US1198024A - Electrolytic apparatus. - Google Patents

Description

W. E. GREENAWALT.

ELECTROLYTIC APPARATUS.

FILED DEC. 14,1911. RENEWED MAY H, 1916.

Patented Sept. 12, 1916.

M19 @1 19 22IHEH 1 APPLICATION I. A IIIIIj/II/I INVENTOR.

,impeded while the anode bell oscillates-and withdraw it. Faucet '10 serves to introduce the anolyte into theapparatus and the tubing 11 serves to withdraw it.. This tubing is made flexible and is immersed in the catholyte; it is fastened to the anode bell, passes through the catholyte and sides of the cathode tank, so that the anolyte flows out'unwithout mingling with the catholyte.

It may be found desirable to introduce a reducing agent into either the anolyte,

the catholyte, or both. In such a case the solution from the faucets 1 2 and 13, con- 1 and 17 into the bottom of the tower. In this ,ferred.

necting with the source of supply, is pref.- erably sprayed into the towers 14 and 15, while the reducing agent, as for example sulfur dioxid, is forced through the pipes 16 way the solution may be saturated with the reagentand flowed into the electrolyzer, or, the reagent may be introduced direct into the apparatus. The first method is pre- The anodes 4, are suspended from conducting bars 18, which in turn are suspended I by an adjustable device 19, whereby the anode may be raised or lowered at will, even when the apparatus is in operation. Similarly the anode bell may be raised orlowered by the adjusting device 20.

In Figs. 1 and '2 the anodes are shown stationary, and the anode bell, with the attached diaphragm, oscillated independently of the anode. This is the preferred arrange' ment.

In Figs. 4 and 3 the anodes are attached to the bell and are oscillated with it, but the results so obtained are inferior to the arof asbestos paper between two thicknesses of asbestos cloth, and the whole fastened between two mullioned frames. The frame is then fastened to the anode bell, preferably with copper screws. The mullions 2i, serve to support the diaphragm and act as an agi tator for 'both the anolyte and catholyte, and this is an important 'function, because it reduces the necessary voltage required in the operation, and increases both the anode and cathode efliciencies, and'assists in continuously removing the disintegrated anode material from the cell. These mullions, or cross strips, are not absolutely necessary though desirable. Good results have been obtained without them,- especially in the smaller sized apparatus. Instead of asbestos cloth, ducking may be used; while drogen,

in some respects ducking performs the function of a diaphragm better than asbestos cloth, it is not so durable.

Unless suitable provision is made, air, hy-

or other gases may become entrained under the diaphragm, and thus reduce the efficiency of the apparatus. This may happen with hydrogen released at the cathode When the deposition is not going on smoothly or when the catholyte becomes impoverished in copper. To overcome this difiiculty, means are'prov-ided for the escape of the gas as rapidly as formed. This is preferably done by saw cuts or auger holes, as shown at 25 Fig. 5, which prevents the trapping of the gases, and the motion of the anode bell facilities their expulsion. On the topof the diaphragm proper, is a cloth 21, Fig. 5, fastened to the anode bell to keep it in position, but easily removable. This cloth keeps the disintegrated anode material from getting on the diaphragm, and in case the material becomes lodged, or in case of a clean-11p, the cloth may be easily removed with the disintegrated anode material, thus facilitating the work and saving wear on the diaphragm. In the event of its not being necessary to make an absolute separation between the anolyte and catholyte, a single cloth of asbestos or cotton may be used to function both as diaphragm and means of catching the disintegrated anode material. In case a diaphragm is not necessary, a cloth is still interposed between the electrodes which permits of free diifusion of the electrolyte but sulficiently dense to intercept the disintegrated anode material from getting on the cathode untilit can be expelled with the electrolyzed solution. In such a case, the diaphragm and cloth for intercepting the d1sintegrated anode material are considered the same for the purpose. of this specification. In addition to the saw cuts in the diaphragm frame, the diaphragm may be given a slight tilt to throw the gases toward the outside and thus prevent their lodgment. This may be done by making the mullions slightly thicker at the middle than at the ends.

In the operation of the apparatus, the anolyte and catholyte are introducedinto the electrolyzer, the current turned on, and the anode bell oscillated by the mechanism 7. In the deposition of copper from sulfate solutions, lead anodes are preferably used. It is well known that these anodes disintegrate, the metallic lead being converted into the peroxid of lead by the liberated oxygen, but the disintegration is greatly reduced by oscillating the'anode bell, whereby the anode reactions are greatly facilitated. The resistance is also largely decreased, because the oscillation of the anode bell prevents undue impoverishment of both the anolyte and catholyte in immediate contact with the electrodes. It is well known that agitation of the electrolyte; increases the electrode efficiency." A higher current density can be used than would otherwise be possible, and the deposited copper is pure and reguline.

Under the'action of the current, copper is deposited at the cathode, sulfuric acid and ferric sulfate formed at the anode, and the anode le ad is oXidized to the peroXid of lead, F130,, and thus disintegrated. Under ordin'z'l ryconditions this' peroxid of lead acc'uni ites more [node in quite a considerable 1a @11 andthus'incr'eases the resistance of the' jcurreh finally dropping off in large sealesto the "bottoinfof'the tank, and thus causes shortcii'cuiting-of the current, it not remoted at frequent intervals. Under the action' o't'the oscill ting diaphragm 1aanode bellfthe' p lot-lead is removed from the anode ab nt a s frapidl'y as formedand if it were not thediaphragm or cloth between the rode sf, theperoxidwould settle onfthe'icathiode nd destroy the purity of the (1e15; si te 1; )ppe1; and cause other irregular'itie's'." The action of the oscillation is to anode i-leadi ouc remoye theperoaid,v from the lead about as rapidly as fbrnitlancl confiiie it to the anode;bell nn til it is removed in suspension'with the regenerated anolyte, passing througlrtheflexible tube ll. The oscillatin'g niovemenflke eps the disintegrated anode material stirred up and facilitates its 63- pulsi0n,'. ;Th,e operation is entirely automatic, bo th asm ne removal of the peroxid from theanode and; its expulsion from the cell, -..;A'.jerky inotionfacilitates the expulsion, but -this is a detail easily adjusted by Well known mechanical appliances. 7 p

The ,regeneratml electrolyte, containing the disintegrated anode material in suspension, flows tromgthe electrolyzer, through the flexible-tubing llhinto launder 22, and from thereinto a" settling tank (not shown), where:thedisintegrated anode material settlessto the bottom. The clear supernatant regenerated electrolyte may then be returned to the ,oreto repeat another cycle. The peroxid of leadaat'ter suflicicnt accumulation.isagain reduced with carbonto metallicleinl,andrecast into anodes to again pass through the same cycle. From this it will be seen that the removal of the disinte; grated, anode material and its expulsion "from the cell is practically continuous and. automatic, and -very little loss or expense is incurred in reducing the peroXid-to metallic lead. The largeexpense of continually supplying new anode ,material, is almost entirelfvvobviated. Theoretically at least, the 'mrchased, will last indefinitely; xliyflsiinply reducin the. peroxid formed .at thera node and recasting into new lead anodes. e.

lb-was.noted" in the experimental work terial greatly diminished underthe action described, the anolyte may be kept a'ln'lo'st totally separated from the cz'ltholyte Sup- H pose that the catholyte consists of azvery impure neutral solution of copper sulfate, such as might be obtained fromleaching copper ores in a cyclic process, and'the anolvte consists of slightly acidulated"water, as or example washwater obtained -"in "ti-eating copper ores with an, acid 'sulfhtef solution. As the copper is deposited on the cathode, sulfuric acid is liberated at theanode, and

when the operation is completedfthecopper is removed from the catholyte, and all the a 'ailable aciil transferred to the jan -oly'tc'. It is vident that under these cmiditi'onsg the practically pure anolyte 'f'contag ins 3 all "the available acid, and the catholyte now deprived of its copper and'coiitaih'ing no a va i' l able acid, may be wasted without loss. In this way fouling of solutions cannot occur, and that ditliculty, so troublesoii'ie in the past, is entirely overcome. It may not-be necessary to waste the catholyte at every" cycle otth'e operation: in which case the density otthe diaphragm is not of so much importance, until the solution has sull icientlv t'cnded to make its rejection necessary or desirable.

The apparatus has flexibility enough to adapt it to all the varying conditions,and it would be useless to discuss all these conditions in detail. i

In the electrolysis of copper sulfate solutions, oxygen is released at the anode as set forth in equation (1). To providetor the removal of this oxygen troiii'the under sideof the anode as rapidly :1s"l orh1e l, e'lcajd anodes are cast with pertorati'ons; 'lh'c.

.ily accompl'ishedr hv the ail. aa@1e.11ogaai :20,

andthe :uljustment may'be made while the apparatus is in operation. In this :2; v the cathode may be b ,u| ltv up to d'e. red

thickness, and the cell need onl he stopped e the copat-considerable intervals to ren per. .ln deposit ng the copper" deposit it iii sections to facilitate its rei'ezulily est-ape,"

to p

cath ode ,removed from the tank. Ordinarily, in operating the apparatus, it will be desirable to have the tendency of flow be from the cathode to the anode to overcome diffusion toward the cathode; this is facilitated by keeping the catholyte at a slightly higher level than the anolyte, and its height may be adjusted by the outlet pipe 9.

When it is desired to stop the operation of the apparatus and remove the copper, the anodes are elevated, preferably as a whole, the anode bell gradually elevated and the anolyte allowed to drain out through the tubing 11 so as not to bring undue strain on the diaphragm. If there is any accumulation of disintegrated anode material in the.

anode bell, the removable cloth is taken out with the material on it; after being Washed, it may be replaced. The catholyte is drained from the cell and the copper taken out, after which the original order of things may be established, and the cycle repeated. Or-

dinarily the regeneration of acid in the anolyte will not be sufficient to make up the loss consumed by the gangue of the ore. To overcome this difficulty and also to reduce the voltage necessary for the electrolytic decomposition of the copper sulfate, a depolarizer, such as sulfur dioxid, is introduced into the anolyte, which acts both as a depolarizer and acid generator, as shown by the following reaction:

which amounts to about 0.16 volt, acting with the current. Ordinarily it is diflicult to realize any benefit from this reaction, because the SO, cannot be brought into sufiiciently intimate contact with the liberated 1 SO, as the anion, at a practicable. current density.- \Vith the present invention, the anolyte is agitated by the anode bell and diaphragm as well as the catholyte, and the oscillating anode bell acts both as a suction and a pressure on the anolyte in connection with the perforated anodes, to suck the solution through the perforations and again expel it, and in this way bringing the depolarizer in intimate contact with the anode so that a good anodic efliciency may be realized at apracticable working current denslty. It may also be desirable to introduce a reducing agent into the catholyte to prevent the action of ferric salts in dissolving the copper and reduce the metallic compounds in the catholyte to their lowest valency, and thus make them unable to act on the deposited metal. Where oxidation, instead of reduction, is desired at the anode, the 0x1- dizing agent may be introduced through the same means as described for the reducing agent.

The description given in this specification is for the preferred arrangement, and as particularly applicable to the deposition of copper from sulfate solutions derived from'leaching ores. It is evident that the apparatus may be used for other purposes with equally good results, as for example, in leaching ore with ferric sulfate solution; in which case, during electrolysis, ferric sulfate is regenerated at the anode from ferrous sulfate, and the regenerated ferric sulfate solution again applied tothe ore. It may be used in the'deposition of zinc, in which a neutral or slightly acid electrolyte is easily maintained. It may be used for refining of copper and other metals, etc. If the released anion is a gas which it is desired to use, it may be collected and withdrawn by placing a hood 26 over the anode bell, in which case a. flexible inlet pipe, 10, and a flexible outlet pipe 27 for the gas, are provided.

28 are guides to keep the anode bell in pro er alinement during oscillation.

aving thus described my invention, I claim:

1. In electrolytic apparatus the combinationof a cathode tank containing the catholyte; anode bell suspended within the cathode tank and containing the anolyte; diaphragm interposed between the anode and cathode; means of oscillating the anode bell, and means of introducing and withdrawing the' anolyte and maintaining it distinct from the catholyte.

2. In electrolytic apparatus the combination of a cathode tank containing the catholyte; anode bell suspended within the cathode tank and containing the anolyte; means of oscillating theanode bell; diaphragm attached to the anode'bell and oscillating with it; flexible outlet for the anolyte passing through the cathode tank, and means of introducing and withdrawing separately both the anolyte and catholyte.

3. In electrolytic apparatus the combination of a cathode tank containing the catholyte; anode bell suspended within the cathode tank and containing the anolyte; means of oscillating the anode bell; diaphragm attached to the anode bell and oscillating with it; flexible outlet attached to the anode bell for thewithdrawal of the anolyte without mingling with the catholyte, and means of introducing a reagent into the anode bell which will combineavith the released anions.

4. In electrolytic apparatus the combination of acathode'tank containing the catholyte and, substantially horizontal cathodes; anode bell suspeiided within the cathode tank containing the anolyte and substantially horizontal anodes; diaphragm lnterposed between the electrodes; means ol aitccliing and removingthc disintegrated anode material; means of oscillating the anode bell and flexible means of withdrawing the anolyte with the disintegrated anode ma- .terial in suspension from the anode bell .ing the regenerated anolyte from the anode bell passing through the catholyteand sides of the cathode tank. a

G. In electrolytic apparatus the combination of a cathode tank containing the catholyte and substantially horizontal cathodes; anode bell (:(mtaining the anolyte and substantially horizontal anodes; a diaphragm attached'to the mouth of the anode bell and provided with means for the escape of gases from the under sideot the diaphragm.

7. Inclectrolytic a iparatus the combination of'a cathode tank cimtaining the catholyte and substantially horizontal cathodes; anode bell suspended within the cathode tank containing the anolyte and substantially horizontal anodes; diaphragm interposed between the electrodes; means with said diaphragmot providing for the escape of gases which, may have a tendency tobecome entrained by the dia 'ihragm; means of oscillating the anode bell and meansv of withdrawing the anolyte without mingling with the catholyte. i I

8.In electrolytic apparatus the combination of a cathode tank? containing the catholyta and substantially, horizontal cathodes; anodebell suspended within the cathode tank containing the anolyte and substantially horizontal andv perforated anodes; diaphragm attached to, the mouth of the anode bell; means of catching and removing the disintegrated anodej material, and means of oscillating the anode bell horizontally. 9. In electrolytic apparatus the combination of a cathode tank containing the catholyte and substantially horizontal. cathodes; anode .bell. suspended within the cathode tank =,containing, the anolyte and substantiallyhorizontal anodes; diaphragm interposed between theelectrodes; means of horizontally oscillating the anodeb'ell; means of introducingthe anolyte at one end of. the anode. bell and withdrawing itfrom the other side While the bell is oscillating. and

means. of "withdrawing the anolyte without mingling with the catholyte.

ing. the anode bell: means of adji it). In electrolytic apparatus'the comllination. of a cathode tank cri'ntaining.tlici atliolyte and substantially li'm-izontal"cathoifles; anode bell suspended within'tl' 'thode tank containing the anolyte and tially horizontal anodes; fd-iaphragn javathe mouth of the; anode bell upported" by frame attached to the anode bell, and means in said frame of providing for tlie'esca f gases from the under side of the dia-pl 11. In electrolytic apparatus f nation of a cathode tankco'n'taining t *e catholyte and substantially horizontal odes; anode bell suspended within t'h ode tank containing theanolyte-z tially horizontal anodes: means vertical distance between thefelectrodes and independent.means of adj usti-ngthelyer distance of the diaphragn'ibetween the sled. trodes. I i 12. In electrolytic apparatus the". combination of a cathode-tank containing the catholyte and substantially horizontal cathodes; anode bell suspended within the 'catlr- --.90 ode tank containing the anolyte and-"='substantially horizontal anodes; diaphraginfinterposed between the electrodesg.=1neans -of introducing a reagent into the anolyte to combine with the released" anions; :means of introducing a reagent intothe "catliolyte'to reduce the bivalent compoundsto the univalent condition and retaining them so and means of separately introducing 'and wvithdrawing both the anolyte and catholytemnd means oft-oscillating the anode bell thereby bringing the reagents into intimate contact withthe electrodes. r I

13. In electrolytic apparatus the combination of a cathode tankcontaining the catholyte and stationary cathode; anode bell suspended within the cathode tank by flex-i ble supports and containing the-anol-yteand stationary anode a diaphragm*attzwhedito the anode bell and interposed btwenlthb 1 electrodes; means of oscillating the jSd-iaphragm and anode bell; and means ofintroducing and withdrawing the anolyte and maintaining .it substantially distinct from the catholyte. =1

l-l. In electrolytic apparatus having horizontal electrodes a horizontal. diaphragm interposed. between i the electrodes.- frames supporting said diaphragm, and apertures in connection with the outside" rim of vthe under frame for the escape ()f gaSGSILi-HIL the under side of the diaphragm;

.15. In. electrolytic apparatus ha torizontal electrodes a diaphragm intetposedbe tween the electrodes.supportedrby an.;i1p1

, and, lower frame means. in connection with phraglm and means of oscillating taei,diaphragm between the electrodes 16. In electrolytic apparatus the comlJIIISItI OII Of an electrolyte tank; a stationary anode; a stationary cathode; a. diaphragminterposed between'the electrodes,

dependently of the electrodes. I

17. In electrolytic apparatus a stationary electrolyte tank; a stationary anode; a sta tionary cathode; a diaphragm interposed be tween the electrodes and suspended from an'dmeans of oscillating said diaphragm infixed pivotal points, and means of oscillatthe opposite electrode a diaphragm interposed between the electrodes, and means of moving said diaphragm from fixed pivotal points as the center of oscillation.

19. In electrolytic apparatus the combination of an electrolyte tank containing one electrode; an electrode bell suspended with in the electrolyte tank and containing the opposite electrode; a diaphragm interposed between the electrodes and suspended from fixed pivotal points; means of oscillating said diaphragm, and means of withdrawing the electrolyte from the electrode bell without mingling with the electrolyte in the electrolyte tank.

20. In electrolytic apparatus the combination of an electrolyte tank containing a stationary electrode; an electrolyte bell suspended within the electrolyte tank; a stationary electrode suspended within the electrolyte bell and independently of it; a diaphragm interposed between the electrodes, and means of oscillating said diaphragm independently ot the electrodes.

21. In electrolytic apparatus the combination of an electrolyte tank containing a sta-' tionary electrode; an electrolyte bell suspended Within the electrolyte tank; a stationary electrode suspended within the electrolyte bell and independently of it; a diaphragm interposed between the electrodes; means of oscillating said diaphragm independent-1y of the electrodes, and means of withdrawing the electrolyte from one electrolyte compartment without mingling with the electrolyte in the other compartment.

22. In electrolytic apparatus the combination of an electrolyte tank containing horizontal and stationary electrodes; means of agitating the electrolyte interposed between the electrodes and suspended from fixed pivotal points, and means of oscillating said agitator from the fixed pivotal points independentlyfof the electrolytic tank.

. 23-. In electrolytic apparatus the combination of an electrolyte tank containing the electrolyte and horizontal electrodes; a diaphragm interposed between the electrodes;

means of oscillating said diaphragm; means of adjusting the vertical distance between the diaphragm and cathode, and means of adjusting the vertical distance between the diaphragm and anode.

2+. In electrolytic apparatus having stationary electrodes, a diaphragm oscillating from tixcd pivotal points.

25. .In electrolytic apparatus a stationary anode: a stationary cathode; a diaphragm interposed between the electrodes, and means of oscillating said diaphragm between the stationary electrodes.

26. In electrolytic apparatus an oscillating diaphragm interposed between stationary electrodes and a space arranged for the free circulation of the electrolyte between the diaphragm and both electrodes.

27. In electrolytic ap )aratus the combination of a stationary anode; a stationary cathode; a diaphragm interposed between the electrodes; means of oscillating said diaphragm, and means of withdrawing the anolyte from the electrolyzer without mingling with the catholyte.

2%. In electrolytic apparatus the comhina-,

tion of a stationary anode; a stationary cathode; a diaphragm interposed between the electrodes; means of oscillating said diaphragm; means of escape for the gases from the underside of the diaphragm; and means of withdrawing the anolyte from the electrolyzer without mingling with the catholyte.

v 29. In electrolytic apparatus the combination of an electrolyte tank; a stationary anode; a stationary cathode; a diaphragm interposed between the electrodes; means of oscillating said diaphragm; means of providing for. the escape for the gases from the underside of the diaphragm; means of withdrawing the anolyte from the electrolyzer without mingling with the catholyte, and means of adjusting the vertical distance between the diaphragm and both electrodes.

30. In electrolytic apparatus the combination of an electrolyte tank; a stationary anode: a stationary cathode; a diaphragm interposed between the electrodes; means of oscillating said diaphragm; means of withdrawing the anolyte from the electrolyzer without mingling with the catholyte; means of adjusting the vertical distance between the diaphragm and cathode, and means of adjusting the Vertical distance between the diaphragm and anode.

31. In electrolytic a1' paratus the combination of an electrolyte tank; a stationary anode; a stationary cathode; a diaphragm interposedbetween the electrodes; means of oscillating said diaphragm; means of adj usting the'vertical distance between the diaphragm and electrodes; means of withdrawing the electrolyte from one compartment of the electrolyzer without mingling with the other, and means of adding to the electrolyte a reagent capable of combining with the released ions.

3:2. In electrolytic apparatus a stationary anode: a stationary cathode; a diaphragm dividing: the apparatus into anode and cathode compartments; means of oscillating said diaphragm between the electrodes, and means of withdrawing the e lectrolyte from ment.

itnesses Hi-zxny F. THOMAS Stamens, Huonns.

WILLTA E. (HKEENAVALT.

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