RU2247799C2 - Process of electrolytic deposition of metallic envelope on cathode - Google Patents

Abstract

FIELD: metallurgy, namely processes for electrolytic deposition of metallic envelope on cathode plate.

SUBSTANCE: processes comprises steps of depositing metal onto both sides of cathode plate for forming envelope faces joined at least along one edge through brittle region of deposited metal; dividing envelope faces on cathode plate by two sheets due to bending and turning respective sides relative to fragile region; making recess on cathode plate for forming in said recess and near it brittle region of deposited metal; forming in brittle region breaking line and dividing envelope, mainly by two similar sheets. Cathode plate has recess at least on one edge for forming breaking line in range of recess at depositing metal and for dividing envelope of deposited metal, mainly by two similar sheets.

EFFECT: possibility for making two similar sheets of envelope due to bending and turning respective sides of envelope relative to brittle region.

14 cl, 6 dwg, 1 ex

Description

The present invention relates to electrolytic deposition of a metal sheath on a cathode and a cathode plate for use in electrolytic metal deposition.

Various methods and devices are known for electrolytic cleaning or for producing metal by electrolysis.

One particularly successful electrolytic deposition method for copper is, for example, the so-called ISA Process, in which copper is deposited on a stainless steel source cathode plate. Then, the electrolytically deposited copper is removed from the cathode plate first by bending the cathode plate to cause at least part of the copper coating to separate from it, and then, by wedging or blowing air, the remaining copper is removed from the cathode plate.

In the ISA method, the lower edge of the cathode source plate is usually coated with a release agent, such as paraffin, or a plastic edge strip to prevent copper from depositing thereon. This makes it possible to remove electrolytically deposited copper in the form of predominantly identical separate sheets on both sides of the cathode plate. However, coating the cathode plate with paraffin is time-consuming and expensive both due to the use of paraffin and to restore the paraffin to its original state after the coating removal process and related maintenance actions.

To eliminate these drawbacks, in some electrolytic cleaning / electrolysis operations, a so-called coated cathode process is used. In such a process, the lower edge of the cathode plate is not coated with paraffin and the electrolytically deposited metal is allowed to grow on both sides of the sheet and around the lower edge of the cathode source plate.

After that, the electrolytically deposited shell is removed from the metal by bending the cathode plate and separating the metal from both sides of the sheet so that it forms a V-shape. Then, the cathode source plate is removed from the location between the electrolytically deposited metal sheath, after which the sheath is closed and rotated from its vertical position to a horizontal position and transported to the stacking / binding site.

Such a removal process requires not only a complex device for opening the metal shell, removing the cathode initial plate before closing the shell and turning the shell from a vertical position to a horizontal position for stacking, such a system takes a lot of time and is generally not as fast as the cleaning operation ISA way.

As the closest analogue, the applicant proposes to consider the method of electrolytic deposition of a shell from a metal on a cathode plate known from document GB 2196989, C 25 C 7/08, 11/11/1988, including the deposition of metal on both sides of the cathode plate with the formation of the sides of the shell connected at at least one edge by a brittle region of the deposited metal, and dividing the sides of the shell from the cathode plate into two sheets by bending and rotating the respective sides of a relatively brittle region having a list techniques, are above disadvantages.

The aim of the present invention is to eliminate or reduce at least one of the disadvantages of the known solutions or to create a preferred alternative to the known technology.

In a first aspect, the present invention provides a method for electrolytically depositing a shell of a metal on a cathode plate, comprising depositing metal on both sides of the cathode plate to form sides of the shell connected by at least one edge by a brittle region of the deposited metal, and separating the sides of the shell with the cathode two-sheet plates by bending and turning the respective sides of a relatively fragile region, characterized in that a recess is performed on the cathode plate To form a recess, and next to the fragile area of the deposited metal him formation fracture line therein, and separating the shell from the metal to be deposited mainly on the two identical sheet.

The method consists in manufacturing a recess on the cathode plate, whereby the metal deposited in and adjacent to the recess forms a brittle portion, wherein the recess is shaped so that a fracture line is formed in the metal deposited inside the recess, whereby the separation of two sheets of the deposited metal is initiated along the line of destruction.

In the first embodiment, the recess is V-shaped, with a fracture line formed within the V-shaped arc.

In another embodiment, the angle of the V-shaped recess is between 75 and 105 degrees, and most preferably the angle of the V-shaped recess is preferably 90 degrees.

The present inventor has determined that the size and shape of the recess in the cathode source plate greatly affects the ability to separate the deposited metal shell from the cathode plate into two substantially identical sheets.

By appropriately dimensioning and shaping the recess, it is possible to reliably obtain a fracture line between two sides of the electrolytically deposited shell, whereby separation or separation of two separate sides of the deposited metal shell sheets is initiated along the fracture line within the recess.

If the fracture line does not form within the recess, the fracture line may be initiated outside the boundaries of the recess, and in some cases may continue to propagate around the end of the plate to the outside of the cathode metal plate sheath, as shown in FIG. 3. Then the sheets can break in the vicinity of a point outside a fragile area. The presence of such a line of destruction outside the brittle region creates difficulties in the process of separation of the coating. Firstly, this can lead to a very difficult splitting of these two sheets. In some cases, it may be necessary to rotate or swing the sheets several times to ensure separation. It is clear that this is undesirable and increases the residence time of the plate in the stripper machine and, thus, slows down the production.

Further, as a result of the fracture along the fracture line extending outside the brittle region, two sheets are formed which are substantially not symmetrical or not uniform in size. One sheet may be predominantly flat, while the other sheet may have a small protrusion or edge having a hook shape, as shown in FIG. The resulting sheets with uneven edges are unsightly and difficult to process, especially on high-speed automated equipment.

The applicant has found that the size and shape of the recess can be adjusted so that the line of destruction between the two sheets remains within the boundaries of the recess. The shape of the recess is the symmetry between the growth of the deposited metal in the recess, while still allowing you to simply separate the two sheets.

Indeed, in another embodiment, the recess may take the form of allowing the deposited metal to advantageously completely fill the recess. In yet another embodiment, the recess has a shape that allows the deposition of metal immediately adjacent to the top of the recess.

In another aspect, the invention provides a cathode plate for electrolytic metal deposition, the cathode plate having a recess of at least one edge and shaped so that, when used, a fracture line is formed in the metal deposited within the recess, whereby during metal removal said cathode plate, the separation of the metal shell into two predominantly identical sheets is initiated along said fracture line.

Unless the circumstances clearly require otherwise, throughout the description and claims, the words “contains”, “comprising”, etc. should be considered in a sense opposite to an exclusive or exhaustive meaning; that is, in the sense of "including, but not limited to."

The following describes a preferred embodiment of the invention, given only as an example of execution, with reference to the accompanying drawings, in which:

on figa-2D presents end views in vertical section of the process of separation of electrolytically deposited metal shells, shown only for the purpose of explaining the method;

figure 3 is an end view in vertical section of the cathode source plate with a shell of deposited metal, partially divided into two separate sheets;

4 is an end view in vertical section of an embodiment of the present invention;

5 and 6 are end views in vertical section, depicting the lower edges of the cathode plates having various shapes.

The initial stage of separating the shell of the electrolytically deposited metal from its cathode source plate consists in at least partially separating either side of the deposited shell from the cathode plate. In this regard, reference is made to FIGS. IA-1D. The cathode with a shell contains cathode sheets 20 and 30 deposited on the original cathode plate 10 and connected at its lower edge by a brittle portion 40. First, the original cathode plate to ensure separation of at least the upper end portion 50 of the sheets 20, 30.

The partially separated casing, as shown in FIG. 1D, is then subjected to a coating separation operation, as shown in FIGS. 2A and 2B. Partially separated sheets 20 and 30 are arranged in a coating separation device on rollers or conveyor belt 50. The device includes a wedge separator or air blast device 130. These wedge separators 130 are inserted into the gap between the sheets 20, 30 and the original cathode plate 10. The wedge separators 130 release the sheets 20 and 30 of the electrolytically deposited shell from the original cathode plate 10. However, the sheets 20 and 30 are still held together by the brittle portion 40 extending along the lower edge of the cathode plate 10, as shown in FIG. 2B. It is necessary to perform a complete separation of the shell of the electrolytically deposited metal into separate predominantly identical sheets. These sheets 20 and 30 are held by grippers 25, 35 and rotate relative to the fragile portion 40 primarily from the vertical position shown in FIG. 2B, mainly into the horizontal position shown in FIG. 2C. This rotation divides the deposited metal into two predominantly identical sheets. In many cases, only one rotation of the sheets 20, 30 from vertical to horizontal is required to separate the sheets. This separation of the sheets 20 and 30 from each other, as well as from the original cathode plate can be promoted by grippers 25, 35 as follows. The grippers that still hold the sheets 20, 30 in the horizontal position shown in FIG. 2C are adapted so as to slightly pull the corresponding sheets outward, as shown in FIG. 2D. If the sheets 20, 30 move outward together with the grippers, this helps to separate the sheets 20, 30. However, if the force exerted to move the grippers outward is too large or the grippers do not move, this indicates that the brittle portion 40 is actually did not separate sheets 20, 30, and accordingly, further rotation of the sheets may be required (as shown in FIG. 2C).

If further manipulation / rotation of the sheets 20, 30 is required, the device, using the grippers 25 and 35, rotates the sheets 20 and 30 up and down until the aforementioned confirmation of the separation of the sheets is made.

After separation of the cathode sheets 20 and 30 mainly into identical separate sheets, it remains to simply transport the sheets from the stacker and the subsequent processing.

In some cases, it can be very difficult to separate the deposited metal shell into two separate sheets. It goes without saying that repeated turning or swinging of the sheet parts can be very time consuming and reduces the overall efficiency of the method.

Consider figure 3, which shows a recess 15 in the original cathode plate 10, where the deposited metal extends around the end of the original cathode plate 10. This recess 15 is formed in the lower edge of the cathode source plate, as a “means of growth”, as described in in the process of simultaneous consideration of International Patent Application No. PCT / F 199/00979. However, the applicant found that even with a recess 15, the deposited metal cannot be cleanly removed from the cathode plate or split into two predominantly identical sheets 20, 30. For the purpose of explanation, as shown in FIG. 3, sometimes the metal shell is divided into two sheets with a protrusion 25 attached to one sheet. This protrusion extends around almost the entire end portion of the source plate 10. The crack line 35 between the metal sheets 20 and 30 is located predominantly on one side of the source cathode plate 10, and not in the preferred brittle region 40 at the lower end of the source plate.

It has been found that the recess in the lower end of the original plate can be made so that the fracture line is located in the recess, thus providing a reliable fracture of the deposited metal shell into two predominantly identical and preferably symmetrical sheets.

Consider figure 4, which shows the cathode source plate 100 with a V-shaped recess 150 formed at its lower end end. For clarity, the arc of the recess 150 shown in FIG. 4 is 90 degrees, however, as follows from the above description, the recess does not have to be V-shaped, or it is not necessary that the arch of the recess is 90 degrees.

The shape and size of the V-shaped recess 150 are designed to perform several functions. Their primary function is to separate the deposited metal shell 120 from the source plate 100 in the form of two substantially identical sheets 122 and 124.

It will now be described how the V-shaped recess provides this function. Those skilled in the art will understand that when the source plate 100 is placed in an electrolytic cell, for example for electrolytic cleaning of copper, it is inserted between the copper anodes and is preferably immersed in an electrolyte solution. Copper from the anodes enters the electrolyte for re-deposition at the cathode. In general, to ensure “complete” deposition, the cathode remains in the electrolytic bath for 5 to 14 days.

When copper crystals are deposited on a metal cathode, they are deposited mainly at right angles to the deposition surface. This is shown by the arrows in FIG. 4. Typically, copper chooses the path of least resistance and seeks to deposit on the cathode as quickly as possible. It goes without saying that copper is easier to deposit on the outer side surfaces 102, 104 of the cathode plate 100 than in the V-shaped recess 150. However, it is important to note that copper is deposited in the V-shaped recess, since when the copper cladding is removed from the original the plate 100 by diverting to the opposite sides of the metal shell, as described above, the initiation of a fracture or crack begins in the brittle region 140 at the lower end of the original plate 100. It is desirable that this initiation of a crack starts at the top of the V-shaped recess 150. In tvetstvii this is preferred that V-shaped recess 150 has been shaped to provide the possibility of precipitation of copper in the V-shaped recess near the top, with a fracture line extending between the arc V-shaped recess 150.

Applicants have found that some sizes and shapes of the recesses provide such a “symmetrical” separation of the deposited metal, while others do not. For example, a V-shaped recess with an arc of 90 ° ± 15 ° provides the growth of copper in the V-shaped recess with the formation of a line of destruction, as shown by the dashed line A, between the arc of the V-shaped recess. Then, when the deposited metal shell is removed, the position of the fracture line in the V-shaped recess initiates the splitting of the deposited metal into two predominantly identical sheets along the fracture line or crack line in the brittle region 140.

The recess 150 shown in FIG. 4 can be compared with the V-shaped recess shown in FIGS. 5 and 6.

Figure 5 shows a shallow V-shaped recess 60. The shape of this V-shaped recess 60 does not provide as much copper deposition stability as the recess 150 shown in Fig. 4. Accordingly, copper is very easily deposited in the V-shaped recess 60. This is desirable. However, the applicants have determined that, due to the shape of the recess 60, the length and therefore the effectiveness of the fracture line are reduced. Thus, a stronger bond is formed between the two sides of the metal shell, making it difficult to separate the metal shell into two predominantly identical sheets. Indeed, experimental tests have shown that it may take several rotation or swing cycles in a stripping machine to separate such sheets, and in some cases they can be separated in a manner similar to that shown in FIG. 3.

6, the recess 70 is narrower and deeper. This creates a greater resistance to the deposition of copper ions than for those that fall into the V-shaped recess 150 in figure 4 or the V-shaped recess 60 in figure 5. In some cases, copper is not deposited throughout the V-shaped recess 70 and especially near the top of the V-shaped recess. This causes a bridge connection 80 of the metal across the V-shaped recess. This bridge connection of the metal across the V-shaped recess eliminates the formation of a fracture line in the arc of the V-shaped recess. The bridge 80 can strengthen the bond between the two sides of the metal sheath, which again can lead to the need for several rotation or swing cycles to separate the deposited metal into two sheets, which are most likely not to be the same in size.

In another embodiment of the present invention, which is particularly suitable for electrolytic deposition processes, the V-shaped recess can be shaped and sized to capture gaseous material that further acts to define a line of failure in the arc of the recess.

It goes without saying that the described method and device can be modified without going beyond the scope of the invention and the scope of protection defined by the claims.

Claims (14)

1. The method of electrolytic deposition of a shell from a metal on a cathode plate, including the deposition of metal on both sides of the cathode plate with the formation of the sides of the shell connected by at least one edge by a brittle region of the deposited metal, and the separation of the sides of the shell from the cathode plate into two sheets by bending and turning the respective sides of a relatively fragile region, characterized in that a recess is made on the cathode plate to form a fragile region in the recess and next to it of the metal to be deposited, the formation fracture line therein, and separating the shell from the metal to be deposited mainly on the two identical sheet. 2. The method according to claim 1, characterized in that the recess is V-shaped with the formation of a line of destruction within the V-shaped arc. 3. The method according to claim 1 or 2, characterized in that the sides of the recess form an angle of 75 to 150 °. 4. The method according to any one of claims 1 to 3, characterized in that the sides of the recess form an angle of 90 °. 5. The method according to any one of claims 1 to 4, characterized in that the recess is shaped so that the metal is deposited directly next to the top of the recess. 6. The method according to any one of claims 1 to 5, characterized in that the recess is shaped so that it can be filled with deposited metal. 7. The method according to any one of claims 1 to 6, characterized in that the recess is shaped to allow the capture of gas rising during the deposition of metal from the bottom of the cathode plate. 8. A cathode plate for electrolytic deposition of a metal shell, characterized in that it is made with a recess from at least one edge to form a fracture line within the recess when the metal is deposited and the shell from the deposited metal is divided into predominantly two identical sheets. 9. The cathode plate according to claim 8, characterized in that the recess is V-shaped to form a line of destruction within the V-shaped arc. 10. The cathode plate according to claim 8 or 9, characterized in that the sides of the recess form an angle of 75 to 150 °. 11. The cathode plate according to any one of paragraphs.8-10, characterized in that the sides of the recess form an angle of 90 °. 12. The cathode plate according to any one of paragraphs.8-11, characterized in that the recess has a shape that ensures the deposition of metal directly next to the top of the recess. 13. The cathode plate according to any one of paragraphs.8-12, characterized in that the recess is shaped so that it can be filled with deposited metal. 14. The cathode plate according to any one of claims 8 to 13, characterized in that the recess has a shape that allows the capture of gas rising during the deposition of metal from the bottom of the cathode plate.

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