JPH08193300A - Method for separating and recovering undissolved metal - Google Patents

Abstract

PURPOSE: To propose a method for easily separating and recovering a large amt. of undissolved metal powder difficult to separate with a generally used filter-cloth filter due to clogging. CONSTITUTION: A ferromagnetic powder is dissolved in an acidic soln. in a dissolution tank 1 to produce a plating soln. 5 which is transported to a plating bath 5 from the tank 1, and the undissolved magnetic powder is separated and recovered with a magnet 6 in the intervening passage. In this case, a freely tiltable trough 2 is formed in the plating soln. passage, the magnet 6 capable of being magnetically turned on and off is furnished to the bottom face of the trough, the magnetic force-impressed trough 2 is tilted toward the downstream side to pass the plating soln. 5, hence the undissolved metal is deposited on the trough bottom, the trough 2 is tilted toward the dissolution tank 1, the magnetic force is turned off, and the deposit is dropped into the dissolution tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a plating solution, and more specifically, in a step of producing a plating solution by dissolving ferromagnetic metal powder such as Fe or Ni in an acid solution, the solution is dissolved in a dissolution tank. The present invention relates to a method of separating and recovering the undissolved metal powder from the plating solution during transportation to the plating bath later.

[0002]

2. Description of the Related Art In the production of plated steel sheets, it is necessary to dissolve the plating metal with an acid solution or the like in order to newly produce the plating solution or to supplement the consumption of the plating metal due to the plating. In the melting operation, it is common to load the plating metal powder and the acid solution or the used plating solution into a melting tank, contact and melt both, and supply the plating solution produced there to the plating bath. . What is important in such melting work is to prevent unmelted metal powder from being mixed into the plating solution and causing defects in the plated steel sheet. For this reason, much research and development has been conducted on the separation, recovery, or re-dissolution of undissolved metal powder, and techniques that effectively utilize press filters and leaf filters that mainly use filter cloth filters are known and are actively used. Has been done. One example of this filter-based separation and collection is
No. 10684, “In a method of supplying a liquid in which a hardly soluble substance is suspended to a tank through a filter and using a solution in the tank, a part of the solution is circulated from the tank to the filter. "Dissolves a poorly soluble substance".

On the other hand, when the plating metal is a ferromagnetic material such as Fe or Ni, it is naturally conceivable to use a magnet. For example, Japanese Utility Model Publication No. 3-18511 discloses a method in which the plating solution is sent from the bottom to the top. Disclosed is an iron ion replenishing device for an electroplating solution in which a plating solution trough for receiving an overflow solution is provided around the upper end of the melting tank, a magnet is provided on the inner circumference of the trough, and a collecting net is provided on the outer circumference of the trough. In addition, the actual exploitation Sho 62-198273
The publication discloses a device for separating and recovering undissolved iron particles by disposing a magnet in a liquid gutter that receives the overflow liquid in the above-mentioned dissolution tank, and by disposing a magnetic filter in a supply pipe that sends the overflow liquid to a plating line. Is disclosed. Further, JP-A-50-60868 discloses that a plurality of electromagnets are installed on the bottom surface of a water channel and sequentially magnetized in a certain direction to move a magnetic body in a certain direction, and the collected matter is collected and separated from an aqueous solution. Or the method described in JP-A-51-61073.
The publication proposes a method of applying a magnetic field from the outside to a container holding an aqueous solution and sequentially moving the magnetic field toward the discharge port to collect the magnetic particles at the discharge port and discharge the magnetic particles to the outside. ing.

[0004]

However, the technique of using a filter cloth filter as described in Japanese Patent Publication No. 62-10684 has a problem in that when the amount of undissolved powder is very large, the flow rate of the aqueous solution passing through the filter cloth filter is large. Since it becomes extremely small due to clogging, a very large filter cloth area is required, and not only a large facility is required, but also backwashing work and filter cloth replacement work are frequently required, resulting in poor workability. Also,
In the technology utilizing a magnet, the one disclosed in Japanese Patent Laid-Open No. 50-60868 only collects the magnetic substance at a certain place, and therefore, the work of taking out the collected magnetic substance from the liquid is separately required, and the separation is performed. It is just one step away as an effective means of recovery. Further, in the technique described in Japanese Patent Laid-Open No. 51-61073, it is substantially impossible to discharge only the magnetic particles from the discharge port and to seal without discharging the aqueous solution. That is,
In a steady state in which a certain amount of magnetic particles are accumulated, it is possible to prevent the aqueous solution from flowing out from the outlet, but at the beginning when the aqueous solution is first passed through the container, all the aqueous solution is retained until the magnetic particles are accumulated to some extent. Has the drawback of being leaked.
In addition, as a means for separating ultrafine particles having a particle size of several μm or less, a hollow filter previously filed by the present applicant in Japanese Patent Application No. 6-233194 is also known, but the amount of undissolved powder is large. In this case, as in Japanese Patent Publication No. 62-10684, the filter is often unusable, and there is a problem that the melting operation must be interrupted. The hollow filter is made of a porous ceramics body, and for example, one having a shape as shown in FIG. 3 or a so-called hollow filter may be used.

In view of the above situation, the present invention has a very large amount of undissolved metal powder, and even if a commonly used filter cloth type filter is difficult to separate due to clogging of the filter cloth, The purpose is to propose a method that can easily separate and collect a large amount of undissolved metal powder by magnetic force.

[0006]

Means for Solving the Problems In order to achieve the above object, the inventor introduces a liquid containing undissolved metal powder in a melting tank into a gutter flow path having an electromagnet or a permanent magnet installed on the bottom surface to remove the metal powder. When adsorbing only the liquid on the bottom of the trough with a magnet and letting out only the liquid, attention was paid to the combination of the ON / OFF operation of the magnetic force and the inclination of the above-mentioned trough, and earnestly studied. The present invention embodies the results of the study. That is, the present invention is to prepare a plating solution by dissolving ferromagnetic metal powder in an acid solution in a dissolution tank, and to remove the plating solution from the plating solution in a flow path on the way of transporting the plating solution from the dissolution tank to a plating bath. In the method of separating and recovering the undissolved portion of the ferromagnetic metal powder with a magnet, a tilting gutter that can be tilted is provided in the plating solution flow path, and a magnet that can turn on / off the magnetic force is provided on the bottom surface of the gutter. The undissolved metal is adhered to the trough bottom by tilting the tilted trough to which magnetic force is applied to the downstream side and passing the plating solution, and tilting the tilted trough to the melting tank side to cut off the magnetic force to melt the deposit. It is a method for separating and recovering undissolved metal, which is characterized by dropping into a tank. The present invention is also a method for separating and recovering undissolved metal, characterized in that the above-mentioned slanted trough is tilted to the downstream side and passed through in the direction of the plating bath, and further passed through a hollow filter. Furthermore, the present invention is also a method for separating and recovering undissolved metal, characterized in that the inclination direction of the tilting gutter is automatically changed based on the cumulative flow rate of the plating solution passed therethrough.

[0007]

In the present invention, a ferromagnetic metal powder is dissolved in an acid solution in a dissolution tank to produce a plating solution, and the plating solution is removed from the plating solution in a flow path in the course of being conveyed from the dissolution tank to a plating bath. In the method of separating and recovering the undissolved portion of the ferromagnetic metal powder with a magnet, a tilting gutter that can be tilted is provided in the plating solution flow path, and a magnet that can turn on / off the magnetic force is provided on the bottom surface of the gutter. , The undissolved metal is adhered to the trough bottom by tilting the tilted trough to which magnetic force is applied to the downstream side of the plating solution, and the tilted trough is tilted toward the melting tank to cut off the magnetic force. Since it was dropped into the melting tank, even if there is a large amount of undissolved metal, there is no need to worry about clogging of the filter as in the case of using a filter cloth type filter, and separation and collection can be done smoothly. . As a result, there was no interruption of melting work, and plating work became stable.

Further, in the present invention, the undiluted metal powder is recovered even in the form of fine particles, because the plating solution obtained by inclining the inclined trough toward the downstream side thereof and passing it in the direction of the plating bath is further passed through the hollow filter. As a result, it remains in the generated plating solution and does not deteriorate the quality of plating. Further, in the present invention, the tilt direction of the tilt gutter is automatically changed based on the cumulative flow rate of the plating solution passed therethrough, so that the melting operation can be smoothly performed without human intervention. As a result, work efficiency has been improved and labor has been saved.

In the following, the present invention will be specifically described with reference to FIGS.

[0010]

Example A metallic Ni powder having an average particle diameter of 10 μm was dissolved in a sulfuric acid plating solution having a pH of 1.4 and a temperature of 80 ° C. The capacity of the melting tank used at that time was 10 m ³ , and the metal N
600 kg of i powder was added and dissolved by mechanical means for 20 minutes while stirring. However, about 500 kg of metal Ni powder was undissolved, and a filter cloth filter capable of collecting up to 1 μm was used, but clogging occurred immediately, and efficient filtration was not possible.

Therefore, the method for separating and recovering undissolved metal according to the present invention was applied to the plating solution in such a state. FIG.
[Fig. 1] is a conceptual diagram of the device used at that time. First, the plating solution 5 containing undissolved metal Ni powder is introduced from the dissolution tank 1 to the tilting trough 2 having a magnet 6 at the bottom by a pump P ₁ at a constant flow rate. The magnet 6 may be either an electromagnet or a permanent magnet, but it is important that its magnetic force can be turned ON / OFF as required. The tilting trough is tilted so that the plating solution 5 can flow into the cushion tank 3 located therebelow when the magnetic force is ON. As a result, the undissolved metallic Ni powder in the plating solution 5 is adsorbed by the magnet and adsorbed on the bottom of the tilted gutter, and becomes a deposited state.
Only the soothing liquid containing almost no undissolved powder is transferred to the cushion tank 3.

Next, the method of recovering the undissolved metal Ni powder deposited on the above-mentioned slant gutter 2 is, as is clear from FIG. 2, the slant gutter 2 so that the undissolved metal powder easily flows into the dissolution tank 1. It is performed by tilting and turning off the magnetic force. If the magnet 6 is an electromagnet, the power source may be turned off, and if the magnet 6 is a permanent magnet, the object can be easily achieved by separating it from the gutter bottom surface.
In this case, if the gutter is rinsed with a fresh acid solution (not containing undissolved metal powder) used for dissolution, recovery of undissolved metal powder and injection of new solution into the dissolution tank can be performed simultaneously. Is. Further, in order to increase the cleanliness of the plating solution, as shown in FIG. 1, a pump liquid cushion tank 3 P ₂
Thus, by guiding the powder to the hollow filter 4, it becomes possible to separate even a minute amount of undissolved metal powder that has not been captured by the inclined trough 2. Further, as for the melting method, in the case of a batch method, the states of FIGS. 1 and 2 may be sequentially repeated, and in the case of a continuous method, a plurality of slant gutters are installed in parallel and plating is performed by passing each slant gutter. It suffices to add a known means capable of integrating the liquid flow rate and switching the magnetic force ON / OFF and changing the angle of the tilting gutter for each fixed amount.

By the way, the results of applying the method for separating and recovering the undissolved metal according to the present invention to the dissolution of the metallic Ni powder are as follows:
The content of undissolved metal Ni powder in the plating solution accumulated in the cushion tank 3 was 0.1 g / liter or less. Furthermore, by passing the plating solution through a hollow filter capable of collecting particles having a particle size of up to 0.1 μm, the content of undissolved metallic Ni powder could be eliminated.

[0014]

As described above, according to the present invention, even if the plating solution contains a large amount of undissolved metal and the filter cloth filter is difficult to separate and collect due to clogging, the undissolved metal can be smoothly removed. It became possible to separate and collect.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of equipment for carrying out a method for separating and recovering undissolved metal according to the present invention.

FIG. 2 is a view showing a state in which the tilt angle is changed by the tilt gutter of FIG.

FIG. 3 is a perspective view showing the shape of a hollow filter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Dissolution tank 2 Inclined gutter 3 Cushion tank 4 Hollow filter 5 Plating solution 6 Magnet 7 Hollow part 8 Mechanical stirring means P ₁ pump 1 P ₂ pump 2

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Susumu 1-chome, Mizushima Kawasaki-dori, Kurashiki City (no address) Inside the Mizushima Steel Works, Kawasaki Steel Works (72) Inventor Shuji Kayama 1-chome, Mizushima Kawasaki-dori, Kurashiki City None) Inside Kawashima Steel Works Mizushima Steel Works

Claims (3)

[Claims] 1. A ferromagnetic metal powder is dissolved in an acid solution in a dissolution tank to produce a plating solution, and the plating solution is transferred from the dissolution tank to a plating bath in a flow path during which the plating solution is removed from the plating solution. In the method of separating and recovering the undissolved portion of the ferromagnetic metal powder with a magnet, a tilting gutter that can be tilted is provided in the plating solution flow path,
A magnet capable of turning on / off the magnetic force is provided on the bottom of the gutter,
The undissolved metal is adhered to the trough bottom by tilting the tilted trough to which magnetic force is applied to the downstream side of the tilted trough,
A method for separating and collecting undissolved metal, characterized in that the deposit is dropped into the melting tank by tilting the inclined trough toward the melting tank to cut off the magnetic force. 2. The method for separating and recovering undissolved metal according to claim 1, wherein the tilting trough is tilted to the downstream side and passed through in the direction of the plating bath, and further passed through a hollow filter. . 3. The method for separating and recovering undissolved metal according to claim 1, wherein the tilt direction of the tilting gutter is automatically changed based on the cumulative flow rate of the plating solution passed therethrough. .