JP3407480B2 - Method of manufacturing seed plate for cathode - Google Patents

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 seed plate for producing a cathode used for electrolytic refining and electrowinning, and more particularly to a method for producing a seed plate having less variation in thickness.

[0002]

2. Description of the Related Art Conventionally, in copper refining and nickel refining, products are obtained by electrodepositing a target metal on a cathode made of the target metal. Such a cathode is usually obtained by electrodepositing a target metal on a titanium plate or a stainless plate to obtain a thin plate of the target metal and processing the thin plate.

[0003] For example, in copper electrolytic refining, a stainless steel plate called a mother plate is insulated around its periphery, and a suspender is provided to allow energization, which is immersed in a copper electrolytic solution and energized for a predetermined time.
The obtained electrodeposited copper plate is stripped off to obtain a copper seed plate. Then, the periphery of this seed plate is cut to obtain a single plate having a relatively uniform thickness. Further, a part of the seed plate is cut into strips, and the cathode is assembled by using this one plate and the conductive rod called cross beam.

By the way, since the seed plates stripped from the mother plate have distortions, they are directly processed to obtain a cathode.
If this is suspended in the electrolytic cell as it is, the anode and the cathode come into contact with each other and the electrolytic operation becomes impossible. For this reason,
When assembling the cathode, a certain strain is forcibly applied to the seed plate so as not to come into contact with the anode when the cathode is suspended in the electrolytic cell.

Since the assembly of the cathode is carried out by a series of flow work, it is necessary to incorporate a device for giving strain to the seed plate in this flow, and a method of pressing a roller or the like is often adopted. In such a case, if the seed plate is thick, sufficient distortion may not be given, or the load on the device may increase and an abnormality may occur in the device. On the contrary, if the seed plate is thin, the strain becomes too large, resulting in an increase in defective seed plates.

The recent recession in the yen's appreciation requires more competitiveness than ever before, specifically speaking, a reduction in manufacturing costs, and companies that cannot meet this demand are no longer allowed to survive. There is. Copper refining is no exception, and how to achieve cost competitiveness is a very important issue. As one means for solving this problem, improvement of electrolysis efficiency and labor saving of processes are being promoted.

[0007]

The best way to increase the electrolysis efficiency is to maintain a constant energized state.
This is made possible by the seed plate manufacturing method using the half tank lifting method. This half tank lifting method lifts half of the mother plates after the electrodeposition in the electrolytic tank without stopping the energization,
Insert the same number of undeposited mother boards, then lift the remaining mother boards after electrodeposition, insert the same number of new mother boards at the same position after the last electrodeposition, and then The total number of mother boards after wearing is replaced with new mother boards.

In this half tank lifting system, the mother plate for the half tank is set as one unit, and the energization time and the energization amount are likely to differ for each unit. For this reason, although the effective electrodeposition area of the mother plate is usually almost uniform, the thickness of the seed plate to be obtained tends to be nonuniform. As a result, it is difficult to save labor in the cathode assembly process.

This is because if the seed plate becomes too thick and the device is overloaded, it will be necessary to readjust manually, and the seed plate will become too thin, resulting in too many distortions. This is because it will be artificially excluded.

The present invention has been made in view of the above situation, and in order to stably operate a device for applying strain to a seed plate,
The task is to obtain a seed plate with a constant thickness.

[0011]

According to the method of the present invention for solving the above-mentioned problems, a mother plate is charged into an electrolytic cell, and a current is applied, and the mother plate on which a target metal is electrodeposited is pulled up, and a seed plate is obtained from this. When obtaining it, the value of the cell voltage is taken into the computer at regular intervals and the amount of electrodeposition is controlled by integrating this value, more specifically, the lifting of the mother plate installed in the electrolytic cell. , Insert at least twice and lift,
The integration of the tank voltage is started with the change in the tank voltage due to insertion as a reference point, and when the desired integrated value is reached, the mother board is pulled up to make the amount of electrodeposition on the mother board uniform. The thickness of the seed plate can be made uniform.

[0012]

When the mother plate, which has been electrodeposited for half a tank, is lifted from the electrolytic cell, the cell voltage rises, and after the new mother board is loaded into the electrolytic cell, the cell voltage drops and becomes stable thereafter.

Now, the cell voltage V is schematically expressed by Equation 1 where A is the current flowing in the electrolytic cell and R is the total combined resistance value.

Equation 1 V = A · R Considering a set of mother plate and refined anode, the combined resistance value is the contact resistance between the electrode and the cross beam, or the contact resistance between the cross beam and the mother plate, and the polarization of the mother plate surface. Resistance, the resistance of the electrolytic solution between each mother plate and the refining anode, the resistance due to the polarization of the refining anode, and the contact resistance between the refining anode and the electrode. Since the electrodes are normally energized in parallel, when the combined resistance of the set of mother plate and the refined anode is represented by R _n , R is schematically represented by Equation 2.

Equation 2 1 / R = 1 / R ₁ + 1 / R ₂ + 1 / R ₃ + ... + 1 / R _n Now, _assuming that R ₁ = R ₂ = R ₃ = ... = R _n , Formula 2 becomes like Formula 3.

Equation 3 1 / R = n / R₁ Therefore, R = R₁/ N. From this,
If you pull up half of the mother board, R will be doubled.
Become. The present invention utilizes this principle. By the way
In FIG. 1, using a seed plate electrolytic cell in which 50 mother plates are inserted,
At the time of cell voltage system when seed plate electrolysis is carried out by the half-batch lifting method
Showed a change.

In FIG. 1, peak A and peak B are changes in the cell voltage due to the lifting and charging of half the mother board, and it can be seen that they show extremely characteristic movements. A1 is half of the mother board (A
(Block) indicates the start of lifting, A2 indicates the completion of lifting, A3 indicates the start of charging, and A4 indicates the end of charging. Similarly, B1 indicates the time when the lifting of the other half of the mother board (B block) is started, and B1
2 indicates completion of lifting, B3 indicates charging start, B4
Indicates the end of charging. From Figure 1, block A is A4
It will be understood that the integration of the cell voltage can be started from B4 and the integration of the cell voltage can be started from B4 in the B block.

[0018]

EXAMPLES Examples of the present invention will be described below.

(Example 1) 51 refined anodes and mother plate 5
A seed plate production test was conducted for 1 week under the following conditions using two sets of electrolytic cells each having zero sheets. In this embodiment, the cell voltage is recorded in the hybrid recorder, the value of the hybrid recorder is input to the computer every 5 minutes, and the computer integrates the value. When the total of the recorded integrated values reaches the planned energization integrated amount, an alarm is issued and the mother board is replaced.

[0020] The average unit weight of the obtained seed plate was 7.5 Kg. The weight of each plate was measured, the daily average was calculated, and the variation in the daily average was calculated. The standard deviation was 0.05. Further, the surface condition of the obtained seed plate was observed, and the defective rate was calculated to be 0.04%.

(Comparative Example 1) A seed plate production test was conducted for one week in the same manner as in Example except that the conventional management method was aimed at one life of 24 hours instead of management by the cumulative amount of energization.

The average unit weight of the obtained seed plate was 6.6 Kg. The weight of each plate was measured, the daily average was calculated, and the variation in the daily average was calculated. The standard deviation was 0.11. In addition, the surface condition of the obtained seed plate was observed and the percent defective was determined to be 0.50%.

From these results, the superiority of the method of the present invention is clear.

[0024]

【The invention's effect】 [Brief description of drawings]

FIG. 1 is a diagram showing a system voltage change of a cell voltage when a seed plate is electrolyzed by a half-cell lifting method.

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-7-48689 (JP, A) JP-A-5-156482 (JP, A) JP-A-59-67385 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C25C 1/00-7/08

Claims (2)

(57) [Claims] 1. When a mother plate is placed in an electrolytic cell, electricity is applied, and the mother plate on which a target metal is electrodeposited is lifted up, and when a seed plate is obtained from this, the value of the cell voltage is taken into a computer at regular intervals. A method of manufacturing a cathode seed plate, characterized in that the electrodeposition amount is controlled by integrating the data. 2. The lifting and insertion of the mother plate installed in the electrolytic cell is divided into at least two times, and the integration of the cell voltage is started with the change in the cell voltage associated with the lifting and insertion as a reference point. Manufacturing method.