JPS587717B2 - Conductor and energizing device for metal salt electrolyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conductor for power supply and a wet type energizing device for supplying power to a metal salt electrolytic cell.

In general, in the electrolysis of metal salt aqueous solutions, such as electrolytic refining of copper, the energizing device installed on the side wall of the electrolytic cell simply consists of anode and cathode power supply terminals placed directly on a copper conductor.

When such an energizing device is used, the contact resistance at the contact point between the conductor and the power supply terminal of the anode or cathode becomes large, causing various damage.

That is, due to the increase in contact resistance, the power required for electrolytic refining etc. increases, and if there is variation in contact resistance at each contact point in the electrolytic cell, this will lead to variation in current, which will cause variation in product weight. Furthermore, due to variations in current, a cathode with a high current density may be formed in some areas, leading to a deterioration in product quality.

The causes of increased contact resistance between the cathode and anode power supply terminals and the conductor, which cause the various damage mentioned above, are (1) dirt on the electrode side contact and the action of oxygen in the air; Possible causes include the formation of an oxide film, and (2) the formation of a film due to dirt on the conductor surface and precipitation of metal salts in the electrolyte.

Various proposals have been made to reduce this contact resistance, but the so-called wet contact method, which constantly moistens the contact area between the electrode and the conductor, is particularly effective, as disclosed in Japanese Patent Publication No. 49-16686. It is.

That is, according to the wet contact method, the contact area between the conductor and the electrode is always kept moist with a conductive liquid, which blocks the contact area from oxygen in the air and prevents the oxide film on the contact area from forming. can be prevented from occurring and the condition of the contact surface can be maintained in good condition.

Furthermore, according to this method, it is possible to prevent the electrolytic solution from adhering to the contact portion and crystallization of the metal salt, and therefore, it is possible to prevent poor contact due to crystals.

However, according to the wet contact method, it is necessary to form a groove or hole in the conductor, which is usually made of copper, to provide a liquid-containing part. The disadvantage is that it is difficult to

In addition, it is necessary to simultaneously support the anode and cathode power supply terminals on the conductor, but at this time, the power supply terminal that does not come into contact with the conductor must be supported on the conductor via an insulator. Therefore, it has the disadvantage that it is extremely complex in structure and requires care when handling the electrode plates, which is inconvenient in terms of work.

In addition, in the wet contact method, an impregnated spongy object (sponge) that supplies conductive liquid to the contact area between the conductor and the electrode is significantly deteriorated by the action of sulfuric acid mist, etc. in an acidic atmosphere such as electrolytic refining. , the lifespan is short and the sponge must be replaced frequently.

Furthermore, since the sponge is a soft material, its setting position is likely to shift, and it is necessary to correct the setting, making it difficult to handle.

In order to solve the various drawbacks of the above-mentioned wet contacts, the present invention provides a structure in which the conductor itself carries the power supply terminal of the anode or cathode and supplies power, and furthermore, the conductor itself has the ability to keep the contact part in a wet state, for example. The present invention aims to provide a conductor made of a porous conductive material such as a metal sintered body, a metal stranded wire, or a metal thin plate laminate made of a plurality of metal thin plates bundled in a layered manner.

A further object of the present invention is to provide a current-carrying device which can reduce the contact resistance between the anode or cathode power supply terminal and the conductor, thereby significantly reducing the required power.

Another object of the invention is that no special insulating support means are required to support the plates which do not need to be in contact with conductors.
An object of the present invention is to provide an energizing device that is simple in structure and handling.

Another object of the present invention is to provide an energizing device that is easy to manufacture and inexpensive since it is only necessary to process the insulator that holds the conductor.

Another object of the present invention is to reduce contact resistance and its variation, thereby reducing voltage drop and its variation, reducing required power supply, improving product quality and reducing product weight variation. It is an object of the present invention to provide an energization device that can reduce the amount of electricity.

Still another object of the present invention is to provide an energizing device that has a simple structure, can withstand long-term use, and is therefore easy to maintain.

Next, a conductor according to the present invention and an energizing device using the conductor will be explained in more detail with reference to the drawings.

Referring to FIGS. 1 to 3, the current supply device 1 has a conductor support member 4 made of an insulating material, such as an insulator, at the upper edge of the side wall 2 of the metal salt electrolytic cell.

A recess 6 is provided in a portion of the upper surface 4a of the insulating conductor support member 4, usually approximately at the center of the upper surface 4a, and a porous conductor 8 is disposed in the recess.

The porous conductor 8 is provided with one power supply terminal 16a of the anode and one power supply terminal 16 of the cathode during electrolysis.
b are alternately placed in contact with each other.

Also, the other power supply terminal 16a' of the anode and cathode
and 16b' directly represent the upper surface 4 of the insulating conductor support member 4.
It is placed on a part of a.

In one preferred embodiment of the present invention, the porous conductor 8 is a porous copper powder sintered body formed by compression molding and sintering copper powder, and its shape may be arbitrary.

For example, some have a circular cross section, a square cross section, etc., and the figure shows one with a circular cross section.

A conductor 8 made of such a porous sintered copper powder body is placed in the recess 6, and then a conductive liquid such as water is poured into the recess as illustrated in FIG. If you inject 10,
The conductive liquid 10 is sucked up by capillary action due to the large number of slits formed inside the porous conductor 8, and the conductive liquid 10 is sucked up to the electrode 1.
6a.

Therefore, the contact portion between the conductor 8 and the electrode 16a is always maintained in a wet state.

Although the porous conductor 8 is a solid copper powder sintered body in the above description, it can also be a hollow copper powder sintered body as shown in FIG.

When such a hollow porous conductor 8 is used,
As illustrated in FIG. 5, a conductive liquid 10 is fed under pressure into the central hole 8a of the conductor 8, for example via a circulation device 12 comprising a pump P, a conductive liquid tank S and a conduit C. can be provided.

As a result, the conductive liquid 10 advances radially outward from the central hole 8a of the porous conductor 8 by capillary action and water pressure, and maintains the contact area between the conductor 8 and the electrode 16a in a wet state.

The copper powder sintered body constituting the porous conductor 8 does not need to be a sintered body made of only copper, and in some cases, a sintered body consisting mainly of copper mixed with other elements or a carbon sintered body may be used. It is possible.

The conductors used in ordinary electrolytic cells are several meters long, so large presses, molds, and sintering furnaces are required to produce the above-mentioned sintered bodies as porous conductors 8. becomes.

Therefore, in such a case, the porous conductor 8 is placed on a longitudinally extending elongated current carrying body 14, such as a rolled copper material, as shown in FIGS. 6 and 7, for example. 100mm
A plurality of sintered bodies 81, 82, 83, 8 having a length of approximately
4 etc. are arranged at predetermined intervals, and the rolled material 14 and each sintered body 81
- 84 can be integrally joined by welding 18.

Electrodes, that is, power supply terminals 16a, 16b are connected to each sintered body 8.
1 to 84, and the conductor 8 and the electrodes 16a, l6
The contact area with b is maintained in a wet state as in the previous embodiments.

The porous conductor 8 used in the current-carrying device 1 according to the present invention is not limited to the sintered body as described above, but as another embodiment, as shown in FIG. It can also be constructed by bundling a large number of thin metal wires 20 and twisting them together.

The conductive liquid 10 can flow through the slits between the core wires and maintain the contact portions with the electrodes 16a and 16b in a wet state.

In addition, as shown in Figure 9, a laminate is formed by stacking and bundling many thin plates of metal such as copper, and the gaps between each thin plate are used to make contact between the electrode and the conductor. It is also possible to use an electrical conductor consisting of a layered laminate of metal sheets, which maintains the wet state of the parts.

Table ① uses a copper electrolyte containing 45 g/l of copper and 200 g/l of free sulfuric acid at a bath temperature of 60°C and a current density of 250 A/m2.
The results of measuring the contact voltage between the porous conductor and the electrode and the contact voltage between the solid copper rod and the electrode when electrolytic refining was performed under the following conditions are shown.

From Table 1, when the porous conductor is used in a wet state,
It will be appreciated that approximately 20 mV of lower contact voltage can be expected than when using copper rods.

A drop in contact voltage of 20 mV contributes to a power reduction of over 10% of the total power required for electrolysis.

It is also preferable that the conductive liquid be slightly acidic, with a pH of 1 to
It is said to be around 2.

By making the conductive liquid acidic in this manner, oxides at the contact portion between the conductor and the electrode can be removed, and the contact resistance can be significantly reduced.

Since the current-carrying device according to the present invention is constructed as described above, it can significantly reduce the contact resistance at the conductor contact portion during current-carrying, reduce the required power, and have a simple structure.
It has the advantage that it does not have consumables that require frequent replacement, and is easy to manufacture, handle, and maintain.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an energizing device according to the present invention. FIG. 2 is a partial plan view of the energizing device of FIG. 1. FIG. 3 is a schematic exploded perspective view of the energizing device shown in FIG. 1. FIG. 4 is a sectional view showing another embodiment of the porous conductor. FIG. 5 is an explanatory diagram showing the manner in which a conductive liquid circulates when the porous conductor shown in FIG. 4 is used. FIG. 6 is a schematic sectional view of another embodiment of the current supply device according to the present invention. FIG. 7 is a sectional view taken along line 1--2 in FIG. FIGS. 8 and 9 are cross-sectional views showing still other embodiments of the porous conductor. 2: Electrolytic cell side wall, 4: Insulating conductor support member, 6: Recess,
8: porous conductor, 10: conductive liquid, 12: conductive liquid circulation device, 14: current carrying body, 16a, 16b: power supply terminal (electrode).

Claims (1)

[Scope of Claims] 1. A conductor for a metal salt electrolytic cell formed of a porous material for supporting a power supply terminal of an anode or a cathode and for supplying power to the power supply terminal. 2. The conductor for a metal salt electrolytic cell according to claim 1, wherein the porous conductor is a sintered body made of copper, copper and other elements, or carbon. 3. The conductor for a metal salt electrolytic cell according to claim 1, wherein the porous conductor is constructed by bundling and twisting thin metal wires. 4. The conductor for a metal salt electrolytic cell according to claim 1, wherein the porous conductor is constructed by bundling a plurality of thin metal plates in a layered manner. 5. An insulating conductor support member is arranged on the upper side wall of the metal salt electrolytic cell, a recess is formed in a part of the upper surface of the insulating conductor support member, and the anode or cathode power supply is provided in the recess during electrolysis. By arranging a porous conductor to make contact with the terminal and supplying a conductive liquid to the porous conductor, the conductive liquid is applied to the contact portion between the porous conductor and the power supply terminal. An energizing device for a metal salt electrolytic cell, which is supplied with electricity to keep the contact portion in a moist state at all times. 6. The energizing device for a metal salt electrolytic cell according to claim 5, wherein the porous conductor is a sintered body made of copper, copper and other elements, or carbon. 7. The energizing device for a metal salt electrolytic cell according to claim 5, wherein the porous conductor is constructed by bundling and twisting thin metal wires. 8. The current supply device for a metal salt electrolytic cell according to claim 5, wherein the conductor is constructed by bundling a plurality of thin metal plates in a layered manner. 9. The current supply device for a metal salt electrolytic cell according to claim 6, wherein the porous conductor is constructed by integrally disposing a plurality of sintered bodies on a conductive current supply body. 10. The energizing device for a metal salt electrolytic cell according to claim 6, wherein the sintered body is a solid rod, and the conductive liquid flows into the recess. 11. The energizing device for a metal salt electrolytic cell according to claim 6, wherein the sintered body is a hollow rod, and the conductive liquid flows into the through hole of the sintered body.