US 2291209 A
Description (OCR text may contain errors)
Patented July 28, 1942 ELECTROLYTIC UNIT John M. Burkemer and James E. Mason, Tucson, Ariz.
Application June 29, 1933, Serial No. 281,897
3 Claims. (01. 204-248) Our invention relates in general to electrolytic units for recovering precious metals, such as gold and silver from photographic or other baths. These electrolytic units are electro-couples consisting of layers of different metals, generally copper and zinc, separated by interjacent layers of porous materials, as described in Patent No. 1,425,935, dated August 15, 1922. However, electrolytic units built in accordance with this patent are slow in action and of low efficiency, due to the fact that the metal layers of these units consist of straight, practically equally sized metal strips, arranged in slightly spaced relation parallel and opposite to each other so as to prohibit proper exposure of the metals to the solution, and a proper ratio of exposed surfaces of the metal layers to said solution.
The general object of the present invention is the provision of an improved electrolytic unit of the type referred to above, which acts speedily and is highly eflicient by specific construction, size and arrangement of its metal layers.
Another object of the invention is the provision of an electrolytic unit of the type referred to above which includes relatively wide, oppositely arranged zinc plates and a rather narrow strip of copper arranged therebetween opposite the central portion of the zinc plates, the copper strip providing a surface substantially smaller than the surface of each zinc plate so as to effect an eflicient ratio of exposed surfaces of the metal layers of the unit.
A further object of the invention is the provision of an improved electrolytic unit of the type referred to with differently sized, alternately arranged layers of zinc and copper which layers are separated from each other by layers of absorbent material, and in which the zinc layers, forming the outer members of the electro-couple, include areas extended beyond the copper layers for better contact of these zinc layers with the solution from which the precious metals are to be reclaimed.
Still another object of the invention is the provision of an electrolytic unit of the type referred to above with zinc layers approximately three times the size of the copper layer, the zinc layers being formed with straight central areas opposite the copper layer and symmetrically arranged wing portions adjacent and angularly related to said central areas, to effect intimate contact of these wing portions with the solution from which precious metals are to be reclaimed.
In addition the invention has certain other it from presently known structures. These improvements embodying certain novel features of construction are more clearly set forth in the following specification and the appended claims; and a preferred embodiment of the invention-is hereinafter shown with reference to the accompanying drawing formingpart of the specification.
In the drawing:
Fig. 1 is a perspective view of an electrolytic unit embodying the invention, with some of the elements forming the 'unit shown broken away to more clearly disclose the construction of the unit.
Figures 2 through 6 show perspective views of the metal elements of the unit; thus:
Fig. 2 is a perspective view of the shim brass covering for one of the zinc plates;
Fig. 3 is a perspective view of the zinc plate covered by the covering shown in Fig. 1.
Fig. 4 is a perspective view of the copper strip;
Fig, 5 is a perspective view of the other one of the zinc plates, and
Fig. 6 a perspective view of the shim brass covering for the last referred to zinc plate.
The electrolytic unit shown in Fig. 1 of the drawing embodies an electro-couple of two zinc plates 3 and 4 and a copper plate 5 arranged between plates 3 and 4 opposite and parallel to the central portions thereof. Each of the zinc plates 3 and 4 has approximately three times the surface of straight copper plate 5 and is subdivided into three substantially equally sized portions, a straight central portion 6 and two wing-like portions 1, 1, arranged adjacent to central portion 6 and angularly offset with respect thereto for a purpose later to be described.
The zinc and copper plates 3, 4 and 5 are separated from each other by absorbent material such as cotton gauze 8 which is preferably folded around zinc plates 3 and 4 in such a fashion as to form a pocket 9 between central portion 6 of plates 3 and 4 into which pocket copper plate or strip 5 is kept. As shown, zinc plates 3 and 4 are covered and partly encircled by shim brass sheets l0, which sheets are folded around plates 3 and 4 so as to openly expose their inner central surfaces. Shim brass sheets I!) are also covered with cotton gauze and form neutral depositary elements for precious metals to be recovered from a solution, and the gauze permits of any deposited material being readily stripped or released from these sheets.
The thus formed electro-couple is securely tied together by means of a brass band I2 fully' enmarked super'iorities which radically distinguish circling same, which band has its overlapping endsllandllncuredtogetherbyascrew member ll,extendedthroughallmetallayersto.
electrolytic unit is placed into a photographic nxing solution containing silver in solution the silver will readily be recovered by electro-chemical action oi the electro-couple and be deposited on the gauze covered shim brass sheets ll, partly encircling the zinc platu I and I. This recovery action oi the unit is rather speedy due to the iull exposure oi wing portions I, I oi zinc plates I and 4 to the solution, and such exposure is possible and iacilitated by the angular oiisetting oi wing p rtions I, 'I' with respect to central portions s oi the zinc plates.
An electrolytic unit oi this type will recover silver oi pure bullion standard, particularly, when chemically pure zinc and copper elements are used, and use oi chemically pure elements eiiects rejuvenation oi the ilxing solution oi a bath in a high degree.
Having thus described our invention:
What we claim is: r
1. An electrolytic unit for reclaiming precious metals irom baths containing such metals in solution comprising a strip copper, a pair oi zinc plates each having a suriace area at least twice the suriace oi said strip oi copper, said zinc plates being arranged at opposite sides oi said copper strip parallel thereto and iormed with wing portions angularly and outwardly oi!- set with respect to their central portions, layers oi non-conducting porous material spacing said copper strip irom the central portions oi said sine plates, and cotton gauze covered sheets oi shim brasscovering the outer suriace oi each oisaidsinc platesandioldedaround theireely exposedinnersuriaceareasoisaidsincplates.
3. In an electrolytic unit embodying layers oi diiierent metals separated irom each other by layers oi non-conducting porous material a strip oicopper,andapairoizinc plates, eachoisaid plates having approximately three times the surlution comprising a copper strip, a pair oi zinc plates at opposite side oi said copper strip, and a plurality oi interjacent layers oi nonconducting porous material, the zinc plates each having asm'iaceareaatleasttwicethesuriace areaoi the copper strip and being iormed with wing portions angularly and outwardly oiiset with respect to the central portions oi said zinc plates toiormopenchannelsatoppositeedgesoisaid unit and facilitate intimate contact oi said copper strip and zinc plates with a solution into which said unit has been placed.
JOHN M. 13. JAMES E. MASON.