AU620868B2 - Disposable cell for recovering conductive metal and method of use - Google Patents

Description

AUSTRALIA

PATENTS ACT 1952 COMPLETE SPECIFICATION Form

(ORIGINAL)

FOR OFFICE USE 6 2 0 Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: 000

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7 1 TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: Gunter WOOG 5435 BAUERS DRIVE WEST BEND WISCONSIN 53095

USA

Actual Inventor: Address for Service: GRIFFITH HACK CO., 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.

Complete Specification for the invention entitled: DISPOSABLE CELL FOR RECOVERING CONDUCTIVE METAL AND METHOD OF USE The following statement is a full description of this invention including th' best method of performing it known to me:-

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DISPOSABLE CELL FOR RECOVERING CONDUCTIVE METAL AND METHOD OF USE I. Background of the Invention This invention relates to methods and appa- 5 ratus for recovering metals from liquid solutions, and in particular to methods and apparatus facilitating the recovery of silver from bleach fix solutions used in photo processing, by disposable cells, with high efficiency, Up to the present time, zecovery of conductive metals from solution, and particularly recovery of silver from fixer solutions, has been a relatively 4 expensive process, requiring substantial mechanism and moving parts, as well as close supervision or complex computer controls, to accomplish. This is because the recovery process is electrolytic in nature, and the reaction if not closely monitored can cause sulfiding, damage to the solution and loss of silver. Hence continuous agitation is required as well as close control of the current being supplied to the reaction.

For instance, X-Rite Company offers a number of silver recovery systems, all of which include some type of device provided specifically for agitating the solution. Further, most of the systems offered by X- Rite have a cathode which is coiled, thus having a -2 relatively small surface area.

Similarly, Roconex Corporation manufactures a number of lines of silver recovery systems and markets them under the "Rotex" trademark. Al]. of these systems include some devices specifically devoted to agitation, generally with a rotating cathode which must be removed fromt the recovery unit and cleaned, and later reinstalled and reused.

I Moreover, all of the systems referred to above are relatively expensive, and there is a need in the marketplace 19) for systems which are less expensive and mechanically simpler, since mechanical simplicity brings with it a high degree of fee. reliability.

This invention relates to improvements to the apparatus described above and to solutions to some of the problems raised thereby.

.Summary of the Invention The invention relates to an apparatus f or recovering, conductive metal from a liquid which contains that metal, and to a method for recovering that metal using that apparatus.

The invention is particularly well suited for recovery of silver from photographic fixer solutions, According to one aspect of the present invention .::there is provided an apparatus for recovering a conductive metal f rom a liquid containing said metal in solution, said apparatus comprising: I a first container for containing an amount of said lquid; a second container defining a caivity, in liquid communication with said first container and constructed of a material which can be removed from said metal by smelting; a first electrode removably affixed partially within said cavity; a second electrode comprising a thin film applied to the inside surface of said container; a pump having an outlet in said second container, for pumping said liquid from said first container into said second A 4container, said liquid returning to said first container via I It -3return means; and, a power supply electrically connected to said electrodes in such a way as to result in said first electrode being an anode and said second electrode being a cathode, thus causing said metal to be deposited on said second electrode According to another aspect of the present invention there is provided a disposable cell for recovering a conductive metal from a solution containing raid conductive metal, and adapted for connecting to a container containing said solution and a solution pump with an inlet positioned within said container, said cell comprising: a a disposable insulative jar, constructed of a goI material which can be removed from said conductive metal by S. smelting, having a thin film of conductive material applied to S 15 the interior thereof, an outlet of said pump being positioned within said jar; an electrode removably affixed partially within said jar, formed of electrically conductive material; a power supply having two poles, a positive pole and 20 a negative pole, said positive pole being electrically connected to said electrode and said negative pole being electrically connected to said thin film, such that said metal is deposited on said thin film as it is recovered and, after recovery is substantially complete, said power supply and said electrode can be removed and the balance of the cell can be placed in a smelting furnace in its entirety, without further disassembly and without prior removal of said recovered metal from said Jar.

According to another aspect of the present invention there is provided a method for recovering a conductive metal from a solution containAng said metal, comprising the steps of: providing a first container for containing said solution; applying a thin film of said metal to the inside surface of a second container; removably affixing an electrode partially within said second container; ~placing said second container in liquid 4 /'1 e .1 T 3A communication with said first container; circulating said liquid from said first container into said second container and back; generating a potential difference between said electrode and said thin film, thereby causing said metal in said solution to be deposited on said film and to build up thereon.

In one embodiment the apparatus includes a holding container for holding the solution. The recovery container is placed in liquid communication with the holding container. The first electrode in this embodiment is tubular to provide liquid communication between the two containers. This embodiment further includes a pump for circulating the metal laden liquid from the holding container into the recovery container. The 15 recovery container is mounted on the top of the holding container, and recovered solution drains down from the recovery container via the liquid communication means. The pump S• therefore has an inlet in the holding container and an outlet in the recovery container. The pump outlet is positioned *wti t 20 within the recovery container so as to provide agita-_____ I' 2;; -J 1 r -4tion of the solution in the recovery container merely by the discharge of solution from the pump outlet.

In each embodiment the recovery operation is facilitated by the fact that the recovered metal is not required to be removed from the cathode, because the recovery container itself is disposable, constructed from materials such as plastic or glass which can be added to the smelting furnace without contaminating the smelting operation.

Other objects and advantages of the invention will become apparent hereinafter, .Description of the Drawing Fig. 1 is a cross sectional view, partially schematic, especially with respect to the electrical control circuit, of a metal recovery apparatus coni structed according to one embodiment of the invention, Fig, 2 is a cross sectional view, also partially schematic, of a metal recovery apparatus constructed according to an alternative embodiment of the invention.

Fig. 3 is a cross sectional view, also I* partially schematic, of a metal recovery apparatus constructed according to yet another embodiment of the invention.

Description of the Preferred Embodiment While the invention is applicable to Yemov- Sal of any type of conductive ionic metal ia solution, it is particularly well suited to an application Swherein silver is removed from photographic fixer or bleach-fix solutions. The following description will refer to that silver removal application as exemplary, but it should not be considered as limiting the intended scope of the invention.

Single Container Embodiment Referring now to Fig. 1, an apparatus I;-.Now _7 V MMVI. Goo 0 l l- 1 r- l; _;li -c I constructed according to one embodiment of the invention includes a recovery container 12, containing an amount of fixer solution 14. The fixer solutiQn 14 is a solution in which a ionic silver is dissolved. The entire inner surface 12a of the container 12 is coated I with a very thin f ilm 12b of silver, the metal to be LI removed from the oIution, such as by spray painting.

The actual thickness of the film 12b as applied is not critical, as will be shown presently, as long as the interior surface of the container 12 is evenly coated *sufficiently thick to conduct electricity, The **thickness is commonly on the order of 1 mil. The .~:.material of the film may be generally any type of *...paint or other sprayable~ film containing silver, such Acrylic 1, Part No, 73-0002.5, from Tecknit EMI *Shielding Products, or E-K(,)te 3040 from ACME Conductive coatings. Alternativoly, the film 12b may be some other conductive material. For instance, the film 12b may be a thin ~layer' of stainless steel or 0 0gold, app±IL-ed by means of tape orsheigt te $Goa inside surface of container 12.

see aAn electrode 16 is suspended near the center of the container 12, reaching substantially into the solution 14. This electrode 16 can be of any suitable *~2~$and readily available material for such an electrode, such as carbon/gr~aphite rod material, For ease of assembly and mounting of the electrode 16 to the container, the electrode can be mounted in the center of a cover 18, which is attached to the top of and closes the container 1. Preferably the cover 18 is formed of insulative material so as to insulate the electrode from the thin film 12b, The electrode 16 thus mounted reaches downward intQ the solution 14 for the majority of its length.

The apparatus 10 further includes a power I l l ll r I 6 supply 20 for providing energy for an electrolytic reaction to plate the ionic silver out of the fixer solution 14. This power supply 20 is preferably a to 2.2 volt DC power supply, having a positive pole 22 and a negative pole 24. The electrode 16 is electrically connected to the positive pole 22 of the power supply 20, preferably by a positive connector 26, which fits into a receptacle 28 provided for that purpose at the top of electrode 16. Similarly, the thin film 12b coating the inside surface 12a of the i. ,container 12 is preferably electrically connected to the negative pole 24 by a negative connector 30 which .I fits into a receptacle 32 provided for that purpose.

SHence the elect:ode 16, being connected to the positive pole of the power supply 20, is the anode for the Se S electrolytic reaction, while the thin film 12b in effect acts as another electrode, becoming the cathode for the electrolytic reaction because of its con- S* nection to the negative pole of the power supply.

In the simplest mode of operation of the apparatus 10, then, an amount of fixer liquid 14 is placed in the container 12, and the cover 18 carrying the electrode rod 16 is placed on top of the container to close it. The electrode 16 and the film 12b are r* S then connected to the power supply 20 and the electrolytic reaction begins. During the electrolytic reaction, silver from the solution 14 is deposited on the silver film 12b until all or a suitable amount of the silver is plated out of the solution. As the silver builds up on the film 12b, the cathode in effect increases in thickness, improving its performance. This is the reason that the original thickness of the film 12b is not critical, since it increases as the reaction progresses. Because of the relatively large surface area of the cathode film 12b with re- S. 1 r~~~l 7 spect to the anode electrode 16, the current density will be extremely low, on the order of 1.5 milliamperes per square inch, Hence the apparatus 10 may run relatively unattended, since it is clear that the danger of sulfiding and/or dam&ae to the solution, which problem is carefully and expensively controlled and guarded against in the prior art, .is very remote at this low current density level, When a sufficient amount of silver has plated out, the power supply may be disconnected and the electrode 16 and the liquid 14 removed.

eOtt .C The used container 12 may then be placed in its entirety, including the cove., 18, in a silver S* smelting furnace (not shown) to refine the silver for *5 reuse, This is a major advantage of the present invention. In most presently existing silver recovery devices, the deposited silver must be somehow removed from the cathode before smelting, whether by scraping or some other physical means or process. This can be a difficult, expensive and dangerous job, Moreover, 0 some silver is inevitably lost in the process, In order that the container 12 may accompany its contained silver into the smelting furnace, it is required to be made entirely of some material that C 5 easily refines out of the molten silver in the smelting process, such as a common plastic pail. Of course a handle 34. iay be provided for ease of handling the container 12, but if it is of a metal containing copper, such as stainless steel, or some other metal which does not easily refine out of silver, it must be removably attached to the container, so that it can be removed prior to placement of the container in the smelting furnace, and even reused, as is the electrode 16. Preferably, however, it is simply conventional iron or zinc-plated (galvanized) iron, for low cost.

r i i _I .1 I 8 *0*0 a0 be 90 0 S9S 9* 0 SO s S1 0* 00 In the preferred embodiment as shown in the Fig. 1, the silver-containing solution may be continuously introduced into the container 12 by means of a liquid introduction tube 36 which has its outlet 36a near the bottom of the container. As silver is removed from the solution, the solution becomes lighter, rising to the top of the liquid 14 in the container 12 in a naturally occurring phenomenon referred to as "stratified transport", The solution at the top of the liquid, then, will be relatively more desilvered compared to that at the bottom of the liquid, This relatively de-silvered solution at the top may be continuously removed from the container 12 by a liquid drain tube 38, the inlet 38a of which is located in the sidewall of the container at the level of the top of the liquid. By proper relative placement of the source of the silver-containing solution, above the container 12, and of the reservoir of relatively desilvered solution, below the container 12, any necessity for pumps or other mechanically powered devices to move the solution is avoided, since the solution will move by siphoning, Further, since the relatively de-silvered solution may not be completely de-silvered from one pass through the apparatus 10, it may be desirable to connect a number of such apparatus together serially, so as to achieve the greatest possible silver extraction rate.

Both tubes 36 and 38 are preferred to be of plastic in order to be consistent with the objective, referred to above, that the entire container 12 may be placed in the smelting furnace when sufficient silver has been deposited.

The power supply 20 may be a generally conventional plug-in module type, as shown. As an additional aid in controlling and ensuring the integ- 3 5 r" ar I I,

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*5 .2.0 rity of the de-silvering reaction, the power supply may also include certain additional features, In particular, in one embodiment of the present invention, the power supply 20 first includes a generally conventional transformer module 40, which plugs into a conventional 110 volt or 220 volt electrical outlet 42 and outputs 5 volts DC, up to one amp, via a positive lead 44 and a negative lead 46. A calculator-type transformer module with these characteristics mzly be particularly well suited for this application.

Connected between the two leads are a current limiting resistor RI and a light emitting diode DI connected in series, The purpose of the diode Dl is to indicate that the transformer module 40 is indeed receiving power from the outlet 42, Hence, whenever the outlet 42 is supplying power, the diode DI is lit. Also connected to the positive lead 44 is a first lead of a voltage regulator ICl, The anode, or electrode 16, of the apparatus 10 is connected to a second lead of IC1, Finally, a third lead of IC1 is connected to the second lead by a resistor R2 and, via a potentiomete R3, to the negative lead 46 of the power supply transformer module 40. The purpose of the described arrangement of the voltage regulator IC1 and resistors R2 and R3 is to ensure that the current passing to the electrode 16 remains extremely low as described above.

The potentiometer R3 allows adjustment of the circuit for tolerances of the components and for various sizes of containers 12, Preferably potentiometer R3 Would be adjusted so as to provide 1.5 volts DC to the electrodes 12b and 16, resulting in the extremely low current density set forth above, Finally, flashing light emitting diode D2 is connected between the anode and cathode of the electrolysis circuit, that is, between the positive connector 26 and the negative I 24 5 10 connector 30. This diode D2 will flash if there is no current passing between the electrode 16 and the film 12b, thus acting as an indicator of the integrity of the electrolysis circuit.

While it is possible to use the at.us as described above in a "batch mode", it is more efficient to use it in "continuous" mode, as will now be described mainly in referenQe to Fig. 2, In continuous mode, as shown there, fixer solution 14 is constantly being circulated into the container 12, and de-silvered solution is constantly being removed. In the preferred embodiment as shown in the figure, the fixer solution 14 is continuously introduced into the container 12 by means of a pump 48, which is preferab- .15 ly an existing recirculating pump of an existing, o•."conventional, film processing machine solution tank which is normally connected to a film processing machine 52 via the recirculating pump and appropriate MO tubing 54, In general, tank 50 serves as a holding .0 tank for the film processing solution 14, which is thereby continually recirculated to tne film processing machine 52, This solution 14 builds up silver content with use, however, so that it has been conventional procedure to periodically replace the solution, and to attempt to recover the silver from solution because of the intrinsic value of the silver, The advantage of the embodiment shown in Fig. 2 is that the solution 14 does not need to be replaced, at least not as often, it the silver can be removed and recovered from the solution without removal or replacement, by use of the apparatus shown there, The embodiment shown in Fig. 2 includes valve means 58 for, in one position, permitting normal flow of solution 1,4 from the pump 48 to the film Processing machine 52, while in the other position S. uposaDie cell for recovering a conductive metal from a solution containing said conductive metal, and adapted 11 diverting the flow to container 12. While one valve 60 is shown to accomplish the function of valve means 58, the same effect can be achieved by use of a plurality of valves. Valve means 58 includes one outlet 59a to which is attached an inlet 62 of the I container Inlet 62 of Fig. 2 corresponds to Sliquid introduction tube 36 of the embodiment shown in Fig. 1, although of slightly different configuration because of the pressure supplied by the pump 48, S This inlet 62 terminates inside the container 12, at the bottom thereof, in a deflecting means 64. Thus ^when the valve means 58 is in its "divert" position, solution 14 is pumped by pump 48 into container 12, where deflecting means 64 dOflects the flow of the i *'15 solution, causing substantial and desirable agitation, :I *The solution then returns to tubing 54 via an outlet 66, which again corresponds to liquid drain tube 38 of the embodiment shown in Fig, 1, with minor changes because of the pressurization of the system, Outlet I 66 is preferably connected to and returns the solution 14 to valve means 58.

S" The power supply 20 is basically the same as that shown in Fig, 1. Because of the agitation j referred to above provided by the pump 48 and deflecting means 64, the voltage may be adjusted to be 1 higher, resulting in higher ciurrent density and faster recovery of the silver from t'he solution, 1 -Two-Container Embodiment Referring now to Fig, 3, an apparatus 110 is shown constructed according to another alternative embodiment of the inivention, which in a sense combines the first two embodiments shown. Apparatus 110 includes a holding container 112, holding an amount ef fixer solution 14. This solution 14 may be circulated into and out of holding container 112 by conventional J I I 12 means via an inlet 116 and an outlet 118, so as to make sure that the solution in the holding container 112 at all times contains some dissolved silver. The top of holding container 112 is covered by a suitable cover 120.

The apparatus 110 further includes a cell or recovery container 122, constructed of a material such as plastic or glass, similar to container 12 of the earlier disclosed embodiments, which material is easily separated from the recovered silver during smelting. It may be advantageous that the recovery container 122 be constructed of a clear plastic or glass so as to allow the viewing of the progress of 0 the deposition operation as will be described present- 1 5 ly. The entire inner surface 132a of recovery container 122 is coated with film 12b, as referred to above with respect to the first two disclosed embodiments.

If recovery container 122 is clear as indicated above, then just the side surface 122a should be covered, with the bottom surface 122c left uncovered so as to allow observation cf the progress of the plating operation within the recovery container.

Advantageously, recovery container 122 is provided with a cap 124, which is sized to fit in *2 sealing engagement over the sole opening 122d of the recovery container. An electrode 126 is affixed near the center of the cap 124, for ease of assembly and mounting of the electrode to the recovery container 122, Electrode 126 reaches substantially into the recovery container 122 for the majority of the length of the electrode, when the cap 124 is placed thereon, Electrode 126 may also, however, protrude slightly jeyond cap 124, outside of recovery container 122.

This electrode 126 can be formed of any suitable and readily available material for an electrode in such an -13application, such as stainless steel, since the solutions to be handled thereby can be corrosive. Prefer- I ably the cap 124 is formed of insulative material so as to insulate the electrode 126 from the film 12b.

The cap 124 also includes an opening f or a pump outlet i130, for reasons to be set forth presently. The recovery container 122 is then mounted on the holding container 112 by inverting the recovery container and mounting the cap 124 onto the cover 120, with the openings of the cap mating with similar openings *provided for that purpose in the cover.

The apparatus 110 further includes a pump 128 for pumping the solution 114 from the holding container 112 up into the recovery container 122, via pump outlet 130, already disclosed to be positioned K **inside the recovery container. This pump outlet 130 is positioned so that the output of the pump 128 V...causes substantial agitation of the so---cion 14 within the rei:overy container 122. That is, the pump outlet *2 130 directs the movement of the solution 14 at anI ***.angle, so that the solution in recovery container 122 6 is agitated by the solution being pumped into the, recovery c~ontainer, merely by the force of the pump ,*action. By this means, agitation of the solution 1.4 25 is provided without any apparatus devoted solely to the agitation function, resulting in i substantial economy of parts and mechanism, in turn improving the reliability and efficiency of the apparatus 110.

In the embodiment shown 'n F'ig. 3, the recovery container 122 Ls inverted and placed on. top of holding container 112. The solution 14 pumped into the recovery container 122 is allowed to drain back into the holding container 112 via up 'to two routes, The first route is a higher volume route, and must at least equal thie f.Iow of the pump outlet 130, Elec- 14 trode 126 can be provided in a tubular configuration, to provide the necessary liquid communication means.

Alternatively, electrode 126 could be solid and a separate liquid return tube 132 (in phantom) provided.

In either case, the topmost opening 126a of electrode 126 or the separate liquid return tube 132 inside recovery container 122 is substantially above cap 124 when the recovery container is in its installed, inverted position, a substantial amount of solution 14 remains in recovery container 122, as shown in the figure. The level of the solution 14 within recovery s container 122 is, thus, determined by the location of opening 126a of electrode 126, or the separate liquid return tube 132, above the opening of the recovery c- 1 *5 ontainer. The second route by which solution drains back into holding container 112 is via a drain opening 134 formed in the cap 124 and the cover 120, This S drain opening 134 is always open; but the amount of the flow allowed by this drain opening is substantially less than the output of the pump 128. The purpose Sof drain opening 134 is to allow the solution 14 remaining in recovery container 122 after pump 128 is turned off to drain back into holding container 112, t'heeby preventing the recovered metal from redissolv- 5 ing back into the solution. Hence this apparatus has particular application to recovery of silver from bleach fix solutions used in photo processing, since this type of solution is particularly susceptible to re-dissolution when power is not applied.

The apparatus 110 further includes a power supply 20 similar to that provided for the single container embodiment shown in Figs. 1 and 2.

In operation, an amount of solution 14 is placed in holding container 112, which has already been closed by cover 120, pump 128 having previously r.

15 25 30 been placed in the holding container 112 with pump outlet 130 protruding through the top of the cover.

The cap 124 carrying tubular electrode 126 is then installed on the recovery -container 122, and that assembly is placed, inverted, on top of the cover 120: with the pump outlet 130 reaching just into the recovery container and the electrode reaching just into holding container 112. Pump 128 is then turned on and electrode 126 and film 122b ar-e connected to the power supply 20, and the metal recovery reaction begins. During the reaction, silver from the solution 14 is deposited on the silver film 12b until a suitable amount of the silver is deposited thereon. As with the embodiments shown above, a- the silver builds up on the film 12b, the cathode in effect increases in thickness, so again the original thickness of film 12b is not critical.

When a sufficient amount of silver has plated onto the cathode 12b, pump 128 may be turned off and power supply 20 disconnected, The solution remaining in recovery container 122 will drain back into holding container 112 via drain opening 134, The recovery container 122 is then removed from the holding container 112 and placed wholly in a smelter, where the silver is separated from the material of the container by conventional means, While the apparatus hereinbefore set forth is effectively adapted to fulfill the aforesaid objects, it is to be understood that the invention is not intended to be limited to the specific preferred embodiment of disposable cell for recovering conductive metal and method of using set forth above, Rather, it is to be taken as including all reasonable equivalents within the scope' of the following claims,

Claims (14)

1. 3. An apparatus as recited in claims 1 or 2 wherein said 1 second electrode includes said metal to be recovered,
2. 4. An apparatus as recited in claims 2 or 3 wherein said pump is positioned within said first container, and has an outlet in said second container, for pumping said liquid from said first container into said second container, said liquid returning to said first container via said tube of said first electrode. 0 0 0 *00 0 0* ~0 *0 0 0 0 0 *0 *0 0 0 000**0 00 0* 0 0.0. 0 0 0 0 00*00* I 4 1l7 An apparatus as recitedi in any one of claims 1 to 4 wherein said pump has a predetermined flow rate, and further comprising a drain for allowing said liquid to drain bc~ck into said first container from said second container wh(-,n said pump is not running, said drain having a flow rate less than that of said pump.
3. 6. An apparatus as recited in any one of the preceding claims wherein said second container is substantially smaller '&'aan said first container.
4. 7. An apparatus as recited in any one of the preceding claims wherein said pump outlet is positioned to cause agitation of said liquid within said cavity. 0, An apparatus as recited in any onae of the precs-ding claims wherein said pump is an existing pump of a f iliq processing machine, and wherein said first container is a solution tank of a film processing machine.
5. 9. A disposable cell for recovering a conductive metal from a solution containing said conductive metal, and adapted for connecting to a container containing said solution and a solution pump with an inlet positioned within said container, said cell comprising: a disposable insulative Jar, constructed of a material which can be removed from said conductive metal by smelting, having a thin film of conductive material applied to the interior thereof, an outlet of said pump being positioned within said Jar; an electrode removably affixed partially within said Jar, formed of electrically conductive material; a power supply having two poles, a positive pole and a negative pole, said positive pole being electrically connected to said electrode and said negative pole being electrically connected to said thin film, such that said metal is deposited on said thin film as it is recovrered and, after recovery is substantially complete, said power supply and said I I *9944 9 9 4 9 .4 4 4 9.9* 4 .9 1 LJ~: I 9 9 II i 4. 9* 9.9.9 S 18 electrode can be removed and the balance of the cell can be placed in a smelting furnace in its entirety, without further disassembly and without prior removal of said recovered metal from said jar. A cell as recited in claim 9 wherein said pump is an existing pump of a film processing machine, and wherein said first container is a solution tank of a film processing machine.
6. 11. A cell as recited in claim 9 or 10 wherein said jar is mounted on top of said container, and wherein said pump has a predetermined flow rate, and further comprising a drain for allowing said liquid to drain back into said container from seid jar, said drain having a flow rate less than that of said PUMP.
7. 12. An apparatus as recited in any one of claims 9 to 11 wherein said Jar is substantially smaller than said container. 1.3. An apparatus as recited in any one of claims 9 to 12 wherein said pump ol~tlet is positioned to cause agttation of said liquid within said Jar,
8. 14. A method for recovering a conductive metal from a solution containing said metal, comprising the steps of: providing a first container for containing said solution; applying a thin film of said metal to the inside surface of a second container,* removably affixing an electrode partially within said second container; placing said second coaitainer in liquid communication with said first container; ci: ,:ulating said liquid from said first container into said second container and back; generating a potential difference between said electrode and said thin film, thereby causing said metal, in said solution to be dE thereon. A method as container is a solutior 1,6. A method as electrode is tubular differenit from the mete
9. 17. A met,od as first electrode is tubt I :said second container, :such that said first el both containers; and, 19 posited on said film and to build up recited in claima 14 wherein said first i tank of a film processing machine. recited in claim 14 or 15 wherein said ind constructed of a conductive metal U. to be recovered from said solution. recited in claim 14 or 15 wherein said ilar and further comprising positioning :)pening down, above said first container .ectrode is in fluid communication with aid solution to return to said first r s t electrode after the level of the container has reached a predetermined a 1 I U permitting s container via said fi: lj,quid in said second level. 18, A method as recited in any one of claims 14 to 17 wherein said circulating is done at a circulating flow rate, and further comprising the step of preventing the collected metal from being re-dissolved into the solutiop, by allowing said solution to constantly drain from said second, container into said first container at a rate substantially lower than said circulating flow rate.
10. 19. A method as recited in any one of claims 14 to 18 further comprising the step of agitating the solution in said second container.
11. 20. A method as recited in cl~aim 19 wherein said agitation step is accomplished by directing said circulating within said second container so as to cause agitation Within said second container. 21, A method as recited in any one of claims 14 to I 20 further comprising the steps of: disconnecting said second container from said first container; removing said electrode from said second container, and, placing said second container, including said deposited metal, in a smelting furnace and smelting said metal,
12. 22. An apparatus for recovering a conductive metal frnm a liquid containing said metal in solution substantially as herein described with reference to and as illustrated in Figure 3 of the accompanying drawings.
13. 23. A disposable cell for recovering a conductive met al from a solution containing said conductive metal, substantially as herein described with reference to and as illustrated in Figure 3 of the accompanying drawings,
14. 24. A method of recovering a conductive metal from a solution containing said conductive metal, substantially as j herein described with reference to and as illustrated in Figure 3 of the accompanying drawings. 9* Dated this 13th day of December, 1991. GUNTER WOOG By its Patent Attorneys: \GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. Iv