US1810535A - Method of reworking finely divided metal particles - Google Patents

Description

Jun@ la 331.l

METHOD 'OF REWORKING FINELY' DIVIDEDMETAL PARTCLES J. SHMELLER, su@ LSIQSBS Grginal Filed Apxfil 3, 1926 2 Sheets-5h69?. l

I N VEN TOR.

Jo/Hi 50/1 mel/ver, 5l:

A TToRNEYs Jim@ 69 931- J. SCHMELLER, SR

METHOD OF REWORKING FINELY DIVIDED METAL PRTICLES Original Filed April 3, `11.926 2 Sheets-Sheet 2 w/ MW mm fr, N R d f MMQWW I@ A .r 5 b fa M f L M/ Jgd@ rnengedfJnnefglef 51931 V UNITEp STAT-Es HJEISSUED PATENT oFFlc-E JormscHMELI-.m or mxnwoon, omo, assumer. 'ro scimmia. nomme corrrm,- or cLEvELANn, omo, a conroaarrou or omo.

METHOD or nEwoaxINe rINmY mvmnn METAL PAnrIcLEs origina; application, med piu s, 1926ser1a1' No. salsa Divided anatun'appncaaon mea February 8,

1928.-. serial No. suaves.

like materialfrom finely divided stock for` l casting purposes. Another object of vthis in- This invention as indicated relates. a method of remelting-finely dividedv particles of metal such as aluminum or brass or alloy borings, turningsand thel like, and making castings oringotstherefromas a single, con,-

'as discarded castings, sheets and scrapof every.; character, as well asborings,-turnings andjfskimmingsandwhich will produceas a continuousoperation. supplyof molten aluminum. suitable. for' casting `cr ingct` purposes.

Heretofore the remelting of.: aluminum, particularly. nely divided aluminum such as has been mentioned, has involvedmany difliculties because of the light character of the stock and the readiness withwhich the same is oxidized.'` The processof recovering said metal from such finely divided stock in most instances heretofore has involved a preliminary melting at low heat-in small individual furnace pots stirred by hand or. by rotary stirring devices, and then casting into ingots following by remelting of said mgotsg preliminary to use in making various articles of 'manufact-ure. Open furnaces :for -producing ingots from finely divided stock, also have been used, but such apparatus cannot be used to bringthe metal to casting heat because ofthermal losses. It has not been the practise heretofore with a single apparatus to remelt finely divided aluminumV or the like, and to maintain the same at any adequate temperature as a liquid supply of alumlnum from which the necessary quantities for casting purposes mi ht be drawn in'to casting ladles as requir The rincipal lobject of the present invenvtion,'t erefore, is' to provide an limproved method of supplying molten aluminum or vention is toA provide a continuous process for furnishings molten aluminum sup l whereby inely divided aluminum maybe -the stock v for remelting..`v and wherein the recovery from such stock may be equal to or in excess of the values for such stock determinable in an industrial assay laboratoryl thoroug intermixtuie' of the added stock with the molten mass and removal 'of all which will operate continuously and with a minimum expenditure of fuel and labor and maximum out-putI of product. A still fur. y ther object of the invention to provide a furnacefwherein agitating means will operate verticall iin the molten metaljat the chargi 0f si ev of the furnace` and insure grease and vthe foreign Amatter therefrom# v preliminary to the carrying of the pure mol;

ten metal into the discharge' side of said furnace, and through this agitating action, termed vertical -puddlin to im rove the quality of the metal, pudl "ng out t e oxides n n and foreign substances including free iron borings which are caused to float and may be. readilyr skimmed from! the top. The grease is removed in the first chamber and usedas fuel.

A still 'further object of the invention is to provide a furnace for the purpose specified without a draft or exit for the gases other than those provided by lateral o enings in the Walls of the upper portion of t e furnace yand, wherein the amount of oxygen or air charged into the furnace is kept at a minimum, and below the point necessary for complete combustion of the fuel gases admitted thereto. Still another object of the invention is to provide a counter-balance for the mechanism of the furnace whereby the agitating devices may be easily removed from Ithe furnace bath and also to provide an ad-A justinent for` suchagitating devices whereby the position of the same, relative' to the liquid content of the furnace, may be varied as desired. Other and furtherv objects of the such disclosed lmeans and mode illustrating,

however, but several of various ways inl wslich the principle of the vinvention may be u In said annexed drawings:

Fig. 1 is a Side elevation partiauy in secs tion of a furnace installation embodying the principle ,of my invention; Fig. 2 is a top plan view of the a paratus shown inFig. 1';

ig. 3 is a sectiona plan view of the furnace proper; Fig. 4 is a side elevation of the grid; Y

ig. 5 is atop plan view of the grid; and Fig. 6 is an enlarged sectional detail view showing the grid attaching means.

As has beenindicated, the general practice heretofore followed in reworking orremelting finely divided aluminum has been to place the same in open furnaces and to agitate the same by hand or by means of mechanically rotated propelling devices. Such method of remelting involves thermal losses and the average heat therein is below good casting temperature. This requires castin into ingots and thereafter remelting of suc in ots to obtain metal which is of high enoug temperaturefor use in casting into the various articles of' commerce for which the metal is employed. This procedure `entails a remelting loss of from 1 to 2 per cent. as well as the cost of the additional remelting operation. Thus to obtain a quan- 'tityl of aluminum sufficient for foundry purposes it is necessary to employ a large number of laborers and accumulate the product from a series of individual furnace pots or `open furnaces in a remelting furnace in order to carry on the casting operations.

- My improved method of reworking finely I A divided aluminum consists in preparing a bath of molten aluminum into which the finely divided ,aluminum is fed as raw stock,

and in continuously agitating the' portion of said bath to which said stock is added in order that it may be rapidly absorbed into the molten mass in said bathand the impurities such as oil grease and dirt, free iron, oxide and the like, maybe rapidly freed therefrom, and in Withdrawing'from another por-` tion of said bath the aluminum freed of such impurities and at a temperature suitable for casting. My method is preferably carried one of drawings, the furnace 1 comprises a brick structure formed of piers and arches and promay be varied in accordance with special re-v quirements or with the character of the stock and the rate of use of the product or other conditions. At a point above the level ofthe molten metal in `sa1d chambers, charging and skimming doors are provided.

While a singlefurnace unit might be pro vided, it has been found more economical to construct` three or more furnace units in series in a sin le structure, as shown, which may besimultaneously operated by a crew of Workmen more economlcall than a single lfurnace unit or a series of in ependent furnaces. Likewise the operating mechanism for a of furnace units may be more economically installed and the heat losses may be proportionately reduced.A In the drawings, therefore, I have illustrated three furnace units in series. The units are each operatively distinct from the others and a different alloy may be run in each chamber. Each of said units is divided centrally by a partition wall 5 so as to provide on one side a combined charging and agitating chamber 2 through which the metal stock is fed into the furnace and on the opposite side with a heating chamber 3 for the rece tion and temperature control of the castlng supply of molten metal.

The dividing wall 5 preferably extendsy from the ground to the roof of the furnace. Beneath each of the'series of chambers 2, 3, arched heating chambers 6, 7, extend. The

iioors 8, 9, of the communicating chambers 2,

3, rest upon these arches and are packed with ganister or other heat resisting material, and the walls of said chambers are formed of or lined with lire-brick. Where da series of three furnace units is provided, it is found more economical of f-uel to have the division walls between the several casting sections extend only to a point slightly above the side doors so that the gases in the upper part of the 4furnace on the respective sides of the dividiv wall 5 may travelfreely into any nxe three adjacent charging chambers or the three adjacent casting chambers. Centrallyy of the outer wall o f eachlof the charging. chambers Ya chargin adapted to be closed by a sli 'ng charging door 12 formedof lire brick, is provlded.

lire-brick door 14. Within the upper openk portion of the series of casting chambers, a.

opening 11l y fuel supply nozzle .(notshown) is provided throu h which `atomized crudeA oil or some such el mixture may be projected into the casting u chambers. Counterweights (not shown) may be individually applied to each of the doors of the several charging andcasting chambers so that the same may be readily lifted and lowered when the furnace is in operation. In addition to the fuel supply charged directly into the upper portion of the casting chambers above the metal reservoirs, rovision is made for the heating of each of said series of furnaces by means of nozzles (not shown) within one end of the arched chambers v6 and 7 heretofore described. An opening- 10 is provided at the end of the chamber 7 to permit egress of excess hot gases at that end of the furnace, and this lower opening also constitutes a safety overflow inthe event of a leak in the metal reservoirs.

On the dischargeor'casting side of the.l

furnace, a tap hole 1'5 and spout 16.is provided adjacent lthe central lower portion of each ofthe metal reservoirs. Along each lateral side of the furnace tanks or troughs 1,7, 18, adapted to be filled with water are ,provided 4into which hot skimmings from the top surface of the `'molten metal may be dropped as'the occasion arises. l The depositing of the skimming in the troughs sepau v -provided t rough which the lower end ofthe rates the aluminum from the ,dirt and the aluminum may be again used as -part of a charge for the furnace.l u

At each end of the charging side of the series of furnace units adjacent the top arch an opening 2 1 is provided, over which a door 22 lined with lire-brick is hung, and through which the furnace gases lcarrying light dustA and dirt and the burningparticles of grease and oil, which ma fbe mingled therewith,

partiallyescapehese doors Lalsoserve as safety orexplosion doors and preventun due pressure within the furnace. 4

It will be noted that-above the surface of the molten massjof metal 'the furnace carries va heavy bank of hot gases whichare -sufcient 'in quantity to completely fill the space 'referred to and that such gases are at a slightly higher pressure than the outside atmosl an lof theseveralzo. ,enin s intothe 'char'l'n y P g g1 g Lthemo ten mass ofmet'al.

chambers,1but little air enters at such points because vfof vthe;higher pressure vofithe Qgases withinithe 'furnac'e which seelrfegressy :ii-...such

time."*EachA f thefend: andinternal.wallsal bothfthe `f-:hargi-ng .-fandwast'ingrehaibers;

charge might freeze and require a high degree of heat to remelt. f

The means' for agitating the molten mass of metal on the charging side of the furnace emergency use, at times 'whennthe furnace will now be described and while al particular embodiment of such apparatus'is illustrated, it is to be understood that other mechanism for accomplishing the same `result may be employed instead of that illustrated. Within each of the charging chambers a grid or stirring member 31 is provided which is of an outline similar to that of the furnace chamber and of slightly smaller size than said chamber. Said-member comprises a heavy central portion or boss, 32, and-.a seriesof radial arms 33gradually"decreasingin thickness toward their free endsra'nd'joined at such ends by a rim 34 of metal corresponding in outline to the outline ofthe furnace chamber and spaced from the walls thereof. Between the radiating arms spaces 35 are provided through which the molten metalv may freely pass as the grid is plunged downwardly into the molten metal and withdrawn 'therefrom by themechanism presently toA be described. l

Centrall ofthe grid a beveled socket 36 1s operating stem 37 of the agitating device may be received. The lower end of the stirring rod or operating member is providedgwith notches `38 ,to receive projections 39 uponv a Y series of shoes 41 which have beveled sides 42 terminating in outwardly extending flanges, 43. In order to engage thegrids .with the operating rods, thelower'ends of said rods are inserted through thecentral apertures of said, grids land the shoes .or tapered `plates vare engaged with said rods and the. id lowered on the outer beveledV surfaces o said p1ate`s xl :about eachrod above thegrid prevents the plunged into f burnin out of the rod as 1t -is through said furnace roof. These rollers are preferably anged rollers engaging in pairs on opposite sides of the square operating rod and suitable lubricating devices for said rollers may be provided. The rod is set angularly to provide for easyl removal of oxide and refuse or skimming.

, The upper end of the rod is provided with an aperture 51 for attaching a lifting cable 52. Adjacent the upper end of the rod .an

lextension arm 53 is provided to which agrid depressing cable 54 is secured. The respective cab-les are passed about pulleys 55, 56, secured to fixed supports above the rod and adjacent the roof of the furnace respectively and thence passed in opposite directions to a pair of sheave wheels' 57, 58 mounted upon a shaft 59 preferably located on a platform 6l above the levelof the furnace roof. The shaft carryingr the respective-pairs of sheave wheels is oscillated by suitable mechanism shown in this instance. as an electric motor com' )lete rotation.` of the 62 coupled with a suitable reducin r gear 63 to a crank arm 64 which 11s joined y -a connecting rod 6 5 with a similar crank arm 66 on the oscillating shaft. The proportions of weights for the grids and supporting arms and spring take-up means to prevent excessive. strains nponthe mechanism. Accordingly, a spring 71 is'inserted' in the line of the grid depressing cable and conntm'weight 2 is carried at the end of 4the grid elevating cable. 'lhecounterweight is adapted tobi-ar against a stirrup bar 73 supported on a pair of springs 74 which are secured to a fixed support 76 above the top range of motion of the counte'rweight so'as to hold said bar in the path of movement of the counterweight when the grid is drawn from the metal bath. 'The counter-weights are guided upon a pair of bars 77 supported at each end in' the frame of the operating mechanism and springs 78 on said bars serve. as buli'ers. An adjusting pulley 81 is provided in the line of grid elevating. cable preferably supported on a pair of arms 82 pivotcd to the frame ata point adjacent the sheaves and supporting said .pulley rearwardly in alignment. therewith. Each of said pairs of frames is provided with a stationary nut 83 through which the upper end of a screw threaded rod 84 is adaptedto engage. `A hand-wheel 85 is attached at the lower end of said rod whereby said pulley may be adjustedupwardly or downwardly to the necessary ,extent to lift the grid to any point desired with respect to the liquid mass in the furnace chamber. Thus by turning the screw in one direc-tion the' grid may be full)1 withdrawn from the ybath of liquid metal and heldl at a point above the charging opening ofits furnace. When adjusted in the opposite'direction, the Grid may be forced'to a considerable depth within the molten mass of lmetal as it reaches its lowest limit of motion in thel chargingside of the furnace. 'lhespring provided in the grid'dep-ressing cable is put under tension as the grid is elevated and is relieved of the larger part of such tension when the grid is lowered to its usual operative position. safety device when the grid strikes an obstruction in its descent. Thus complete control of the agitating mechanism of the furnace is provided both asto the starting and stopping of the agitation and the position ot the agitator with res ect to the molten mass of metal maybe rea ily adjusted.- Through a suitable rheost'at the motor speed of the operating device may be controlled and thus the rate of agitation may be regulated.

VThe construction ofthe apparatus has been described. The method of operationwillnow be briefly outlined.

In order to start an individual furnace or a series of furnaces, the burner above the casting'or'dischargesidev of the furnaces is ignited and the entire furnace structure is thor- Italso serves as 'a' resllient oughly heated. The burner below the casting side also ma be used tocarry on the-heating more rapid y., It is ordinarily not necessar to use the burner beneath the ioor of the c urging chamber as the heat -in the casting chamber is adequate to bringthe temperature of the entire structure to the proper point; The charging side of the furnace is then filled with ingot-s and scrap sulicient in quantity to form a liquid mass of metal of substantial depth in the two furnace chambers when the sane has been melted. When the charge in ldie casting side of the furnace becomes a molten mass and flows into the charging side of the furnace through the aperture centrally of the dividing wall-of said furnace, the apparatus is ready to receiietinely divided stock on the charging side. l-Vhen a suitable temperature has been attained, the lower burner may be extinguished if desired. 'lhe agitating mechanism of the furnace is then started and finely divided stock is supplied through the charging openings. -The grease and oil found upon the stock will provide adequate fuelfor the (dial-ging section of the furnace topmaii'itan a high temperature therein and the fuel in g. r am the casting chambefwi-ilmantain theimolten mass at that side o f the furnacefat the desired `rature foncasting. f

l e agitatlng mechanism 'f' continuous operation andthe chargin ldoorsv are `opened in 'succession .l and fine y vided aluminum for other' stock l(which it is desired to charge into the furnace is fed therein. When moisture ispresent -in the raw stock, it

is' .desirable torst place thegreater portion of the char uponthe sill ofthe char ing opening an after the chargingdoor has een closed to again open said. door and push 'the dried mass fromA the sill into the furnace.

The agitating 'devices ordinarily rise and fall `once ever two seconds although the speed may be c anged in accordance with the amount of metal inthe furnace,;the characterv of the raw stock,A and the rate-ofy withdrawal 2o on the casting side ofthefurnace;

As thev finely divided aluminum 1s fed into A s the furnace it is plunged beneath the surface of -the molten metalvthrough the action of -the grid and the particles are intermingled and combined with the molten massthrough the successive strokes of the grid. The'iinely divided particles arethus-rapidly ,and completely -incorporated with the molten'mavss onv the chargin side of the furnace. 'Thei purer metal will escend .into the reservoir in the charging side-of the'furn'aceand as metal is withdrawn from the ycasting side will low through the aperture 'centrally of the base of the partition wall of the. furnace and will rise. in the castin side of the furnace ltomaintain the level in te res ctive sides of the furnace reservoir at a uni ormpint.y

Inthe casting side of the ffu-rnac'e the metal is exposed-to the direct heatin 1actionv ofthe flame projected from` the nozz e adjacent theyl .upper portion of said section and may -also be subjected' to heat from the burner atthe base of the furnace-shouldsuch heating aetion be required. The temperature o the furnace may thus `beregulated to maintain the metal'in the furnaceat a suitable tempera-l tureforcasting. 1 v

During the course of .thel operation the workmen about the furnace may skim the sur-A face of the molten metalto .remove impurities fromtime to time. f Such skimmings may be dro d into the .tanksattherespective sides o iee furnaceandlater may be again ine `trodueed into the furnace through :the chargving.openings#along with other stock. usedft`o vfeed the furnace. j f j It mayalso be 4found desirable to place into the furnaceon the charging side', quantities.

efflux, such as cryolite, calcium chloride, zinc` chloride, and thelike, inonder to facilitate theremoval of impurities.

i Thus it will be apparent` the inethodand mechanismabove-described-.provide fora continuousfsupply of aluminum 'for casting pur- 55.:poses'and-permittheuselfg-very finely di` tideanuminumwan which a v largeparcela age' of l.greaseand oil may beintermin led -.andpermit` the reworking of such meta at 1a highrate ofzspeedand with a recovery equal or'superiorfto-the quantities which are ascertained to be' recoverable ,by"labo ratory' assays.

While reference has been made in the speciication and some of the claims to the use of two chambers, it is to be understood that eguivalent construction such as a plurality o charging chambers and an associated casting chamber or a single charging chamber and a plurality of casting chambers associated therewith, would be within'the purview ofthe invention. Likewise Awhile the invention has been described as particularly 1 adapted for use with nely divided aluminum,

itis to be understood that the process and `apparatus is not intended to be limited to use Withthat metal or its alloys and may be-used with any other inelydivided metal requiring similar treatment for successful commercial reworking.

Other modes .ofapplying theprinciple of my invention may be employed instead of the one explained, change being made vas regards `the means and the steps herein disclosed,

provided those stated byany ofthe'following claims or their equivalent be employed.

I therefore particularly point out and dis- `tinctly-claim as my invention:

l. In a method of melting and refining metal, the steps *which consist in applying heatto bring-fA the metal to a molten condition and thereafter maintainingv the" molten con ition fofv said metalv and reningv and deoxfidizingthe same by paddling the molten material from al osition above the level thereofdownwar yy in a substantially vertical direction and'setting up aplurality of substantially vertical current streams of molten metaltointeract-upon each-other'.

In av methodlofmelting and refining aluminum, the stepsswhich consist in ap ly'- ing heat to bringthe aluminum to .amo tencondition, and`v thereafter maintaining the molten condition of said aluminum and re- .iining and'deoxidizin'g the-same by.p1fddling the kmolten :material from aiposition ve the vvlevel'thereof downwardly in a substantially vertical .direction and setting .upfaplu- 'rality of su bstantiaily'V vertical4 .current 'streams of molten aluminum to'interact 'upon each. other.'

` L Y. I, 3. "Ina methodof meltingy and ',refipihg aluminum, .the stepswhich ,cnnsistinap lying heat to bring saidaluminum :to ai mo ten condition, maintaining a' reducing atmos- :p here over said molten mass, continuously puddling said molten! mass` from a .position above the levelthereofdownwardly .ina substantially: vertical direction, addingsubdivided aluminiferous material to `said 'mass whilefcontinuing the verticalpuddlingfof vertical direction continuousl deoxidize said molten mass `o aluminum.

5. A method of melting and refining aluf minum as asingle continuous operatlon to produce a product suitable foruse in commercial fabrication which includes the steps of maintaining melting temperature in a..

mass of molten aluminumthrou h a source of heat applied indirectly to said mass of aluminum and puddlin said mass of aluminum' from a -positiona ove the level thereof downwardly in a substantiallyvertical direction eontinuousl to refine and deoxidize said molten mass o aluminum.

6. A method of melting and refining alu-Y minum as a single continuous operation to p roduce a product suitable for use in commercial fabrication which includes the steps of maintaining melting tem erature in a massof molten aluminum, pu dling said mass of aluminum in a substantially vertical direction from a point above said molten mass, addingmaterial to saidmass of molten aluminum from a point above the same, and continuing to puddle the same in a substantially 'vertical direction to carry such added material downwardly into said mass of molten aluminum, and settin up overlapping currents of molten meta to incorporate said.

added material and thereafter continuously puddling ina substantially vertical direction said mass of molten aluminum and added material to reiineand substantially to deoxidize all of said material.

.7. A method of melting and refining' aluminum as a single continuous operation to produce a .product suitable for use in commercial fabrication whichncludes the steps of maintaining melting temperaturelin a mass of molten aluminum, puddlng said mass of aluminum in a substantiallyvertical direction from a point above said molten mass, adding raw aluminiferous material and suitable fluxes and continuously pud-A dling the. same in a substantially vertical direction to carry such added material and ilux downwardly into said mass of molten aluminum and setting up overlapping currents of molten metal to incorporate said added material and fluxes and thereafter continuously puddling in a substantially vertical direction said mass of molten aluminum to refine and.-

' withdrawin and added material to refine and substantially to` deoxidize all of-said material.

Y 8. A method of melting and refining aliiminum as a single continuous operation to vproduce a product suitable for use for commercial fabrication which includes the steps of maintaining meltin temperature in coinmunicating masses o p aluminum, adding aluminiferous material to one of said masses, and withdrawing molten aluminum from the other of said masses, applying heat adequate for casting purposes to one of said masses and puddling in a substantially vertical direction the other of said masses, to incorporate the added material and refine the contents of said mass, and to interchange heated metal between` said masses to maintainadequate melting temperature in said puddled mass.

9.. A methodof melting and refining aluminum which includes the steps of maintaining melting temperature in communicating masses of'molten aluminum in adjacent chambersz adding aluminiferous material containing rease and oil and other heat lproducing e ements to one of said masses in a reducing atmosphere' and heating said mass through the fuel material thus added, and

molten aluminum from the other' of said masses after applying heat thereto adequate for casting purposes, and puddling the material in the rst mass in a substantially vertical direction Ito incorporate the added material in a molten metal and refine said mass, and to'interchange heated metal between said masses to maintain adequate melting temperature in said puddledmass.

10. A method of melting and refilling aluminum which includes the steps of maintaining melting tem rature in two communicating-mass'es o molten aluminum by heating one of-sid masses maintaining a blanket of reducing gases above said mass, feeding material into the other of said masses and thereafter puddling said material from the up r surface of said molten mass to. which .e material was added toward the bottom of said'mass.

11. A method of meltin and refining aluminum which includes t e steps which consist in maintainingv themolten condition of said metal, adding aluminiferous material, carrying a percentage of impurities including iron particles, to said molten material, and continuously paddling the material from a position above the, level thereof downwardly in a substantially vertical drectionand setting up a plurality of substantially vertical current streams of molten metal to interact upon eachother and to float any iron particles at the surface of s'aid metal bath, and skimming said iron particles and other impurities from the surface of said bath.

12. A method of melting and refining metal. at 'high temperatures, which Min'- cludes the steps which consistin -maintainf ing the molten condition of saidmetal beneath a bank of hot gases having a reducing action, and refining and deoxidizing the same by continuously puddling the molten lmaterial .from a position above the level thereof downwardly in a substantially vertical direction and setting up a plurality of substantially vertical current streams of molten metal to .interact upon each other.

13. In a method of melting and refining metal at'high temperatures, the steps which Aconsist in maintaining the molten condition of such metal and continously puddling the material from a position above, the level thereof downwardly in a substantiallyvertical direction and setting up' a plurality of substantially vertical current streams *of molten metal to interact upon' each other and to oat any foreign particles within said metal bath at the surface thereof. I

14. A-method of producing metal aluminum from secondary raw material irrespec.

ltive of admixtures of' iron, oxides, alloys,

-iron particles and other impurities, skimand the like, which. includes the steps of heating aluminum to form a molten mass, addin secondary material from above the level o said lmolten mass, puddliiig the molten mass of material from a position abovethe level thereof downwardly in a substantially verticaldirection ,from a point above'the liquid' level and setting up overlapping currents of molten metal to incorporate the individual portions of added material to substantially of said masses, a plying heat to one of said masses and with rawingl molten metal from the mass subjected to' heat for fabricating purposes.

18. In amethod of reworking finely divided aluminumf the steps which consist of maintaining separate vmasses of molten aluminum in communication With one another through a narrow passageway adjacent the base of said masses; heating one of said massesu and agitating theA other of said masses, addinmfinely ,divided aluminum to the mass undergoingagitation and withdrawingmolten metal from the other mass of;

metal for fabricating purposes.

- 19. A `method pf melting 'and refining readily oxidizablemetal, consisting in' maintaining communicating masses of molten Ametal in agitation while -in a non-oxidizing deoxidize the molten mass, and to fioat said 'mingsaid impurities from the surface and drawing casting metal from said mass.

15. yIn a method of melting and refining metal, the steps which consists in applying heat to bring the metalto a molten condition, and thereafter maintaining the molten condition ofsaid metal and refining and `deoxidizing the same by puddling the molten material 4from a position outside of the contents downwardly toward the bottom of said mass, and setting up a plurality of interactcurrent streams of. mplten metal within saigdm'ass. l

16. A method of melting and refining aluminum consisting in heating one of two commun-icating masses 'of'y molten metal whileagl tating the metal to cause interchan eof metal oetween said masses adding finely divided aluminum to one of said masses and withdraw# ing molten metal from the other mass fof metal for fabricating purposes.

. 17, AJ method of. melting and` refining i aluminum as a single, continuous'operation l consisting in heating one of two communicating masses of molten aluminum while agitatf ing. the metal to cause interchange of metal between said masses, 'adding material to one -heating directly the other4 of said masses,

fidizable metal to one of said masses, and withdrawing molten metal from the other ebruary, Y

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