherical nickel hydroxide particles or cobalt and cadmium, wherein Rukoto.