JP2012087394A - Electrowinning equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrowinning equipment which restrains generation of metal particles and prevents an anode box from being damaged even if there is a failure in the shape of a metal fitting of a cathode hanger.SOLUTION: In the electrowinning equipment, a set comprising a cathode 2 and an anode 1 arranged to oppose to the cathode 2 is disposed in an electrolytic cell, and electrowinning is carried out. The cathode 2 comprises a cathode plate 21 which is suspended from a cathode beam 22 through a cathode hanger 23. The anode 1 comprises: an anode plate 11 suspended from an anode beam 12 through an anode hanger 13; and a box-shaped anode box 14 surrounding the anode plate 11. A filter fabric 19 serving as an electric shielding matter is stuck to a portion opposing to the cathode hanger 23 in the anode box 14. Since the passage of electric current between the cathode hanger 23 and the anode box 14 is shielded by the filter fabric 19, metal particles hardly occur, and the anode box 14 is prevented from being damaged when being pulled up.

Description

  The present invention relates to electrolytic collection equipment. In electrolytic collection, a large number of anode and cathode pairs are inserted into an electrolytic cell. The present invention relates to an electrowinning facility having an improved anode box for protecting the anode.

  In the hydrometallurgical method for non-ferrous metals, nickel matte produced from dry smelting and nickel sulfide produced by sulfuric acid leaching from low-grade laterite ore are used as raw materials, and are contained in the raw materials. Chlorine leaching of most metals such as nickel, cobalt and copper. Then, after removing metal impurities and the like from the solution obtained by leaching with chlorine, electric nickel and electric cobalt are produced by electrowinning.

Electrolytic extraction involves leaching the target metal from the ore with an appropriate solvent, and removing the impurities and concentrating the target metal ions from the leachate in the liquid purification process to deposit the target metal on the cathode by electrolysis. It is a process to make.
The electrolytically-collected anode functions only as a conductor and serves as a generation electrode for generating, for example, chlorine gas.
The cathode is the same as in the case of electrolytic purification, and there are a case where the same pure metal as the target metal is used as a seed plate and a case where a different metal is used and this is peeled off after electrodeposition.
The cathode is put into operation by attaching a handle made of the same kind of metal ribbon to a pure metal cathode plate. The electrolytic bath uses an aqueous solution of a soluble salt of the target metal as an electrolytic solution.

  The anodic reaction used in the electrowinning is to make the current flow through the system, and the generation reaction of chlorine gas or the like on the insoluble anode is used. For example, in the electrowinning of zinc from an aqueous solution of zinc chloride, chlorine gas is generated at the anode and zinc is deposited at the cathode. In order to continuously carry out this electrolysis, it is operated by applying a voltage of a certain magnitude or more.

  The electrolytic collection equipment is usually operated in about 50 electrolytic cells, and about 50 sets of anodes and cathodes are alternately inserted into the electrolytic cell for each electrolytic cell. As shown in FIG. 6, the electrolytic cell has an electrolytic solution stored inside the electrolytic cell 10, and a set of anodes 1 and cathodes 2 are alternately arranged and immersed in the electrolytic solution. The anode 1 is suspended from the anode beam 12, and the anode beam 12 is fixed to the edge of the electrolytic cell with a bolt or the like. The cathode 2 is suspended from a cathode beam 22 via a cathode hand 23, and the cathode beam 22 is hooked on the edge of the electrolytic cell.

In the above-described electrowinning, chlorine gas or the like is generated from the anode 1 side, so that the insoluble anode is housed in a partition wall called an anode box 14 and the generated chlorine gas or the like is separately collected.
The cathode 2 is manufactured in a pre-process of the electrowinning process. At this stage, a cathode plate 21 having a square shape and a large area is attached with a cathode handle 23 that has been processed into a tweezers shape. The cathode plate 22 is suspended by the cathode beam 22.

By the way, as shown in FIG. 7A, the cathode suspension 23 may have a bifurcated one side portion due to a defect in the manufacturing process, and a protruding portion 123 floating from the cathode plate 21 may be generated. In order to eliminate such a protruding portion 123, it is sufficient to strictly manage the manufacturing conditions of the hanging metal fittings, but this requires a long time, which is not preferable for operation.
However, if it is used forcibly, the distance between the poles is locally short in the vicinity of the protrusion 123, so that the electric resistance is small. As shown in FIG. Precipitates to form metal particles mp. When this metal grain mp grows and comes into contact with the anode box 14 as shown in FIG. 5C, and further contacts the anode plate through the anode box 14, an electric short circuit (short) occurs. The above problem occurs.
Further, since the grown metal particles mp pass through the filter cloth constituting the anode box 14 before the short circuit occurs, the anode box 14 is cleaved when the cathode is pulled up even when the short circuit does not occur. The problem of the equipment cost that the exchange frequency of 14 rises will generate | occur | produce.

  Patent Document 1 discloses a method for preventing the generation of metal particles mp at the peripheral edge of the cathode by appropriately shielding current using a cathode spacer. However, although the prior art of Patent Document 1 is effective in shielding the current around the cathode, it cannot prevent the growth of metal particles mp in the metal part of the cathode suspension.

Japanese Patent Laid-Open No. 06-287787

  In view of the above circumstances, the present invention provides an electrowinning facility that can suppress the generation of metal particles and can continue operation without damaging the anode box even if there is a defect in the shape of the metal fitting of the cathode suspension. For the purpose.

An electrowinning facility according to a first aspect of the present invention is an electrowinning facility in which a set consisting of a cathode and an anode used in opposition to the cathode is placed in an electrolytic cell and electrowinning is performed. A cathode plate suspended through a suspension, the anode comprising an anode plate suspended from an anode beam through an anode suspension, and a box-shaped anode box surrounding the anode plate, An electrical shield is affixed to a portion of the anode box facing the cathode suspension.
The electrowinning equipment of the second invention is characterized in that, in the first invention, the electrical shield is a filter cloth.
The electrolytic collection equipment of the third invention is characterized in that, in the second invention, the filter cloth is pasted by silicon caulking.
According to a fourth aspect of the present invention, in the second or third aspect, the portion of the anode box where the filter cloth is attached is larger in the width direction and the vertical direction than the cathode suspension.

According to the first aspect of the present invention, the electrical shield shields the electric current between the cathode suspension and the anode box, so that it is difficult for metal particles to be generated, no short circuit occurs, and the anode box is cleaved when pulled up. Does not occur.
According to the second aspect of the invention, since the electrical shield is a filter cloth, it can be thinned, the distance between the anode and the cathode in the electrolytic cell can be kept narrow, and the operation can be performed while keeping the electrolytic efficiency high. .
According to the third invention, since silicon is not attacked by the solution after leaching with chlorine, the filter cloth is not peeled off, and the growth of metal particles can be prevented over a long period of time.
According to the fourth invention, since the area of the filter cloth is wider than that of the cathode suspension, even if there is a slight shift in the insertion position of the anode or the cathode into the electrolytic cell, the current is effectively shielded and the metal particles are generated. It can be prevented.

It is a front view of the anode in the electrowinning equipment concerning one embodiment of the present invention. (A) is a side view of the anode shown by the arrow IIa in FIG. 1, and (B) is a sectional view of the anode shown by the arrow IIb in FIG. (A) is a front view of a cathode, (B) is the side view. It is a front view of the state which accumulated the cathode on the anode. FIG. 5 is a side view taken along line VV in FIG. 4. It is a fragmentary sectional view of an electrowinning equipment. It is explanatory drawing of the problem which arose with the conventional electrolytic collection equipment.

Next, an embodiment of the present invention will be described with reference to the drawings.
Although the electrowinning equipment of the present invention is devised for the anode box, it is also devised in relation to the structure of the cathode, and therefore the structure of the anode and the structure of the cathode will be described below in that order.

First, the anode will be described with reference to FIGS.
The anode 1 includes an anode plate 11, an anode beam 12 that suspends the anode plate 11, and an anode suspension 13 that connects the anode plate 11 to the anode beam 12.
The anode plate 11 is a metal plate that functions as a conductor in the electrolytic cell, and a titanium plate, a copper alloy plate, a cobalt alloy plate, or the like is used.

  The anode suspension 13 is a flat plate of the same kind of metal as the anode plate 11, and two are used. The anode beam is obtained by applying nickel plating to a copper bar, and is fixed to the anode suspension 13 with a bolt or the like.

Since the anode plate 11 of the anode 1 serves as a generation electrode for chlorine gas or the like, the anode plate 11 is surrounded by an anode box 14 for collecting the generated gas and releasing it to the outside.
The anode box 14 has a structure in which a filter cloth 16 is attached to a synthetic resin frame 15 such as vinyl chloride, and an upper edge of the filter cloth 16 is fixed with a rubber O-ring 17 or the like. That is, the anode plate 11 has a configuration in which the front, back, and both sides are surrounded by the filter cloth 16.
Note that a suction pipe 18 is attached to the frame 15 at an appropriate position on the upper end, and the generated gas is discharged from the suction pipe 18 to the outside.

A filter cloth 19 as an electrical shield is attached to the filter cloth 16 on the front side and the back side of the anode box 14 having the above configuration.
The electrical shield used in the present invention may be any shield that prevents energization, but is preferably a thin object that can be attached to the filter cloth 16 constituting the anode box 14.
In this embodiment, the filter cloth 19 is used as such an electrical shield. The filter cloth 19 may be the same material as the filter cloth 16 constituting the anode box 14 or may be slightly different.

The cathode 2 will be described with reference to FIG.
The cathode 2 includes a cathode plate 21, a cathode beam 22 that suspends the cathode plate 21, and a cathode suspension 23 that connects the cathode plate 21 to the cathode beam 22.
The cathode plate 21 includes those using the same metal as the target metal and those using a different metal.
The cathode handle 23 is formed by bending a thin flat plate of the same kind of metal as the cathode plate 21 into a bifurcated shape similar to tweezers. Two cathode suspensions 23 are used, and the respective ends are fixed to the upper edge of the cathode plate 21 by spot welding or the like. The cathode beam 22 is passed through the upper end curved portion of the cathode suspension 23.

As shown in FIG. 4, the filter cloth 19 as an electrical shield is stuck on the filter cloth 16 constituting the anode box 14 at a portion facing the cathode handle 23.
Since the filter cloth 19 is thin, the distance between the anode and the cathode in the electrolytic cell can be kept narrow, and operation can be performed while keeping the electrolytic efficiency high.

  The adhesive for affixing the filter cloth 19 may be anything as long as it is not affected by the solution after leaching with chlorine. For example, it is preferable to use Cemedine Co., Ltd., product name: Cemedine 8060 Pro). This is because silicon is not attacked by the solution after leaching of chlorine, and the caulking agent does not have to be prepared with a separate adhesive or the like.

It is preferable that the size of the filter cloth 19 is larger in both depth and width than the portion of the cathode suspension 23 immersed in the electrolytic cell. The margin size to be increased may be determined empirically, but is about several tens of millimeters, for example.
By doing so, the position where the cathode 2 or the anode 1 is inserted into the electrolytic cell is slightly shifted each time. Even if such a position shift occurs, if the filter cloth 19 has a sufficient size, the energization shielding is performed. Will be done effectively. Therefore, the current is shielded between the cathode suspension 23 and the anode box 14, and the metal particles mp are less likely to be generated.

  The cathode 2 in the electrowinning equipment is generally inserted into the electrolytic cell using an electrode crane called an electrolytic crane in an electrolytic cell in which the anode 1 is already fixed in the cell. In the electrowinning equipment using the filter cloth 19 of the present invention, it is not necessary to obtain accuracy in the operation of the crane, particularly when the anode is inserted.

  Note that the size of the electrical shielding filter cloth 19 is larger when the size is larger than the size for the purpose of electrical shielding, but conversely, from the original purpose of electrolytic collection, the operation efficiency is lowered. Since it becomes a direction, it is desirable to make it the minimum size while ensuring the above-described margin dimension.

Next, the effect will be described with reference to examples.
(Common conditions for Examples and Comparative Examples)
Cathode 2: A cathode 2 made of a cobalt alloy about 1 m square was prepared.
There is a defect in the cathode hanging bracket 23, and in about 10% of the manufactured cathodes 2, the cathode hanging portion 23 has a 40 mm square dipping portion, whereas One hanger was as long as 60 mm, and the end face was lifted about 5 mm. The width was 40 mm.
Anode 1: An insoluble anode plate 11 is provided in an anode box 14, and the anode 1 is installed in the electrolytic cell by bolting an anode beam 12 to the edge of the electrolytic cell through a bus bar as an electrode. ing.

Example 1
The anode box of the present invention was used for the anode box 14 at the position facing the cathode handle 23 where the defect occurred.
Except for the above, the electrowinning operation was performed in the same manner as in the case where there was no problem with the cathode handle 23.
As a result, in Example 1, during one electrolytic operation (the cathode 2 is charged in the electrolytic cell, a predetermined amount of metal is electrodeposited and pulled up (the cathode 2 is taken out from the electrolytic cell)), 1 Zero occurrences of shorts per tank. The number of anode box breakage when the cathode 2 was pulled up was zero per tank.

(Comparative Example 1)
Instead of using the anode box of Example 1, a current shielding cover made of a vinyl chloride plate was hung between the anode box 14 and the cathode suspension 23.
Otherwise, the electrolytic operation was performed in the same manner as in Example 1.
As a result, the number of shorts occurred during one electrification operation, one per tank. The number of anode box breakage when the cathode was lifted was 4 per tank.

(Comparative Example 2)
Instead of using the anode box of Example 1, a current shielding cover made of filter cloth was hung between the anode box 14 and the cathode suspension 23.
Otherwise, the electrolytic operation was performed in the same manner as in Example 1.
As a result, the number of shorts that occurred during one electrification operation was two per tank. The number of anode box breakage when the cathode was pulled up was 5 per tank.

  According to the electrowinning equipment of this embodiment, even if the cathode handle 23 has a problem, the generation of the metal particles mp is suppressed, and the operation can be continued without damaging the anode box 14. Conventionally, if the cathode suspension 23 is operated during a period of trouble, it is necessary to replace the anode box of 5 sheets / tank (50 sheets, 250 sheets) in one electrolytic operation. After the use of the anode box 14 of the present embodiment, the anode box exchange was zero.

DESCRIPTION OF SYMBOLS 1 Anode 2 Cathode 14 Anode box 16 Filter cloth 19 Filter cloth as an electrical shield 23 Cathode lifter

Claims (4)

An electrowinning facility for performing electrowinning by installing a set of a cathode and an anode used in opposition to the cathode in an electrolytic cell,
The cathode comprises a cathode plate suspended from a cathode beam via a cathode suspension;
The anode comprises an anode plate suspended from an anode beam via an anode hand, and a box-shaped anode box surrounding the anode plate,
An electrowinning facility, wherein an electrical shield is affixed to a portion of the anode box that faces the cathode suspension. The electrowinning equipment according to claim 1, wherein the electrical shield is a filter cloth. The electrolytic collection equipment according to claim 2, wherein the filter cloth is attached by silicon caulking. The electrowinning equipment according to claim 2 or 3, wherein a portion of the anode box to which the filter cloth is attached is larger in the width direction and the vertical direction than the cathode suspension.

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