US2331988A - Continuous furnace for the separation of a metal alloyed with other metals - Google Patents

Description

Oct. 19, 1943. 4 H. LoEvENsTElN v CONTINUOUS FURNAGE FOR THE SEPARATION 0F A' METAL ALLOYED WITH OTHER METALS Filed Nof. 2. 1939 2 Sheets-Sheet 1 imams y 2,331,988 S FURNACE FOR THE SEPARATION 0F ALLOYED WITH OTHER METALS Filed Nov. 2, 1939 Oct. 19, 1943. H. LoEvENs'rl-:IN

, CONTINU A ME 2 Sheets-Sheet 2 fig-2 Patented Oct. 19, 1943 CONTINUOUS FUnNAcE Fon 'run SEPARA- Trouv oF A METAL ALLorEn wrm o'rnEn METALS Hirsch Loevenstein, Paris, France, assignor, by direct and mesne assignments, to Independent Aluminum Corporation, New York,N. Y., a corporation of New York Aptlieatien November 2, 1939, serial No. 302,481 In France November 3, 1938 (Cl. 26S-16) This invention relates to metallurgical furnaces, more particularly, a furnace for the continuous extraction of individual components from 'an yalloy or mixture containing 'a plurality of components. The continuous furnace of this invention may be used, for example, in carrying out-in a continuous mannerthe process described in my U. S. Patent No. 2,198,673, but is not of course in any Wayrestricted or limited thereto. The said patent relates to the extraction of aluminum from an'alloy having as additional components, silicon, iron and other elements.

The metallurgical process to which the con-` tinuous furnace of this invention pertains, may be stated in general terms thus: If it is desired to extract a metal or other substance A from an alloy or mixture having one or more components in addition to the metal A, (for example two additional components B and C, the alloy itself being designated ABC), the alloy ABC is first treated with an agent as metal D which alloys with the comporent A but not, or to a very slight extent, with the other components B and C. The resulting intermediate alloy AD is then separated from the original alloy and subjected to distillation to break it into its component parts, A, the metal component soughtto be extracted, and D, the alloying vagent which is again used for further extraction. In the patent above referred to, the original alloy ABC is an alloy of aluminum (A), silicon (B) and iron (C), and the alloying agent is zinc (D), the intermediate alloy AD being an alloy of aluminum and zinc.

The continuous furnace of this invention has an extraction chamber in which the raw material or alloy ABC in a crushed, solidf state is treated with alloyingl agent D in a liquid state.

The liquid agent D iiows in a downward current through the solid particles of raw material ABC and becomes converted into the intermediate alloy AD (likewise in a liquid state) which is received in the lower part of the chamber, to-

' gether with such portions of D which had not succeeded in alloying itself with A. From the extraction chamber the intermediate alloy AD ows into a distillation or rectiiicationcolumn appropriately heated to cause the vaporization of component D which is required to have a. lower boiling point than the metal A. The alloying agent D, ina vapor state, ows upwardly through the rectification column while the metal A, still in a liquid state, ows downwardly into the lower part of the column-from which the extracted The vapor of the agent D is conducted to a'. condenser at the upper region ofthe furnace where it is reconverted into its liquid state, and from which the alloying agent D, now in a liquid state,

"is conducted to the head of the extraction chamtherethrough, as already,

ber for downward iiow described.

The prime object of this invention is the provision of a furnace capableoi carrying out the s'aid metallurgical process in a continuous man, ner. A like object is the provision of a continu- `ous furnace as briefly described hereinabove.l

Allied with these objects, it is sought herein to` design, locate, and coordinate the various parts of the furnace in a manner to vprovide for the vcontinuous operation herein of the metallurgical or refining process of the type described. A further object isto provide a continuous Vfurnace for carrying out the aforementioned process in which the reagent (the alloying metal D), is continuously circulated in a closed circuit with substantially no or at the most, very little loss of the reagent'. A further object ofv .this invention is the provision in a. metallurgical -furnace of. a heating arrangement which will afford continuous operation therein of processes of the character described. A still further'object is to provide the said heating arrangement in a manner to reduce heating losses, and to make the most economical benefits of heat gradient.

For the attainment of the above and such other objects as may appear. or be pointed out herein, I have shown one embodiment of my ine vention in the accompanying drawing, wherein:

the condenser, for removing the last traces vofmetal from the raw material.

In Fig. 1, the region I represents the extraction chamber of the continuous furnace of this invention, wherein the metal A is extracted from the raw alloy ABC, by means of the alloying agent D. The crushed solid alloy ABC, contained in perforated. cups I' made of metal, earthenware or other suitable material arranged one above the other in an elevating system of metal or product A is continuously removed. any known type, formed for Aexample by endless chains actuated by a motor I located outside the furnace. The cups containing the raw alloy ABC enter through the lower door 2 of the furnace, and are placed on the elevating system. The alloying metal D in the liquid state enters at the head of the extracting chamber I through distributing orifices I 9 in the manner of a shower, and flows downwardly, through the crushed masses of the raw alloy contained in the cups. In its downward passage through the solid material ABC, the liquid agent D dissolves out or alloys with the metal A of the alloy ABC, without becoming charged with appreciable amounts of the metals B and C. It should be noted that the raw material ABC and the alloying agent D flow in a counter-current manner, so that the alloying agent D in its most active condition (as it issues from the distributing orifices I9'), encounters (at the topmost cup) the material ABC A in its most exhausted condition, and so that the material ABC.in its initial condition (in the lowermost cup), encounters the most worn-out agent D (as D ows away from the lower portion of the extraction chamber).

The residual alloy ABC, containing hardly any more metal A and containing perhaps a little metal D, leaves the furnace through the upper door 3.

Underlying the extraction chamber I, more particularly, the lowermost elevator cup thereof, is provided a 'decanting reservoir II, into which flows the intermediate alloy AD together with the portion of the alloying agent D, which had not succeeded in contacting the raw material ABC, and solid particles of the alloy ABC, carried along by the liquid current of the alloy AD. These particles will float when they are lighter than the alloy AD, or fall to the bottom ofthe reservoir in case they are of greater density. They are eliminated, 4either through the upper plug 4 in the rst case, or through the lower Voutflow hole 5 in the second case. From the decanting reservoir II the intermediate alloy AD is conducted to a rectification column designated III and IV, where it is broken up into its components, metal A and agent D, as will be shortly described. For this purpose there is provided a conduit I connecting the decanting reservoir II (at outlet 6), to the rectiilcation chamber (at inlet 8) The outlet is located at a point in the decanting reservoir II removed from both the floor thereof and the surface of the liquid standing therein. so that the outflowing liquid AD will not become contaminated by the floor deposits or the surface dross, respectively. Preferably, the outlet 6 is positioned at a point in the reservoir II as low as possible (but sufiiciently removed from the door, as explained above), so that the minimum of stagnant liquid Will be allowed to remain below the point of outlet B. The conduit 1 from the decanting reservoir connects to the rectification column at inlet 8, which is substantially at the level of the surface of the liquid standing in the decanting reservoir II, so that as the intermediate alloy AD from the extraction chamber I streams into reservoir II, equal amounts of AD will overflow into the rectication chamber at 8. In this manner there is provided a flow from the decanting reservoir to the rectication column.

The intermediate alloy AD is separated into its two components (extracted metal A and alloying agent D) in the rectification column by a process of distillation. The rectification column may be considered to consist of two zones,`a lower zone III between the inlet 8 and the bottom of the column, and an upper zone IV between the inlet 8 and the top of the column. There are provided in lower zone III a plurality of fiat rectication plates 9 superposed in staggered relation. In the distillation of intermediate alloy AD (liquid), the alloying agent D is evaporated, and rises in a vapor state through zone IV to the top of the column, from where it is conducted away at outlet II. The extracted metal A, on the other hand, remains in a liquid state and flows downwardly through zone III of the column, to be collected at the lower portion thereof. This part of the column is directly over the combustion chamber 30 of the furnace.

The liquid alloy AD entering at 8 flows over the fractionating plates 9, so that as the liquid alloy flows towards the botom it is continually in contact with the metallic vapors which are rising from the more heated bottom of zone HI. Even if metal A has a much higher boiling point than metal D, its evaporation is facilitated by the continuous removal of the vapors of metal D from the distillation zone, whereas moreover, the tension of the vapor of metal D is decreased owing to the presence of the liquid metal A. The metal D, as it evaporates, therefore carries with it vapor of metal A. Owing to the staggered plates, the vapor of metal A which has been carried along comes into intimate contact with the liquid alloy AD.Y An exchange of calories takes place between the vapor of metal A, which is thus condensed, and the liquid metal D, which is thus vaporized.

'I'he rectification plates 9 are provided on their top surfaces with a plurality of ledges 9', which are arranged in staggered relation as clearly seen in Fig. 2. The edges of the plates 9 are provided with overflow notches 9" as also seen in Fig. 2. The liquid intermediate alloy AD, entering the rectification column at 8, is caused to flow in a zig-zag course downwardly (as viewed in Fig. 1) from plate to plate, and also in a zigzag course horizontally on each individual plate (as viewed in Fig. 2), the liquid metal iiowing in a shower from the overflow notches 9" of the plate onto the next lower plate.

The devices indicated are in no way limitative. All the devices that are used for fractionating columns can be used for the purpose described. The liquid metal A, completely or almost completely free from metal D, collects in the heated lower part of zone III. It leaves the furnace through an overflow I0 and may be directly cast into ingots.

The almost pure vapors of metal D may undergo a further separation from metal A in lzone IV which is above the inlet 8. This zone is provided with arches 2" which are slightly curved and also arranged in staggered relation; they are provided with ribs on their lower surface and with holes 28. The vortices created in the ascending vapor cause drops of the metal A to be deposited; such deposited drops fall through the holes and eiect an efficient exchange of calories with the vapor they encounter to extract metal A therefrom.` The pure vapor of metal D leave zone IV through outlet I I, flow through the channel I2 and through the inlet I3 enter the condenser I4 which, with the refilling reservoir IB, form the zone V of the furnace. The condenser is a reservoir containing metal D in the liquid state. In order to facilitate the condensation of the vapors, they are compelled to pass through the liquid metal, and they are thus washedby orices I9' provided at the top of the chamber.

for the introduction of the liquid alloying agent D. 'I'he condenser maybe further provided with a plurality of staggered baille plates 65 and 66, arranged as clearly seen in Fig. 3. Any known type of condenser may be employed instead of the ones shown in Figs. 1 and 3. The condenser is capped by a tower I5, provided with a safety valve 2 I, in which any entrapped vapors are further condensed by cooling.

The reservoir I6 contains metal D, which is used for compensating the losses of said metal that may occur in the extraction process. It is connected to the condenser through an overiiow pipe I1.

In summary, the extracting operation is effected as follows:

The raw alloy ABC, loaded in the perforated cups, enters the furnace through the lower door 2. The Ixtraction ofthe metal A by the alloying metal D takes place in zone I, and the residual alloy containing none or very little of the metal A, leaves the furnace through the upper door 3. The downwardly flowing shower of liquid metal D, encounters the broken solids of the material ABC in the perforated cups of the conveyor, and interacts therewith to form the intermediate alloy AD. It should be noted that the alloy ABC is moved upwardly against the downward iiow of the alloying agent, so that the counter-current principle comes into full.play. The intermediate alloy AD (a liquid), together with such portions o fliquid agent D which had not succeeded in contacting the material ABC, are caught in the reservoir II. -There is also carried down and caught in the reservoir II some amounts of lsolid particles of Athe alloy ABC, A

which floats on the surface if lighter than alloy AD, or which sink therein if heavier. Reservoir II is also'a decanting reservoir, in that the solid particles are allowed to settle (to be removed at lower opening 5), or to float to the surface (to be removed at upper opening 4) i The 'intermediate alloy AD which is free of particles of alloy ABC flows in a continuous stream from decanting reservoir 1I into the rectiilcation column, more particularly into zone III. In this zone is effected the separation of the extracted metal A from the alloying metal D. The extracted metal A in the liquid state, ows

downwardly and leaves the furnace through the overflow pipe III, the alloying metal D, inV the vapor state, rises to the top of the column, and flows through the pipe I2 into the zone V, where it is condensed to its liquid state. The extracting metal D ows through the furnace in a closed circuit. and its losses which are comparatively small, are replaced from the lstore of this metal contained in the reservoir I6. i

'I'he arrangement of the heating system is governed by the necessity of producing different temperatures in different parts of the furnace. 'I'he heating may be eiected by means of hearths,

' gas-producers, burners, or electricity.

The heating system shown diagrammatically in Fig. 1 by way of a non-dimitative example, is a producer-gas heating system. Combustion ,takes place in chamber 30 of -the lower part of none III where inlets 3 I are located for the heated air. The combustion gases are conducted through conduits 32. 'I'he temperature of the hot gases gradually decreases all along the two circuitsv just traced, corresponding to the decreasing temperature which is to prevail in the' vvarious zones passed through. -The burnt gases or rather the hot gases duct 32L. That is, the

hot gases duct is between the rectification column and the preheated air fiues, which are thus furthest removed from the column. The preheatedv air ues 36a` on the right of the column, connect with ues 36h positioned to the left of the hot gases duct 32B, which surrounds the extraction chamber I. Here also the hot gases duct 32R is between the preheated air flues 36h and the chamber I. The ues 36h connect with a fresh air inlet 34. 'Ihe preheated air ilues 36c on the left of the rectification column, are positioned on the outside left wall of the furnace, and connect with a horizontal flue 36d at the top of the furnace, which leads to a second fresh air inlet 35. It will be observed that the hot gases duct 32H lies between the`condenser V andf the preheated air iiues 36d, which are nearest the roof of the furnace. The .v combustion air entering at comparatively cool points of the furnace, namely, points 34 and 35, is gradually preheated as it is conducted xto the combustion chamber 30. The distribution of the temperature in the various zones of the furnace is of capital importance. The temperature reaches its maximum, for example about 1,000 to 1,500 C., in the lower part of zone III and its minimum, for example about 300 to 500 C., in zone II. It is between these two zones, which are adjacent each other, that there is the greatest difference of temperature of the furnace. However, there is no danger of zone II being undesirably heated by conductivity from zone III, because ofthe fact that the metal circulates from zone II towardzone III. e

In zone III, which is the hottest part of the furnace, there should be a temperature which is considerably higher than the boiling point of metal D. For example, where zinc is used as the alloying agent D, zone III is required to be maintained at at least 907 C. Furthermore, the quantity of heat supplied should be sufficient to completely evaporate the extracting metal D, and the temperature of the upper part IV should be lower than that of the lower `part III. Actually, as the intermediate alloy AD flows downwards in zone III, it becomes enriched in metal A which has a substantially higher boiling point than that of D. The boiling point of the alloy therefore rises, and the vapor-tension of metal D, the percentage of which decreases, would gradually decrease if the temperature were not gradually increased.

In zone IV, the prevailing temperature should be near the boiling point of alloying metal D. This is to cause the condensation of portions of vapor of metal A whichvmay have been carried along by D. Also, in this zone the temperature is not everywhere the same, but as in zone III, gradually decreases, and near the outlet I3 of the pipe I2, the temperature of the furnace is scarcely higher than the boiling point of metal D.

In zone V, the` temperature should be below mains constant throughout the entire zone; it is chosen in accordance with the desired conditions of extraction. It is at this temperature that the metal D flows into the extracting chamber I. Extraction in the cups I', is therefore effected under the best temperature conditions, thereby facilitating the extraction of the last traces of metal A from the alloy ABC.

In zone I (extraction chamber), the temperature again gradually decreases, but from the top towards the bottom. In the region of the lowest cup, the prevailing temperature will be slightly `higher' than the melting temperature of the intermediate alloy AD, depending upon the per- 'centages of extracted metal A and extracting metal D. Zone II (decanting reservoir), should be maintained at the same temperature as prevails in the lower portion of zone I (extraction chamber), Y

The cup containing the alloy ABC which is not yet suiiiciently impoverished in metal A, and which leaves the furnace of Fig. 1 through the upper part 3, may be conveyed into a small auxiliary chamber provided in the path of the vapors D, as shown diagrammatically in Fig. 4. Before entering the condenser, the metallic vapors D come into contact with the metal A of the alloy ABC. 'I'he alloy thus formed flows in the liquid state through the pipe I3 into the condensing tank I4. 1

.While I have illustrated and described the preferred forms of construction for carrying my invention into effect, this is capablevof Variation and modification, without departing from the spirit ofthe invention. I therefore do not Wish to be limited to the precise details of ocnstruction set forth, but desire to avail myself of such variations and modications as come within the scope of the appended claims.

I claim:

1. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said extracted metal, the combination of an extraction chamber, means for introducing the alloying agent D in its liquid state -into the top of the chamber in the form of flowing streams, means for presenting broken solids of the raw alloy ABC to the said downwardly flowing streams of alloying agent, means for charging the said presenting means with fresh amounts of the raw alloy, means for removing therefrom the exhausted raw alloy, and a reservoir underlying the said extraction chamber for receiving the ow of the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together with the re- -;maining.part of the alloying agent .yvhich had not succeeded in reacting with the raw material. 2. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said extracted metal, the combination of an extraction 'chamber provided with means for introducing the alloying agent D in its liquid state into the top of the chamber in the form of flowing streams and means for presenting broken solids of the raw alloy ABC to the said downwardly owingstreams of alloying agent, and a. reservoir underlying the said extractiony chamber for receiving the flow of the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together with the remaining part of the alloying agent ,streams and means for presenting broken solids of the raw alloy ABC to the said downwardly flowing streams of alloying agent, and a decanting reservoir underlying the said extraction chamber into which the flow of the intermediate alloy AD formed by the alloying of the agent D with the'co'mponent A of the raw material ABC together with the remaining part of the alloying `agent which had'not succeeded in reacting with the raw material is received together with particlesv of the solid raw material carried downward with the liquid stream, and means for removing the said solid particles from the liquid in the said decanting reservoir.

4. The combination of claim 3 wherein the last mentioned means comprises an aperture in the wall of the said reservoir at the surface of the liquid therein for removing floating particles and an aperture at the foot of the reservoir for removing settled particles.

5. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said extracted metal, the combination of an extraction chamber provided with means for introducing the alloying agent D in its liquid state into the chamber in the form of flowing streams and means for conveying broken solids of the raw alloy ABC through the chamber, and a reservoir underlying the said extraction chamber for receiving the flow of the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw material, the said alloying agent introducing means being located at the top of the said chamber and the said conveying means passing the said broken solids upwardly and counter-current to the downwardly owing. stream of the said alloying agent.

6. In apparatus of the type which employs an alloying agent D for extracting a component vmetal A from a raw alloy or mixture ABC by i the top of the chamber-in the form of 'owing the remaining part of the alloying agent which' streams and means for presenting broken solids of the raw alloy ABC to the said downwardly v flowing streams of alloying agent, a reservoir underlying the said extraction chamber for receiving the flow of the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together with had not succeeded in reacting with the raw material, a rectification column for separating the said intermediate alloy AD into its components, a conduit connecting the said ectiiication column with the said reservoir, the said rectification column including a receptacle at the bottom of the column for collecting liquid ow of extracted metal A and an outlet at the top 0I the column al A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said ex tracted metal, the combination of an extraction chamber provided with means for introducing the alloying agent D in its liquid state into the chamber in the form of a iiowinlg stream and means for presenting broken solids of the raw alloy ABC. to the said downwardly flowing stream of alloying agent, a rectification column connected to the said chamber to receive the flow of the intermediate alloy AD formed by the alloying of vthe agent D with the component A of the raw l material ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw material, the said rectification column being adapted to separate the said intermediate alloy AD into its components and provided with a receptacle at the bottom for collecting the liquid flow of extracted metal A and an outlet at the top of the column for the vapor of alloying metal D, and a condenser between the said vapor outlet and the said alloying agent introducing means of the extraction chamber for liquefying the said vapor.

8. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said extracted metal, the combination of an extraction chamber provided with means for introducing the alloying agent D in its liquid state into the top of the chamber in the form of iiowingstreams and means for presenting broken solids of the raw alloy ABC to the said downwardly flowing streams of alloying agent, a reservoir underlying the said extraction chamber for receiving the ow of the in'- termediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together with the remaining part of the alloying agent which 'had not succeeded in reacting with the raw material, a rectification column for separating the said intermediate alloyv D into its components,

including a receptacle at the bottom of the column for collecting liquid i'low of the extracted metal A and an outlet at the top of the column for escape of vapor of the alloying metal D, and a condenser connected to the said outlet for liquefying the said vapor.

9. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said extracted metal, the combination of an xtraction chamber provided with means for introducing the'alloying agent D in its liquid state into the top of the chamber in the form of owing streams a-nd meansv for presenting broken solids of the raw alloy ABC to the said downwardly flowing streams of alloying agent, a. reservoir underlying the said extraction chamber for receiving the ow of the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material 'ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw material, a distillation vessel and a conduit between the said reservoir and the said vessel, lthe said conduit connecting to the said vessel to form an inlet into the vessel at a point substantially level with the sur face of the liquid in the said reservoir whereby the said liquid flows continuously into the said distillation vessel.

10. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said extracted metal, the combination of an extraction chamber provided with means for introducing the alloying agent D in its liquid state into the top of they chamber in the formA of owing streams and means for presenting broken solids of the raw alloy ABC to the said downwardly iiowing streams of alloying agent, a reservoir underlying the said extraction chamber for receiving the flow of the intermediate alloy AD formed by the alloying of lthe agent D with the component A of the raw material ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw. material, a distillae tion vessel for separating the said alloying agent D in vapor form from the said extractedv metal A in liquid form by distillation of the said intermediate alloy AD, and a condenserv for liquefying the said alloying agent vapor.

1l. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC K by forming an intermediate alloy AD with the said extracted 'metaL the combination of an extraction chamber provided with means for introducing the alloying agent D in its liquid ,state into `the top of the chamber in theform of flowing streams and means for presenting broken solids of the raw alloy ABC to the said downwardly flowing streams of alloying agent, a reservoir underlying the said extraction chamber for receiving the flow of the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw material, and a distillation vessel for separating the said alloying 'agent D in vapor form from the said extracted metal A in liquid form by distillation of the and intermediate alloy AD.

12. In apparatus of the Atype which employs an alloying agent Difor extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the saidextracted metal, the combination of an extraction chamber provided with means for introducing the alloying agent D in its liquid state into the chamber` in the form of a iiowing stream and means for presenting broken' solids of the raw alloy ABC to the said downwardly flowing stream of alloying agent, a distillation vessel connected to the said chamber.

to receive the ow of the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw material, the said distillation vessel being adapted to separatethe said intermediate alloy AD into its components.

13, In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy, AD with the said extracted metal, the combination of an extraction chamber provided with means for introducig the alloying agent D in its liquid state into the top of the chamber in the form of flowing streams and means for presenting broken solids of the raw alloy ABCl to the said downwardly flowing streams of alloying agent, a reservoir underlying the said extraction chamber for receiving the now of the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw ma,- terial, and a rectification Acolumn for separating the said intermediate alloy AD into its components, including a receptacle at the bottom for collecting liquid flow of extracted metal A and an outlet at the top of the column for escape of vapors of the alloying metal D.

14. In apparatus oi the type which employs an alloying agent D -for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said extracted metal, the combination of a main extraction chamber provided with means for introducing the alloying agentD in its liquid state into the top of the chamber in the form of ilowing streams and means for presenting broken solids of the raw alloy ABC to the said downwardly flowing streams of alloying agent, a reservoir underlying the said extraction chamber for receiving the flow the intermediate alloy AD formed by the alloying of the agent D with the component A of the raw material ABC together rwith the remaining part of the alloying agent which had not succeeded in reacting with the raw material, a rectification column for separating the said extracted metal A in liquid form from the said alloying agent D in vapor formed by distillation of the said intermediate alloy AD, a condenser for liquefying the said alloying agent vapor, and an auxiliary extraction chamber between the said condenser and rectiiication column for subjecting the exhausted raw alloy taken from the main extraction chamber, to the said vapors of the alloying agent.

l5. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermedaite alloy AD with the said extracted metal, the combination of an extraction chamber provided with means for introducing the alloying agent D in its liquid state into the top of the chamber in the form of vflowing streams andfmeans for presenting broken solidsof the raw alloy ABC to the said downwardly ilowing streams of alloying agent, a reservoir underlying the said extraction chamber for receiving the ilow of the intermediate alloy AD formed by the alloying of the agent D with the companent A of the raw material ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw material, a rectification column for separating the said intermediate alloy AD into its components, including a receptacle at the bottom ci the co1- umn for collecting liquid iiow of extracted metal A and an outlet at the top of the column for escape of vapors of the alloying metal D, a condenser between the said vapor outlet of the rectiiication column and the said alloying agent introducing means of the extraction chamber for liquefying the said vapor, and a heating system including a furnace underlying the said extracted metal receptacle and a hot gases duct passing the rectification column, condenser, extraction chamber and reservoir in succession. adapted to maintain the rectification column at a temperature above the evaporation point of the alloying metal D, to maintain the condenser at a temperature below the said evaporation point, and to maintain the extraction chamber and reservoir at a point above the solidification point of the intermediate alloy AD.

16. In apparatus of the type which employs an alloying agent D for extracting a component metal A from a raw alloy or mixture ABC by forming an intermediate alloy AD with the said extracted metal,A the combination of an extraction chamber provided with means for introducing the alloying agent D in `its liquid state into the top of the chamber in the form of flowing streams and means for presenting broken solids of the raw alloy ABC to the said downwardly flowing streams of alloying agent, a reservoir underlying the said extraction chamber for receiving the flow of Iche intermediate alloy AD formed by the alloying of the agent D with the component A of the raw materiall ABC together with the remaining part of the alloying agent which had not succeeded in reacting with the raw material, a rectification column for separating the said intermediate alloy AD into its components, a conduit connecting the said rectification column with the said reservoir, the said rectification column including a receptacle at the bottom of the column for collecting liquid ow of extracted metal A and an outlet at the top of the column for. escape of vapor of the alloying metal D, a condenser for liquefying the said Vapor, a conduit for conducting the said vapor from the said column outlet to the said condenser, a conduit for conducting the liquid agent D from the said condenser to the said agent introducing means of the extraction chamber, and for ymaintaining a continuousgcirculation of the said alloying agent through the apparatus.

HIRSCH LOEVENSTEIN.

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