US2119936A - Method of recovering pure copper from scrap and residues - Google Patents

Description

C. B. WHITE June 7, 1938. 2,119,936

METHOD oF REGOVERING PURE COPPER FROM ,SCRAPl A ND RESIDUES Filed oct; 2, 193s fhlt-1r 11.14F. L

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Patented June 7, 1938 UNITED STATES PATENT OFFICE BETHOD 0F RECOVERING PURE COPPER FROM SCRAP AND RESIDUES 1 Claim.

This invention relates to the recovery of electrolytically pure copper from scrap material, metallurgical by-products and residues containing metals in the form of alloys.

The primary object of the present invention is to eliminate the partial furnace refining which is employed at the present time in all metal recovery methods thereby simplifying the recovery of the copper content of commercial scrap alloy materials and greatly reducing the expense.

The-scrap materials and residues are rst reduced in a blast or smelting furnace to separate the metals from the non-metallic contents. The molten metal is then cast directly into the form of anode plates vsuitable for deposition in the electrolytic tanks. These cast anode plates may contain besides copper, various other metals, such as tin, lead, zinc, iron, antimony, nickel, bismuth, cadmium, gold, silver, platinum, etc.

The cast anodes are placed in the electrolytic tank in alternate arrangement with lead plates or other suitable nonsoluble cathodes, the anodes and cathodes being connected to a suitable source of current. When the copper of the anodes has been deposited upon the lead cathodes, they are replaced by thin sheets of electrolytic copper and the current is then reversed to thereby transfer the copper previously plated upon the lead sheets to said thin copper sheets. 'I'he resulting copper plate will be perfectly pure electrolytic copper, running over 99.97% pure.

My process of producing pure copper plates.

from commercial scrap material, metallurgical bi-products and residues will be more clearly understood from the following description in connection with the accompanying drawing, in Which- Figures 1, 3, 4 and 5 are diagrammatic views illustrating the manner of obtaining electrolytically pure copper from cast metal plates obtained from the smelting of the scrap metal; and Fig. 2 is a cross-sectional view on the line 2 2 of Fig. 1 showing the manner of suspending the plates in the tank.

In the first stage of my process the cast anodes A from the smelting furnace are suspended in the copper sulphate electrolyte in alternation with lead plates L, as shown in Fig. 1, the cast anodes being connected to the positive pole and the lead plates to the negative pole of the electrical source. The copper content of the anodes is deposited upon the lead plates, as outlined in broken lines, the anodes Wasting away to a thin Some of the metals, such as zinc and iron, pass into solution while others form suldeposited upon the lead plates and the cast 10 anodes have been reduced to a mere shell, the electrolyte is removed and the sludge is washed. from the bottom of the tank. 'I'he lugs of the anodes with their attached cores may be returned to the scrap to be remelted. The metals 15 in solution and in the sludgel or slimesmay be' p recovered and the electrolyte understood by metallurgists.

In the next stage of my process thin electropuried asis wellv lytic copper sheets C2 are substituted for the 20 cast anodes of the i'lrst stage and the tank is filled with fresh copper sulphateelectrolyte vas indicated in Fig. 3. 'I'he switch S is then reversed to cause the copper Cl which was plated upon the lead plates during the ilrst stage, to 25 now be transferred to the copper starting sheets C2. When substantially all of the copper has been removed from the lead plates and deposited upon the copper sheets C2 as indicated in broken lines in Fig. 3, the resulting plates Cu, thus- 30 formed are practically pure copper, running over 99.97% and having an electrical conductivity ln excess of that required by commercial standards. y 'I'he thin copper sheet electrodes C2 for starting the second stage or step in my process, may '35 be obtained by suspending a number of the cast anodes A, A1 in the electrolytic tank and connecting them alternately to the opposite poles of the battery or electrical source, as indicated in Fig. 4, or preferably alternating the anodes and lead plates as indicated in Fig. 5. When a thin copper sheet has been plated, the cathodes are removed and the plated sheets are vstripped off to be used as the starting cathodes in the second stage.

45 Instead of connecting the alternate plates forming the anodes and cathodes in multiple to the current source, it Will be evident that they may be connected in a series circuit.

The advantages of my method of producing 50 plates of pure copper direct from smelted scrap metal will be appreciated from the above description of my process. 'I'he plates cast from the molten scrap metal of the smelting furnace are introduced immediately into the electrolytic 55 cast 40 tank as anodes from whichv the pure copper is electrolytically extracted andplated upon lead or other insoluble electrodes and from the latter by reversing the current, said plated copper is deposited upon thin sheets of electrolytic copper. I have eliminated the steps of furnace refining' 15 anodes, arranging said anodes in alternate relation with insoluble cathodes in a. copper sulfate electrolyte, connecting the anodes and cathodes to the positive and negative poles respectively .of a source of electric current until substantially all the copper content of the anodes is deposited upon the cathodes the cast anodes being reduced to a thin strip or shell, removing the electrolyte and sludge, replacing the strip or shell with a sheet of electrolytic copper, adding fresh copper sulfate electrolyte and reversing the polarity of the current from said source to the electrodes to thereby transfer the copper deposited upon the cathodes to said sheets to form plates of pure electrolytic copper.

CLARENCE IB. WHI'I'E.

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