WO2004094088A1

WO2004094088A1 - Method and arrangement for controlling anodes

Info

Publication number: WO2004094088A1
Application number: PCT/FI2004/000243
Authority: WO
Inventors: Juha Lumppio; Aleksi Hiltunen; Kalle Huju; Kristian MYLLYMÄKI
Original assignee: Outokumpu Technology Oy
Priority date: 2003-04-23
Filing date: 2004-04-21
Publication date: 2004-11-04
Also published as: AR044059A1; FI20030613A0; FI20030613A; PE20040969A1; CL2004000842A1

Abstract

The invention relates to a method and arrangement for controlling plate-like objects, such as anodes (4), in which case the anodes are cast, said casting process comprising a casting arrangement (2) and a data system (5) for managing the data of the casting arrangement, so that the anodes (4) are after the casting process marked by a separate marking mechanism (1) in order to classify the anodes (4).

Description

METHOD AND ARRANGEMENT FOR CONTROLLING ANODES

The invention relates to a method and arrangement according to the independent claims for controlling cast plate-like metal objects, such as anodes, so that the anodes are after the casting process marked by a separate marking mechanism for tracking and classifying said anodes.

The blister copper created in the conversion stage of the pyrometallurgical production of copper is further refined in an anode furnace in order to lower the sulfur content contained by said blister copper. After anode furnace treatment, copper is cast as copper anodes by pouring molten copper in casting molds. The currently used casting equipment comprises a rotating casting table, where several tens of casting molds are arranged in a circular arrangement. Generally the casting table is provided with a cooling unit where objects are cooled in their casting molds for instance by water. In connection with the casting table, there is also arranged a preloosening unit, by means of which the cast object is detached from the mold when it has somewhat cooled off. Generally anode plates are lifted from the casting table after casting by the adjacent take-off device to a cooling bosh tank. The tank is filled with cooling liquid. Cast copper anodes are purified in copper electrolysis into copper cathodes with a copper content of over 99.99 %.

Anode furnace treatment and subsequent anode casting are batch processes, where the chemical composition of the batches varies. The chemical composition of anodes, such as precious metal content and the contents of substances that are harmful for the electrolysis are bound to each casting batch. When using copper anodes in the production of copper cathodes, it is essential that the harmful effects of even small contents in the electrolysis are eliminated or detected. It is advantageous to know the chemical composition of each copper anode with respect to the optimization of the electrolysis and the recovery of precious metals. A typical feature of a casting table comprising several casting molds is that there are individual differences in the casting molds. Consequently, for quality control and anode casting equipment and the process development, it is advantageous to know in which mold and at what point of time a given anode is cast. Thus it is possible to identify the effect of the mold on the anode quality and on the electrolytic process.

According to the method described JP 1136985, copper anodes are marked with separate labels attached on the anode end faces, in which labels there is written information as regards the casting batch as well as properties of the anode in question.

In the take-off device and cooling bosh tank, the process conditions are difficult owing to the fluctuation and bubbling of the cooling liquid, which also requires certain features of the anode marking method. Thus separate labels may be harmfully detached from the anode surface during the process of cooling or electrolysis. JP 1136985 does not disclose a solution for the problem as to how the marking method ensures that an anode rejected in the middle of the anode queue, for example owing to a breaking of the suspending lug, does not mix up the individual marking system. In case the tracking the anode is not ensured in a feasible way, the data concerning an individual anode may only contain the casting batch code and marking time information. For instance the actual casting time can only be estimated in average, backwards from the marking time to the casting time. It remains unclear from which casting mold each anode originates.

The anode marking process must be performed in the anode casting plant in extremely demanding conditions, where the temperatures alone varies due to the casting operations and casting pauses, typically between about -5 and +50 degrees Centigrade. In addition, the radiation heat increases local temperatures even higher than this. Thus the marking method must be fast, in order to prevent the marking process from creating a bottleneck in the process. In modern casting arrangements the different process steps, such as casting, last for about 10 - 45 seconds.

So far a reliable solution for marking anodes immediately on the anode casting table is not disclosed. In the casting machine anodes could be marked individually, without a danger of the anode markings getting mixed up owing to anodes that are rejected somewhere in between.

The object of the present invention is to introduce a novel solution for tracking and controlling copper anodes. A particular object of the invention is to mark the anodes by a separate marking mechanism after the casting process in order to classify the anodes.

The invention is characterized by what is set forth in the characterizing parts of the independent claims. Other preferred embodiments of the invention are characterized by what is set forth in the other claims.

Remarkable advantages are achieved by the arrangement according to the invention. In the marking made according to the present invention, there can be included information as to in which mold and at what point of time the anode is cast. Thus there is obtained useful information for developing the process, for instance when the anode for some reason has a poor quality. The marking made in the anode may include information concerning for example the casting mold, the casting batch or the casting time. Thus it is possible to arrange a database, by means of which for instance the condition of the mold as well as its effect on the electrolytic process can be controlled. The individual differences between the molds may include for example the position of the mold in the casting table, differences in shape and possible damages and wearing effects. Said features affect the physical quality of the manufactured anode, and may result in shape defects, such as wedge-like shape or protuberances.

With the present invention the features affecting the anode quality, such as the anode weight, the anode temperature when lifting off the mold, the mold temperature, cooling method prior to lifting off the mold, and the quantity of the mold refractory dressing, can be collected mold-wise in the data system of the casting table, and each anode can be marked accordingly. It is essentially important that the information connected to each anode can be transferred in the database anode by anode, and that the identifier corresponding to said database can be reliably marked in the anode immediately after casting. By means of the invention, there is achieved the remarkable advantage that there is no risk of getting the anodes mixed up. When the anodes thus can be tracked even by their molds, all information connected to the anodes can be collected reliably, and the effects of the various factors on the electrolysis can be compared.

By means of the invention, the research and development of the anode casting and electrolytic processes becomes remarkably easier. In prior art techniques, anodes can be marked, but the range of information provided in the markings is limited.

The invention relates to a method for controlling plate-like objects, such as anodes, in which case the anodes are cast, and said casting process comprises a casting arrangement and a data system for managing the data of the casting arrangement, so that after the casting process, the anodes are marked by a separate marking mechanism for tracking and classifying them.

In a method according to the invention metal objects are cast in a casting arrangement provided with a casting table comprising several casting molds and a data system for managing the data connected to the casting process, a unit for preloosening the cast object from the casting mold, and a take-off device and cooling bosh tank for cooling and grouping the metal objects, the metal objects are detached from the casting mold and lifted in the take-off device and cooling bosh tank, and the metal objects are marked by a marking mechanism in the casting arrangement for tracking and classifying them.

According to a preferred embodiment of the invention, metal objects are marked by a marking mechanism arranged in connection with a preloosening unit. According to another preferred embodiment of the invention, metal objects are marked by a marking mechanism arranged in connection with the cooling bosh tank. According to a preferred embodiment of the invention, metal objects are marked after lifting from the mold by a marking mechanism arranged in a special marking station arranged in connection with the casting arrangement.

In the preloosening site, the cast object, such as an anode, is first lifted off the mold in order to make sure that the object can be detached from the mold. In the same connection it is advantageous to reject defective objects from the line. In the preloosening site, the anodes are usually lifted off the molds so that the lug-side edge of the anode remains for a while, typically for the duration of 2 - 15 seconds, lifted off the mold. At the same time it is advantage to mark at the anode edge, advantageously at the top surface of the lug, a marking that can later be easily read for instance in the electrolytic tank. At the preloosening site, the temperature of the cast object is still high, about 800 - 1,000 degrees Centigrade. The temperature of the object can be utilized when selecting a suitable marking method.

In the cooling bosh tank, the anodes are advantageously marked immediately after immersing them in the cooling liquid. This is recommended to ensure flexible proceeding of the process. The anodes are typically collected on the conveyor of the take-off device and cooling bosh tank in compact bundles of 5 - 30 anodes, and when a bundle is ready, the conveyor moves the bundle forward in the tank, from which it is removed either by a truck or by a bridge crane. In case the lifting is carried out by a bridge crane, the anodes are typically collected on the conveyor in several successive bundles. When unloading the bundles in a truck, each bundle is typically driven immediately when the bundle is ready to the opposite end of the tank with respect to the casting table, where the bundle is compacted against a bundle lifting device. After compacting, the bundle lifting device lifts the bundle, so that the truck forks are positioned underneath the anode lugs.

Both of the above described preferable anode marking sites have their specific features that make the performed anode marking an extremely challenging task. A challenge relating ot the preloosening site is the high temperature of both the environment and the target to be marked, which make it difficult both to carry out the marking and to maintain the marking equipment. Typically the temperature of an anode plate at the preloosening site is about 800 - 1 ,000 degrees Centigrade. At this site, the anode lug, in which the marking should be realized, still has a temperature of about 400 degrees, which means that the marking agents must have high temperature resistance. Marking agents that are suitable for metal surfaces are typically solvent-based paints that are disadvantageously flammable and harmful for the environment. The preloosening site is a challenging spot also because here defective anodes are rejected, which means a threat that an anode plate having a temperature of 1 ,000 degrees and a weight of about 200 - 600 kg should fall directly on top of the marking equipment.

The marking of anodes in the take-off device and cooling bosh tank sets special demands for the method and arrangement. Immersing an anode plate having a temperature of about 800 - 1 ,000 degrees in the cooling tank results in vibration, boiling and splashing of water, scattering of metal flakes to the vicinity and a remarkable formation of vapor. The vaporization of water around the anode continues, until the anode temperature has decreased below 100 degrees. Typically the vaporization continues for 30 - 100 seconds. Said water bubbling phenomenon takes place at a site where it would be most advantageous to mark the anodes. It is difficult to decrease the bubbling phenomenon of the cooling water and its effect on the marking of anodes in the take-off device and cooling bosh tank without simultaneously weakening the cooling effect of air.

For optimizing the cooling effect, the water height in the cooling bosh tank is adjusted to rise above the anode lugs. In practice, the water surface is positioned on the level of the top surface of the chain conveyor of the tank. Owing to the above-mentioned reasons, in the vicinity of the site of immersion, there continuously occur disturbances on the water surface, which means that the anode lugs near the location where the anodes are immersed are frequently washed by water.

The present invention provides a reliable, individual marking of anodes in the vicinity of the cooling bosh tank irrespective of the demanding conditions. A marking device according to the invention advantageously comprises an especially developed cover element that protects the marking mechanism and the marking point during the marking operation. The cover element can be removed from the anode surface immediately after the marking operation, and the performed marking is resistant to the influences of the water and vapor washing over it. In practice it has been found out that the clarity of markings carried out by certain techniques is only improved, even if an occasional wave should wash the marking surface. The essential thing is that the marking realized by marking agents is dried to be water- resistant during one process cycle, i.e. about 10 - 45 seconds, of the casting arrangement.

In the arrangement according to the invention, the thermal energy of the anode is utilized so that the protected area is dried prior to the marking operation, and that the base marking agent, preferably a water-solvent agent that is not hazardous for the environment, is dried sufficiently quickly in order to endure the washing by water immediately after the marking operation. In order to perform the marking and the tracking in a successful way, it is essential that the marking is made as rapidly as possible after the anode is immersed in the tank, typically about 1 - 10 anode positions after the immersion. The marking that is carried out in this way after the positioning increases uncertainty with respect to the success of the marking and the tracking of the anode.

According to a preferred embodiment of the invention, the arrangement is provided with a marking device moving in the lengthwise direction with respect to the take- off device and cooling bosh tank, which marking device follows the anodes from the immersion site to the marking site.

The marking operation carried out in the cooling bosh tank is disturbed by the anode fins and thickness variations, because an anode that is thicker or has fins requires a larger space on the chain than a thinner one, and in a case where there are sufficiently many anodes arranged in succession, the created error may even be of the order of the width of one whole anode, which means that the risk of applying the marking in the adjacent anode is clearly existent. A marking according to the invention makes it possible to clarify and eliminate the drawbacks connected to the fins and thickness variations in anodes, because the marking operation is carried out at the casting table side end of the cooling bosh tank, where the thickness variation cannot result in an error of the size of one whole anode. At most, the marking may be applied past the anode, but an erroneously marked anode bundle cannot be created. In a preferred embodiment of the invention, the marking end of the marking device is set, with respect to the lengthwise direction of the tank, in a slight motion (of about 5 - 40 mm) that is smaller than the anode lug, in which case the controlling is arranged so that the marking is always applied on an anode, and not in between anodes, irrespective of possible variations in the anode thicknesses. The most reliable mold-wise marking is carried out at the preloosening site, in which case the anode at the moment of marking is still in the same mold in which it was cast. In the cooling bosh tank, a reliable anode marking is realized so that the marking is performed sufficiently near to the point of immersion into the tank, in which case possible thickness variations of the anode cannot divert the marking from being applied on the correct anode. If the anode-suspending lug is broken in the tank, the automatic system interprets that the anode is still positioned on the conveyor, and the marking is applied in between anodes, because the location of the missing anode has not yet been filled. Thus the anodes following an anode with a broken lug obtain the correct marking by a simple checking method.

A marking device according to the invention, operated in the cooling bosh tank, can be connected to the take-off devices and cooling bosh tanks of existing anode casting plants rapidly and easily, without separately installed timers and actuators. Thus the risks of possible production losses caused by the marking device can be minimized.

The arrangement according to the invention for marking cast metal objects comprises a casting arrangement and a marking mechanism arranged in connection thereof. According to a preferred embodiment of the invention, the marking mechanism is arranged in connection with the preloosening unit of the casting arrangement. The marking mechanism can be arranged so that in the preloosening step, when the cast object is lifted off the mold, the marking can be made on the surface of the cast object. According to another preferred embodiment of the invention, the marking mechanism is arranged in connection with the cooling bosh tank. The cooling bosh tank is provided with a take-off device for lifting anodes from the casting table into the cooling bosh tank. The marking of anodes is advantageously applied on the top surface of the anode lug. According to the invention, anodes are marked with a marking device included in the marking mechanism. According to a preferred embodiment, the employed marking device is a marking end of an ink jet printer. The marking mechanism is moved both in the vertical direction and in the directions along the length and width of the take-off device and cooling bosh tank by means of a control arrangement. The marking mechanism is positioned at a desired height above the take-off device and cooling bosh tank by means of a sensor element included in the marking mechanism. According to a preferred embodiment of the invention, anodes are advantageously marked in the take-off device and cooling bosh tank. The marking is advantageously made on the anode top surface, which is located above the surface of the cooling liquid contained in the cooling bosh tank. According to a preferred embodiment of the invention, the anode color is prior to the marking proper changed by painting the marking point by a painting device included in the marking mechanism. In this way, possible drawbacks caused by the shifting of the anode color are avoided later on. The marking device according to a preferred embodiment of the invention comprises a cover element, by which the marking point is protected for the duration of the marking process. Thus possible splashes of cooling water from the cooling bosh tank at the marking point can be avoided during the marking operation. According to a preferred embodiment of the invention, the cover element is an annular, lip-like element that can be pressed on the marking surface, made of a elastic, heat-resistant material, such as rubber or silicon. The marking agent is arranged to be applied on the marking surface through the middle of the lip-like cover element. According to another preferred embodiment of the invention, the cover element is a metal brush, the bristles of which are pressed against the marking surface, and the marking agent is applied on the surface from the middle of the bristles. Another method according to the invention is that the cover element is a pressurized air jet, which is directed to protect the marking agent spray at the moment of marking.

Prior to the marking, the marking point of the anode can be dried by a drying arrangement belonging to the marking mechanism. Thus any possible extra water can be removed from the spot to be marked prior to the marking process proper. According to a preferred embodiment of the invention, the marking mechanism is positioned in the immediate vicinity of the take-off device and cooling bosh tank.

According to a preferred embodiment of the invention, the marking is made to be read by an automatic reader. According to a preferred embodiment of the invention, the marking is realized as a bar code. According to another preferred embodiment, the marking is composed of a desired . number of written symbols. According to a preferred embodiment of the invention, the control unit included in the marking mechanism is connected to the data system of the casting process. Thus the marking mechanism identifies the anode to be marked. According to a preferred embodiment of the invention, the anodes are marked by mechanically manipulating the anode surface. In that case the alternative marking methods are welding, grinding, engraving, cutting, etching, point marking, punching, laser or printing.

The invention also relates to an arrangement for controlling plate-like objects, such as anodes, in which case the anodes are cast, and the casting process includes a casting arrangement, as well as a data system for managing the data of the casting arrangement, in which case the anodes are arranged to be marked by a separate marking mechanism after the casting process in order to classify said anodes. According to the invention, the marking mechanism includes a marking device for producing the mark in the anode. According to a preferred embodiment, the marking device is the writing end of an ink jet printer. The marking mechanism includes a control arrangement for moving the marking mechanism both in the vertical direction and in the direction of the length and width of the take-off device and cooling bosh tank. In addition, the marking mechanism comprises a painting device for changing the anode color, as well as a protecting element for protecting the top surface of the anode for the duration of the marking process. According to a preferred embodiment of the invention, the protecting element is made of a heat- resistant, pneumatic material, such as rubber. According to another preferred embodiment of the invention, the protecting element is a metal brush. Another preferred embodiment of the invention is that the employed protecting element is a pressurized air jet. In addition, the marking mechanism includes a drying equipment for drying the anode prior to the marking, as well as a detector element for optimizing the position of the marking mechanism above the take-off device and cooling bosh tank.

The invention is explained in more detail below, with reference to the appended drawings.

Figure 1 An arrangement according to the invention.

Figure 2 An arrangement according to the invention.

Figure 3 An arrangement according to a preferred embodiment of the invention for marking anodes.

Figure 4 An arrangement according to another preferred embodiment of the invention for marking anodes.

Figure 1 illustrates a marking mechanism 1 according to the invention for marking anodes 4, such as copper anodes, to be lifted from a casting arrangement 2 to the take-off device and cooling bosh tank 3. The anodes are cast as anode casting in given casting batches that may contain anodes with mutually different qualities. In connection with the anode casting, there is provided a data system 5, in which there is collected data of casting times and other process parameters important for the casting process. The anodes 4 are immersed in the take-off device and cooling bosh tank 3 to be cooled off, and from there, the anodes are later picked up in bunches of a certain size to be conveyed to further treatment. The marking mechanism 1 can be positioned in the immediate vicinity of the takeoff device and cooling bosh tank 3 and transferred to a desired location therefrom. The control unit 12 belonging to the marking mechanism 1 is connected to the casting process data system 5, so that the marking mechanism detects which anode 4 is originally from which casting batch. The marking mechanism control unit 12 contains the necessary information in order to control the marking mechanism. The marking to be produced by the mechanism can include for instance information regarding in which mold and when the anode in question was cast. The marking can be for instance a bar code or a series of written symbols.

Figure 2 illustrates a marking device 6 belonging in the marking mechanism 1 , such as the writing end of an ink jet printer, in order to produce the mark on the anode surface. The marking mechanism 1 can be moved by means of a control arrangement 7 connected to the marking mechanism. The control arrangement 7 comprises a required number of mutually movable support arms, such as steel bars, and it is supported against the floor of the anode casting plant. By means of the control arrangement, the marking mechanism can be moved both in the vertical direction and in the direction of the length and width of the take-off device and cooling bosh tank above the take-off device and cooling bosh tank 3. The anode to be marked is transferred in a certain rhythm to the marking mechanism along conveyors provided in the take-off device and cooling bosh tank. The protecting element 10 belonging to the marking mechanism is lowered to protect the top edge of the anode for the duration of the marking operation. According to the example, the protecting element 10 is an element made of rubber, and it is positioned to protect the top part of the anode 4 against any water splashes from the take-off device and cooling bosh tank 3 during the marking operation. The marking mechanism 1 is lowered at a suitable height above the anodes by means of a detector element 14, such as an inductive sensor. The anodes can also be dried prior to marking, which improves the quality and permanence of the mark. The drying is carried out by a drying equipment 13 belonging to the marking mechanism 1 , such as a pressurized air jet. The marking mechanism moves towards the center part of the anode, i.e. in the width direction of the take-off device and cooling bosh tank, and that spot on the anode that should be marked is painted by the painting device 11 belonging to the marking mechanism. Any difficulty caused later on in the mark detection by a possible shifting of the anode color is avoided, when the marked spots in the anodes are painted by the same color. Thereafter the marking device 6 belonging to the marking mechanism makes a mark on the top surface 8 of the anode. The marking is made in one anode at a time, and the anode top surface 8 is in the take-off device and cooling bosh tank positioned above the surface 9 of the cooling liquid. After making the marking, the mechanism can be moved away from the vicinity of the anode top surface 8.

In the arrangement according to the invention illustrated in figure 3, there is provided a casting^" table 32 rotating in the direction of the arrow 33, in which there are arranged the casting molds 35. The molten metal is poured in the casting molds from the casting ladle 34. The arrangement comprises the anode precooling unit 36 covered by a lid, the anode preloosening unit 37 and the take-off device and cooling bosh tank 38. In connection with the cooling bosh tank 38, there is arranged a marking mechanism 31.

In the arrangement according to the invention illustrated in figure 4, there is provided a casting table 32 rotating in the direction of the arrow 33, in which there are arranged the casting molds 35. The molten metal is poured in the casting molds from the casting ladle 34. The arrangement comprises the anode precooling unit 36 covered by a lid, the anode preloosening unit 37 and the take-off device and cooling bosh tank 38. In connection with the preloosening unit 38, there is arranged a marking mechanism 41.

The marked anodes are conveyed to a desired further treatment, such as electrolysis. After marking the anodes, the information given by the marking can be utilized for instance when arranging the anodes in electrolysis, or when investigating a possible poor quality of a given anode. The marking can include data for instance of the anode properties, such as weight or casting batch, and each marking can also be read automatically by those who are in charge of the further treatment of the anodes. In the control unit 12 of the marking mechanism, there can be created a database containing information of the properties of the anodes to be marked. The database can be connected to the data systems of the further treatment, such as electrolysis.

The marking mechanism is capable of marking anodes either one by one as the anode moves to the marking mechanism, or the marking mechanism can be moved above the take-off device and cooling bosh tank in the lengthwise direction of said tank to beside the anodes that should be marked.

For a man skilled in the art, it is obvious that the various preferred embodiments of the invention are not restricted to the examples given above, but may vary within the scope of the appended claims.

Claims

1. A method for tracking and controlling cast metal objects, where the metal objects are cast in a casting arrangement comprising a casting table including several casting molds, as well as a data system for managing the data connected to the casting process, a unit for preloosening the cast object from the casting mold, and a take-off device and cooling bosh tank for cooling and grouping the metal objects, the metal objects are detached from the casting mold and lifted to the take-off device and cooling bosh tank, characterized in that the metal objects are marked by a marking mechanism in the casting arrangement.

2. A method according to claim 1, characterized in that the marking mechanism is arranged in the preloosening unit.

3. A method according to claim 1, characterized in that the marking mechanism is arranged in the cooling bosh tank.

4. A method according to claim 1 , characterized in that the anodes (4) are marked by a marking device (6) included in the marking mechanism in (1).

5. A method according to claim 4, characterized in that the employed marking device (6) is the writing end of an ink jet printer.

6. A method according to any of the preceding claims, characterized in that the marking mechanism (1) is moved both in the vertical direction and in the direction of the length and width of the take-off device and cooling bosh tank by means of a control arrangement (7).

7. A method according to any of the preceding claims, characterized in that the marking mechanism (1) is positioned at a desired height above the cooling bosh tank (3) by means of a detector element (14) belonging in the marking mechanism.

8. A method according to any of the preceding claims, characterized in that the marking is advantageously applied on the top surface (8) of the anode (4), which is located above the surface (9) of the cooling liquid contained in the cooling bosh tank (3).

9. A method according to any of the preceding claims, characterized in that the color of the anode (4) is prior to the marking changed by a painting device (11) belonging to the marking mechanism (1).

10. A method according to claim 9, characterized in that the top surface of the anode is protected for the duration of the marking operation by a cover element (10) belonging to the marking mechanism (1).

11. A method according to claim 10, characterized in that the employed cover element (10) is a heat-resistant, pneumatic material, such as rubber.

12. A method according to claim 10, characterized in that the employed cover element (10) is a metal brush.

13. A method according to claim 10, characterized in that the employed cover element is a pressurized air jet.

14. A method according to any of the preceding claims, characterized in that prior to the marking operation, the anode (4) is dried with a drying equipment (13) belonging to the marking mechanism (1).

15. A method according to claim 4, characterized in that the marking mechanism (1) is arranged in the immediate vicinity of the take-off device and cooling bosh tank (3).

16. A method according to claim 1 , characterized in that the anodes (4) are marked by a separate marking line array.

17. A method according to any of the preceding claims, characterized in that the marking made in the anode is made to be read by an automatic reader.

18. A method according to any of the preceding claims, characterized in that the marking made in the anode is realized as a bar code.

19. A method according to any of the claims 1 - 18, characterized in that the marking made in the anode is composed of a desired number of written symbols.

20. A method according to any of the preceding claims, characterized in that the control unit (12) belonging to the marking mechanism (1) is connected to the casting process data system (5).

21. A method according to claim 1 , characterized in that the anodes are marked by mechanically manipulating the surface of the anode (4).

22. An arrangement for controlling cast metal objects, such as anodes, wherein the anodes (4) are cast, said casting process comprising a casting arrangement (2), as well as a data system (5) for managing the data of the casting arrangement, characterized in that the anodes (4) are arranged to be marked by a separate marking mechanism (1) after the casting process in order to classify said anodes (4).

23. An arrangement according claim 22, characterized in that the marking mechanism (1) includes a marking device (6) for realizing the marking on the anode.

24. An arrangement according claim 22 or 23, characterized in that the employed marking device (6) is the writing end of an ink jet printer.

25. An arrangement according to any of the preceding claims, characterized in that the marking mechanism (1) includes a control arrangement (7) for moving the marking mechanism (1) both in the vertical direction and in the direction of the length and width of the take-off device and cooling bosh tank.

26. An arrangement according any of the preceding claims, characterized in that the marking mechanism (1) includes a painting device (11) for changing the anode color.

27. An arrangement according any of the preceding claims, characterized in that the marking mechanism (1) includes a protecting element (10) for protecting the marking surface (8) of the anode (4) for the duration of the marking operation.

28. An arrangement according claim 27, characterized in that the employed protecting element (10) is a heat-resistant pneumatic material, such as rubber.

29. An arrangement according claim 27, characterized in that the protecting element (10) is a brass brush.

30. An arrangement according claim 27, characterized in that the protecting element (10) is a pressurized air jet.

31. An arrangement according any of the preceding claims, characterized in that the marking mechanism includes a drying equipment (13) for drying the anode prior to the marking operation.

32. An arrangement according any of the preceding claims, characterized in that the marking mechanism (1) includes a detector element (14) for optimizing the position of the marking mechanism above the take-off device and cooling bosh tank (3).