MÖLLER, Sven-Göran (Granliden 20, Forshaga, S-667 33, SE)
NORD, Peter (Rinmansgatan 21, Deje, S-669 30, SE)
MÖRNHOLM, Bengt (Kiselvägen 5, Kil, S-665 35, SE)
MÖLLER, Sven-Göran (Granliden 20, Forshaga, S-667 33, SE)
NORD, Peter (Rinmansgatan 21, Deje, S-669 30, SE)
| Claims 1. A method for securing together stripped metal deposit sheets (1) such as stripped metal deposit halves stripped from a mother plate of a permanent cathode used as an electrode in an electrolytic process such as metal electrowinning or metal electrorefining, characterized by a step for receiving a stack (2) of stripped metal deposit sheets (1) in a welding station (3) that is provided with at least one friction stir spot welding tool (4a and 4b), and by a welding step for friction stir spot welding together at least two adjacent stripped metal deposit sheets (1) of the stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3). 2. The method according to claim 1, characterized by using a conveying means (5) for receiving stripped metal deposit sheets (1) to form a stack (2) of stripped metal deposit sheets (1) and/or for receiving a stack (2) of stripped metal deposit sheets (1) and for transporting the stack (2) of stripped metal deposit sheets (1) to the welding station (3) that is provided with at least one friction stir spot welding tool (4a and 4b), by a step for receiving stripped metal deposit sheets (1) by means of the conveying means (5) to form a stack (2) of stripped metal deposit sheets (1) and/or by a step for receiving a stack (2) of stripped metal deposit sheets (1) by means of the conveying means (5), and by a step for transporting the stack (2) of stripped metal deposit sheets (1) by means of the conveying means (5) to the welding station (3) that is provided with at least one friction stir spot welding tool (4a and 4b). 3. The method according to claim 1 or 2, characterized by using a welding station (3) that comprises at least one friction stir spot welding tool in form of a first friction stir spot welding tool (4a) comprising a first welding pin (6) that is movable in a direction in which the first welding pin (6) can penetrate at least two adjacent stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) to attach together by friction stir spot welding at least two adjacent stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3), and by the welding step comprises penetrating by means of the first welding pin (6) of said at least one first friction stir spot welding tool (4a) at least two adjacent stripped metal deposit sheets (1) of the stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) to attach together by friction stir spot welding said at least two adjacent stripped metal deposit sheets (1) of said stack (2) of stripped metal deposit sheets (1). 4. The method according to claim 3, characterized by the welding step comprises penetrating at least the two uppermost stripped metal deposit sheets (1) of the stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) by means of the first welding pin (6) of said at least one first friction stir spot welding tool (4a) to attach together by friction stir spot welding at least the two uppermost stripped metal deposit sheets (1) of said stack (2) of stripped metal deposit sheets (1). 5. The method according to claim 3 or 4, characterized by moving the first welding pin (6) said at least one first friction stir spot welding tool (4a) vertically. 6. The method according to any of the claims 1 to 5, characterized by using a welding station (3) that comprises at least one friction stir spot welding tool in form of a second friction stir spot welding tool (4b) comprising a second welding pin (7) that is movable to and from an edge of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) so that the second welding pin (7) simultaneously can penetrate at least partly the edges of at least two adjacent stripped metal deposit sheet (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) to attach together by friction stir spot welding at least two adjacent stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3), and by the welding step comprising simultaneously penetrating by means of the second welding pin (7) of said at least one second friction stir spot welding tool (4b) at least partly the edges of at least two adjacent stripped metal deposit sheets (1) of the stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) to attach together by friction stir spot welding said at least two adjacent stripped metal deposit sheets (1) of said stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3). 7. The method according to claim 6, characterized by moving the second welding pin (7) of said at least one second friction stir spot welding tool (4b) horizontally. 8. The method according to any of the claims 1 to 7, characterized by using a welding station (3) that comprises positioning means (8) for positioning a stack (2) of stripped metal deposit sheets (1) in the welding station (3) in a predetermined welding position with respect to said at least one friction stir spot welding tool (4a and 4b). 9. The method according to any of the claims 1 to 8, characterized by using a welding station (3) that comprises a pressing means (9) for pressing (clamping) together the stripped metal deposit sheet (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3), and by a pressing step for pressing together the stripped metal deposit sheet (1) of the stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) during the welding step. 10. The method according to any of the claims 1 to 9, characterized by forming the stack (2) of stripped metal deposit sheets (1) of solely the two stripped metal deposit sheet halves () that are detached from one permanent cathode. 11. An apparatus for securing together stripped metal deposit sheets (1) such as stripped metal deposit halves stripped from a mother plate of a permanent cathode used as an electrode in an electrolytic process such as metal electrowinning or metal electrorefining, characterized by a welding station (3) for receiving a stack (2) of stripped metal deposit sheets (1), and by the welding station (3) being provided with at least one friction stir spot welding tool (4a and 4b) for friction stir spot welding together at least two adjacent stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3). 12. The apparatus according to claim 11, characterized by a conveying means (5) for receiving stripped metal deposit sheets (1) to form a stack (2) of stripped metal deposit sheets (1) or for receiving a stack (2) of stripped metal deposit sheets (1), and for transporting the stack (2) of stripped metal deposit sheets (1) to the welding station (3) that is provided with at least one friction stir spot welding tool (4a and 4b). 13. The apparatus according to claim 11 or 12, characterized by the welding station (3) of the apparatus comprising at least one friction stir spot welding tool in the form of a first friction stir spot welding tool (4a) comprising a first welding pin (6) that is movable in a direction in which the first welding pin (6) can penetrate at least two adjacent stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) to attach together by friction stir spot welding said at least two adjacent stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3). 14. The apparatus according to claim 13, characterized by the first friction stir spot welding tool (4a) being configured for friction stir spot welding together at least the two uppermost stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3). 15. The apparatus according to claim 13 or 14, characterized by the first welding pin (6) being movable vertically. 16. The apparatus according to any of the claims 11 to 15, characterized by the welding station (3) of the apparatus comprising at least one friction stir spot welding tool in form of a second friction stir spot welding tool (4b) comprising a second welding pin (7) that is movable to and from an edge of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3) so that the second welding pin (7) can simultaneously at least partly penetrate the edges of at least two adjacent stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) to attach together by friction stir spot welding said at least two adjacent stripped metal deposit sheets (1) of a stack (2) of stripped metal deposit sheets (1) that is received in the welding station (3). 17. The apparatus according to claim 16, characterized by the second welding pin (7) being movable horizontally. 18. The apparatus according to any of the claims 11 to 17, characterized by the welding station (3) comprises positioning means (8) for positioning a stack (2) of stripped metal deposit sheets (1) in the welding station (3) in a predetermined welding position with respect to said at least one friction stir spot welding tool (4a and 4b). 19. The apparatus according to any of the claims 11 to 18, characterized by the welding station (3) comprising a pressing means (9) for pressing together the stripped metal deposit sheet of a stack (2) of stripped metal deposit sheets (1) in the welding station (3). 20. The apparatus according to any of the claims 11 to 19, characterized by the conveying means (5) being configured for forming a stack (2) of stripped metal deposit sheets (1) consisting solely of the two stripped metal deposit sheet halves () that are detached from one permanent cathode. |
Field of the invention
The invention relates to a method for securing together stripped metal deposit sheets such as stripped metal deposit halves stripped from a mother plate of a permanent cathode used as an electrode in an electrolytic process such as metal electrowinning or metal electrorefining as defined in the preamble of independent claim 1.
The invention also relates to an apparatus for securing together stripped metal deposit sheets such as stripped metal deposit halves stripped from a mother plate of a permanent cathode used as an electrode in an electrolytic process such as metal electrowinning or metal electrorefining as defined in the preamble of independent claim 11.
The refining of many metals, such as copper, zinc and nickel, includes an electrolytic process where harmful impurities are separated from the metal to be produced. The metal produced in the electrolytic process is gathered to the permanent cathode by means of electric current. Usually the electrolytic process is carried out in tanks filled with an electrolyte containing sulphuric acid and, immersed therein, a number of plates like anodes and cathodes made of some electroconductive material and placed in an alternating fashion. At the top edges the anodes and cathodes are provided with lugs or bars for suspending them at the tank edges and for connecting them to the power circuit. The cathodes, i.e. the mother plates, used in the electrolytic process are made for instance of stainless steel, aluminum or titanium.
After the electrolytic process the anodes are removed from the tanks and the metal deposit is separated from the mother plate for further processing. For separating the metal deposit from the anode many various processes are used. For example the metal deposit is opened slightly from one edge of the anode plate, grabbed with grip members and pulled apart from the anode. Another possibility is to cut the metal deposit from the surface of the anode with cutting blades.
The invention relates to the handling of stripped metal deposit sheets such as stripped metal deposit halves that has been separated from a mother plate. After that the stripped metal deposit sheets have been separated from a mother plate the stripped metal deposit sheets can be placed upon each other to form a bundle. An apparatus for this is presented in document CA 2,041,927. In this document CA 2,041,927 it is presented that every second pair of stripped metal deposit sheets is corrugated in a 100 tonne corrugating press prior to arranging the pairs of stripped metal deposit sheets into a bundle where corrugated pairs of stripped metal deposit sheets and planar pairs of stripped metal deposit sheets are alternated. The bundle is thereafter wrapped and steel straps are clamped about the bundle. The bundle of stripped metal deposit sheets is thereafter further processed for example by melting and casting copper products of the copper of the stripped metal sheets.
Publication JP2003-170232 presents a method for connecting electrolytic copper plates comprising a step for disposing two superposed electrolytic copper plates between a punch and a die. The method further comprises the steps of pressing the punch to the two superposed plates, inserting the plates into the die, and simultaneously deforming the two plates to caulk the plates with each other.
Objective of the invention
The object of the invention is to improve the handling of stripped metal deposit sheets such as stripped metal deposit halves stripped from a mother plate of a permanent cathode used as an electrode in an electrolytic process such as metal electro winning or metal electrorefining.
Short description of the invention
The method of the invention is characterized by the definitions of independent claim 1.
Preferred embodiments of the method are defined in the dependent claims 2 to 10. The apparatus of the invention is correspondingly characterized by the definitions of independent claim 11.
Preferred embodiments of the apparatus are defined in the dependent claims 12 to
20.
The method of the invention is characterized by a step for receiving a stack of stripped metal deposit sheets in a welding station that is provided with at least one friction stir spot welding tool, and by a welding step for friction stir spot welding together at least two adjacent stripped metal deposit sheets of the stack of stripped metal deposit sheets that is received in the welding station. The apparatus of the invention is correspondingly characterized by a welding station for receiving a stack of stripped metal deposit sheets.
The invention is based on fixing together the stripped metal deposit sheets by stir spot welding. This provides for fixing stripped metal deposit sheets together without adding material.
The stack of stripped metal deposit sheets which are attached together by friction stir spot welding may be a stack consisting of the two stripped metal deposit sheet halves that are detached from one permanent cathode. Alternatively the stack of stripped metal deposit sheets may comprise more than two stripped metal deposit sheets. List of figures
In the following the invention will be described in more detail by referring to the figures, of which
figure 1 shows a preferred embodiment of the invention where the welding station is provided with a friction stir spot welding tool in the form of a first friction stir spot welding tool having a first welding pin which is movable vertically,
figure 2 shows a preferred embodiment of the invention where the welding station is provided with a friction stir spot welding tool in the form of two friction stir spot welding tools, each having a second welding pin which is movable horizontally,
figure 3 shows the embodiment shown in figure 1 provided with a supporting arrangement for the friction stir spot welding tool, and
figure 4 shows the embodiment shown in figure 2 provided with a supporting arrangement for the friction stir spot welding tools.
Detailed description of the invention
The invention relates to a method and to an apparatus for securing together stripped metal deposit sheets 1 such as stripped metal deposit halves stripped from a mother plate of a permanent cathode used as an electrode in an electrolytic process such as metal electro winning or metal electrorefining.
First the method and some preferred embodiments and some variants of the method will be described.
The method comprises a step for receiving a stack 2 of stripped metal deposit sheets 1 in a welding station 3 that is provided with at least one friction stir spot welding tool 4a and 4b.
The method comprises a welding step for friction stir spot welding together at least two adjacent stripped metal deposit sheets 1 of the stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3.
Friction stir spot welding (FSSW) is a variant of the friction stir welding (FSW) process presented for example in WO 93/10935.
A preferred embodiment of the method comprises using a conveying means 5 for receiving stripped metal deposit sheets 1 to form a stack 2 of stripped metal deposit sheets 1 and for transporting the stack 2 of stripped metal deposit sheets 1 to the welding station 3 that is provided with at least one friction stir spot welding tool 4a and 4b. This preferred embodiment of the method comprises a step for receiving stripped metal deposit sheets 1 by means of the conveying means 5 to form a stack 2 of stripped metal deposit sheets 1. This preferred embodiment of the method comprises a step for transporting the stack 2 of stripped metal deposit sheets 1 by means of the conveying means 5 to the welding station 3 that is provided with at least one friction stir spot welding tool 4a and 4b.
Another preferred embodiment of the method comprises using a conveying means 5 for receiving a stack 2 of stripped metal deposit sheets 1 and for transporting the stack 2 of stripped metal deposit sheets 1 to the welding station 3 that is provided with at least one friction stir spot welding tool 4a and 4b. This preferred embodiment of the method comprises a step for receiving a stack 2 of stripped metal deposit sheets 1 by means of the conveying means 5. This preferred embodiment of the method comprises a step for transporting the stack 2 of stripped metal deposit sheets 1 by means of the conveying means 5 to the welding station 3 that is provided with at least one friction stir spot welding tool 4a and 4b.
A preferred embodiment of the method comprises using a welding station 3 that comprises at least one friction stir spot welding tool in the form of a first friction stir spot welding tool 4a comprising a first welding pin 6 that is movable in a direction in which the first welding pin 6 can penetrate at least two adjacent stripped metal deposit sheets 1 of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 to attach together by friction stir spot welding at least two adjacent stripped metal deposit sheets 1 of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. In this preferred embodiment of the method the welding step comprises penetrating by means of the first welding pin 6 of said at least one first friction stir spot welding tool 4a at least two adjacent stripped metal deposit sheets 1 of the stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 to attach together by friction stir spot welding said at least two adjacent stripped metal deposit sheets 1 of said stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. In this preferred embodiment of the method the welding step comprises preferably, but not necessarily, penetrating at least the two uppermost stripped metal deposit sheets 1 of the stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 by means of the first welding pin 6 of said at least one first friction stir spot welding tool 4a to attach together by friction stir spot welding at least the two uppermost stripped metal deposit sheets 1 of said stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. In this preferred embodiment of the method the welding step comprises preferably, but not necessarily, moving the first welding pin 6 of said at least one first friction stir spot welding tool 4a vertically during the welding step.
A preferred embodiment of the method comprises using a welding station 3 that comprises at least one friction stir spot welding tool in the form of a second friction stir spot welding tool 4b comprising a second welding pin 7 that is movable to and from an edge of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 so that the second welding pin 7 simultaneously can penetrate at least part of the edges of at least two adjacent stripped metal deposit sheet of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 to attach together by friction stir spot welding at least two adjacent stripped metal deposit sheets 1 of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. In this preferred embodiment of the method the welding step comprises penetrating by means of the second welding pin 7 of said at least one second friction stir spot welding tool 4b simultaneously at least part of the edges of at least two adjacent stripped metal deposit sheets 1 of the stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 to attach together by friction stir spot welding said at least two adjacent stripped metal deposit sheets 1 of said stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. In this preferred embodiment of the method the welding step comprises preferably, but not necessarily, moving the second welding pin 7 of said at least one second friction stir spot welding tool 4b horizontally during the welding step.
A preferred embodiment of the method comprises using a welding station 3 that comprises positioning means 8 for positioning a stack 2 of stripped metal deposit sheets 1 in the welding station 3 in a predetermined welding position with respect to said at least one friction stir spot welding tool 4a and 4b.
A preferred embodiment of the method comprises using a welding station 3 that comprises a pressing means 9 for pressing together the stripped metal deposit sheet of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. This preferred embodiment of the method comprises a pressing step for pressing together the stripped metal deposit sheet of the stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 when performing the welding step.
A preferred embodiment of the method comprises using a welding station 3 that comprises a stopping means 10 against which the stripped metal deposit sheets 1 of the stack 2 of stripped metal deposit sheets 1 in the welding station 3 can be pressed with at least one friction stir spot welding tool 4a and 4b when performing the welding step. This preferred embodiment of the method comprises a pressing step for pressing together the stripped metal deposit sheets 1 of the stack 2 of stripped metal deposit sheets 1 in the welding station 3 by pressing the stack 2 of stripped metal deposit sheets 1 by means of said at least one friction stir spot welding tool 4a and 4b against the stopping means 10 when performing the welding step. A preferred embodiment of the method comprises forming the stack 2 of stripped metal deposit sheets 1 of the two stripped metal deposit sheet halves that are detached from one permanent cathode.
Next the apparatus and some preferred embodiments and some variants of the apparatus will be described.
The apparatus comprises a welding station 3 for receiving a stack 2 of stripped metal deposit sheets 1. The welding station 3 is provided with at least one friction stir spot welding tool 4a and 4b for friction stir spot welding together at least two adjacent stripped metal deposit sheets 1 of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3.
Friction stir spot welding (FSSW) is a variant of the friction stir welding (FSW) process presented for example in WO 93/10935.
A preferred embodiment of the apparatus comprises a conveying means 5 for receiving stripped metal deposit sheets 1 to form a stack 2 of stripped metal deposit sheets 1 and for transporting the stack 2 of stripped metal deposit sheets 1 to the welding station 3 that is provided with at least one friction stir spot welding tool 4a and 4b.
Another preferred embodiment of the apparatus comprises a conveying means 5 for receiving a stack 2 of stripped metal deposit sheets 1 and for transporting the stack 2 of stripped metal deposit sheets 1 to the welding station 3 that is provided with at least one friction stir spot welding tool 4a and 4b.
In a preferred embodiment of the apparatus the welding station 3 comprises at least one friction stir spot welding tool 4a and 4b in the form of a first friction stir spot welding tool 4a comprising a first welding pin 6 that is movable in a direction in which the first welding pin 6 can penetrate at least two adjacent stripped metal deposit sheets 1 of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 to attach together by friction stir spot welding said at least two adjacent stripped metal deposit sheets 1 of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. In this preferred embodiment of the apparatus the first friction stir spot welding tool 4a is preferably, but not necessarily, configured for friction stir spot welding together at least the two uppermost stripped metal deposit sheets 1 of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. In this preferred embodiment of the apparatus the first welding pin 6 is preferably, but not necessarily, movable vertically.
In a preferred embodiment of the apparatus the welding station 3 comprises at least one friction stir spot welding tool in form of a second friction stir spot welding tool 4b comprising a second welding pin 7 that is movable to and from an edge of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 so that the second welding pin 7 can simultaneously penetrate at least partly the edges of at least two adjacent stripped metal deposit sheet of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3 to attach together by friction stir spot welding said at least two adjacent stripped metal deposit sheets 1 of a stack 2 of stripped metal deposit sheets 1 that is received in the welding station 3. In this preferred embodiment of the apparatus the second welding pin 7 is preferably, but not necessarily, movable vertically.
In a preferred embodiment of the apparatus the welding station 3 comprises positioning means 8 for positioning the stack 2 of stripped metal deposit sheets 1 in the welding station 3 in a predetermined welding position with respect to said at least one friction stir spot welding tool 4a and 4b.
In a preferred embodiment of the apparatus the welding station 3 comprises a pressing means 9 for pressing together the stripped metal deposit sheets 1 of the stack 2 of stripped metal deposit sheets 1 in the welding station 3.
In a preferred embodiment of the apparatus the welding station 3 comprises a stopping means 10 against which the stripped metal deposit sheets 1 of the stack 2 of stripped metal deposit sheets 1 in the welding station 3 can be pressed with at least one friction stir spot welding tool 4a and 4b.
In a preferred embodiment of the apparatus the conveying means 5 is configured for forming a stack 2 of stripped metal deposit sheets 1 consisting of the two stripped metal deposit sheets 1 that are detached from one permanent cathode.
Figure 3 and 4 shows additionally supporting arrangements 11 for the friction stir spot welding tools 4a and 4b.
It is apparent to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in various ways. The invention and its embodiments are therefore not restricted to the above examples, but they may vary within the scope of the claims.