JP2001335326A - Method for manufacturing basic nickel carbonates - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method of cost effectively manufacturing basic nickel carbonates of high bulk density, which is proper to a use for nickel supplementation in a nickel bath in nickel-plating. SOLUTION: At least one nickelate solution among nickel sulfate, nickel nitrate and nickel chloride, at least one alkali carbonate solution selected from sodium carbonate, ammonium carbonate, potassium carbonate and lithium carbonate as a neutralizer, and carbon dioxide are quantitatively and simultaneously fed to a reactor. The generated basic nickel carbonate is successively taken out from the reactor to obtain the basic nickel carbonate of the tapping bulk density of 0.5 to 1.5 g/ml.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing basic nickel carbonate, and more particularly to a method for producing basic nickel carbonate having a high bulk density.

[0002]

2. Description of the Related Art Basic nickel carbonate has been used for replenishing nickel in a nickel plating bath. In order to produce the basic nickel carbonate, a method has generally been employed in which a nickel sulfate solution is neutralized with an alkali carbonate such as sodium carbonate in a reaction vessel to produce a basic nickel carbonate.

However, in the case of this production method, a bulky basic nickel carbonate having a very large water retention capacity is generated, it is difficult to remove impurities and by-products by washing, and powder which tends to generate dust after drying is obtained. There was a problem that is.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a powder of basic nickel carbonate having a high bulk density, which is suitable for use as a replenisher for nickel in a nickel bath when performing nickel plating. It is an object of the present invention to provide a method for economically producing the same.

[0005]

In order to solve the above problems, the present invention provides a method for simultaneously and quantitatively supplying a nickel salt solution, an alkali carbonate solution as a neutralizing agent, and carbon dioxide gas into a reaction tank. The tapping bulk density is 0.5 g, characterized by continuously taking out the generated basic nickel carbonate.
This is a method for producing basic nickel carbonate at a concentration of 1.5 g / ml to 1.5 g / ml.

In the above method, the nickel salt solution is preferably at least one of nickel sulfate, nickel nitrate and nickel chloride, and the alkali carbonate solution used as a neutralizing agent is sodium carbonate, ammonium carbonate. , Potassium carbonate, and lithium carbonate.

The supply amount of the alkali carbonate used as the neutralizing agent is 1.
The blowing amount of carbon dioxide gas is preferably 3 to 8 times the molar ratio of the carbonic acid amount of the excess alkali carbonate supplied.

In the above method for producing basic nickel carbonate, by setting the residence time in the reaction system to 2 hours or more and 10 hours or less, high-density basic nickel carbonate can be economically produced.

[0009]

DETAILED DESCRIPTION OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to continuously produce basic nickel carbonate having a high bulk density. Thus, a basic nickel carbonate powder suitable for nickel plating is obtained. Hereinafter, the present invention will be described in detail.

As described above, conventionally used basic nickel carbonate has a fine powdery and bulky shape, has a high dusting property, and has many problems in handling. The tapping bulk density of these conventional basic nickel carbonates is usually 0.5 g /
Milliliters or less and the tapping bulk density is
If it is 5 g / ml or more, preferably 0.8 g / ml or more, the above problem can be solved, and it is advantageous when packing as a product. Further, the upper limit of the tapping density of the basic nickel carbonate obtained by the method of the present invention,
It was about 1.5 g / milliliter.

The neutralizing agent used in the present invention is an alkali carbonate. As for the supply of the alkali carbonate to the reaction tank, it is desirable to continuously supply 1.05 to 1.2 times the neutralization equivalent of the supplied nickel.

If the supply of alkali carbonate is set to 1.05 times or less, carbonate ions in the liquid will decrease, and nickel which cannot be neutralized will be present in the liquid, and unreacted nickel will be discharged out of the system. In addition to reducing the yield, basic nickel carbonate having a low bulk density without grain growth is produced. Also,
If the ratio is 1.2 times or more, excess alkali carbonate not contributing to the reaction will only be lost.

The present invention is characterized in that carbon dioxide gas is blown into the reaction tank. The amount of carbon dioxide gas blown is desirably 3 to 8 times the molar ratio of the amount of carbonic acid of the alkali carbonate added in excess of the neutralization equivalent of the nickel salt.

If the amount of carbon dioxide gas blown is insufficient, fine basic nickel carbonate is generated, the bulk density becomes low, and washing and filtering in the next step become difficult. Also, if the amount of carbon dioxide is too large, the loss of carbon dioxide increases, and although basic nickel carbonate having a high bulk density is generated, the amount of nickel eluted into the liquid also increases, and the loss of nickel cannot be ignored. . At the same time, wastewater treatment is affected and the cost increases, which is industrially disadvantageous.

Next, in the present invention, there is no need to control the concentration of hydrogen ions when producing basic nickel carbonate.
The reason is that when the injected carbon dioxide gas dissolves in the liquid, the hydrogen ion concentration in the tank is kept constant by the buffering action with the carbonate present in the liquid. At the same time, nickel also has solubility in the excess carbonate ion solution, and can crystallize while repeating dissolution and precipitation to grow particles of basic nickel carbonate.

The residence time of the basic nickel carbonate in the reaction tank in the reaction system of the present invention may be appropriately selected depending on the particle size and bulk density of the basic nickel carbonate to be produced. It is desirable to do.

If the residence time in the reaction system is set to 2 hours or less, the particles of basic nickel carbonate are discharged at the stage of growth, and not only basic nickel carbonate having a high bulk density cannot be obtained, but also the yield of nickel is reduced. Decrease. In addition, if the bulk density is low, the generated basic nickel carbonate is finely suspended in the liquid during washing, filtration and drying, resulting in loss, or dusting in the air at the time of packing and handling, which worsens the working environment. There are also problems.

On the other hand, even if a residence time of 10 hours or more is secured, it cannot be said that this method is economical in view of the fact that some of the particles may collapse at the stage of growth or a decrease in productivity.

[0019]

EXAMPLES (Example 1) Nickel chloride concentration: 220 g /
A liter of nickel chloride aqueous solution and a sodium carbonate concentration of 200 g / liter sodium carbonate aqueous solution were prepared.

Next, the nickel chloride aqueous solution and the sodium carbonate aqueous solution were each mixed at 18.5 ml / min (retention time) while stirring the inside of the reaction vessel having an inner volume of 11 liter filled with the aqueous sodium chloride solution with a stirrer at 200 rpm. (Time 5 hours), and further, carbon dioxide gas was added at 0.1 times.
Basic nickel carbonate was continuously produced by blowing at a flow rate of 5 liter / min. Take out the nickel carbonate suspension by overflow, after filtration, further washed with pure water,
Basic nickel carbonate was obtained. At this time, the added amount of the alkali carbonate was 1.1 times the theoretical equivalent, and the blowing amount of the carbon dioxide gas was 7.5 times the theoretical amount.

10 g of the produced nickel carbonate was placed in a 20 ml measuring cylinder, and the cylinder was tapped 500 times to obtain 11.1 ml. From this, the tapping bulk density was 0.9 g / ml. The obtained powder had fluidity and was easy to handle. Further, when the obtained basic nickel carbonate was added to the chloride-based electrolytic plating solution, it was easily dissolved.

When the basic nickel carbonate formed was analyzed, no sulfur was detected and the content of chlorine was 0.01% or less.

(Example 2) [0023] Except that the volume of the reaction vessel was 1.6 liters, the supply amount of each liquid was 3 ml / min, and the blowing amount of carbon dioxide gas was 80 ml / min.
Nickel carbonate was produced in the same manner as in Example 1. At this time, the addition amount of the alkali carbonate is 1.1 times the theoretical equivalent,
The blowing amount of carbon dioxide gas was 7.5 times the theoretical amount.

The produced basic nickel carbonate was tapped in the same manner as in Example 1 to obtain 10.5 ml. From this, the tapping bulk density was 0.95 g /
Milliliters. The resulting powder is fluid,
It was easy to handle. Also, when added to the chloride-based electrolytic plating solution, it was easily dissolved.

When the basic nickel carbonate formed was analyzed, no sulfur was detected and chlorine was 0.01%.
It was below.

Example 3 Nickel carbonate was produced under the same conditions as in Example 1 except that the nickel salt solution was an aqueous solution of nickel sulfate having a nickel sulfate concentration of 260 g / liter.

The resulting basic nickel carbonate was tapped in the same manner as in Example 1 to obtain 11.6 ml. From this, the tapping bulk density was 0.86 g /
Milliliters. The powder was fluid and easy to handle. When added to the chloride-based electrolytic plating solution, it dissolved easily. When the generated basic nickel carbonate was analyzed, a sulfur content of 0.2% was detected.

Comparative Example 1 Nickel carbonate was produced under the same conditions as in Example 1 except that no carbon dioxide gas was blown. The produced nickel carbonate was very bulky, retained a large amount of water during washing and filtration, and required a large amount of water and time until the filtrate became neutral. When 5 g of this nickel carbonate was put into a 20 ml graduated cylinder and covered so as not to be spilled, the cylinder was tapped 500 times.
It became 4 ml. From this, the tapping bulk density was 0.44 g / ml.

The powder generated a great deal of dust and was difficult to handle. Also, when added to the chloride-based electrolytic plating solution, it was easily dissolved.

When the formed basic nickel carbonate was analyzed, no sulfur was detected. In addition, chlorine is 0.1
5%.

(Comparative Example 2) The same as Example 3 except that instead of blowing in carbon dioxide gas, the pH was controlled, the pH value was targeted at 7.89, and neutralization was performed within an error range of 0.02. The production of nickel carbonate was attempted under difficult conditions, but the production was extremely difficult. In this production method, when the control value of the pH fluctuated and the error range fluctuated toward the neutral side, fine powder was generated. When the pH became alkaline, particles having a large bulk but a low bulk density were formed. By optimizing the pH value, stirring, and the like in the tank, a powder having desired characteristics was obtained, but the production was very difficult.

10 g of the produced basic nickel carbonate was added to 20
Tapping the cylinder 500 times in a milliliter graduated cylinder yielded 11.6 milliliters.
From this, the tapping bulk density was 0.93 g / ml. The powder was fluid and easy to handle. When added to the chloride-based electrolytic plating solution, it dissolved easily. When the obtained basic nickel carbonate was analyzed, 0.3% of sulfur was detected.

As to the basic nickel carbonate produced when the reaction was unstable, the basic nickel carbonate produced on the neutral side was fine and bulky similar to that of Comparative Example 1,
The powder had a low tap density. In addition, the powder produced under alkaline conditions had a very low bulk density and was a powder that easily generated dust.

[0034]

According to the method of the present invention, a powder of basic nickel carbonate having a high bulk density and suitable for use as a replenisher for nickel in a nickel bath at the time of nickel plating can be economically produced.

Claims (6)

[Claims] 1. A tapping bulk density of 0.1, characterized by simultaneously and quantitatively supplying a nickel salt solution, an alkali carbonate solution, and carbon dioxide gas to a reaction vessel and continuously taking out basic nickel carbonate produced. A method for producing basic nickel carbonate having a content of 5 g / milliliter to 1.5 g / milliliter. 2. The method for producing basic nickel carbonate according to claim 1, wherein the nickel salt solution is at least one kind of solution among nickel sulfate, nickel nitrate and nickel chloride. 3. The method according to claim 1, wherein the alkali carbonate solution used as the neutralizing agent is at least one aqueous solution selected from sodium carbonate, ammonium carbonate, potassium carbonate, and lithium carbonate. A method for producing basic nickel carbonate. 4. The production of basic nickel carbonate according to claim 3, wherein the supply amount of the alkali carbonate used as the neutralizing agent is 1.05 to 1.2 times the neutralization equivalent of the nickel salt solution supplied. Method. 5. The method for producing basic nickel carbonate according to claim 1, wherein the amount of carbon dioxide blown is 3 to 8 times the molar ratio of the amount of carbonic acid of the excess alkali carbonate supplied. 6. The method for producing basic nickel carbonate according to claim 1, wherein the residence time in the reaction vessel is 2 hours or more and 10 hours or less.