JPS6053117B2 - Copper electrolysis operation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in nonferrous metal electrolytic operation methods.

Conventionally, in copper electrolytic refining, for example, instead of a single tank, multiple stages of electrolytic refining sets, each consisting of a large number of cathode and bipolar plates, are charged into a large tank without a partition plate. A device that performs multistage electrolysis is in operation.

This method reduces the wall surface of the cell, which reduces the cost of lining, etc., and eliminates the need to provide separate outlets and inlets for the electrolyte, compared to conventional unit electrolytes. This not only has a great advantage in reducing the overall construction cost of an electrolytic plant, but also facilitates operational management.

However, in actual operation, leakage current occurs between adjacent unit cells, and the cathode on the cell side with a higher potential tends to deposit on the adjacent cell electrode on the lower potential side, resulting in a decrease in current efficiency. It can also cause

This current can be prevented by providing a passive sheet or the like between the unit cells of the large electrolytic cell.
However, as electrolysis continues, the concentration in the electrolyte, particularly the concentration of copper ions and free sulfuric acid, changes locally, and this tendency increases with the residence time of the solution and the amount of electrolytic deposition.

Therefore, in the case of the above-mentioned multi-stage electrolytic cell, near the final liquid outlet, a concentration difference occurs in the depth direction of the electrolyte that cannot be ignored in terms of operation. As a result, the dissolution of the anode and the deposition on the cathode vary depending on the position in the electrolytic cell, resulting in disadvantages such as an increase in the residual rate of the anode in some areas and deterioration of the quality of the cathode. The present invention is intended to improve the above-mentioned troubles and improve the efficiency of large multi-electrolytic cells, and will be specifically explained in detail with reference to the accompanying drawings.

1 is a large multi-stage electrolytic cell, in which individual unit electrolytic cells 2, 2',
A large number of anodes 3 and cathodes 4 are combined and immersed in spaces such as .

At this time, since there is no partition between the adjacent unit cells and there is no partition between them, the electrolyte 10 supplied from the supply box 5 provided at one end of the electrolytic cell 1 is supplied to each electrolytic unit according to the arrow. The liquid flows through the cell to the other end, and is taken out of the container by a drain tank (not shown) provided at the other end. In this mechanism, partition plates, which are a combination of partitions and cutting plates 6 and 7, are provided at appropriate intervals (in the figure, every three unit cells) in the middle of the battery case. ; This partition plate is for reversing the upper and lower layers of the reflux liquid and eliminating the concentration gradient, so two plates are used as a set. For example, as shown in the figure, 6 protrudes above the liquid surface, and the lower side meets the bottom of the tank. By providing a gap 8 between them to serve as a liquid passage port, the electrolytic solution 10 passes under the partition plate 6 and flows from the upper part of the partition plate 7 into the adjacent unit cell side.

The partition plates 6, 7 can be formed by simply inserting, for example, a vinyl chloride board, and the equipment cost is minimal, and the installation position can be easily moved or increased or decreased as required.

In addition, although this example shows the partition plate as a combination of genin and upper parts, it is of course possible to turn the partition plate upside down and use a top-in and bottom-in part, or a combination of the two as appropriate.

When this mechanism is incorporated, the flow of electrolyte in the container is bent, so resistance increases to some extent, but by adjusting the distance between the partition plates and the upper and lower gaps, the flow resistance can be practically ignored.
It is possible to increase only the electrical resistance to a level that does not cause electrolysis between adjacent battery cells, prevent leakage of electrolysis, and improve cathode quality, which has high industrial effects.

Example 1 A large electrolytic cell with a length of 28.1 m, a width of 4.1 m, and a depth of 1.3 n1 was divided into 2 parts in the length direction, with desiccators placed on the top of the tank.
In a multistage electrolytic cell equipped with a tributator, a pair of partition plates were provided at three locations.

For testing, we used a combination of upper entry and lower removal method and genin upper removal method for every other partition, and the spacing between the two partition plates at each partition location was 20 ~
30! The height of the n1 lower outlet was 150 to 300 m1, and the upper overflow part was electrolytic; the test was conducted by varying the height from 200 to 5007 m from the upper edge of the tank. The electrolytic solution flowed in at 700 e/min from the liquid supply box provided at one end of the short side, and was discharged from the opposite side.

As a result, the copper concentration distribution in the 20th cell at the reflux liquid outlet was as follows. In other words, the copper concentration gradient in the depth direction in the electrolyte is less than about 1 h, and electrolysis no longer occurs between the cells on both sides of the partition plate, so homogeneity or sorting is obtained, and the current efficiency is also improved. This has improved from the previous 90 to 91.8%.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a large electrolytic cell used in carrying out the present invention, and FIG. 2 is a side view of FIG. 1. 1 is a large multi-stage electrolytic cell, 2 and 2'' are electrolytic cell cells, 3 is an anode, 4 is a cathode, 5 is a liquid supply box, 6 and 7 are partition plates, 8 is a gap, 9 is a suspension member and a conductor, 10 is an electrolyte.

Claims (1)

[Claims] 1. In an electrolytic refining electrolytic cell that performs multi-stage electrolysis in the same tank, a set of two partition plates is provided in the direction perpendicular to the flow of the electrolyte, and the top and bottom of the circulating electrolyte are reversed by the partition plates. , a copper electrolysis operation method characterized by reducing the concentration difference in the liquid and preventing leakage electrolysis between adjacent unit cells.