JPH06287787A - Cathode spacer for electrolytically refining metal - Google Patents

Abstract

PURPOSE:To dispense with straightening of a distorted cathode plate and to improve productivity in electrolytic refining by using a frame-shaped spacer having a V-shaped section and specifying the angle between the cathode plate surface and the spacer surface. CONSTITUTION:A spacer 1 is formed into a frame to restrict both sides and bottom of a cathode plate 2, and the cathode plate 2 is inserted from the upper open part. The section of the spacer 1 is formed in the shape of a V, and the angle between the V-shaped frame surface and the cathode plate 2 surface is controlled to 10-80 deg., preferably to 15-50 deg.. Since the frame section is V-shaped, a volume is provided so that a current is not interrupted even if the cathode plate 2 is brought into contact with the spacer 1 but applied to some extent, and the cathode plate 2 is easily inserted and pulled up. A current efficiency is improved because the abnormal electrodeposition of metal is prevented by the spacer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode spacer provided for preventing contact with the anode due to distortion of the cathode used in aqueous metal electrolysis.

[0002]

2. Description of the Related Art In the electrolytic refining of metals such as nickel, cobalt and copper, it is well known that a thin seed plate made of SS, SUS, Ti, etc. as a mother plate is used as a cathode plate in an electrolytic cell. The cathode plate and the anode plate or the anode diaphragm (hereinafter referred to as the anode plate) are alternately arranged on the cathode plate, and the electrolytic metal is electrodeposited on the cathode plate for purification. In electrolytic refining, since the cathode plate used is extremely thin, distortion occurs due to the stress of the electrodeposit on the cathode plate during electrolytic operation.

Generally, in electrolytic refining, it is customary to make the distance between the electrodes as small as possible in order to increase the electrolysis efficiency. There is a problem that the contact causes the deterioration of electrolysis efficiency and the quality of electrodeposited metal.

In order to avoid such a problem, usually after the completion of electrolysis or during electrolysis, the work of removing the cathode plate and mechanically correcting the strain using a roller, a press or the like is carried out. In addition to being bothersome, it is impossible to completely correct the strain. Therefore, even if the cathode plate subjected to the strain correction is reused, it may come into contact with the anode plate again in a short time.

[0005]

Therefore, in order to prevent contact between the cathode plate and the anode plate, an electrically insulating material such as vinyl chloride surrounding both sides and the bottom of the cathode plate 2 shown in FIG. 5 (A) is used. A spacer 1 made of a frame material was developed, and it became possible to avoid contact due to strain between the cathode plate and the anode plate by using this spacer, but on the other hand, by using the spacer, both sides and the bottom of the cathode plate were Since a current-shielding portion is generated at the portion, the thickness of the electrodeposited metal in this portion becomes extremely thin, and the current density locally increases the current density in the vicinity of the spacer end portion, resulting in abnormal deposition of the electrodeposited metal. This abnormally-deposited metal grows and wraps around the spacer, causing damage to the spacer and contacting the grown metal with the anode plate. New rata issue of Mau has occurred (see FIG. 5 (B)).

The present invention solves the above-mentioned problems due to the use of spacers in the cathode plate in metal electrolytic refining, and the deposition of electrodeposited metal is not problematic in terms of quality even when the shielding part of the cathode plate is generated by the spacers. It is an object of the present invention to develop a cathode spacer that is formed so as to have a thickness and in which the abnormal deposition and growth of the electrodeposited metal at the frame tip of the spacer are unlikely to occur.

[0007]

According to the present invention for solving the above-mentioned problems, a frame-shaped spacer is formed in a V-shaped cross-section, and a frame of the cathode plate surface and the spacer fitted in the spacer is formed. It is a cathode spacer for electrolytic refining formed so as to form an angle of 10 to 80 ° with the surface.

[0008]

The details of the present invention and the operation thereof will be described below based on this preferred embodiment. FIG. 1 is a perspective view showing one embodiment of a cathode spacer for electrolytic refining according to the present invention, and FIG. 2 is a schematic view of the AA cross section in FIG. 3 and 4 are schematic cross-sectional views of the same portion as FIG. 2 in another embodiment of the present invention. In the figure, 1 is a cathode spacer and 2 is a cathode plate. Further, θ represents an angle formed by the frame surface of the cathode spacer and the inserted cathode plate surface.

As can be seen in the figure, the spacer 1 of the present invention is formed in a frame shape so as to restrain both side portions and the bottom portion of the cathode plate 2, and the cathode plate is inserted into the spacer from the open upper portion thereof. Then used. The frame cross section of the spacer is basically V-shaped, and the angle between the V-shaped frame surface and the inserted cathode plate surface is 10 to 80 °, preferably 15 to 50 °. . The frame cross section is basically formed in a V-shape so that even if the cathode plate comes into contact with the spacer frame, there is provided a volume that allows the cathode plate to wrap around to some extent without shielding the current, and the work of inserting and pulling up the cathode plate This is to make it easier.

If the angle between the V-shaped frame surface and the inserted cathode plate surface is less than 10 °, the volume into which the current can flow becomes too small, and the thickness of the electrodeposited metal on both sides and the bottom of the cathode plate is extremely thin. In addition, the width of the V-shape becomes small, and the efficiency of the work of inserting and pulling up the cathode plate becomes poor. On the other hand, when the angle exceeds 80 °, the height of the V-shape becomes small, so that the cathode plate is easily disengaged from the spacer due to distortion, and the efficiency of the work of inserting and pulling up the cathode plate also deteriorates. Reference numeral 3 denotes a reinforcing brim for fixing, which is provided at the upper end of the spacer and serves both to fix the spacer to the electrolytic cell and to reinforce it. The bottom of the spacer frame may form a flat bottom 4 of a length to facilitate insertion of the cathode plate as shown in FIG. 3, and the V-shaped frame as shown in FIG. The outside may be reinforced by the reinforcing plate 5 so that the tip portion does not spread due to the electrodeposition stress of the plate 2. Further, as the constituent material of the cathode spacer, it is suitable to use an easily insulating electrically insulating material such as wood, FRP, or vinyl chloride.

Since the cathode spacer of the present invention is formed as described above, it does not cause a current shielding portion, and thus the thickness of both side surfaces of the cathode plate is such that there is no quality problem. The electrodeposition can be performed and contact with the anode plate due to partial growth of the deposited metal due to abnormal deposition can be avoided.

[0012]

EXAMPLE A frame (height 1065 mm, width 830 mm, thickness 55 m) so that both sides and bottom of the cathode plate (thickness 0.9 mm) are inserted over 30 mm from the end thereof.
m) a cathode spacer according to the invention as shown in FIG. 3 (test number 1) and a conventional cathode spacer having a circular cross section and a rectangular shape (test numbers 2 and 3, frame cathode plate insertion) Three kinds of cathode spacers (all have the same depth as above) were prepared, and the above-mentioned cathode plates, which had been strain-corrected by a 300t press, were inserted into the respective cathode spacers, and the cathode spacers were not used. Cathode plate (test number 4)
Regarding the above, using a nickel-containing liquid as an electrolytic solution, electrolytic refining of nickel was carried out for 8 days by a conventional method at a current density of 2.3 A / dm ² , and the presence or absence of abnormal electrodeposition on the obtained cathode plate and the anode during electrolytic operation An evaluation test was conducted on the rate of occurrence of short circuits with the plate. The results are shown in Table 1.

[0013]

[Table 1]

From the results shown in Table 1, in the case of no spacer (Test No. 4), the short-circuit rate was remarkably high due to the remarkable distortion of the cathode plate. In case of using the spacers (Test Nos. 2 and 3), although the occurrence of strain can be prevented, abnormal current deposition of nickel occurs in this portion due to the current shielding of the insertion portion, and this growth portion shorts with the anode Therefore, the short-circuit rate does not decrease so much. On the other hand, when the spacer of the present invention is used (Test No. 1), no abnormal electrodeposition of nickel is observed in the inserted portion and, of course, the cathode plate is not distorted, so that a short circuit is hardly generated. I know there isn't.

[0015]

As described above, according to the present invention, when electrolytically refining a metal, it is not necessary to carry out a correction work due to distortion of the cathode plate. Since the abnormal electrodeposition of metal is not caused by the use of the spacer, it has many effects such as improvement of current efficiency and improvement of product quality.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a cathode spacer of the present invention.

FIG. 2 is a schematic cross-sectional view taken along the line AA of FIG.

FIG. 3 is a schematic cross-sectional view showing the other embodiment of the cathode spacer of the present invention in the same portion as FIG. 1.

FIG. 4 is a schematic cross-sectional view showing the other part of the cathode spacer of the present invention at the same portion as FIG. 1.

FIG. 5 is a view showing a conventional cathode spacer, (A).
FIG. 4A is a perspective view, FIG. 8B is an enlarged cross-sectional view of portion B of FIG.

[Explanation of symbols]

 1 Spacer frame 2 Cathode plate 3 Reinforcing collar for fixing

Claims (1)

[Claims] 1. A frame-shaped spacer is formed in a V-shaped cross-section, and the cathode plate surface fitted into the spacer and the frame surface of the spacer are formed at an angle of 10 to 80 °. Cathode spacer for electrolytic refining.