JP3353600B2 - Apparatus and method for producing nickel hydroxide powder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is an alkali secondary batteries
The present invention relates to a production apparatus and a production method for a nickel hydroxide powder used in the present invention.

[0002]

2. Description of the Related Art Conventional methods for producing nickel hydroxide include a method in which an aqueous solution of sodium hydroxide and an aqueous solution of nickel salt are mixed to carry out a neutralization reaction, or a method in which ammonium ions are supplied to an aqueous solution of nickel salt to adjust the pH. After doing
A method of adding an alkali hydroxide to precipitate a hydroxide (Japanese Patent Publication No. 53-6119) has been proposed and put to practical use. As a method of internally adding cobalt or the like to the nickel hydroxide powder, a cobalt salt and a cadmium salt are added to the above nickel salt solution, or a cobalt salt is quantitatively added to an alkali hydroxide to be reacted with the nickel salt solution. And a method of adding a cadmium salt.

An example of a conventional synthesizing apparatus used in the above synthesizing method will be described with reference to FIG. In FIG. 2, reference numeral 22 denotes a reaction tank equipped with a stirrer. A nickel salt aqueous solution is supplied from a pipeline 23, an ammonia water is supplied from a pipeline 24, and an alkaline aqueous solution is supplied from a pipeline 25 to the tank via a quantitative pump. Is done. 26 is a pH sensor for detecting the pH value of the solution in the tank, and 27 is a temperature sensor. The suspension containing the generated nickel hydroxide particles is continuously withdrawn from the discharge pipeline 28 to the outside. The suspension obtained by the neutralization reaction is subjected to treatments such as washing with water and drying to obtain nickel hydroxide powder. When the reaction is carried out under the conditions shown in FIG. 2, the supply amounts of the nickel salt solution and aqueous ammonia in the reaction system are kept constant, and the temperature during the reaction is 20 to 80.
The pH and the pH are maintained in the range of 9 to 13 by adjusting the alkaline solution. Thus, a nickel hydroxide powder having a certain particle size distribution and an average particle diameter of about 2 to 50 μm is obtained.

[0004]

However, in the above-described production method and apparatus, in order to obtain powder having the same particle size, the conditions in the reaction tank must be kept constant.
Also, changing the supply amount of the metal salt solution to change the amount of the internal additive changes the salt concentration in the reaction tank, the particle size, the physical properties of the powder, etc. change rapidly, and the uniform spherical shape Alternatively, a nickel hydroxide powder having a nearly spherical shape cannot be obtained.

In order to continuously synthesize nickel hydroxide powders having different internal additive compositions, two or more reaction tanks for synthesizing nickel hydroxide are required, and a mixing step tank is also required. In the process tank, it is difficult to perform uniform mixing in units of particles.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a method and apparatus for producing a nickel hydroxide powder that can be obtained at low cost and with high productivity by uniformly mixing nickel hydroxide powders having different internal additive compositions in particle units. To provide.

[0007]

Means for Solving the Problems In order to solve the above problems, the apparatus for producing nickel hydroxide powder of the present invention synthesizes a nickel ammonium complex with a reaction tank for continuously crystallizing nickel hydroxide. The nickel ammonium complex synthesis tank is mainly provided with a pure water supply device for adjusting the concentration of the nickel salt solution and the metal salt solution of the additive, and the nickel ammonium complex synthesis tank includes a nickel salt solution synthesis tank and a metal salt solution synthesis tank. A certain amount of solution is supplied.

[0008] With the above structure, the ion concentration of the raw material supplied to the reaction tank for continuously performing the crystallization reaction is always constant, so that the crystallization reaction does not change rapidly and the composition and the like are not changed. Even if it changes, a uniform product will be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention defines a production apparatus, and comprises a reaction tank for continuously performing a crystallization reaction, a nickel ammonium complex synthesis tank,
Since it is equipped with a pure water supply device that adjusts the concentration of the nickel salt solution and the metal salt solution of the additive, it is possible to obtain nickel hydroxide powder having a uniform composition and differing only in the amount of the additive. By providing a pure water supply pump for adjusting the concentration supplied to the solution and a supply amount adjusting device, the ion concentration of the metal salt solution and the nickel salt solution can be kept constant.

According to a second aspect of the present invention, a step of adjusting the concentration of a metal salt solution with pure water, a step of adjusting the concentration of a nickel salt solution with pure water, and using the resulting solution as a starting material, By the step of synthesizing a nickel ammonium complex from this starting material and aqueous ammonia and the step of reacting the ammonium complex with an alkali, only the composition of the internal additive is homogeneously mixed in units of particles and according to the concentration of the metal salt solution. Different nickel hydroxide powders are obtained.

According to the third aspect of the present invention, a mixed powder of nickel hydroxide powders having different additive compositions can be continuously obtained, and the productivity can be improved. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of an apparatus for producing nickel hydroxide powder according to the present invention. In FIG. 1, reference numeral 1 denotes a reaction tank for continuously performing a crystallization reaction, and 2 denotes a stirrer for uniformly performing a crystallization reaction in the reaction tank. It is installed as follows. Reference numeral 3 denotes a heater for controlling the temperature in the reaction tank, and the heater is controlled by a temperature controller. 4 is a supply port of an alkaline aqueous solution for adjusting the pH value in the reaction tank, 5 is a pH sensor for measuring the pH value in the reaction tank,
6 is a supply pipeline of the nickel ammonium complex solution. 7 is a lid for preventing the volatilization of ammonia gas;
Is an outlet of the suspension containing the synthesized nickel hydroxide powder. Further, the ammonium complex supplied from the line 6 is synthesized in the synthesis tank 9 from ammonia water from the metering pump 10 and a nickel salt solution containing a metal salt as an additive from the metering pump 11. The nickel salt solution containing the metal salt as an additive is adjusted by mixing the nickel salt solution from the 14 metering pump and the metal salt solution as the additive from the 13 metering pump in the mixing tank 12. Reference numeral 17 denotes a synthesis tank for a metal salt solution as an additive.
Reference numeral 5 denotes a supply port of a constant concentration metal salt solution from a metering pump. 18 is a synthetic tank nickel salt solution, 16 is a supply port from the metering pump of nickel salt solution having a constant concentration. Reference numeral 21 denotes a supply control device for controlling the amount of pure water to be added to the metal salt solution synthesizing tank 17 and the nickel salt solution synthesizing tank 18 so as to be always constant. This is a pipe connecting the tank and the nickel salt solution synthesis tank with the supply amount control device. Here, the nickel ammonium complex in the synthesis tank 9 is synthesized by maintaining the pH value and the respective supply amounts of ammonia water at 0 to 6 mol / l with respect to 1 mol / l of the nickel salt solution. . The amount of the additive to the nickel salt solution used at that time is controlled by changing the supply amount of the 21 pure water supply device. Hereinafter, the nickel hydroxide powder synthesized by the nickel hydroxide powder manufacturing apparatus configured as described above will be described in more detail.

[0013]

EXAMPLE A nickel hydroxide powder was continuously synthesized using the apparatus for producing nickel hydroxide powder shown in FIG.
The used aqueous solutions and reaction conditions are as follows.
The volumes of the used nickel hydroxide synthesizing tank and the nickel ammonium complex synthesizing tank were 7 l, and the mixing tank of the nickel salt solution containing the metal salt as an additive was 20 l.

Nickel sulfate is used as a nickel salt at the start of nickel hydroxide synthesis, and the concentration of the solution is 1.0 mol / mol.
The metal salt to be dissolved, for example, cobalt sulfate, was adjusted by the amount of pure water so that the amount was 1.4% by weight.

The concentration of the aqueous ammonia is 2.0 mol / mol.
1. The feed rate to the nickel ammonium complex synthesis tank was 210 ml / hr for the nickel salt solution and 10
It was adjusted to 5 ml / hr. A nickel ammonium complex was synthesized under the above conditions and supplied to a nickel hydroxide synthesis tank. The average residence time in the nickel ammonium complex synthesis tank was about 22 hours, and the ratio of aqueous ammonia to the nickel salt solution was controlled by the pH value in the nickel ammonium complex synthesis tank. The concentration of the aqueous alkali solution supplied to the nickel hydroxide synthesis tank was 2.0 mol / mol.
1 and the supply rate was 210 ml / hr. The condition in the nickel hydroxide synthesis tank in a steady state is a pH value of 1
Synthesis was performed at 2.7 at a temperature of 35 ° C.

The nickel hydroxide powder is synthesized under the above conditions, and the residence time in the nickel hydroxide synthesis tank is about 13 hours. On the sixth day after the crystallization reaction was started, the amount of pure water was adjusted so that the amount of cobalt sulfate dissolved in the nickel salt solution was 4.0% by weight. As a result, the obtained cobalt-containing nickel hydroxide powder was spherical nickel hydroxide having an average particle diameter of 10 μm and a tapping density of 2.0 g / cc or more.
Here, it can be seen that the amount of cobalt as an internal additive gradually increases after changing the concentration of cobalt dissolved in the nickel salt solution as shown in FIG. After that, when the internal addition amount of the above nickel salt solution is adjusted to pure water amount every day, the internal additive composition of the obtained nickel hydroxide powder changes periodically, and the final nickel hydroxide As the powder, a powder in which the internal additive composition was mixed was obtained.

Here, cobalt sulfate is used as an internal additive, but any metal salt such as zinc sulfate, cobalt nitrate, cadmium sulfate, manganese nitrate, lithium nitrate, etc. may be used, and two or more types of additives may be used. Can also. The amount of the internal additive is nickel 100
% In the range of 0 to 50% by weight.

[0018]

As described above, a reaction tank for continuously performing a crystallization reaction, a synthesis tank for synthesizing a nickel ammonium complex, a supply means for supplying an aqueous ammonia solution to the nickel ammonium complex synthesis tank, A supply means for supplying a nickel salt solution containing the additive to the synthesis tank is provided, and the nickel salt solution mixing tank containing the additive metal is used for supplying the mixing tank and the additive metal salt solution to the synthesis tank. By providing a supply means, a supply means for supplying the nickel salt solution to the synthesis tank, and a pure water supply device for adjusting the concentration of the nickel salt solution and the metal salt solution of the additive, the particles are homogeneously mixed in units of particles. Further, nickel hydroxide powders having different internal additive compositions can be produced at low cost with improved productivity.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for synthesizing nickel hydroxide powder for carrying out the present invention.

FIG. 2 is a schematic view of a conventional nickel hydroxide powder synthesizing apparatus.

FIG. 3 is a graph showing the change over time in the amount of cobalt added to the nickel hydroxide powder obtained in an example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction tank 2 Stirrer 3 Heater 5 pH sensor 9 Mixing tank 10 Ammonia water 12 Mixing tank 13 Metal salt solution 14 Nickel salt solution 17 Metal salt solution synthesizing tank 18 Nickel salt solution synthesizing tank 21 Pure water supply device

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Kamiya 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. Field (Int.Cl. ⁷ , DB name) H01M 4/52 C01G 53/04

Claims (3)

(57) [Claims] 1. A reaction tank having a discharge port for continuously crystallizing nickel hydroxide from a supplied reaction solution and discharging a suspension containing the generated nickel hydroxide to the outside, A stirrer for stirring the reaction liquid and a sensor for measuring the pH of the reaction liquid, a heating device for externally heating the reaction tank, and an alkali aqueous solution supply means for supplying an alkaline aqueous solution to the reaction tank are provided. means for supplying to the reaction vessel of nickel ammonium complex solution, a mixing tank for mixed-metal salt solution is additive nickel salt solution, a nickel salt solution and aqueous ammonia added was mixed from the mixing tank And a synthesizing tank for synthesizing a nickel ammonium complex. 2. A step of adjusting the concentration of the metal salt solution with pure water.
A step of adjusting the concentration of the nickel salt solution with pure water, and a step of synthesizing a nickel ammonium complex from this starting material and aqueous ammonia using the obtained solution as a starting material,
Adding an alkaline solution to the obtained nickel ammonium complex solution and reacting the solution. 3. The method for producing nickel hydroxide powder according to claim 2, wherein in the step of reacting , a mixed powder of nickel hydroxide powders having different additive compositions is continuously obtained.