JPH09176898A - Method for supplying nickel ion to plating solution and equipment therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an equipment for supplying nickel ion to a nickel plating soln. by which the dissolving rate is increased when metallic nickel is chemically dissolved by using a metallic nickel dissolving tank and the productivity of a continuous nickel electroplating equipment is improved. SOLUTION: In a nickel electroplating equipment of metallic strip using an insoluble anode, nickel ion is supplied to a plating soln. as a supply raw material, a metallic nickel having 0.01-1.0m<2> /g specific surface is used, and the metallic nickel is incorporated by the amt. of 2-20 times the saturation solubility into a plating soln. kept at 70-100 deg.C and pH1-2, and chemically dissolved. Meanwhile, the equipment for supplying nickel ion to the plating soln. is provided with an electroplating tank 1, plating soln. circulating tank 2, metallic nickel dissolving tank 5, filter 7 for filtering a plating soln. contg. undissolved metallic nickel, plating soln. receiving tank 9 storing a filtered plating soln. and supplying it to the circulating tank 2 and means 8 for transferring the undissolved nickel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nickel-based continuous electroplating facility for a metal strip such as a steel strip using an insoluble anode, which is used to replenish the plating solution with consumed nickel ions. Supply method and equipment.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for improved corrosion resistance in automobiles, home appliances and the like, and in addition to the galvanized steel sheets that have been conventionally used, there is a marked demand for nickel-containing alloy plated steel sheets such as zinc-nickel alloy plated steel sheets. It has increased. In order to cope with such an increase in demand, high-speed electroplating method with high current density that enables high-efficiency production is adopted.However, in the high-speed electroplating method, the anode is more preferable than the soluble anode method, which requires frequent replacement of the anode. It goes without saying that a method of using an insoluble anode such as an iridium-based material that does not require replacement and continuously replenishing metal ions such as consumed nickel ions into the plating solution is advantageous.

As a method of supplying metal ions such as nickel ions to the plating solution, a method of dissolving in the form of a metal compound such as nickel oxide or nickel carbonate, or a method of providing electrolytic equipment to dissolve nickel metal by electrolysis (JP-A-1-234598, JP-A-4-1390)
No. 0, JP 4-99198 A, JP 5-2
5700), and a method in which metallic nickel or the like is directly brought into contact with an acidic plating solution and chemically dissolved.

In the above-mentioned method using a metal compound, the metal compound such as nickel carbonate is an expensive industrial chemical, which is one of the factors that hinder the cost reduction, and because it is a fine powder, it also causes environmental problems such as dust generation. In addition, impurities such as sodium, calcium, chlorine, and silicon usually contained in these metal compounds cause the following problems.

That is, since sodium improves the electric conductivity of the plating bath, if it is present in excess, it causes abnormal plating such as "plating burn". Since calcium is not consumed in the plating operation, it is accumulated in the plating bath and, when saturated, precipitates as gypsum and causes troubles such as pipe blockage. Chlorine reduces the plating adhesion when the concentration in the plating bath increases.

Further, when the concentration of silicon in the plating bath becomes high, silicon reacts with iron in the plating bath to form a highly adherent compound, which causes troubles such as clogging of pipes like calcium. Therefore, in nickel-based electroplating equipment that uses a metal compound as a nickel ion source, it is common to provide dedicated equipment for removing these impurities, but the equipment is complicated and maintenance of the equipment is difficult. There was a problem that various kinds were needed.

On the other hand, in the above-described method using metallic nickel, the metallic nickel is cheaper at a price per unit weight of nickel of 50 to 60% as compared with metallic compounds, which is industrially advantageous. . However, in the case of the method of dissolving metallic nickel by electrolysis, there is a problem that not only the power cost is large, but also the equipment itself becomes large-scale.

Although the method of directly contacting metal nickel with a plating solution and chemically dissolving the same is not problematic in terms of cost and working environment, it is used for Zn-Ni alloy electroplating, which is the object of the present invention. It was difficult to dissolve a large amount of metallic nickel in a short time because the dissolution rate was low at the acid concentration of the nickel-based plating solution.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems of the prior art, to increase the dissolution rate when chemically dissolving metallic nickel using a metallic nickel dissolving tank, and An object of the present invention is to provide a method and equipment for supplying nickel ions to a nickel-based plating solution capable of improving the productivity of electroplating equipment and further downsizing the metal nickel dissolving tank and its associated equipment.

[0010]

The first aspect of the present invention is a method for supplying nickel ions to a plating solution in a nickel-based electroplating equipment for metal strips using an insoluble anode, wherein the specific surface area is 0.01 to 1.0 m ² as a feed material. / g granularity and /
Alternatively, flaky metallic nickel is used, and 2 to 20 times the saturated amount of the metallic nickel is dissolved in the acidic plating solution in which the liquid temperature in the metallic nickel dissolving tank is maintained at 70 to 100 ° C and the pH is 1 to 2. It is a method for supplying nickel ions to a plating solution, which comprises stirring and stirring the acidic plating solution.

In the first aspect of the present invention, the undissolved metal nickel-containing plating solution is extracted from the metal nickel dissolution tank and supplied to a filter, and the plating solution, which is a filter filtrate, is electrically supplied via a plating solution receiving tank. Supply to the plating tank,
It is preferable to circulate the undissolved metallic nickel or the concentrated metallic nickel plating solution, which is the filter residue, in the metallic nickel dissolving tank for re-dissolution.

Further, in the first aspect of the present invention, it is preferable that the filter is a porous body having a plurality of liquid passages in the axial direction. Furthermore, the first
In the invention, the concentration of nickel ions in the plating solution transferred to the plating solution receiving tank is measured, and a plating solution corresponding to the amount of nickel ions consumed in the electroplating tank is supplied from the plating solution receiving tank to the electroplating tank. Preferably.

A second aspect of the present invention is a nickel ion supply facility for a plating solution arranged in a nickel-based electroplating facility for a metal strip using an insoluble anode, the nickel ion supply facility being used in the electroplating tank 1. A plating solution circulating tank 2 for circulatingly supplying the plating solution, a metal nickel dissolving tank 5 for dissolving metal nickel in the plating solution transferred from the plating solution circulating tank 2, and an undissolved metal extracted from the metal nickel dissolving tank 5. Filter 7 for filtering nickel-containing plating solution
And a plating solution receiving tank 9 for storing a plating solution which is a filtered solution from the filter 7 and supplying the plating solution to the plating solution circulating tank 2, and an undissolved metal which is a filter filtration residue from the filter 7. An undissolved metallic nickel transfer means 8 for transferring a nickel or metallic nickel concentrated plating solution to the metallic nickel dissolving tank 5; and a nickel ion concentration measuring device 16 for the plating solution in the plating solution receiving tank 9. This is a facility for supplying nickel ions to the plating solution.

In the second invention, the filter 7 is used.
Is preferably a filter composed of a porous body having a plurality of liquid passages in the axial direction.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. INDUSTRIAL APPLICABILITY The present invention is preferably applied as a method for supplying nickel ions to an acidic plating solution in Ni-based electroplating such as Zn-Ni alloy electroplating and Zn-Ni-Cr alloy electroplating.

Further, in order to solve the problems of the method using the above metal compound and the metal nickel electrolysis method, the present invention is an economical and simple method by chemically dissolving metal nickel in a plating solution. A method and equipment capable of rapidly supplying nickel ions into a plating solution in the equipment. FIG. 3 shows the electroplating equipment according to the present invention.

In FIG. 3, 1 is an electroplating tank, 2 is a plating solution circulating tank, 3 is a temperature raising tank, 4 is a metal nickel storage hopper, 5 is a metal nickel dissolving tank, 6 is a stirrer, 7 is a filter, and 8 is Undissolved metallic nickel transfer means, 9 is a plating solution receiving tank, 10, 11 and 12 are plating solution feeding pumps, 13 is a stirrer motor, 14 is a heat-up heat exchanger, 15 is a heat exchanger for cooling, 16,
Reference numerals 17 and 18 indicate a nickel ion concentration measuring device for plating solution, 19 indicates a metal strip such as a steel strip, 20 indicates a traveling direction of the metal strip, 21 indicates a backup roll, 22 indicates a conductor roll, and 23 and 24 indicate insoluble anodes.

In the plating solution nickel ion concentration measuring devices 16, 17, and 18, only the plating solution sample collecting device or the sensor is individually attached to the plating solution receiving tank 9, the plating solution circulating tank 2, and the temperature raising tank 3. The main unit of the measuring device may be used as a single unit,
There is no limit. The method and apparatus for supplying nickel ions to the plating solution of the present invention will be described below with reference to FIG.

The nickel ion-containing plating solution circulates between the electroplating tank 1 and the plating solution circulating tank 2. The metal strip 19 such as a steel strip is electroplated in the electroplating tank 1 according to the reaction of the following equation (1), and at that time, the nickel ion concentration in the plating solution is reduced. Ni ²⁺ ＋ 2e ⁻ → Ni ・ ・ ・ ・ (1) Acid plating solution such as sulfuric acid plating solution extracted from the plating solution circulation tank 2 is transferred to the temperature raising tank 3 by the plating solution feeding pump 10 and vaporized. After the temperature is raised by a heat-up heat exchanger 14 composed of a heater, an electric heater, etc., it is supplied to a metal nickel melting tank (hereinafter referred to as a melting tank) 5.

In the melting tank 5, the metallic nickel charged from the metallic nickel storage hopper 4 is stirred in a plating solution by a stirring machine 6 of an impeller type or a pump type.
Chemically dissolve according to the following formulas (2) and (3), and supply nickel ions into the plating solution. Ni → Ni ²⁺ + 2e ⁻ ··· (2) 2H ⁺ + 2e ⁻ → H ₂ ↑ ··· (3) Undissolved metallic nickel-containing plating solution withdrawn from the dissolution tank 5 at intervals or continuously. Is transferred to the filter 7 by the plating solution feed pump 11, and the plating solution which is the filter filtrate is passed through the plating solution receiving tank 9 and the plating solution circulating tank 2 by the plating solution feed pump 12 and the like to the electroplating tank. Supply to 1.

The plating solution is cooled by the cooling heat exchanger 15 of the plating solution receiving tank 9 to a preferable plating solution temperature in the electroplating tank 1. Further, in the present invention, the plating solution transferred to the plating solution receiving tank 9 and the plating solution in the plating solution circulating tank 2 and the nickel ion concentration of each are measured by nickel ion concentration measuring devices 16 and 17, and the electroplating tank It is preferable that the plating solution corresponding to the amount of nickel ions consumed in 1 is supplied from the plating solution receiving tank 9 to the electroplating tank 1 via the plating solution circulating tank 2.

It is more accurate to measure the nickel ion concentration of the plating solution in the temperature raising tank 3 by the nickel ion concentration measuring device 18 instead of measuring the nickel ion concentration of the plating solution in the plating solution circulating tank 2. Good concentration control is possible and more preferable. On the other hand, the undissolved metallic nickel or the undissolved metallic nickel-containing plating solution (hereinafter referred to as the metallic nickel concentrated plating solution), which is the filter residue, is dissolved by the undissolved metallic nickel transfer means 8 such as a conveyor, a screw feeder or a pump. It circulates in the tank 5 and is used for redissolution.

The state of the undissolved metallic nickel circulated in the metallic nickel dissolving tank 5 includes a slurry state. Hereinafter, preferred embodiments of the present invention and their effects will be described. As described above, when an insoluble anode is used as the anode of the electroplating bath, it is necessary to replenish nickel ions from the outside.
The method of the present invention is performed by chemically dissolving metallic nickel in an acidic plating solution.

However, metallic nickel has, for example, a pH of 1:
In the present invention, in order to increase the dissolution rate, in the present invention, granular and / or flaky metallic nickel having a specific surface area of 0.01 to 1.0 m ² / g is used. Used as a raw material, the metallic nickel is charged and dissolved in an acidic plating solution in which the liquid temperature is maintained at 70 to 100 ° C. and the pH is maintained at 1 to 2 in the melting tank.

When the specific surface area of the metallic nickel is less than 0.01 m ² / g, the contact area between the metallic nickel and the plating solution is small, and the target dissolution rate cannot be obtained. Conversely, when the specific surface area of the metallic nickel exceeds 1.0 m ² / g. It is difficult to produce nickel, and the specific surface area of metallic nickel is limited to the above range in terms of safety and economical efficiency when handling fine metal powder. If the temperature of the plating solution in the metal nickel solution bath is less than 70 ° C, the target dissolution rate cannot be obtained. Conversely, if it exceeds 100 ° C, the plating solution will boil and the structure of the dissolution tank will be complicated. Since the corrosion of the inner wall becomes remarkable, the temperature of the plating solution in the metal nickel dissolving tank 5 is limited to the above range.

The temperature of the plating solution in the melting tank should be 70-100.
As a method of adjusting the temperature to (1), as shown in FIG. 3 above, the temperature raising tank 3 or a temperature raising device (not shown) is arranged in front of the dissolution tank 5, and the temperature is adjusted to 70 to 100 ° C. in advance. The plating solution is supplied into the melting tank with heat insulation material,
(2) A heating device (not shown) is provided in the melting tank to adjust the plating solution temperature to 70 to 100 ° C, and (3) the plating solution is heated in the temperature raising tank 3 or the temperature raising device in the preceding stage of the melting tank. Preheat,
Moreover, a heating device is provided in the melting tank 5 to control the plating solution temperature to 70 to 10
A method of adjusting the temperature to 0 ° C. is exemplified, and preferably,
The temperature raising tank method shown in FIG. 3 of (1) is preferable because of excellent temperature controllability.

The pH of the plating solution in the dissolution tank 5 is 1 to
Hold at 2. This is because when the pH of the plating solution is less than 1, when the plating solution is sent to the plating solution circulation tank 2, the pH of the plating solution in the electroplating tank is lowered and the plating efficiency is significantly reduced. This is because if it exceeds, the dissolution rate of the metallic Ni is significantly reduced.

The pH of the plating solution can be adjusted by adding an acid such as sulfuric acid, a concentration method by an evaporation method or an electrodialysis method, and is not particularly limited. The dissolution operation in the dissolution tank is (1) a batch type in which a plating solution and metallic nickel are charged in a predetermined amount in a dissolution tank, stirred and dissolved, and after dissolution, an undissolved metallic nickel-containing plating solution is extracted from the dissolution tank and filtered. (2) A continuous system in which the plating solution and metallic nickel are continuously supplied, and in parallel, the undissolved metallic nickel-containing plating solution is withdrawn from the dissolution tank and filtered, (3) The plating solution is supplied to the dissolution tank, and metallic nickel Various operation methods are possible, such as a method of continuously performing at least one of inputting, withdrawing the undissolved metal nickel-containing plating solution from the dissolution tank, and filtering, and performing at least one of the other at intervals. Is.

Among the various operation methods described above, a plating solution having a constant nickel concentration can be continuously supplied, and since stirring, dissolution, extraction and filtering are simultaneously performed, there is no loss time and efficiency is high (1 Method) is preferred, but is not limited to these dissolution operation methods. Next, the content of metallic nickel in the plating solution will be described.

In the dissolution of metallic nickel in the dissolution tank, the amount of metallic nickel before or during the melting operation is limited to the required amount, and stirring is carried out until all the metallic nickel is dissolved to prevent the undissolved metallic nickel from remaining. Although it is also possible, as described above, the dissolution rate of the metallic nickel in the plating solution is small, and it takes a considerable time for all the metallic nickel to dissolve. On the other hand, add an excessive amount.

That is, the liquid temperature in the melting tank is 70 to 100 ° C.,
It is preferable that the acidic nickel plating solution whose pH is maintained at 1 to 2 contains 2 to 20 times, and more preferably 5 to 10 times, the above-mentioned metallic nickel of the saturated dissolution amount. When the content of metallic nickel in the plating solution in the dissolution tank is less than twice the saturated dissolution amount, the dissolution rate decreases, and when it exceeds 20 times, it takes time to separate and recover the undissolved metallic nickel. Needed and not preferred.

The amount of metallic nickel to be added in order to contain 2 to 20 times the saturated amount of metallic nickel in the plating solution in the melting tank is determined as follows. That is, in any of the batch method, the continuous method, etc.,
The dissolution time is t (hr), the effective volume of the dissolution tank (= the volume that can hold the plating solution) is V, and the saturated dissolution amount per unit volume of the dissolution tank (= effective unit volume) is W ₀ (kg / m ³ ). And when
The initial amount W (kg) of metallic nickel is given by the following equation (4).

W = 2 to 20W ₀ × V (4) In the case of the batch type, the charged amount W _i (kg) after the second time is the following formula.
It is shown in (4-1). W = (a−a ₀ ) × V (4−1) where a: Nickel ion concentration of plating solution in plating solution receiving tank 9 (kg / m ³ ), a ₀ ; Electroplating tank It is the nickel concentration of the plating solution in 1 (= the nickel ion concentration of the plating solution in the plating solution circulating tank 2) or the nickel ion concentration of the plating solution in the temperature raising tank 3 (kg / m ³ ).

In the case of the continuous type, the feeding rate V _W (kg / hr) of metallic nickel fed into the melting tank is expressed by the following equation (4-2). V _W = (a−a ₀ ) × f (4-2) where f is the plating solution flow rate (m ³ / hr) sent from the dissolution tank to the plating solution receiving tank 9 after being filtered by the filter. is there.

That is, in any of the batch system and the continuous system, the amount of metallic nickel W (kg) previously derived from the above formula (4) is always constant in the melting tank before and / or before the melting. Or, it is put in during the dissolution and the dissolution time t
Dissolve during. The undissolved metallic nickel-containing plating solution extracted from the dissolution tank 5 after the dissolution operation or during the dissolution is
The plating solution feed pump 11 transfers the plating solution to the filter 7.

In the present invention, undissolved metallic nickel is transferred to the filter together with the plating solution for separation, and the metallic nickel is circulated in the dissolution tank and redissolved to prevent loss of metallic nickel and clogging of the filter. It has become possible. The plating solution, which is a filter filtrate, is stored in the plating solution receiving tank 9 or is temporarily stored in the plating solution receiving tank 9, and a necessary amount is supplied to the electroplating tank 1 via the plating solution circulating tank 2 to obtain the electroplating tank. The nickel ion concentration of the plating solution inside is controlled.

The undissolved metallic nickel or the concentrated metallic nickel plating solution, which is the filter filtration residue, is circulated to the metallic nickel dissolving tank 5 for re-dissolution. Note that the filter 7
As the above, a filter constituted by a porous body having a plurality of liquid passages in the axial direction illustrated in FIG. 4 (hereinafter referred to as a cross-flow type filter) is preferable.

FIG. 4 is a perspective view showing the structure of the cross-flow type filter 25. In FIG. 4, 26 is a filter element, and 27 is a through hole (lumen). The cross-flow type filter 25 includes a filter element 26, which is a columnar body made of porous ceramics, in the longitudinal direction (=
A plurality of through holes (lumens) 27 are provided in the axial direction.

While the undissolved metallic nickel-containing plating solution supplied to the cross-flow type filter 25 passes through the lumen 27, a part thereof is filtered by the filter element 26 to become a filter filtration plating solution. The remaining plating solution passes through the lumen 27 together with undissolved metallic nickel, and is filtered and filtered, that is, circulated in the metallic nickel dissolving tank as a concentrated metallic nickel plating solution or slurry.

In the present invention, by adopting the cross-flow type filter, the undissolved metallic nickel is not deposited in the filter and the lumen 27 together with the plating solution is used.
In order to pass through the inside, by providing a liquid feeding path from the melting tank 5 to the filter 7 and a path of the undissolved metal nickel transfer means 8 as shown in FIG. 3, which circulates between the melting tank 5 and the filter 7, Dissolution of metallic nickel and separation / recovery of undissolved metallic nickel and re-dissolution can be performed continuously, and the equipment can be made compact as a whole.

The undissolved metallic nickel or concentrated metallic nickel plating solution, which is the filter residue collected by the filter, is circulated to the metallic nickel dissolving tank 5 and is subjected to re-dissolution, whereby the yield of metallic nickel to nickel ions is increased. Can be 100%. As the porous body of the cross-flow type filter, for example, a ceramic material containing alumina and / or silica as a main component is preferable, and further an alumina ceramic material is preferable.

In the case of a ceramic material containing alumina and / or silica as a main component, it is possible to prevent the undissolved metallic nickel from being mixed into the plating solution which is the filter filtrate, and the adhesion of the metallic nickel fine particles to the metal band during plating Can be prevented and the plating quality is improved. Furthermore, as a porous body,
When a ceramic material containing alumina and / or silica as a main component is used, the separation property of fine undissolved metallic nickel is improved, and the particle size of metallic nickel supplied to the melting tank 5 can be made considerably smaller than in the conventional case. The rate of nickel dissolution is increased, enabling efficient melting work.

After or during the dissolution operation, the plating solution, which is the filtrate filtered out by the filter after being taken out of the dissolution tank 5 at intervals of time or continuously, is transferred to the plating solution receiving tank 9, and preferably. Once stored in the plating solution receiving tank 9, the concentration of nickel ions in the plating solution is made uniform, and the concentration of nickel ions in the plating solution in the plating solution receiving tank is measured. It is preferable to control the nickel ion concentration of the plating solution in the plating tank 1.

In this case, the plating solution amount v (m ³ ) supplied to the electroplating tank 1 is calculated by the following equation (5). v = X / (a−a ₀ ) ... (5) where X: nickel ion decrease amount (kg), a: plating solution nickel ion concentration in plating solution receiving tank 9 (kg / m) ³ ),
a ₀ : Nickel ion concentration of plating solution in the electroplating tank 1 (= nickel ion concentration of plating solution in the plating solution circulating tank 2) or nickel ion concentration of plating solution in the temperature raising tank 3 (k
g / m ³ ).

As will be described later, the X is a change over time in the measured value of the nickel ion concentration of the plating solution in the plating solution circulating tank 2, the amount of plating solution in the electroplating tank 1 and the plating solution circulating tank 2. It can be obtained from both of the total values of the plating solutions. According to the present invention, as the nickel ion feedstock, a granular and / or flaky metallic nickel having a specific surface area of 0.01 to 1.0 m ² / g is used, the liquid temperature in the metallic nickel melting tank is 70 to 100 ° C., and the pH is It was possible to achieve the target high dissolution rate by containing 2 to 20 times the saturated dissolution amount in the acidic plating solution held at 1 to 2 and chemically dissolving it under stirring.

Further, in the present invention, a cross-flow type filter composed of a porous body containing alumina and / or silica as a main component, more preferably a porous body containing alumina as a main component, is used together. This allows the dissolution of metallic nickel and the separation of undissolved metallic nickel.
It became possible to carry out recovery and redissolving continuously and quickly, making it possible to make the equipment compact overall.

Further, it becomes possible to prevent the undissolved metallic nickel from mixing into the plating solution which is the filter filtrate, and to prevent the metallic nickel fine particles from adhering to the metal strip during plating, thus improving the plating quality. Furthermore, the separation of fine undissolved metallic nickel is improved, and the particle size of metallic nickel supplied to the melting tank 5 can be made considerably smaller than before, so the rate of metallic nickel dissolution is increased, and efficient melting work is possible. became.

In the present invention, as shown in FIG. 3, the nickel ion concentration in the plating solution is controlled by using the plating solution receiving tank 9 provided separately from the electroplating tank 1 and the plating solution circulating tank 2. As a result, for example, in nickel-based alloy electroplating such as zinc-nickel alloy electroplating, the nickel content in the plating film, which greatly affects the plating quality, can be controlled very accurately, and the management of the plating quality becomes extremely easy. Have.

[0049]

EXAMPLES Next, the effects of the present invention will be specifically described based on examples. (Example 1) A dissolution test of metallic nickel was conducted in the electroplating equipment shown in FIG. That is, the specific surface area of the metallic nickel charged into the metallic nickel dissolving tank 5 is changed variously, and the relationship between the specific surface area of metallic nickel and the dissolution rate of metallic nickel is shown as follows.
The condition was H: 1.5.

The specific surface area; SA (m ² / g) was determined by measuring the average particle diameter with a Microtrac, and from the result, the following formula (6) was used.
Was calculated by SA = [6 / (D _p · ρ)] × 10 ⁻⁶ (6) where D _p : average particle size of metallic nickel (m), ρ; density of metallic nickel (g / cm ³ ). Is.

The results are shown in FIG. From Fig. 1, the larger the specific surface area, that is, the smaller the average particle size, the larger the dissolution rate of metallic nickel. Especially, when the specific surface area becomes 0.01 m ² / g or more, the dissolution rate rapidly increases. I understand. It was also found that the specific surface area must be 0.01 m ² / g or more in order to obtain the target dissolution rate: 4 kg / m ³ · hr.

Next, the relationship between the plating solution temperature in the dissolution tank and the metal nickel dissolution rate was changed by variously changing the plating solution temperature in the dissolution tank, and the plating solution pH: 1.5 and the metal nickel specific surface area:
It was investigated under the condition of 0.07 m ² / g. The results are shown in FIG. FIG.
Therefore, the higher the temperature of the plating solution in the dissolution tank, the higher the dissolution rate of metallic nickel, and the temperature of the plating solution in the dissolution tank was 70 ° C.
By the above, it was found that it is possible to obtain the target dissolution rate: 4 kg / m ³ · hr.

(Example 2) An example of the present invention based on the experimental results obtained in Example 1 will be described with reference to FIG. First, a plating solution having a reduced nickel ion concentration of pH: 1-2 (for example, pH: 1.5, Ni: 65 wt%, Zn: 25 wt%,
H ₂ SO ₄ : 10 wt% Zn-Ni alloy electroplating solution) is transferred from the plating solution circulating tank 2 to the temperature raising tank 3 by the plating solution feeding pump 10.

The plating solution transferred to the temperature raising tank 3 is heated to 70 to 70 ° C by the temperature raising heat exchanger 14 including a steam heater or the like.
The temperature is raised to 100 ° C. The plating solution heated in the temperature raising tank 3 is transferred to the metal nickel dissolving tank 5 and stirred by the impeller-type stirrer 6. On the other hand, the specific surface area is 0.01-1.
Metallic nickel powder in the range of 0 m ² / g, for example with a specific surface area
0.1m ² / g of metallic nickel powder is the saturated amount of metallic nickel dissolved depending on the composition and temperature of the plating solution, eg 4-10kg
The amount is 2 to 20 times, for example, 10 times as much as / m ³ , is initially charged into the plating solution in the metal nickel dissolving tank 5 from the metal nickel storage hopper 4.

In the metallic nickel dissolving tank 5, metallic nickel is chemically dissolved in the acidic plating solution according to the above equations (2) and (3), and nickel ions are supplied to the plating solution. The amount of metal nickel dissolved and the dissolution time are the effective volume of the metal nickel dissolution tank 5, the specific surface area of the input metal nickel, the amount of input metal nickel, the temperature of the plating solution in the dissolution tank, the pH of the plating solution in the dissolution tank, and the type of the input metal nickel. It is possible to control so as to achieve the target value by selecting.

In the plating solution in the melting tank, the above formula is used.
At the same time as the reaction of (2), the reaction of the above formula (3) occurs, the hydrogen ions are consumed, and when all the hydrogen ions are consumed, the reaction does not proceed further even if undissolved metallic nickel is present. It may be determined depending on the amount of consumed ions. In the present invention, for example, the saturation dissolution amount of metal nickel per effective unit volume of the dissolution tank is 6 kg / m ³ , and the target dissolution time is
In the case of 15 to 20 min, the effective volume of the melting tank 5: 15 m ³ , the amount of metallic nickel input: 1000 kg, the temperature of the plating solution in the melting tank: 90 ° C,
Plating solution pH: 1.5, specific surface area of input nickel metal powder:
By setting the amount to 0.1 m ² / g, the saturated dissolution amount of the metallic nickel and the target dissolution required time can be achieved.

After the completion of the dissolution of the saturated amount of metallic nickel or during the dissolution operation, the undissolved metallic nickel is transferred to the filter 7 by the plating solution feed pump 11 together with the plating solution.
As the filter, the cross-flow type filter shown in FIG. 4 is preferable. Cross-flow type filter 25
As an example, Millipore Ceraflow (trade name, manufactured by Japan Millipore Co., Ltd.) is exemplified.

Table 1 shows the specifications including the filtration conditions. Table 1
As shown in, by using the alumina-based ceramic material as the porous body, the undissolved metallic nickel in the nickel-based plating solution can be efficiently filtered even under the condition of the high-temperature and low-pH plating solution. The plating solution, which is the filtered solution filtered by the filter 7, is transferred to the plating solution receiving tank 9.

The undissolved metallic nickel, which is the filter residue collected by the filter 7 or the filter residue (particle size ≧ 0.2 μm) that has passed through the through holes 27 of the cross-flow type filter, is conveyed by a conveyor or a screw feeder. Alternatively, it is circulated to the metal nickel dissolution tank 5 by the undissolved metal nickel transfer means 8 composed of a pump or the like, and is provided for remelting.

The plating solution stored in the plating solution receiving tank 9 is cooled by the cooling heat exchanger 15 to the optimum plating solution temperature in the electroplating tank 1. The optimum plating solution temperature in the electroplating tank is 50 to 70 ° C, and more preferably 55 to 65 ° C in the case of Zn-Ni alloy electroplating. Separately, the plating solution receiving tank 9
The nickel ion concentration measuring device 16, 17 or 18 is used to measure the nickel ion concentration of each of the plating solution inside and the plating solution in the plating solution circulating tank 2 or the plating solution in the temperature raising tank 3.

The measuring method of the nickel ion concentration measuring devices 16, 17, 18 is, for example, fluorescent X-ray analysis, but is not particularly limited. Alternatively, a method of previously filtering the plating solution sample as needed and measuring the specific gravity to measure the nickel ion concentration can also be used. From the obtained measurement results of the nickel ion concentration of the plating solution in the plating solution receiving tank 9 and the plating solution circulating tank 2 or the temperature raising tank 3, the above formula is obtained.
The plating solution of the plating solution amount v calculated according to (5) is supplied from the plating solution receiving tank 9 to the electroplating tank 1 by the plating solution feeding pump 12 via the plating solution circulating tank 2.

[0062]

[Table 1]

[0063]

According to the present invention, nickel in the plating solution is
Ion source with a specific surface area of 0.01 to 1.0 m ^Two/ g metal nickel
And the metallic nickel was heated to 70-100 ℃
Contain 2 to 20 times the saturated dissolution amount in the plating solution.
By doing so, the dissolution rate during chemical dissolution can be increased.
To improve the productivity of nickel-based continuous electroplated metal strips.
Miniaturization of metal nickel melting tank and its ancillary equipment
It becomes possible to supply nickel ions economically.
became.

Further, as a filter for filtering the undissolved metallic nickel-containing plating solution extracted from the metallic nickel dissolving tank, in particular, by using a cross-flow type filter composed of a porous body made of a ceramic material,
The following effects were obtained. Dissolution of metal nickel, separation / recovery of undissolved metal nickel, and re-dissolution can be carried out continuously and rapidly, and it has become possible to further downsize the equipment.

It is possible to prevent undissolved metallic nickel from being mixed into the plating solution which is the filter filtrate, prevent the metallic nickel fine particles from adhering to the metal strip during plating, and improve the plating quality. Separation of fine undissolved metallic nickel is improved, and the particle size of metallic nickel supplied to the melting tank can be made considerably smaller than before, so the dissolution rate of metallic nickel is increased and more efficient melting work becomes possible. .

Furthermore, according to the present invention, by controlling the nickel ion concentration in the plating solution by using the plating solution receiving tank provided separately from the electroplating tank and the plating solution circulating tank, for example, zinc-nickel alloy In nickel-based alloy electroplating such as plating, the nickel content in the plating film, which has a great influence on the plating quality, can be accurately controlled, and the management of the plating quality becomes extremely easy.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the specific surface area of metallic nickel and the dissolution rate of metallic nickel.

FIG. 2 is a graph showing a relationship between a plating solution temperature in a metal nickel dissolving tank and a metal nickel dissolving rate.

FIG. 3 is a schematic explanatory diagram of electroplating equipment according to the present invention.

FIG. 4 is a perspective view showing the structure of a cross-flow type filter.

[Explanation of symbols] 1 electroplating tank 2 plating solution circulating tank 3 temperature raising tank 4 metal nickel storage hopper 5 metal nickel dissolution tank 6 stirrer 7 filter 8 undissolved metal nickel transfer means 9 plating solution receiving tank 14 heat exchanger for heating 15 Cooling heat exchanger 16, 17, 18 Nickel ion concentration measuring device 19 Metal band 21 Backup roll 22 Conductor roll 23, 24 Insoluble anode 25 Cross flow type filter 26 Filter element 27 Through hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Sekita, Takashi Sekida 1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama Prefecture (without address) Inside the Mizushima Works, Kawasaki Steel Co., Ltd. Chome (No house number) Kawasaki Steel Co., Ltd. Mizushima Steel Works

Claims (5)

[Claims] 1. A method for supplying nickel ions to a plating solution in a nickel-based electroplating equipment for metal strips using an insoluble anode, wherein a specific surface area of 0.01 to
1.0 m ² / g of granular and / or flaky metallic nickel is used, and the liquid temperature in the metallic nickel melting tank is 70-100 ° C, pH
Of saturated dissolution amount of 2 in the acidic plating solution in which
A method for supplying nickel ions to a plating solution, wherein the acidic nickel plating solution is stirred in an amount of about 20 to 20 times that of the metallic nickel. 2. An undissolved metal nickel-containing plating solution is extracted from the metal nickel dissolution tank and supplied to a filter, and a plating solution that is a filter filtrate is supplied to an electroplating tank via a plating solution receiving tank. The method for supplying nickel ions to a plating solution according to claim 1, wherein the undissolved metal nickel or metal nickel concentrated plating solution which is a filter filtration residue is circulated in a metal nickel dissolution tank and is used for re-dissolution. 3. The filter according to claim 2, wherein the filter is a porous body having a plurality of liquid passages in the axial direction.
A method for supplying nickel ions to the described plating solution. 4. A nickel ion concentration in the plating solution transferred to the plating solution receiving tank is measured, and a plating solution corresponding to the amount of nickel ions consumed in the electroplating tank is transferred from the plating solution receiving tank to the electroplating tank. The method for supplying nickel ions to the plating solution according to claim 2, wherein the nickel ions are supplied. 5. A facility for supplying nickel ions to a plating solution arranged in a nickel-based electroplating facility for metal strips using an insoluble anode, the nickel ion supplying facility circulatingly supplying the plating solution to the electroplating tank 1. Plating solution circulation tank 2
A metal nickel dissolving bath 5 for dissolving metal nickel in the plating liquid transferred from the plating liquid circulating bath 2; and a filter 7 for filtering the undissolved metal nickel-containing plating liquid extracted from the metal nickel dissolving bath 5. And the filter 7
A plating solution receiving tank 9 for storing a plating solution which is a filtered solution from the above and supplying the plating solution to the plating solution circulating tank 2.
The undissolved metal nickel transfer means 8 for transferring the undissolved metal nickel or the concentrated metal nickel plating solution, which is the filter residue from the filter 7, to the metal nickel dissolution tank 5, and the plating solution in the plating solution receiving tank 9 Equipment for supplying nickel ions to a plating solution, which is equipped with a nickel ion concentration measuring device 16.