STRIPPING OF METAL FROM CATHODES

Abstract

An apparatus for stripping metal (12, 14) deposited on a cathode plate (16), comprises a first robotic arm (46) carrying a first stripping apparatus (40), the first stripping apparatus having a first gripping apparatus (62, 63) to grip the cathode plate such that the first robotic arm operates to lift the cathode plate out of the stripping station following stripping of the metal sheets from the cathode plate. A second robotic arm (48) carrying a second stripping apparatus (42) is located on a second side of the cathode plate, the second stripping apparatus having a second gripping apparatus (76, 77) for gripping one or both of the first sheet of metal (12) and the second sheet of metal (14). The second robotic arm can be operated to move the first sheet of metal and the second sheet of metal to a metal storage region following stripping from the cathode plate (16). The metal is stripped from the cathode plate without breaking the bridge of metal that interconnects the first sheet of metal and the second sheet of metal.

Claims

1. A method for stripping metal deposited on a cathode plate, wherein the cathode plate has a first sheet of metal deposited on a first side and a second sheet of metal deposited on a second side, with a bridge of metal formed at a lower edge of the cathode plate interconnecting the first sheet of metal with the second sheet of metal, the method comprising: moving a first stripping apparatus with a first robotic arm to separate the first sheet of metal from the first side of the cathode plate, moving a second stripping apparatus with a second robotic arm to separate the second sheet of metal from the second side of the cathode plate, wherein the first sheet of metal and second sheet of metal remain interconnected by the bridge of metal at the lower edge, gripping the cathode plate with a first gripping apparatus, the first gripping apparatus being associated with the first robotic arm, and operating the first robotic arm to remove the cathode plate from the stripping station and place the cathode plate into a storage region or a transport region, and moving the first sheet of metal and the second sheet of metal to a metal storage region or a metal transport region.

2. The method as claimed in claim 1 wherein the step of moving the first sheet of metal and the second sheet of metal to a metal storage region or a metal transport region comprises moving the first sheet of metal and the second sheet of metal to a metal storage region or a metal transport region using the second robotic arm.

3. The method as claimed in claim 2 comprising gripping one or both of the first sheet of metal and second sheet of metal using a second gripping apparatus associated with the second robotic arm, and operating the second robotic arm to move the first sheet of metal and the second sheet of metal to the metal storage region or the metal transport region.

4. The method as claimed in claim 1 wherein the second sheet of metal is held in position by side guides and a pusher pushes the first sheet of metal towards the stripping apparatus, and a second gripping apparatus associated with the second robotic arm grips the first sheet of metal and/or the second sheet of metal and the second robotic arm is operated to move the first sheet of metal and the second sheet of metal to the metal storage region or metal transport region.

5. The method as claimed in claim 4 wherein the second sheet of metal is gripped by second gripping apparatus associated with the second robotic arm and a pusher pushes the first sheet of metal towards the stripping apparatus to close up a gap between the first sheet of metal and the second sheet of metal, and the second robotic arm is operated to move the first sheet of metal and the second sheet of metal to the metal storage region or metal transport region.

6. The method as claimed in claim 5 wherein the second gripping apparatus grips the first sheet of metal once it has been pushed towards the second sheet of metal.

7. The method as claimed in claim 1 wherein the second robotic arm moves the first sheet of metal and the second sheet of metal to a movable support and the second gripping apparatus is actuated to let go of the first sheet of metal and the second sheet of metal, and the movable support is moved so that the first sheet of metal and the second sheet of metal are moved onto a conveyor.

8. The method as claimed in claim 7 wherein the movable support comprises a down ender having a support surface, the support surface being movable between a lower position at which the support surface at least partly located below a conveyor and an upper position at which the support surface extends upwardly above the conveyor, wherein the first metal sheet and the second metal sheet are moved by the second robotic arm to a position where first metal sheet and the second metal sheet are supported by the support surface in the upper position, the second gripping apparatus releases the metal sheets and the second robotic arm is operated to move the second gripping apparatus away from the metal sheets, and the down ender is operated so that the support surface moves to the lower position and the metal sheets come into contact with the conveyor and are transported away by the conveyor.

9. The method as claimed in claim 1 wherein the steps of separating the first sheet of metal and the second sheet of metal from the respective sides of the cathode plate comprises positioning a first stripping apparatus between the cathode plate and the first sheet of metal, positioning a second stripping apparatus between the cathode plate and second sheet of metal, the first stripping apparatus being moved by the first robotic arm and the second stripping apparatus being moved by the second robotic arm, moving the first stripping apparatus between the first sheet of metal and the cathode plate to thereby separate the first sheet of metal from the cathode plate and moving the second stripping apparatus between the second sheet of metal and the cathode plate to thereby separate the second sheet of metal from the cathode plate, wherein the first sheet of metal and second sheet of metal remain interconnected by the bridge of metal at the lower edge.

10. The method as claimed in claim 1 wherein the cathode plates have been flexed prior to positioning in the stripping station to open up a small gap at the top between the deposited sheets of metal and the cathode plate and the stripping apparatus is subsequently inserted into the small gaps in the stripping station in order to complete the stripping process.

11. An apparatus for stripping metal deposited on a cathode plate, the apparatus comprising: a stripping station having a support for supporting a cathode plate having a first sheet of metal deposited on a first side of the cathode plate and a second sheet of metal deposited on a second side of the cathode plate, the first sheet of metal and the second sheet of metal being interconnected by a bridge of metal deposited at a lower edge of the cathode plate; a first stripping machine located on a first side of the cathode plate, the first stripping machine comprising a first robotic arm carrying a first stripping apparatus, the first stripping machine having a first gripping apparatus associated with the first robotic arm, the first gripping apparatus adapted to grip the cathode plate such that the first robotic arm can be operated to thereby lift the cathode plate out of the stripping station following stripping of the first metal sheet and the second metal sheet from the cathode plate, a second stripping machine located on a second side of the cathode plate, the second stripping machine comprising a second robotic arm carrying a second stripping apparatus, the second stripping machine having a second gripping apparatus associated with the second robotic arm, the second gripping apparatus adapted for gripping one or both of the first sheet of metal and the second sheet of metal, wherein the second robotic arm can be operated to move the first sheet of metal and the second sheet of metal to a metal storage region or a metal transport region following stripping of the first sheet of metal and second sheet of metal from the cathode plate, the first stripping apparatus and the second stripping apparatus being operable to strip the first sheet of metal and the second sheet of metal from the cathode plate without breaking the bridge of metal that interconnects the first sheet of metal and the second sheet of metal.

12. The apparatus as claimed in claim 11 wherein the first stripping apparatus is connected to the first robotic arm and the second stripping apparatus is connected to the second robotic arm.

13. The apparatus as claimed in claim 12 wherein the first stripping apparatus is mounted directly to the first robotic arm and the second stripping apparatus is mounted directly to the second robotic arm, or the first stripping apparatus is mounted indirectly with one or more intermediate portions between the first robotic arm and the first stripping apparatus and the second stripping apparatus is mounted indirectly with one or more intermediate portions between the second robotic arm and the second stripping apparatus.

14. The apparatus as claimed in claim 11 wherein the stripping apparatus includes one or more insertion means adapted for insertion between the metal and the cathode plate in order to separate at least a portion of the metal from the cathode plate.

15. The apparatus as claimed in claim 14 wherein the insertion means comprises one or more pincers, knives, chisels, wedges or the like, or any combination thereof.

16. The apparatus as claimed in claim 14 further comprising complementary means adapted to be positioned adjacent the external surface of the metal such that the insertion means and the complementary means form a pair of pincers adapted to grip at least a portion of the metal.

17. The apparatus as claimed in claim 14 comprising a plurality if insertion means, the insertion means being spaced apart from one another such that the insertion means are inserted into a gap between the metal and the cathode plate at points along at least a portion of the width of the cathode plate in order to ensure that the entire width of the metal is separated from the cathode plate.

18. The apparatus as claimed in claim 11 wherein the stripping apparatus comprises stripping means and the shape of the stripping means is such that driving the stripping means between the metal and the cathode plate is sufficient to result in the stripping of the metal from the cathode plate.

19. The apparatus as claimed in claim 18 wherein the stripping means comprises a wedge-shaped portion, wherein the wedge-shaped portion is driven point-first between the metal and the cathode plate.

20. The apparatus as claimed in claim 19 wherein a tip of the wedge-shaped portion is driven to the bottom of the cathode plate during stripping.

21. The apparatus as claimed in claim 19 wherein the dimensions of the wedge-shaped portion are such that an angle between the metal sheet and the cathode plate is no more than 20°, or no more than 15°, or between about 10° and 12° when the wedge-shaped portion is driven to the bottom of the cathode plate.

22. The apparatus as claimed in claim 21 wherein an angle between the sides of the wedge-shaped portion is no more than 20°, or no more than 15°, or between about 10° and 12°.

23. The apparatus as claimed in claim 19 wherein the dimensions of the wedge-shaped portion are such that the height of the wedge-shaped portion is approximately equal to the height of the metal sheet and the width of the wedge-shaped portion is approximately equal to the width of the cathode plate

24. The apparatus as claimed in claim 19 wherein a plurality of wedge-shaped portions is provided.

25. The apparatus as claimed in claim 24 wherein the wedge-shaped portions are spaced approximately equidistantly from one another across the width of the cathode plate.

26. The apparatus as claimed in claim 11 wherein the stripping means are provided with one or more rollers to reduce friction as the stripping means is driven into the gap between the metal and the cathode plate.

27. The apparatus as claimed in claim 26 wherein the stripping means comprises a pair of rollers, with one of said pair of rollers being adapted to contact the internal face of the metal, while the second of said pair of roller is adapted to contact the surface of the cathode plate.

28. The apparatus as claimed in claim 26 wherein the one or more rollers are adapted to be located at or adjacent a vertical edge of the metal when the apparatus is in use.

29. The apparatus as claimed in claim 28 wherein one or more rollers are adapted to be located at each of the vertical edges of the metal and the wedge-shaped portion is located intermediate the one or more rollers adapted to be located at each of the vertical edges of the metal.

30. The apparatus as claimed in claim 11 wherein the stripping means comprises at least one roller that contacts the cathode plate and at least one projection that contacts the metal.

31. The apparatus as claimed in claim 30 wherein the at least one roller contacts the cathode plate, thereby minimising damage to the cathode plate.

32. The apparatus as claimed in claim 11 wherein each robotic arm comprises a first arm having a second arm pivotally connected thereto, the stripping apparatus being pivotally connected to the second arm of the robotic arm, the first arm of the robotic arm being pivotally connected to a base, the base being rotatable about a vertical axis, the first robotic arm being pivotally connected about a horizontal axis to the base, the second arm being pivotally connected to the first arm.

33. The apparatus as claimed in claim 11 wherein the first robotic arm and the second robotic arm are controlled such that the first stripping apparatus and the second stripping apparatus move simultaneously with each other during stripping of the sheets of metal from the cathode plate.

34. The apparatus as claimed in claim 11 wherein the stripping means is formed integrally with the robotic arm, or the robotic arm is adapted to allow the stripping means to be attached thereto.

35. The apparatus as claimed in claim 11 wherein the first gripping apparatus comprises one or more clamps, suction devices, clips or any combination thereof and the second gripping apparatus comprises one or more clamps, suction devices, clips or any combination thereof.

36. The apparatus as claimed in claim 35 wherein the first gripping apparatus comprises one or more clamps and the one or more clamps are actuated electrically, hydraulically, pneumatically, or any combination thereof and the second gripping apparatus comprises one or more clamps and the one or more clamps are actuated electrically, hydraulically, pneumatically, or any combination thereof.

37. The apparatus as claimed in claim 11 wherein the first gripping apparatus comprises at least one clamp located at one side of the first stripping apparatus and at least one clamp located at an opposite side of the first stripping apparatus and the second gripping apparatus comprises at least one clamp located at one side of the second stripping apparatus and at least one clamp located at an opposite side of the second stripping apparatus.

38. The apparatus as claimed in claim 11 wherein the first gripping apparatus is mounted to a frame or a support that forms part of the first stripping apparatus and the second gripping apparatus is mounted to a frame or a support that forms part of the second stripping apparatus.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0061] Various embodiments of the invention will be described with reference to the following drawings, in which:

[0062] FIGS. 1 to 14 show side views and perspective views of the various steps involved in stripping deposited metal from cathode plates in accordance with one embodiment of the present invention. In FIGS. 1 to 14, the robotic arms to which the stripping apparatus is attached have been removed for clarity;

[0063] FIG. 15 shows a perspective view of apparatus in accordance with the present invention operating the step of stripping the deposited metal from the cathode plate. In FIG. 15, the robotic arms are shown;

[0064] FIGS. 16 to 18 show a stripping apparatus that can be used to strip deposited metal from a cathode plate and move the cathode plate out of the stripping station; and

[0065] FIGS. 19 to 21 show a stripping apparatus that can be used to strip deposited metal from a cathode plate and move the stripped metal deposit out of the stripping station.

DESCRIPTION OF EMBODIMENTS

[0066] It will be appreciated that the drawings have been provided for the purpose of illustrating preferred embodiments of the present invention. Therefore, the skilled person will understand that the present invention should not be considered to be limited solely to the features as shown in the drawings.

[0067] Turning initially to FIG. 15, which shows an apparatus suitable for use in the method of the present invention, it can be seen that sheets of deposited metal 12, 14 are removed from a cathode plate 16 upon which the sheets of metal been deposited during an electricowinning or an electrodeposition process. The cathode plate 16 typically comprises a stainless steel plate connected to a hanger bar 18. The cathode plate is of conventional construction and need not be described further.

[0068] The deposited metal 12, 14 is removed from the cathode plate in a stripping station 20. Stripping station 20 includes a support frame comprising 4 uprights, 3 of which are shown at 22, 23, 24 and upper horizontal members 25, 26. The support frame carries a cathode plate support (obscured in FIG. 15) which typically guides the hanger bar of the cathode plate such that the cathode plate 16 extends in a generally vertical direction. The guides are mounted to the frame along the traverse conveyor and keep the cathode upright during travel on the conveyor. It also has a cathode lifting device, in this case operated by a hydraulic cylinder, that lifts the cathode plate during the stripping operation. Again, the stripping station is of generally conventional construction and will be well understood by a person skilled in the art.

[0069] A chain conveyor 28 is located underneath the stripping station. A pusher 30 is located to one side of the cathode plate. Pusher 30 comprises two uprights 31, 32 and a horizontal contact member 33. The lower end of the uprights 31, 32 are pivotally mounted about an axle 34 and an actuator 35 is used to pivot the pusher to the right from the position shown in FIG. 15 so that the pusher comes into contact with one of the sheets of deposited metal and moves that sheet of deposited metal towards the second stripping apparatus (and the other sheet of deposited metal that was deposited on the cathode plate. The actuator can also move the pusher back up to the position shown in FIG. 15.

[0070] The stripping station also includes a down ender (obscured in FIG. 15) located on the opposite side of the cathode plate 16 to the pusher 30. Construction and operation of the down ender will be described in further detail hereunder.

[0071] The first robot 36 is positioned to one side of the stripping station. A second robot 38 is positioned to the other side of the stripping station. First robot 36 is partially obscured in FIG. 15. First robot 36 carries a first stripping apparatus 40 and second robot 38 carries a second stripping apparatus 42. These described in further detail hereunder.

[0072] The first robot 36 comprises a base 43. The base 43 is fixed in positioned to the floor. The base 43 carries a robot base unit 44. Robot base unit 44 can rotate about a vertical axis. The robot base unit 44 carries a first robot arm 46. First robot aim 46 is mounted to the robot base unit 44 about axle or pivot pin 47. Axle or pivot pin 47 allows the first robot arm to rotate about a horizontal axis. A second robot arm 48 is mounted to the distal end of the first robot arm 46 at axle or pivot pin 49. Again, axle pivot pin 49 allows the second robot arm to rotate about a horizontal axis. The distal end of the second robot arm 48 is fitted with a universal joint 50 and the first stripping apparatus 40 is mounted to the universal joint 50. Universal joint 50 includes a horizontal axis 51 and a vertical axis 52 and a further axis 52A that is generally coincident with the longitudinal axis of the arm 48. By virtue of the construction of the second robot arm 38, the second stripping apparatus 42 has a wide range of movements. It can move horizontally, vertically, as well as rotatably about horizontal and vertical axes. It will be appreciated that other robots of different design may also be used in the present invention.

[0073] The first robot 46 and the second robot 48 are suitably of conventional design. Movement of the robots is controlled by appropriate controllers and actuators built into the robots. Again, these may be conventional and need not be described further.

[0074] FIGS. 16, 17 and 18 show a front view, a perspective view and a side view, respectively, of the first stripping apparatus 40. The first stripping apparatus 40 comprises a frame having vertical members 53, 54, 55, a top member 56 and a bottom member 57. Bottom member 57 either has a wedge 58 integrally formed therewith or attached thereto. A number of crossmembers, some of which are shown at 59 and 60, are bolted or otherwise connected between adjacent vertical members to provide additional strength to the frame.

[0075] The top member 56 has a mount 61 attached thereto. Mount 61 enables the first stripping apparatus to be mounted to the first robot arm. The mount 61 includes a short cylinder welded to the top member 56, the short cylinder having a flange attached thereto, and a number of gusset plates welded to the flange and the top member to provide additional strength. Other designs for the mount may also be used.

[0076] The first stripping apparatus 40 also has two gripping means in the form of clamps 62, 63 mounted to oppose sides of the frame. The clamps 62, 63 are essentially identical to each other. Clamp 62 includes two ears 64, 65 that are welded or otherwise joined to the side plate 53. These ears support a pin 66. A rotatable clamping plate 67 is mounted via short arms 68, 69 to the pin 66. An eccentric arm 70 is mounted for rotation about axis 71. A drive, such as a hydraulic cylinder or a pneumatic cylinder 72 can be extended and retracted to move the eccentric arm 70 about axis 71 which, in turn, causes the pin 66 to rotate which also causes the rotatable clamping plate 67 to rotate. In this manner, the clamping plate can be selectively opened and closed.

[0077] Clamp 63 is of essentially identical construction. Other drive arrangements may replace the hydraulic cylinder or pneumatic cylinder 72. As best shown in FIG. 18, clamp 62 extends beyond the inner periphery of side member 53. In this way, when the clamp is actuated, the clamping plate 67 can move around an edge of the cathode plate 16 so that the clamping plate 67 can clamp the cathode plate 16 to the first stripping apparatus 40. Clamp 63 operates in a similar manner to clamp the cathode plate 16 to the first stripping apparatus 40.

[0078] The first stripping apparatus 40 also includes a plurality of rollers, some of which are numbered at 73, 74. As can be seen from FIG. 17, rollers 73 are offset from rollers 74. In use, one of the rollers 73 or 74 can contact and roll on the surface of the cathode plate or the deposited metal and the other of the rollers 73, 74 can contact and roll along the face of the deposited metal sheet. In this manner, possible damage to the cathode plate and the deposited metal sheet that may be caused by movement of the first stripping apparatus along the cathode plate and the first metal sheet can be minimised. The rollers also support the wedge during the downward stripping operation and reduce friction between wedge, copper deposit and cathode plate during travel.

[0079] FIGS. 19, 20 and 21 show a front view, perspective view and side view, respectively, of a second stripping apparatus 42. The second stripping apparatus 42 has a number of features in common with the first stripping apparatus. For convenience, where the second stripping apparatus 42 has features in common with the first stripping apparatus 40, the same reference numerals used to denote those features in relation to the first stripping apparatus 40 will be used to denote the same features in FIGS. 19 to 21, but with the addition of a′. For example, the wedge 58 of the first stripping apparatus 40 corresponds to the wedge 58′ in the second stripping apparatus 42. These features need not be described further.

[0080] Second stripping apparatus 42 differs from first stripping apparatus 40 in that second stripping apparatus 42 includes a second set of clamps 76, 77. The second set of clamps 76, 77 may be of essentially identical construction with essentially identical drive arrangements to the clamps 62, 63. However, as can be seen from FIG. 21, clamps 62′ and 63′ have clamping plates that can extend past the outer periphery of the second stripping apparatus 42 whereas clamps 76, 77 have clamping plates that extend past the inner periphery of the second stripping apparatus 42. In this manner, the clamps 76, 77 can clamp onto a sheet of deposited metal that has been stripped from the cathode plate and is located adjacent to the inner periphery of the second clamping apparatus 42 (this corresponds to the sheet of deposited metal that is removed from the cathode plate on the side of the cathode plate along which the first stripping apparatus moves), whilst the clamps 62′, 63′ can clamp onto a sheet of deposited metal that has been stripped from the cathode plate by the second stripping apparatus (this corresponds to the sheet of deposited metal that is removed from the cathode plate on the side of the cathode plate along which the second stripping apparatus moves).

[0081] The second stripping apparatus 42 also includes side guides 78, 79 that are mounted to respective side members 53′, 54′ of the second stripping apparatus 42. The guide 78 comprises an angled guide plate having a first section 80 and an outwardly angled second section 81. The guide 78 is mounted to or formed with a side plate 82 that is welded to the side member 53′. Guide 79 is of essentially similar construction. The guides assist in holding the second sheet of metal 14 in position by the side guides and the pusher pushes the first sheet of metal towards the stripping apparatus The guides prevent titling of the cathodes during the stripping operation, which could otherwise result in the cathode deposits moving out of reach of the clamps/grippers.

[0082] As mentioned above, first stripping apparatus 40 is mounted to the robotic arm of the first robot 36 and second stripping apparatus 42 is mounted to the robotic arm of second robot 38.

[0083] Operation of the first and second stripping apparatus and the first and second robots to strip deposited metal from a cathode plate, remove the stripped cathode plate from the stripping station and move the stripped metal to a transport region or storage region will now be provided with reference to FIGS. 1 to 14. In FIGS. 1 to 14, the robotic arms have been omitted for clarity. However, the person skilled in the art will understand that the robotic arms are used to achieve the required movements of the first and second stripping apparatus. The robotic arms may be programmed with the appropriate sequence of commands to ensure that the required movements occur. Similarly, the control system that controls movement of the robotic arms may also control operation of the clamps on the first stripping apparatus and the second stripping apparatus.

[0084] Prior to positioning the cathode plate having the sheets of deposited metal thereon in the stripping station, the cathode plate is flexed to open up a small gap at the top between the deposited sheets of metal and the cathode plate. The stripping apparatus can be inserted into the small gaps in the stripping station in order to complete the stripping process. The step of flexing the cathode plates to partly separate the deposited metal from the cathode plate prior to placing the stripping apparatus between the cathode plate and the deposited sheets of metal is well known in the art and need not be described further.

[0085] Conventional cathode handling apparatus is used to place the thus-flexed cathode plate in the stripping station 20. This is shown in FIGS. 1 and 2. FIG. 1 shows the cathode plate 16 having the flexed sheets of deposited metal 12, 14 thereon. FIG. 1 also shows the first stripping apparatus 40 being located such that the wedge 58 of first stripping apparatus 40 is positioned into the gap between the sheet of deposited metal 12 and the cathode plate 16. Similarly, second stripping apparatus 42 is positioned such that its wedge 58′ is positioned in the gap between sheet of deposited metal 14 and cathode plate 16.

[0086] FIGS. 1 and 2 also show a down ender 84. Down ender 84 comprises two spaced frame members 85, 86 that are pivotally mounted at their lower ends about an axle 88. In another alternative, rather than using an axle, the lower ends of frame members 85, 86 may be independently journaled in separate bearings. The bearings are suitably in alignment with each other. An actuator 90, which may be an electric motor having an associated gearing system, can be used to move the down ender 84 from an upright position shown in FIG. 1 to a position at which the upper end of the down ender 84, as shown in FIG. 1, is lowered to a position at which the down ender is located beneath the upper surface of the chain conveyor 28. Operation of the down ender will be described in further detail hereunder.

[0087] FIGS. 1 and 2 also shown the pusher 30. As best shown in FIG. 1, the pusher 30 is positioned such that the horizontal contact member 33 is spaced from the deposited sheet of metal 12 at this stage of the stripping cycle.

[0088] After the wedges 58, 58′are inserted into the gap between the sheets of deposited metal 12, 14 and the cathode plate 16 (as shown in FIG. 1), the first robot arm and second robot arm simultaneously move the first stripping apparatus 40 and second stripping apparatus 42 downwardly along the cathode plate 16 and the respective sheets of deposited metal 14, 12. As can be seen from FIGS. 1 and 3, first stripping apparatus 40 is located to one side of cathode plate 16 and second stripping apparatus 42 is located to the other side of cathode plate 16.

[0089] FIGS. 3 and 4 show the first stripping apparatus 40 and the second stripping apparatus 42 located such that the lower ends of the respective stripping apparatus are located adjacent to the lower edge of the cathode plate 16. At this stage, the sheets of deposited metal 14, 16 are still connected to each other along their lower edge but they have been effectively separated from the cathode plate 16. A lifting device (obscured in the drawings), which may form part of the stripping station 20, may also lift the cathode a short distance upwardly (such as around 70 mm) to ensure release of the cathode plate from the deposited metal during the stripping operation.

[0090] At this stage, the clamps 62, 63 on the first stripping apparatus are actuated to grip the cathode plate 16. Similarly, the clamps 62′, 63′ on the second stripping apparatus are actuated to clamp onto the sheet of deposited metal 14. The first robot arm is then operated to start to lift the first stripping apparatus 40 upwardly. This also starts to lift the cathode plate 16 out of the stripping station 20. The first step of this movement is shown in FIG. 5. As shown in FIG. 5, the first stripping apparatus 40 has been moved upwardly by a small distance such that there is now a small gap between the sheet of metal 12 and the first stripping apparatus 40. As the second sheet of deposited metal 14 is being gripped by the clamps 62′, 63′ on the second stripping apparatus 42, the second sheet of metal 14 and the attached sheet of metal 12 remain in position.

[0091] FIGS. 7 and 8 show the first stripping apparatus 40 continuing to be raised upwardly by the first robot arm, which effectively removes the cathode plate 16 out of the stripping station 20. The pusher 30 is actuated such that the horizontal contact member 33 comes into contact with the sheet of metal 12 and pusher the sheet of metal 12 towards the second stripping apparatus 42. Clamps 76, 77 are then actuated to grip the other sheet of metal 12. In this manner, both sheets of metal 12, 14 are gripped by the clamps or grippers that are mounted on the second stripping apparatus 42.

[0092] In FIGS. 9 and 10, the first stripping apparatus 40 has been moved by the first robot to a cathode plate transport or storage region. At this stage, the clamps 62, 63 on the first stripping apparatus 40 may be operated such that they release the cathode plate 16. The cathode plate 16 is then either stored or moved as required. Typically, the cathode plate 16 will be placed in storage until it is required for re-use in the electrodeposition plant or the electrowinning plant.

[0093] FIGS. 11 and 12 show the second stripping apparatus 42 being moved by the second robot arm so that the sheet of deposited metal 14 is brought into contact or abutment with the down ender 84. The clamps 76, 77, and 62′, 63′ are then operated to release the respective cathode sheets/sheet of deposited metal 14 and 12. The second robot arm is then operated to lift the second stripping apparatus 42 upwardly and away from the sheets of deposited metal 12, 14 such that the sheets of deposited metal 12, 14 remain resting on the down ender 84. It will be appreciated that the step shown in FIGS. 11 and 12 can commence as soon as the bottom part of first stripping apparatus 40 has been raised clear of the upper end of sheet of deposited metal 12. In other words, the step shown in FIGS. 11 and 12 can take place as soon as the first stripping apparatus 40 reaches the position as shown in FIGS. 7 and 8.

[0094] Once the second stripping apparatus 42 has been removed from between the sheets of deposited metal 12 and 14, the down ender 84 is lowered to the position shown in FIGS. 13 and 14. Following withdrawal of the second stripping apparatus 42 from between the sheets of deposited 12 and 14, but whilst the down ender 84 was still in the position shown in FIG. 11, the pusher 30 may be further operated to push the sheet of deposited metal 12 closer to the sheet of deposited metal 14, which closes up to gap at the upper ends of the sheets of deposited metal 12, 14. This may be an optional step. In some embodiments, the down ender rotates sufficiently far so that the back end 92 of the down ender 84 (see FIG. 14) contacts and pushes the metal stripped by the first robot up against the metal stripped by the second robot so that the sheets of deposited metal of brought close together in the horizontal position on the conveyor.

[0095] When the down ender 84 reaches the position as shown in FIG. 13, the down ender 84 is located below the upper surface of the chain conveyor 28. However, as the sheets of metal 12, 14 are wider than the distance between the adjacent chains of the chain conveyor 28, the sheet of deposited metal 14 comes into contact with the chains of the chain conveyor 28. These chains desirably start to operate when a pair of sheets of deposited metal 12, 14 are received and move along with the chain conveyor after down ender 84 reaches the position shown in FIGS. 13 and 14. This removes the sheets of deposited metal 12, 14 from the stripping station 20 and clears them from the down ender. In one embodiment, the conveyor has driving dogs and the chains start and travel a fixed distance everytime a pair of cathode deposits are received. The conveyor maybe of conventional design and operation.

[0096] In order to ready the stripping station 20 for stripping deposited metal from another cathode plate, the pusher 30 is returned to a more upright orientation (as shown in FIG. 13) and the down ender 84 is raised back to the position shown in FIG. 1. The next cathode plate with deposited metal thereon can then be placed in the stripping station 20, and the sequence of operations can be repeated.

[0097] Preferred embodiments of the present invention allow for efficient handling of cathode plates and the stripped metal that has been removed from the cathode plates. This can result in improved productivity and increased metal production from the stripping stations. Further, as the cathode plates are removed from the stripping stations by one of the robots, separate cathode plate handing apparatus for removing the stripped cathode plates from the stripping station is not required.

[0098] In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0099] Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0100] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.