US1470883A - Cathode for the electrolytic refining of metals - Google Patents

Description

C. H. SCHUH CATHODE FOR THE ELECTROLYTIC REFINING OP METALS Filed Nov. 22. 1922 Metallic Depositing Maierzlal 3 0 2 0 0 O O O O O Insulating Frame 2 E H mmllu rl mli I H in Z 3 I l V Z,

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CATODE FOR THE ELECTROLYTIC REFINING- 0F METALS.

Application filed November 22, 1922; Serial No. 602,552.

and the best manner in which I have contem lated its application.

y invention relates to an improvement in the electrolytic refining of metals, partic'ularly of the metal, copper.

In a co-pending application, Serial No. 589,945, filed Sept. 22, 1922, there is described a device for obtaining an evenly deposited cathode starting sheet of uniform thickness throughout, which may be easily removed from the cathode blank without being torn or injured in any way. These advantageous results are secured by enclosing two metallic sheets within a non-conducting frame, so that one side of the metallic sheets onl is exposed to the action of the electnol yte with subse uent deposition of a film of refined metal t ereon, by protecting all decreased thicknesses of metal so that even thickness is obtained throughout the deposit and by using preferably what is known as a film-formin metal, so termed in the application, so t at the cathode starting sheet is easily stripped ofi the cathode blank.

The present invention secures all these and the other advantages, described in detail in the above-mentioned co-pending application, combined with certain other important additional features, which are herein described. 7 My invention consists essentially of enclosing a single-sheet metallic cathode, to be electro-deposited with metal on both sides, whose eripheral edges have been specially formed so as to afford good fastening and holding properties, with a non-conducting non-metallic frame, fitting tightly around the metallic cathode and being made flush with the surface of the same. To make the joint between the metallic cathode and the non-conducting, non-metallic frame as tight as possible, a little asphaltic or other suitable acid-proof, non-conducting paint is first smeared over the edges of the metallic cathode priorto the fastening thereto of the frame, and then these two parts, namely,

the metallic cathode and the frame, are either riveted together or fastened together with screws. It is also possible to mold the non-metallic frame around the metallic edges by inserting the cathode in a mold and processing in the regular manner.

In order to facilitate the fastening together of the conducting and non-conductlng parts of the cathode, the peripheral edges of the metallic cathode and depressions of corresponding form, out into the peripheral edges of the frame, are shaped in various suitable forms, preferably in the form of a mortice and tenon joint. The shape of these peripheral edges and. depressions is immaterial to the purpose of this invention, their sole purpose being to afford suitable connecting and fastening edges between the two parts of the cathode. In the drawing accompanying this application, the preferred shape of the edges is shown.

Similarly it is unimportant for the purpose of this invention just how the metallic cathode and the non-conducting, non-metallic frame are fastened together. The high melting point acid-proof, asphaltic paint, used as described above, may in certain cases provide enough cementing action to make the joint tight enough for all practical purposes, but it is generally preferred to make certain of the tightness of the jointure between the metallic cathode and the non-conducting, non-metallic frame by the use of screws and rivets. The screws may be made of the same material as the frame,

and similarly the rivets, but if the latter are made of copper, then itis well to use a little non-conducting, acid-proof paint to smear over the exposed surface of the same. It is also possible to mold the plastic materials, that are'used in making the non-conducting .frame, around the edges of the metallic cathode, and vulcanize or process in other suitable ways the molded frame to produce a hard, solid structure. In this case the holes drilled into the metallic edges of the cathode are filled with the plastic material and both cathode proper and frame are formed into one single, solid piece. a

The non-conducting frame maybe and is preferably made from hard rubber. The screws and rivets that fasten it to the cathode proper may be and are preferably made from the'same material. It is possible to use all sorts of plastic materials and compositions, such as phenol condensation products, artificial resins of all sorts, artificial rubber compositions, Galalith (a formaldehyde treated casein compound), casein compositions of various sorts, etc. for this purpose.

Particular attention is called to the fact that this form of frame may and can be used with cathodes, made of any metal, metallic composition or alloy. The composition of the metallic art of the cathode is not pertinent, as the frame may be fitted around any shape, form, size or composition of metallic cathode. In all cases the frame is finished ofi' flush with the surface of the metallic cathode, which. feature con stitutes an important characteristic of this invention. Furthermore, it is important to note that the frame protects all decreased thicknesses of metal, so that even and uniform deposits of metal are secured, which are free from all knobular protuberances. Similarly the effective area of the cathode is made at least as large as that of the anode, so as to avoid the formation of irregular dc osits.

he metallic part of the cathode is made preferably from aluminum, aluminum alloy or brass, which avoids the necessity of using graphite and oil compositions to secure an easily and perfectly stripped cathode starting "sheet. However, the cathode may be made from copper or any other suitable metal, in which case it ma become necessary to use grease, oil an igraphiteconipositions to render it possib e to strip ofi the starting sheet without tearing or otherwise ihjurin the same.

It is possi le to make the cathode from such a heavy metal as lead, preferably alloyed with antimony to the extent of 5 to 10 percent, to make it more resistant to the action of acids, by coating the main body of the cathode, which may be made of aluminum or copper or other suitable metal with an electrolytically de osited coatin of lead. This coating may a so be secure by mechanical means, casting the alloyed lead on the surface of the aluminum. In this way' there is avoided the important disadvantage of the great weight of the lead and there is gained the advanta' e of the greater resistivity of the lead to axe action gf Ithe sulphuric acid in the electrolytic The drawin illustrates by example one wa of carrying out this invention, as fol ows:

Figure 1, is a cathode blank in elevation.

Figure 2, is a plan view of such blank.

Figure 3, is a section on the line 3-3 of Figure 1, showing screw method of fastening the non-conducting frame to the metallic blank.

Figure 4, is a similar section of a modification, showing rivet'method of fastening.

narosee Figure 5, is a similar section, showing molded frame secured thereon.

Figure 6, is a section on the line 6-6 of v F i ure 5.

i ure 7, is a partial plan view of the edge of the metallic cathode, showing cut-out tenon portion.

Figure 8, is a section of the cathode in Figure 1 on the line 33, showing metallic cathode with surface coating.

In Figure 1 the mainbody of the cathode, of metallic composition, is shown at 1, the edge at 2 and the fastening device at 3. It will be seen that the fasteners are distributed evenly around the edge, so that the frame is fastened firmly at every point. The jointure between the strips of the frame may be made as indicated in the figure, or else the simple form of mortise and tenon joint may be used. The holes, bored in the cutout strips at the top of the cathode, are for the purpose of fastenin the cathodeto the cross-bar on the electro ytic cell.

Figure 2 is a plan view of the cathode blank, and being self-explanatory needs no further description here.

Fi ire 3 shows the screw method fastening t e frame to the metallic cathode. The screw is indicated at 3. 1' indicates the tenon edge of the metallic cathode. Figure 4: shows the rivet method of fastening the frame to the metallic cathode. In this case, when the rivet is made of copper, it will be well to cover the exposed head of the same with a film of acid-proof paint, a non-con; ductor of the electric current, as shown at 4 in the figure. Figure 5 indicates the molding method of attaching the frame to the edge of the cathode. This is done by wellknown methods of attaching plastic compositions to metallic parts. The plate 1 is inserted -into..- a' mold permitting material of the shape of the frame 2 to be poured or cast about-the tongue or tenon edge. The plastic composition is allowed to harden or set in such mold. The holes, bored in the tenon ed e of the cathode plate, are completely filed with the molded lastic composition, so as to give a firm joint between the frame and the cathode proper.

3" shows the filled-in hole.

Figure 6 is a section on Figure 5. Th filled-in holes are seen at 3". 1 indicates the tenon edge of the cathode plate and 2 the frame, fitting around it.

Fi re 7 is a plan view of the tenon ed of t e cathode plate. This edge may e cut out of the formed cathode plate or else the plate may be cast or molded in this form Figure 8 shows the cathode plate made up of an aluminum body, 1 and a lead or lead-antimony coating 5. 2 is the frame and 3 the screw fastener, made of the same material as the frame.

The term film-forming metal is used vgrease, oil or gra .mean to include as equivalent the cathodes havingthin non-conducting or non-adherent coatings, such as formed by coating with bite or combinations thereof, to aid in t ormation of an easily stripable deposit. Havin thus described my invention in full detall I claim as follows: 1. A cathode comprising a plate having achamferededge and a frame-work carried by said plate, said frame-work being fastened to said cathode by fasteners, spaced at proper intervals.

2. A cathode comprising a plate having a chamfered edge and a frame-work carried by said plate, said frame-Work being fastened to said cathode by fasteners, spaced at proper intervals and cut off flush with the surface of the said cathode.

3. A cathode comprising a plate having a chamfered edge and a frame-work carried by said plate, said chamfered edge being 6. A single sheet cathode plate having a chamfered peripheral edge forming a tenon portion, a non-conducting frame about said plate, morticed to fit said tenoned portion and fitting flush with the depositing surfaces.

7. A single sheet cathodeplate, as in claim 6, in which the tenoned port10n is fitted with fastening engaging means, means on said plate coacting with said first-named means securely attaching the frame to said plate.

8. A sin le sheet cathode plate as'in claim 6, in Whic said tenoned part is provided with screw engaging means, screws passing through said frame and said screw engaging means.

9. A cathode plate as in claim 6 in which the metal body thereof is formed of a filmforming metal.

10. A cathode plate as in claim 6 in which the metal bod 1s formed of an aluminum containing bo y.

11. A cathode plate as in claim 6 in which the metal body is formed of an aluminum core and an acid resisting coating met-a1.

12. A cathode plate as in claim 6 in which the metal body is formed of an aluminum core and an acid resisting coating metal comprising lead.

13. A cathode plate as in claim 6 in which the metal body is formed of an aluminum core and an acid resisting coating metal consisting'of a lead-antimony alloy.

14. A cathode plate as in claim 6 in which the non-conducting frame is rubber.

15. A cathode frame as in claim 6 in which the non-conducting frame is molded hard rubber.

CHARLES H. SCHUH.

Witnesses:

WIILIAM A. Scrum, MADELINE L. Hmscn.

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