US1005718A - Arrangement of electrodes for the electrolytic refining of metals. - Google Patents

Description

' F. M. K'OHLER. ARRANGEMENT 0F ELECTRODES FOR THE ELECTROLYTIC BEFINING 0F METALS. APPLIOATION FILED DEC. 28, 1909.

1 ,005 ,7 1 8. Patented Oct. 10, 1911.

2 SHEETS-SHEET 1' FIE-4- 7 F :I m A mmesses p L Inventor COLUMBIA PLANOGRAPH CO.,WAS"INGTDN D c I. M. K'OHLER.

ARRANGEMENT 01 ELECTRODES FOR THE ELECTROLYTIC REFINING OI METALS.

APPLICATION FILED DEC. 28, 1909.

1,005,? 1 8. Patented 001. 10, 1911.

I 2 SHEETS-SHEET Z.

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WM MAZM l'vornqys LOLUMHIA PLANOGRM'H C0.,WASIIINGTON, 1). c4

FRIEDRICH MAX KfiHIaER, OF ST. PETERSBURG, RUSSIA.

ARRANGEMENT 0F ELECTRODES FOR THE ELECTROLYTIC REFININGOF METALS.

Specification of Letters Patent.

Patented Oct. 10, 1911.

Application filed December 28, 1909. Serial No. 535,327.

To all whom it may concern:

Be it known that I, FRIEDRICH MAX Kort- LER, a subject of the Emperor of Germany, residing at St. Petersburg, in the Empire of Russia, have invented certain new and use ful Improvements in the Arrangement of Electrodes for the Electrolytic Refining of Metals; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention consists in an arrangement and apparatus for the electrolytic refining of metals which derives its material technical advantages from the fact that an electrolytic cell is formed of two oppositely arranged plates, consisting of the metal to be refined, so that the containers, tanks or the like now required can be dispensed with. The electrolytic process is utilized free from any secondary chemical reactions or influences occasioned by secondary lateral electric currents or short circuits during the passage of the electrolyte through the cell and to and from the auxiliary containers, the process acting thereby on each pair of electrodes independently of the others. Further, the electrolyte being in this arrangement excluded from contact with the air, it is rendered practically possible to employ electrolytic solutions which give twice the quantity of metal deposit owing to the fact that the salts of oxids of a lower stage are dissolved in such electrolytes and kept in solution during the whole process. A particular advantage of the invention consists further in making visible the field of work of the cell, since this arrangement facilitates the controlling of the process, the formation of the degrees of oxidation being discernible by the alteration of the color of the electrolyte. In all processes which have hitherto been employed for such electrolytic refining, separation or plating the electrolyzing operations are carried out in open vessels, baths or the like filled with the electrolytic solutions; and current conducting bars are usually arranged above the vessels and 011 them are hung the several electrode plates, anodes and cathodes, immersed in the electrolyte solution. It has been found that this method of arranging the electrodes can only be employed with those electrolytes with which access of the air and the possibility of oxidation are allowable without of the fittings above the baths produces current deviations and short-circuits, which limit the quantity of metal deposit. The means hitherto proposed for keeping the electrolyte solution in circulation do not preclude the defects above mentioned, because these means do not remove the deposits or sludge from the field of work of the electrolytic process. Furthermore, there has hitherto not been found a practical method for excluding the air from contact with the electrolyte by means such as n1echanical closure and other devices arranged on the vessels or by the employment of an air excluding substance, such as oil or grease. Likewise all attempts to make the process visible in order that it may be controllable have hitherto not given results fit for use in practical working for baths of larger sizes. On the other hand practical chemists have for a long time recommended electrolytic processes which are in many respects superior to the methods followed hitherto, provided that the electrolyte, remaining insulated from contact with the air, is kept in active motion and works in an always clear field exempted from the influence of secondary processes.

According to the present invention an entirely new arrangement of electrodes is employed composed substantially of the electrolytic cell, the electrolyte containers and the current conductors.

In the accompanying drawings Figure 1 shows front and side views of one anode plate A and Fig. 2 similar views of the other anode plate A both of said plates constituting the metal itself, which is to be refined. Fig. 3 shows front and side views of the cathode plate K. Fig. 4 shows one of the two intermediary frames R and Fig. 5 the second intermediary frame R F i 6 shows a part of the assembled cell with the front half of same taken off, thus displaying the cathode K and the frame R Fig. 7 is a cross section and Fig. 8 an external general view of the assembled cell respectively. Figs. 9, 10 and 11 show a modification in the construction of the cell.

; valve 1".

In this modification Fig. 9 shows the frame It. Fig. 10 a part of the cell corresponding to Fig. 6; and Fig. 11 shows a cross section of the cell corresponding to Fig. 7

Lastly, Fig. 12 is aview of the general disposition of the cells and of the means for connecting same with the electrical circuit. In this figure cells I and II are constructed according to Figs. 6 and 7 and cells III and IV, according to Figs. 10 and 11.

The electrolytic cell is composed, as will be seen on reference to the accompanying drawings, of the two anode plates A and A (Figs. 1 and 2), the cathode plate K (Fig. 3) and the intermediary frames R and R (Figs. 4.: and 5). These frames are made of a material which resists the chemical action of the electrolyte and is nonconducting electrically.

The sides of the frames may be wholly or partly of transparent material, for in stance, glass. Into the sides of the frames which adjoin the metal anode plates is inserted an elastic collar of rubber to make a tight closure. Through the top side of the frame B (Fig. i) passes the connecting tube r provided with the air exhausting There is also let into the side of the bottom of the frame a metal block m which, with the corresponding metal block of in the frame R forms the clamping contact for the cathode plate K (Fig. 7) and supplies it with current from the main bar.

Through the bottom of the frame 1 (Fig. 5) passes the connecting tube 1 and it is into this side of the frame that the metal block m is let. By using two cathodes, however, and one anode plate, or by combining several cells in one it is possible to alter the form of the cell. Similarly the contact blocks m and m can be let into the top sides of the frames R and R so that one pole joins the contact below in the cell and the other above. (Figs. 9, 10 and 11; also III and IV on Fig. 12). The tubes r and rare provided with valves h and 77/2 respectively.

In mounting the cell according to Figs. 6, 7, 8, or I and II in Fig. 12 the parts are put together in the following order: A B K, B A and they are then all clamped together by the clamping device M (Fig. 8).

The means for taking in the electrolyte solution consists of the container with connecting pipes, taps and a coil shaped heater Z. This container serves to hold the freshly prepared, or renovated electrolyte, or the solution coming from the container which is likewise furnished with connecting. pipes and taps, and also with sludge collector H and filtering chamber F, and finally with pumps P and P and the necessary connection pipes.

The means for furnishing the current consist of a stable rigid platform in which channels are recessed to take metal bars; these are not connected with the platform or with the earth, but are insulated on glass supports.

The apparatus operates as follows :-The electrolyte solution is admitted from collecting reservoirs to the container and ifnecessary heated. The valve k above the frame is then opened and the valve 7L2 below the frame closed. The electrolyte is thus admitted into the cell forcing the air contained therein through the valve 7 and the latter is closed as soon as the cell is full. The valve 72, below the frame is then opened again and the electrolyte flows into the container 7 It is drawn off by the bump P and led back tothe container W after first passing through the sludge collector and filtering chamber formed in divisions of the container II, and collecting in sufficient quantities in the filtering chamber of the container In this manner a continuous circulation of the electrolyte is effected and the latter is set in motion so that the dissociation of the anode ions is assisted. As the sludge or deposit which is separated out from the anodes, is carried away with the solution, the anodes are kept clean and the formation of sediments, which so injuriously affect electric current with a large working field, is prevented. As at the same time oxidation of the electrolyte by the air is prevented, salt-s of oXids of the electrolyte of a lower stage are formed at corresponding current densities and compounds are produced by which quantitatively larger amounts of metal particles are freed from the anodes than it would be at the same expenditure of current with an electrolyte from which air is not excluded and which is not circulated in the manner described.

With this system it is actually rendered practically possible to employ oxids of proto salts, these proto salts, that are themselves insoluble, forming chemical compounds by means of which, owing to the prevention of oxidation by admission of air, they are kept in solution. Such proto salts are known to give twice the quantity of metal deposit, given by the compounds in per salt solutions for the same consumption of current. This arrangement also offers advantages in connection with the erection of metal refining plants in which neutral or alkali electrolytes are employed, capable only of dissociating a particular metal. Foreign bodies and other metals which may be contained in the anode plates, are not dissolved in a solution having such limited properties, nor are they transferred to the cathode, but are deposited as sludge. As it is rendered impossible that gathering of such sludge should take place at the bottom of the cells, the field of work of the electrolytic process itself remains always clean and the electrolyte is not affected by any secondary influences; also deviations and short-circuits occasioned by the contamination of the fittings are prevented, as these fittings are disposed outside the field of work. According to the present invention the entire removal of the sludge from the field of work is an extremely simple matter and can be effected at any time without interrupting the working of the plant. The sludge collecter H in the container W can be quickly removed and the filter when choked can as quickly be replaced with new ones. Moreover, testings of the electrolyte can be taken at any time for the purpose of analysis from various points of the field of work, and fresh or renovated solution may be added during the working of the plant.

The arrangement for carrying the circuit conductors is extremely simple in construction, and all kinds of connection contacts are avoided. The thick anode plates rest with the whole of their lower surfaces upon the conducting bars m as also do the cathode plates K by means of the clamping blocks m and m when these are arranged at the bottom of the frames. For refining very impure metals the cathode contacts should be attached to the upper sides of the frames (Figs. 10 and ll-III and IV in Fig. 12). This obviates any possibility of short-circuits being formed at the bottom of the cell even with deposits from the anode very rich in metal, for with this new arrangement the cathode hangs free in the cell and the poles, where the current enters and leaves are separated from one another. In any case a good contact is insured here for transmitting the current, as the current lies beyond the reach of the oxidizing electrolyte solution, which cannot be done with open tanks, that being one great objection to the latter type of apparatus.

Each cell is a unit complete in itself, and works independently of every other cell; it can be removed from the line of cells at any time in a few minutes; the cells are moreover coupled up in series one behind the other, whereby the utmost use is made of the current.

I claim 1. An electrolytic cell for refining metal comprising anodes consisting of the metal to be refined and separated by a frame, the anodes and frame forming a container for an electrolyte, and a cathode arranged in the container, substantially as described.

2. An electrolytic cell for refining metal comprising anode plates consisting of the metal to be refined, a frame arranged between the anode plates forming with the anodes a container for an electrolyte, the frame having a transparent side, acathode arranged in the container, and means for supplying the electrolyte to the container, substantially as described.

3. An electrolytic cell for refining metal comprising anode plates consisting of the metal to be refined, a frame arranged between the anode plates forming with the anodes a container for an electrolyte, means for binding the anode plates to the frame, a cathode arranged in the container, and

'said container provided with pipes for the supply and discharge of the electrolyte, substantially as described.

4. The combination of a number of electrolytic cells arranged in series for refining metal, each cell comprising anode plates consisting of the metal to be refined and separated by a frame forming with the anodes a container for an electrolyte, the frame having a transparent side, means for binding the anode plates to the frame, a cathode arranged in each container, each container provided with pipes for the supply and discharge of the electrolyte, the pipes being provided with means for excluding air from said container, and means for connecting the anode plates of one container to the cathode plates of the adjacent container, substantially as described.

In testimony whereof, I aflix my signature, in presence of two witnesses.

FRIEDRICH MAX KoHLEn.

Witnesses H. A. LOVIAGEIW, A. MIGHIS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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