US1869493A - Lithium alloys and process of producing the same - Google Patents

Description

Patented Aug. 2, 1 932 PATENT OFFICE HANS OSBORG, OF FRANKFORT-ON-THE-MAIN, GERMANY LITHIUM ALLOYS AND PROCESS OF PRODUCING THE SAME No Drawing.

The present invention relates to alloys of lithium and more particularly to alloys of lithium and members of the alkaline earth family.

Heretofore, it has been proposed to pro-' duce various lithium alloys by adding the lithium to a fused bath of the metal with which it is to be alloyed or by mixing lithium and the other metal or metals together in a solid or fused state and then forming an alloy of lithium therefrom. These procedures were accompanied by many serious disadvantages, the most important of which was the loss of lithium due to volatilization of the lithium. As lithium was very costly in price it made the cost of production of the lithium alloy excessively high and in many cases exhorbitant and unavailable commercially. Although various attempts have been made to remedy the shortcomings of the old process, none, as far as I am aware, has been satisfactory and successful in practical operation. It is an object of the present invention to overcome the. disadvantages noted hereinabove with respect to old processes of producing lithiumalloys and to provide the art with a simple, practical and satisfactory proc'edure with which lithium alloys can be made on an industrial and commercial scale.

It is 'a further object of the invention to provide an electrolytic method for producing alloys of lithium which can be conducted in a practical manner. a

A further object of the invention is to provide a convenient method of producing lithium alloys by the electrolysis of salts which are readily and commercially available.

Other objects and advantages of the in-:

vention will become apparent from the following description.

I have discovered that I can produce alloys of lithium and members of the alkaline earth family by the electrolysis of fused salts. By

constituting the fused bath of .such a com- Application filed July 8,1930. Serial No. 466,583.

" position, with respect to the components thereof'or by arranging conditions within the bath so that the decomposition voltage of the components of the lithium alloy to be made lie relatively close to each other, by passing electric current therethrough having a potential approximating the decomposition voltages, 1 have found that a lithium alloy can be produced. In some cases, I have found it preferable to add a neutral material to the bath in order tobring the decomposition voltages of the components of the lithium alloy relatively close to each other. By proceeding in the foregoing manner, I have been able to produce various alloys constituted of lithium and a member of the alkaline earth family. 7

The following examples are given for the purpose of illustration and for a better understanding of my invention by those skilled in the art. It is to be noted however, that although, in the illustrative example, certain substances, temperatures, voltages, amperages, anodes, cathodes and other operating conditions are specifically given, nevertheless, the invention is not to be limited thereto but is only to be restricted by the appended claims.

Example N0.1

A bath comprising fifty parts of lithium chloride and fifty parts of calcium chloride is maintained at an elevated temperature preferably within a range from about 400 C. to about 500 (3., While an electric current is passed therethrough having a voltage of about 4.9 volts and an amperage of about 21 amperes. In carrying out the electrolysis in the aforesaid bath, I prefer to use a graphite anode having an area of about 7 5 sq. centimeters and located preferably in a lower portion of the bath. For a cathode, I prefer to employ a low carbon steel cathode having an area of about 1.5 sq. centimeters and located preferably in the upper part of .9

.conditions, I have been able to produce alloys of calcium and lithium. An analysis of these alloys showed that the calcium content varied from 80.6% to 81.9% and the balance lithium.

Example No.2 7

The bath in the present instance was constituted of about 48 parts of lithium chloride, 32 parts of potassium chloride and about 20 parts of calcium chloride. The bath was maintained at a temperature from about 350 C. to about 370 C. and the electric current passed therethrough at a voltage of about .5 volts and an amperage of about 15 amperes. The same type of graphite anode and steel cathode which were used for Example No. l were used in this case. The lithium alloy skimmed from the surface of the fused bath showed a composition having a calcium content varying from about 53.6% to .about 57.9% and the balance lithium.

E wample N 0. 3

A bath constituted of about 54.5 parts of lithium chloride, about 36.4 parts of potassium chloride, and about 9.1 parts of calcium chloride was used. The bath was maintained at a temperature from within a range of 350 C. to about 370 C. An electric current having a Volta e of about 5.0 volts and an amperage of a out 12.0 amperes was employed. Specimens of the lithium alloy showed that the calcium contained therein varied from about 38.5% to about 41.0% and the balance lithium. The same anode and cathode as used hereinabove were employed.

In case a cathode is employed which has an ability to alloy or combine with the lithium alloy, an alloy is produced directly on the cathode. For instance, I have been able to produce various lead-lithium alloys by employing a lead cathode instead of a steel cathode. In a particular case I was able to produce a master lead alloy for bearing metals. This matter alloy was previously of pigs and used as a bearing alloy in the production of bearing metal.

In case it is desired to manufacture the heated with a fused bath of lead and mixed in the latter so as to give a bearing lead alloy having a calcium content of about 0.7%, a sodium content of about 0.6% and a lithium content of about 0.04%.

In case molten lead is used in place of steel cathode, then' the molten lead is flowed through the bottom of the electrolytic cell in "'the same manner as mercury is used, in the production of sodium and sodium hydroxide as one skilled in the art will readily understand. When molten lead is used, the lead has to be removed from the bath-or cell prior to or at the saturation point of lead with the lithium alloy which is about 6 to 10 with respect to calcium. Of course, the higher the temperature of the molten lead, the higher the percentage of saturation. By removing the molten lead which contains lithium, calcium and sodium and permitting said lead to solidify, a lead alloy containing lithium, calcium and sodium can be produced.

Alloys other than lead alloys may be obtained in a similar way by making the base metal the cathode in the bath in which the lithium alloy is being electro-deposited.

The term dissociation voltage or decomposition voltage as used herein, means the voltage at which the lithium alloy electro-de posits at the cathode. Generally speaking, this voltage is approximately 2 volts. In addition to this voltage, a higher voltage must be applied to the bath in order to overcome the electro-deposition of lithium alloys. In the cell or bath mentioned herein, about 4.5 volts to about 5.5 volts were employed.

Of course, if the anode and cathode are placed closer together, then the voltage required to be impressed on the anode and cathode is lower. Similarly if the anode and cathode are spaced farther apart, then a higher voltage is needed, as one skilled in the art will readily understand. Then again if the electrical current is also used to heat the bath, a

still higher voltage has to be used forthis purpose, i. e. a greater amount of current or amperage has to be passed through the bath to furnish the required heat. r.

When in the specification and claims the term member of the alkaline earth family is used, it refers to and includes calcium, barium and strontium and equivalents thereof, such as magnesium and the like.

Although reference to certain specific tem peratures, voltages, electrodes, raw materials and the like have been made in the specification, it is to be observed that the invention is not to be limited thereto but is to be construed with reference to the appended claims. What is claimed is: 1. The process of electrolytically producing alloys of lithium and a inetallic member of the alkaline earth family which com;- prises establishing a fused bath containing a mixture of a lithium halide and a halide of a metallic member of the alkaline earth family in such proportions with respect to each other that an alloy of lithium and a member of the alkaline earth family having g approximately selected proportions is electrodeposited, providing an anode and cathode in said fused bath and passing an electrical current through said fused bath by said means of anode and cathode, and arranging the conditions of said bath so as to cause the simultaneous electro-deposition of lithium and said metallic member in the form of an alloy having approximately selected proportions at the cathode. 1

2. The process of electrolytically producing alloys of lithium and a metallic member 1 of the alkaline earth family which comprises establishing a fused bath containing a halide of lithium and a halide of a metallic member of the alkaline earth family and a neutral salt tending to bring the decomposition otentials of lithium and said metallic memer close to each other, providin a cathode and a graphite anode insaid used bath, passing an electric current through said bath by means of said cathode and said graphite anode and arranging the conditions of said bath so as to cause the simultaneous electrodeposition of lithium and said metallic member of the alkaline earth family in the form of an alloy at the cathode without depositing I alloy containing a metallic member of the the metallic member of the neutral salt.

3. The process of electrolytically producing alloys of lithium and a metallic member of the alkaline earth family which comprises fusing a bath containing chloride of lithium and a chloride of a metallic member of the alkaline earth family, regulating the proportions of said lithium chloride and chloride-of a metallic member of the alkaline earth family with respect to each other to assist in effecting the electro-deposition of a lithium alloy having selected proportions, placing a cathode and a graphite'anode in said fused bath, maintaining said bath in a fused condition, passing an electrical current through said bath by means of said cathode and said graphite anode, and arranging the conditions in said fused bath so as to cause the simultaneous electro-depos'ition of lithium and said metallic member of the alkaline earth family in the form of an alloy.

4.. The process of electrolytically producing alloys of lithium and a metallic member "upper portion of the bath.

of the alkaline earth family which comprises establishing a fused bath containing lithium chloride and a chloride of an alkaline earth metal in selected proportions, placing a cathode and a graphite anode in said fused bath;

anode and cathode, and arranging the condi- Y tions within said fused bath so as to cause the simultaneous electro-deposition of lithium.

and a metallic member of the alkaline earth roup in the form of an alloy of lithium at the cathode.

5. The process set forth in claim 2 in which the neutral salt is potassium chloride.

6. The process set forth in claim 2 in' which the anode is placed in a lower portion of the fused bath and the cathode is placed in an 7. The process set forth in claim 2 in which the cathode is constituted of a ferrous metal. 8. The process set forth in claim 2 in which the cathode is constituted of low carbon steel; 9. The process of producing a lithium alloy containing a metallic member of the alkaline earth family which comprises establishing a fused bath containing lithium halide and a halide of a metallic member of the alkaline earth family, placing a graphite anode and a metallic cathode in said fused bath, said metallic cathode being capable of alloying with lithium and said metallic member of the alkaline earth family, maintaining an elevated temperature within said bath within a range of about 350 C. to about 500 0., passing an electrical current through said bath, and arranging the conditions within said fused bath so as to cause the simultaneous electro-deposition of a lithium in selected proportions, placing a gra hite' anode and a lead cathode in saidfused ath,

maintaining a relatively elevated temperature in said bath, passing electrical current through said fused bath by means of said graphite anode and lead cathode, and arranging the conditions within saidfused bath so as to cause the simultaneous electrodeposition of a lithium alloy containing sodium and calcium in said lead cathode.

11. The process set forth in claim 10 in which the bath is so constituted that the lithium alloy deposited on said lead cathode contains approximately 0.04%

lithium, 0.7% calcium and 0.6% sodium,

v 12. The process of electrolytically producing lithium alloy containing calcium and sodium which comprises establishing a fused bath containing the chlorides of lithium, sodium, and calcium in selected proportions, providing acathode and an inert anode in said bath, maintaining a relatively elevated temperature in said fused bath, passing an electrical currentjhrough the bath by means of said inert anode and cathode, and arranging conditions within said bath so as to cause the deposition of a lithium alloy containin about 3% lithium, about 45% sodium and about 52% calcium. I

In testimony whereof I have hereunto set my hand.

HANS OSBQRG.