JPH0510437B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to an improvement in a conductor to be installed in an electrolytic cell in order to supply electricity to the electrodes of the metal salt electrolytic cell. <Prior art> In general, in the electrolysis of metal salt aqueous solutions, the contact resistance of each contact point between a conductor installed on the side wall of an electrolytic cell and an anode/cathode in contact with the conductor is reduced and variation is reduced. Various efforts have been made for this purpose. For example, Japanese Patent Publication No. 49-16686 discloses a conductor that has a low contact resistance and less variation even during long-term electrolysis by keeping the contact portion wet with a conductive liquid. There is. As shown in FIGS. 1 and 2, which are examples of copper electrolytic refining, this conductor has a liquid-impregnated part 2 in a conductor main body 1, and an impregnable sponge material such as a sponge inside the liquid-impregnated part 2. 3, and this impregnable sponge object 3
The electrode or the electrode beam 4 (crossbar or shoulder) is supported through the liquid-containing part 2, and conductive liquid is continuously dropped or replenished to the liquid-containing part 2 so that the sponge object 3 is connected to the electrode 4. The contact area is always kept hydrated. Tap water, industrial water (groundwater, etc.), etc., have been used as the conductive liquid. <Problems to be Solved by the Invention> However, in the conventional conductor as described above, deposits are generated, and it is said that this deposit cannot be removed by spraying dilute sulfuric acid, which is normally used to clean the oxide film. There was a problem. Therefore, in the above conductor, in addition to replacing the impregnated sponge body 3 impregnated with the conductive liquid when it deteriorates, it is necessary to polish the deposits generated on the conductor. In view of these circumstances, an object of the present invention is to provide a conductor for a metal salt electrolytic cell that prevents the generation of deposits. <Means for Solving the Problems> As a result of various studies conducted by the present inventors in order to solve the above problems, the main component of the deposits generated inside the conductor is calcium sulfate, and this calcium sulfate is A reaction between Ca in the conductive liquid, which was volatilized and concentrated due to the resistance heat generated by the conductor's energization, and the sulfuric acid in the scattered electrolyte or the dilute sulfuric acid used for cleaning that remained after washing with water. We found that. The configuration of the present invention based on such knowledge is formed so as to be in contact with an electrode or an electrode beam via a conductive liquid, and is used in a metal electrolytic cell that uses a metal sulfate as an electrolyte or sulfuric acid as a cleaning liquid. A conductor for a metal salt electrolytic cell using a liquid containing a metal salt electrolytic cell is characterized in that the conductive liquid supplied into the conductor has a calcium concentration of 1 mg/min or less. <Example> The present invention will be explained in further detail by showing examples below. A conductor similar to the one shown in Figures 1 and 2 was installed in a copper electrolytic tank at a copper electrolysis factory, and tap water was passed through a softening device (SAT-256 manufactured by Organo) and the softened water was used to make conductors. Supplied as a liquid. The Ca content of the softened water at this time is 1 mg/or less. In this example, periodic pickling with dilute sulfuric acid followed by water rinsing enabled stable operation over a long period of time, and it was sufficient to remove deposits by polishing once a year. Table 1 shows the average composition of the removed deposits. In addition, in a comparative example in which tap water was used as a conductive liquid using a similar device, it was necessary to polish and remove deposits once every three months. The Ca content of the supplied tap water at this time was 19 mg/, and the composition of the deposits was as shown in Table 1.

[Table] From Table 1, it can be predicted that the main component of some of the deposits generated in this example was copper sulfate, which is consistent with the fact that it can be cleaned with dilute sulfuric acid. In the above example, the contact resistance was reduced due to the reduction in deposits, and was reduced by 3 mV compared to the comparative example. This will reduce the basic unit of electrolytic copper production.
We were able to reduce the power by 3kwH/T. In this way, the Ca content in the conductive liquid supplied into the conductor is set to 1 mg/or less, preferably 0.1 mg/
If the amount is set below, the amount of deposits can be greatly reduced. Note that even when using a liquid other than water in the above embodiment, the water used as the mother liquor may be softened water in the same manner as described above. <Effects of the Invention> As specifically explained above in conjunction with the examples, the use of the conductor according to the present invention reduces the generation of deposits, and the sulfuric acid that is easily soluble in dilute sulfuric acid used to clean the deposits that are generated. Since the material is made of copper, the number of polishing operations required to remove deposits can be significantly reduced. This reduces the contact resistance between the conductor and the electrode, and also reduces its variation.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view showing a conductor in contact with an electrode or an electrode beam via a conductive liquid, and FIG. 2 is a cross-sectional view thereof. In the drawings, 1 is a conductor main body, 2 is a liquid-containing part, 3 is an impregnated corpus cavernosum, and 4 is an electrode or an electrode beam.

Claims (1)

[Claims] 1 Metal salt electrolysis formed in contact with the electrode or electrode beam via a conductive liquid and used in a metal electrolytic cell using a metal sulfate as the electrolyte or using a liquid containing sulfuric acid as the cleaning liquid 1. A conductor for a metal salt electrolytic cell, characterized in that a conductive liquid supplied into the conductor has a calcium concentration of 1 mg/min or less.