US2121084A

US2121084A - Production of beryllium

Info

Publication number: US2121084A
Application number: US38399A
Authority: US
Inventors: Kruh Osias
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-09-10
Filing date: 1935-08-29
Publication date: 1938-06-21
Anticipated expiration: 1955-06-21

Description

June 21, 1938. Q KRUH 2,121,084

PRODUCTION oF BERYLLIUM Filed Aug. 29, 1935 2 sheets-sheet 1- 26 5 5 l f5 .-/j--l-lmmmmmmmmmgg f June 21, 1938. Q KRUH 2,121,084

PRODUCTION oF BERYLLIM Fil'ed Aug. 29, 1955 2 sheets-sheet 2 Patented June 2l, 1938 vUNITED STATES Y 2,121,084E p PRODUCTION F BERYLLIUM Osias Kruh, Vienna, Austria Application August 29, 1935, Serial No. 38,399

In Austria September 10, 1934 25 claims.

It has already been attempted to reduce beryllium oxide with the aid of carbon, for instance by heating, a mixture of beryllium oxide and carbon to a high temperature (of the order of 2000 C.) l0 in an electric furnace. But the attempts made in this direction have not as yet led to any useful result, since beryllium becomes re-oxidized by the carbon monoxide formed in the course of the reduction reaction, and also combines with ,carbon to yield beryllium carbide. For this reason beryllium has been produced up to the present electrolytically. The common method of practicing this manufacturing process is to electrolyze a fused mixture of BeFaNa and BeF4Ba at a temperature serve as the anode, the cathode being formed of a water-cooled iron tube. The' voltage required for this process is as high as 80 volts, and this fact, in conjunction with the low atomic Weight of beryllium, results .in a current consumption of 476 kilowatt-hours for the production of 1 kilogramme of beryllium. 'The consumption of electrical energy is thus extremely high in comparison with the electrolytic recovery of other metals. 30 Moreover, the production of the double salts in the required degree of purity is also costly, with the result that the price of electrolytically produced beryllium is so high as to be a bar to its more extensive use. I

'I'he main object of the present invention is to provide a process for the production of beryllium which is simpler and cheaper than the methods hitherto known, and which is not dependent on the use of chemically pure starting materials.

With the process according to the present inventicn it is possible to produce beryllium on a L commercial scale and in a high degree of purity,

the essence of the process being to heat a loose mixture of beryllium oxide and carbon, preferably 5in the correct chemical proportions, to a high temperature, while causing a stream of inert gas, preferably hydrogen, to flow through the charge, the heating being carried to the point at which the beryllium is disengaged in the form of Vapor,- for which purpose the charge is heated to a temperature of at least 1900 C. .The hydrogen surrounds the evolved beryllium vapor and protects 'it from reaction with carbon monoxide and carbon, so that both the re-formation of beryllium 55 oxide and the formation of beryllium carbide are avoided. The gaseous and vaporous mixture is.

conducted continuously out of the reaction chamber, and immediately cooleddown to such an extent that no reaction at all can take place be- 60 tween theberyllium on the one hand and the of 1350 C. in an Acheson Crucible connected to (Cl. 'I5-84) gaseous reaction products and carbon on the other hand. A major portion of the beryllium becomes deposited from the vaporous phase on to the cooled surface of the chilling device employed, while the gases are drawn off together With the remainder of the beryllium. The deposited beryllium can be detached from the cooling surfaces by mechanical means, and conveyed into a collecting chamber. The portion of the beryllium which is not deposited is carried along with the protective gas, which also contains carbon monoxide, and can then be separated out vfrom the gases in any suitable manner, seeing that it in part becomes deposited in the further course ofv its travel and in part can be recovered by mechanical or electrical filtration.

In practicing the process of the present invention it is advisable to make the reaction chamber of trough shape and to provide immediately above this reaction chamber a cooling device which may consist for example of a rotary drum extending over the entire length of the reaction chamber and cooled internally, so that the beryllium vapor rising from the reaction mixture becomes deposited on the peripheral surface thereof. The beryllium is deposited on this surface in a finely divided state, and can be removedtherefrom by means of a scraper and removed from the furnace by means of any suitable conveying device.

The heating of the reaction chamber is best effect-ed electrically, and that preferably by means of alternating current.

It has been already mentioned above'that hydrogen is preferably used as protective gas, the reason being that beryllium is more readily volatile in a current of hydrogen. At the high furnace temperature used, considerable quantities of acetylene are formed by the action of the hydrogen on the carbon contained in the reaction mixture, which takes place at the expense of the heating energy supplied, since the reaction involved is endothermal. This does not, however, imply any loss of energy, since, as is Well known, acetylene exerts a powerful reducing action, and the assistance rendered by the acetylene in effecting the reduction of the'beryllium oxide is equivalent to recovery of the energy absorbed.

If acetylene be consumed in the reaction there results a disturbance of the temperature equilibrium between hydrogen, carbon, and acetylene, with the result that acetylene is again at once formed, the hydrogen generated on the splitting of acetylene combining once more with carbon to l Moreover, the fact that the ployed jointly for the purpose of the reduction in question.

The formation `ofpure beryllium can also be aided by a further expedient. This expedient consists in sintering berylliumoxide, comminuting it to about pea-size, `and mixing it with carbon of about the same size. The result achieved in this manner is that the reduction takes place on the surface of the particles of beryllium oxide, thus rendering the velocity of the reaction uni- Y form. The beryllium disengaged at any moment in the form of vapor at the surface of the` oxide particles is at once surrounded by the protective gas, so that carbide formationv is precluded while at the same time, since the evolution of vapor takes place uniformly, the various measures and phases of the process, that is to say the vsupply of hydrogen, the deposition of the metal vapor, the detachment of the deposited metal from the cooling device, and the like, can also be caused to proceed uniformly, that is to say at a uniform rate.

The quantity of protective gas employed in the carrying out of the process need by no means be large. In consequence of the low molecular weight of hydrogen, the average velocity of the hydrogen particles is considerably higher than that of carbon monoxider or that of beryllium vapor, or that of carbon vapor. Hydrogen thus occupies more space than carbon monoxide and carbon vapor, and an amount of hydrogen about 3-4' times that of the carbon monoxide present is suflicient to protect the particles of beryllium. In order tokeep the charge at an even temperature it is advisable to pre-heat the protective gas outside the furnace.

The following example may serve to illustrate the nature of the reaction. vAssuming the furnace to be operated uninterruptedly, the reaction proceeds on the following lines:

2800 g. BeO-l-1350 g. C|990 g. Hz:

' 1000g. Be+3150 g. CO+990 g. H2

Analyses of the product show beryllium yields of 98-99.5%, the remainder being beryllium oxide.

A constructional example of apparatus for the carrying out of the process according to the invention is shown in the accompanying drawings, in which:

Fig. 1 is a side elevation of the plant, partly in section taken on the line A-A of Fig. 2.

Fig. 2 is a front elevation partly in section taken on the line B-B of Fig. 1. y

Fig. 3 is a plan view partly in section taken on the line C-C of Fig. 1.

In" the furnace .I there is provided an elongated shallow trough 1 which serves as a reaction chamber for the production of beryllium by reduction. The walls of this chamber are provided with a lining 2 of refractory material, protected from the action of excessive temperature by the cooling tubes 8f. I

The reaction chamber 1 communicates through a channel 6 with the top portion 3 of the furnace, this top'portion being provided with a rotary sieve 4 and, lower down, with a gas inlet 5. In rder to carry out the process of reducing beryllium oxide according to the invention the, v'reaction chamber 1 is filled with this Oxide together with the reducing agent, and with the protective gas. For example, a mixture of beryllium oxide and carbon, in the correct proportions is supplied to the chamber 1 through the top -portion 3 of the furnace and the channel E, the sieve 4 being rotated at the speed required to maintain a balance between the rate of feed of the material to thereaction chamber and the rate at which the products of reaction leave the same; at the same time, hydrogen enters at 5, and is introduced into the reaction chamber through the temperature, and in the presence ofhydrogen the reduction of the beryllium oxide to metallic beryllium takes place.

The protective gas flows through the reaction chamber and carries the reaction gases, consisting mainly of carbon monoxide, together with the beryllium vapor towards an internally cooled.

rotary cylinder II located above and longitudinally of the reaction chamber. This gaseous mixture is cooled by the cylinder II to a temable to oxidize beryllium. The beryllium vapor is deposited on t e surface of the cooled'cylinder in the form of kind of metallic snow, and is `then scraped 01T this cylinder by means of a movable scraper I2, and conveyed through the funnel-shaped chute I3 into a cylindrical channel I8 whence it is carried by a conveyor helix I4 through the discharge pipe I9 to the chamber I5 whereit collects. The portion of the beryllium not deposited on the cooling surface but carried on by the flowing gas mixture settles on the conveyor helix I 4, and the last traces of beryllium are retained by the mechanical filter I6 or an electric filter in the chamber I5. A block-shaped packing 20 interposed between the top of the cylinder II'and the inner wall of the furnace I prevents the flow of hydrogen from by-passing the reaction chamber 1.

The mixture of hydrogen and carbon monoxide leaves the chamber I5 at I1, and may be used, subsequently, for any desired purpose. I'prefer, however, to recover the pure hydrogen from this mixture and to re-conduct it into the furnace I in order to obtain in the apparatus a closed circulation of the protective gas. To this end, as shown in Fig. 1 by the chain-dotted lines, the mixture of gases is passed from the chamber I5 through the conduit 2| to a device 22 in which the hydrogen is separated from the carbon monoxide and from other impurities, and returned to the furnace through the conduit 23, a pump or exhauster 24.01 conventional design being interposed in this conduit' for the purpose of maintaining the required circulation of the hydrogen. Fresh hydrogen may be supplied to the furnace or may be fed ,into circulation by the pipe 25 or by the pipe 26. Means for separating .pure hydrogen from a gaseous mixture containing hydrogen are well known in the art, and their special construction does not constitute any part of my invention. Thus, by the' rectangle 22 I have only indicated where such a device could be placed, Without showing the known parts of this device.

The finely divided beryllium collecting in the chamber. I5 may be used in this state for chem- `ical or other purposes. It may also be cast into Aperature at which carbon monoxide is no longer bars or ingots, and used for any purpose for which beryllium is manufactured.

Preferably, the casting process may be carried out at once in the collecting chamber I5 so that it takes place in the presence and under the protective action of the protective gas (e. g. hydrogen) used in the reduction process. For this purpose, the chamber I5 may be constructed in any known manner, but preferably in the manner shown by way of example in Fig. 1. In this iigure the inner Walls of the chamber I5 are covered with a lining 21 consisting of a refractory material which does not react with molten beryllium, for instance cryolite, magnesite, or any other suitable brick, but I'prefer to use sintered aluminium oxide or beryllium oxide, since this lining material gives excellent results. The beryllium collecting in lthe chamber I5 is melted upon a casting bed which is constructed in the manner of a filter, comprising a. perforated botton 28 carrying a heaped layer 29 of a refractory material incapable of reacting with beryllium at elevated temperatures. This material may be the same as that of the 1ining'2l, for instance cryolite, magnesite, or the like, but pref- \erably sintered alumina. To melt the beryllium any suitable heating means may be provided, and

preferably electrical means, for example a high frequency coil 30 disposed outside the chamber I5, as shown in Fig. 1. The construction of electrical heaters for melting and casting vpurposes is well known in the art and, therefore, does not constitute any part of my invention. The molten beryllium passes into the bottom part of the chamber I5 through the filter 28, 29 which retains any impurities, and may then be discharged from the chamber I5 through the :outlet provided thereon.

The apparatus is to be considered as fitted with the requisite cooling and driving instrumentalitiesfit being understood that I do not claim the particular construction of such instrumentalities, since the same are frequently used inmetallurgical and electro-metallurgical processes, and are known per se. In the apparatus shown in the drawings the cylinder Il, the tubes 3, and the electrodes I0 are water-cooled during the operation of the plant.. For this purpose

water inlet pipes

32, 34, 36, and

water outlet pipes

33, 35, 31 are provided. The pipe 32 extends into theinterior of. the cylinder II so as to discharge cooling water into the same. The Water leaving the cylinder Il through the spout 38 ows into the vessel 39, and thence into the pipe 33. 'Ihe ends ofthe cooling tubes 8 are fitted into water distributing chambers 40 and 4I, these chambers being connected to the pipes 34 and 35, respectively, so as to allow the cooling water to flow from 34 through 40, 8, and 4I into 35. Each electrode I0 is partly surrounded by a water-filled casing 42 which is connected on one side to the inlet pipe 3B and on the other to the

outlet pipe

3,1.

The

axles

43, 44, and 45 of the sieve 4, cylinder II, and conveyor I8 are lrotatable in

bearings

46, 41, and 48, respectively, and are fitted with pulleys 49, for rotation therewith at the required speed. The cylinder II is driven by a pulley 5I secured to the tube 38. It will be clear that the

pulleys

49, 50, and 5I may be replaced by any `other suitable transmission or driving means, for instance for electric drive.

The top 3 of the furnace I may be closed by a cover 52 pivoted at 53 and having handles 54.

When electric resistance heating is employed in the furnace, the described process does not even require $430 part of the electrical energy required for carrying out the hitherto usually practiced electrolytic method of manufacture. It is also not necessary with the present process to produce the complex double salts necessary for the electrolytic process. A further advantage of the process according to the present invention over the electrolytic process resides in the fact that alternating current can be employed, implying considerably lower installation costs as compared with direct current. If sufficiently pure carbon ,or acetylene be employed in the presence of hydrogen for the purpose of the reduction, highly refined beryllium is obtained, since this metal sublimes in a current of hydrogen. After sublimation, the beryllium becomes deposited yin the form of fine crystals.

In consequence of its low atomic weight, beryllium is used for a variety of purposes. Thus for example it is very Well suited as material for thev outlet windows for the electrons in electric discharge tubes. A further use for beryllium is in the production of alloys with manyY other metals. When added as an alloying constituent to aluminium it increases the strength of the latter. An alloy of aluminium, copper, and beryllium exhibits particularly valuable properties, for instance.

To produce an alloy ofA aluminium and beryllium it is not-necessary, in the recovering of these metals, to separate the beryllium oxide from the aluminium oxide, since aluminium and beryllium have the same boiling point, so that these metals can be reduced simultaneously by the above described process in one and the same furnace. In this manner there is obtained a high percentage aluminium-beryllium `alloy which can be added to aluminium or its alloys.

When beryllium ore is employed which contains silica in addition to aluminium oxide the silica can be slagged for example by the addition ofiron, whereupon the slag formed flows out of the furnace. The A12O3.3Be0 left behind is then subjected to the process described above, with the result that an aluminium-beryllium alloy is obtained in a simple and inexpensive manner.

I claim:

1. In the manufacture of beryllium or beryllium alloys, the process which comprises reducing beryllium oxide with the aid of carbonaceous material in the presence of a protective gas which is inert to beryllium at a temperature sufficient to vaporize into said gas the beryllium formed by reduction.

2. In the manufacture of beryllium or beryllium alloys, the process which comprises preparing a mixture containing beryllium oxide and carbonaceous material exposing lsaid mixture to the action of a flowing protective gas inert to beryllium while heating the mixture to a temperature suincient to reduce beryllium oxide by the action of the carbonaceous material and to vaporize into said protective gas the beryllium formed by reduction; carrying away the composite of metallic vapour, protective gas, and gaseous reaction products formed during th-e said reduction process; and cooling said composite to a gaseous reaction products formed during the said reduction process; and cooling said composite to a temperature sufficiently low 4to prevent the beryllium particles from reacting with the said gaseous reaction. products and to condense the beryllium vapours so as to obtain the beryllium in the solid state. v

5. In the manufacture of beryllium, the process which comprises loosely mixing beryllium oxide and carbon; heating said mixture to a temperature sufcient to reduce said xide by the action of the carbon and to vaporize the beryllium formed thereby; surrounding the vaporized beryllium particles with a protective gas inert to beryllium so as to protect said particles from the chemical attack by other gases present; carrying away the gaseous mixture of beryllium vapor, protective gas, and reaction gases formed during the reduction process; cooling said gaseous mixture to a temperature suflicient for preventing the beryllium particles from being oxidized by the said reaction gases; and removing from the said gaseous mixture the beryllium in the solid state.

6. The process, as claimed in claim 2, wherein the beryllium oxide and the carbonaceous material are contained in the said mixture inproportions corresponding substantially to the stoichiometrical relation between beryllium oxide and carbon.

7. In the manufacture. of beryllium or beryllium alloys, the process which comprises reducing beryllium oxide with the aid of carbon hydrides in the presence of a protective -gas inert to beryllium at a temperature sufilcient to vaporize into said gas the beryllium formed by reduction.

8.` In the manufacture of beryllium or beryllium alloys, the process which comprises reducing beryllium oxide by acetylene in the presence of hydrogen at a temperature sufficient for vaporizing into said hydrogen the beryllium' formed by reduction.

9. In the manufacture of beryllium o'r beryllium alloys',l the process which comprises reducing beryllium oxide with the aid of a carbonaceous material in the presence of a gas mixture containing hydrogen and at least one hydride of carbon, said reducing process being carried out at a temperature sufficient for vaporizing into said gas mixture the beryllium formed by reduction.

10. In the manufacture of beryllium or beryllium alloys, the process which comprises reducing beryllium oxide with the aid of a carbonaceousv material in the presence of a gas mixture containing hydrogen and acetylene, said reducing process being carried out 'at a temperature sutiltained in a proportion which is sufllcient to protect the beryllium particles from the attack by other gases present and to prevent the forma-` tion of beryllium' carbide.

12. In the manufacture of beryllium, the process which comprises reducing beryllium oxide with the aid of carbonaceous material in the presn ence of iiowing hydrogen at a temperature suillcient to vaporize into said hydrogen the beryllium formed by reduction, the amount of hydrogen supplied to the process being at least three times that of the carbon monoxide formed by the restantially to the temperature equilibrium between hydrogen, carbon and acetylene, said reducing process being carried out at a temperature which is sufficiently elevated for vaporizing into said gas mixture thev beryllium formed by reduction.

14. The process of manufacturing beryllium,

4which comprises heating a mixture of beryllium oxide and carbonaceous materialin a reaction chamber to a temperature which affords the reduction of the beryllium oxide by carbon and the vaporization of the beryllium formed thereby; supplying to said ehamberla protective gas inert to beryllium; withdrawing from the reaction chamber., the mixture of beryllium vapour, protective gas, and gaseous reaction products formed during the said reduction process cooling said mixture when leaving the reaction chamber, to a temperature sufficient to prevent oxidation of the beryllium and formation of beryllium carbide and to condense the beryllium vapour; carrying away the condensate of beryllium from the reaction chamber together with the said gaseous mixture; and separating froml this i latter the beryllium in the solid state.

15. In the manufacture of beryllium or beryllium alloys, the process which comprises heating a mixture containing beryllium 'oxide and carchamber to a temperature suiiicient to condense the metallic vapour; collecting the metallic particles condensed; recovering the said protective glas in a pure state'from the said composite; and repassing the recovered protective gas. through the reaction chamber.

16. The process of manufacturing beryllium, which comprises reducing beryllium with the aid ofcarbonaceous material in the presence of a flowing protective gas inert to beryllium at a temperature suiiicient for vaporizing into4 said gas the beryllium formed by reduction; carrying away and cooling the mixture of gases and vapours formed during the said reduction process;

state; collecting'the beryllium condensed; heating the beryllium collected to a temperature sufficient for fusing the same, and casting the fused beryllium.

17..The process. of manufacturing beryllium as set forth in claim 5 characterized in that the beryllium oxide to be reduced is used in a sintered state and in the shape of particles of condensing the beryllium vapours from the said mixture so as to obtain beryllium in the solid about pea-size and that the carbon as reducing agent is also used in particles of about pea-size.

18. In the manufacture of alloys of beryllium with aluminium, the process which comprises preparing a mixture containing aluminium oxide, beryllium oxide and a carbonaceous material; exposing said mixture to a flowing protective gas inert to aluminium and beryllium while heating the mixture to a temperature sufcient to reduce the beryllium oxide andthe aluminium oxide by the action of the carbonaceous material and to vaporize into said protective gas the aluminium and the beryllium formed by reduction; carrying away the composite of aluminium vapour, beryllium vapour, protective gas and gaseous products formed during the said reduction process; and cooling said composite to a temperature suiilcient to transform the aluminium vapour and the beryllium vapour into the solid state and to prevent the particles of aluminium and beryllium'from reacting` with the said gaseous reaction products.

19. The process as set forth in claim 18, in which the said mixture is prepared of ores containing silica in addition to the beryllium oxide and the aluminium oxide, and of a substance adapted to form with the silica a slag, which flows out of the reaction chamber.

20. In the manufacture of beryllium, the process which comprises preparing a loose mixture of beryllium oxide and carbonaceous reducing material so that gas brought into contact with said mixture has access to the inner particles thereof;.exposing said mixture to a flowing protective gas inert to beryllium while heating the mixture to a temperature suillcient to reduce affords the reduction lof both oxides by carbon and the vaporization of the beryllium and aluminium formed thereby; supplying to said chamber a protective gas inert to beryllium as well as to aluminium; withdrawing from the reaction chamber the composite of beryllium vapor, aluminium vapor, protective gas, and gaseous reaction products formed during the said reduction process, cooling said composite when leaving the reaction chamber to a temperature suiiicient to condense the beryllium vapor and the aluminium Av apor and to prevent the formation of beryllium carbide and aluminium carbide; carrying away the condensate from the reaction chamber together with the said gaseous composite; and lseparating from this latter a beryllium-aluminium alloy in the solid state.

23. In the manufacture of beryllium alloys, the process which comprises heating a loosemixture containing beryllium oxide and carbonaceous material in a reaction chamber to a temperature which affords reduction of the beryllium oxide by carbon and vaporization of the beryllium formed thereby; supplying to said chamber a protective gas inert to beryllium; withdrawing from the reaction chamber the composite of beryllium vapor, protective gas, and gaseous reaction products formed during the said reduction process; cooling said mixture immediately after leaving the reactionchamber to a temperaturesufiicient to prevent oxidation of the beryllium an formation of beryllium carbide and to condense the beryllium vapor; carrying away the condensate from the reaction chamber together with the said protective gas, and gaseous reaction products formed during the said reduction process and cooling said composite to a'. temperature suincient to transform the beryllium vapor-ized into the solidstate and to prevent the beryllium particles from reactingwith the said gaseous reaction products.

21. In the manufacture of beryllium-aluminium alloys, the process which comprises preparing a loose mixture containing beryllium oxide, aluminium oxide and carbonaceous reducing material so that gas brought into contact with said mixture has access to the inner particles thereof; exposing said mixture to a ilowing protective gas inert to beryllium as well as to aluminium while heating the mixture to a tempera- 'ture su'filcient to reduce both, the beryllium oxide and the aluminium oxide, by the action of the carbonaceous material and to vaporize into said protective gas the beryllium and aluminium formed by reduction; carrying away the composite oi' beryllium vapor, aluminium vapor, protective gas, and gaseous reaction products formed during the said reduction process; andcooling said composite to a'temperature sumcient to condense from the said vapors a beryllium-aluminium alloy andto prevent said alloy from reacting with the said gaseous reaction products.

22. The process of manufacturing alloys of beryllium with aluminium, which comprises heating in a reaction .chamber a loose mixture containing beryllium oxide, aluminium oxide and carbonaceous material to a temperature which gaseous mixture; andseparating from this latter the said condensate in the solid state.

24. In the manufacture of beryllium or beryllium-alloys, the process which vcomprises preparing a loose mixture containing pea-sized particles of carbon and of sintered beryllium oxide ;-heat ing said mixture to a temperature suilicient to reduce said oxide by the action of the carbon and to vaporize the beryllium formed thereby; and at the same time exposing said mixture to a flowing protective gas inert to beryllium so as to protect the beryllium from the chemical attack by other gases present; carrying away the gaseous composite of beryllium vapor, protective gas, and gaseous reaction products formed during 'the said reduction process; and cooling said composite to a temperature suiilcient to prevent the beryllium particles from reacting with the said gaseous reactionproducts.

25. In the manufacture of alloys of beryllium with aluminium, the process which comprises preparing a mixture containing beryllium oxide, aluminium oxide and a carbonaceous material; exposing said mixture to ilowing hydrogen while heating the mixture to a temperature suiilcient to reduce both oxides by the action of the carbonaceous material and to vaporize the aluminium.