US1408142A - Electrolytic apparatus - Google Patents

Description

Patented Feb. 28, 1922.

.I) INVENTOR By A llorneys,

RENEWED MAY 3,I921.

. SEWARD.

a' clou Q A MWQQQQQ ELECTROLYTIC APPARATUS.

APPLICATION FILED OCTI II, 19H.

QQQQ/ QQQ WMDQNJJQDQDDQQEDD WITNESS citizen of the United States of UNITED STATES" PATENT, OFFICE.

GEORGE O. SEWABD, OF NIAGARA FALLS, NEW YORK, ASSIGNOR TOAIERIOAN MAGNESIUM CORPORATION, OF NIAGARA FALLS, NEW YORK, A CORPORA- TION OF NEW YORK.

Specification of Letters Patent.

Patented Feb. 28, 1922.

Application filed October 11, 1917, Serial No. 196,027. Renewed May 8, 1921. Serial 1T0. 468,532.

To all whom it may concern:

Be it known that I, GEORGE O. SEWARD, a America, residing in Niagara Falls, in the county .of Niagara and vented certain new and useful Improvements in Electrolytic Apparatus, of which the following is a specification.

, This invention provides an electrolytic furnace adapted for electrolyzing a bath of molten salts or compounds, for example of .haloid salts; and particularly salts of metals which are lighter than the molten bath, so

that upon being electrodeposited or separated the metal rises through the bath and floats upon the top *of the electrolyte. The apparatus is designed especially for use in practicing a process for electrodepositing magnesium which is set forth in another application for patent which I have prepared and which is intended to be filed concurrently, or substantially so, with the present application .(filed November 19, 1917, Serial-K04 202321). l

In a prior United States Patent No.

880,489, patented February .25, "1908, to

Franzvon Kugelgen and George 0. Seward,

there is described and claimed, an electro; lytic process of producing magnesium or alloys thereof, according to which magnesium oxid is added to a molten bath containing magnesiumfiuorid and 'a fiuorid of a metal or metals electropositive' to magnesium. My present invention relates'to 'apparatus' adapted to perform operations of the above general character.

Figure 1 of the accompanying drawing is a transverse section of the preferred construction of an electrolytic furnace laccordinn to the presentinventiony Tig. 2 is a plan of the furnace.

In the/drawings, 1 represents aim'etallic vessel or container forthe bath, which is preferably an unlined vessel of wroughtiron having) preferably a curved bottom and upright ends, and preferably suppiorted upon blocks 2, 2 insuchmanner as to afiord fa freenirculation of air beneath the vessel in order to avoid overheating. The bath so-' lidifies toa greater or lesser extent-upon the -bo'ttom, a s. indicated at 3, the'central portion or pool 4 remaining fluid under the operating conditions. 5, 5 represent the 'cath- Odes, whichamay consist ofiron-or steel cast-- State of New York, haveinings extending longitudinally of the vessel and projecting through apertures 6 in its bottom. Preferably an intervening layer of insulating material, such as asbestos, 20,is interposed between each cathode casting 5, and the vessel 1. The mass of solidified salts 3 is effective to prevent any leakage of electrolyte around the cathodes. The upper edges of the cathodes may be beveled, as indicated, in order to facilitate the upward flow and detachment of the molten magnesium.

9, 9 represent the anodes, which may be of carbon or graphite, and which depend into the bath between the cathodes and out of vertical alignment therewith. The drawing shows two rows of the -anodes'9, 9, which is preferable. Any desired or suitable, number of anodes may be provided. 10 indicates a layer of magnesium oxid or of magnesium carbonate floating upon the surface of the a bath and serving not only to retain the heat, but also as a primary source of rawmaterial for the production of magnesium, the magnesium oxid either dissolving progressively in the bath and undergoing electrolysis therein, or uniting with fiuorin liberated by the current and hence restoring the 'magne-- sium fiuorid content-of the bath. In case magnesium carbonate is used it is eventually converted into magnesium oxid by calcination. 3 Either magnesium oxid or magnesium carbonate is efiective to protect the anodes which are otherwise subject to strong attack:

I at 01; near the surface of the bath.

Cooling pipes 11 are arranged in two vertical series in planes between those of the anodes and those of the cathodes. The function of these is to chill and thereby to solidify a limited portion of the bath to form vertical partitions of insulating material.

'The-oonstruction is such that above the cathodes are formed hoods or collecting chambers 12 for receiving the molten magnesium which ascends from the cathodes. In the constructionshown,- these are formed of cast metal or sheet metal casings 13 located (near the surface of the bath and suitably cooled. They are shown as supported from the upper edges of the side walls of the vessel 1; The inner wall 14: of each hood is located sufficiently adjacent to the cooling j pipes 11 so'that themas's of solidified salts extends to the. wall 14, and seals the space between this wall and the pipes. The pipes 11 also extend preferably below the bottom of the hood so as to more effectually separate the space 12 for the magnesium from the anode chamber between the two series of cooling pipes 11. The casings 13 are preferably filed or packed with insulating material (for example kieselguhr), in order to prevent loss of heat and undesirable cooling. The molten metal may be drawn off continuously, or intermittently, from tap holes 16 communicating with the space within the collecting hood 12.

As a convenient means for supporting the tank and making the current connection with the cathodes, the invention provides a construction, shown in Fig. 1, wherein each cathode 5 is formed with shoulders or ledges 17 for receiving the weight of the vessel, and with a preferably flat bottom 18 which rests on a copper bus-bar which is formed as a fiat plate, which in turn rests upon the supporting block 2. As the plate 19 has a large area of contact with the bottom of the cathode, the current readily flows from one to the other. As the whole weight of the vessel and its contents comes upon the contacting surfaces of 18 and 19, a good electrical contact is assured.

The process to be. practiced with this construction of electrolytic cell or furnace is fully set forth in my companion application above referred to. Suffice it here to say that for the production of magnesium, the bath or electrolyte should be composed of suitable fluorids, such that the molten bath will have a sufficient specific gravity to cause the produced ma surface. his bath is maintained molten by a suitable current, a temperature of 900 to 1000 C. being found suitable. At the same time a suflicient flow of water is maintained through the cooling pipes 11 to insure an incrustation of congealed salt being maintained around these pipes. As the source of heat is between the electrodes, no difficult is experienced in maintaining the layer 3 o incrusted salt as a lining for the tank itself. The layer 10 of magnesium oxid or carbonate is replenished from time to time. The bath of molten magnesium accumulates within the chambers or hoods 12, ta holes 16 being provided which are opene up at intervals to tap off the molten metal. By thus enclosing the molten magnesium within the hoods 12 it is protected against any possibility of loss by burning.

The anodes are best arranged so that they may be mdividually fed downwardly into the electrolyte as they are oxidized and consumed. For this urpose they are carried by rods 170, suitab y connected to them and suitably fastened to a bus-bar 180. The clamping and adjusting means are not shown, as such meansare well known in the art.

esium to rise constantly to the i the bath between the latter and the coo The use of separately adjustable anodes depending into the electrolyte and surrounded thereby is practically necessary, so that they can be fed down from time to time as required, without interfering with the continuous operation of the furnace.

It will be obvious that the proportions and arrangement may be considerably varied according to circumstances, and within the skill and judgment of those Skilled in this art, without departing from the invention.

It will be apparent from Fig. 1 that the electrolytic cell illustrated is in effect a double electrolytic furnace, having duplicate anode series and duplicate cathodes. The cathode and the anodes on one side of the center could be omitted or disused without necessarily departing from the invention.

What I claim is:

1. An electrolytic apparatus for producing a metal lighter than the; electrol te, comprising a vessel for containing a mo ten fiuorid bath, having an insulating layer of congealed salt on its bottom, a cathode projecting upwardly through such layer into the vessel, individually adjustable anodes dependin into the vessel out of vertical ali ment with the cathode, a collectin cham 1 above the cathode for receiving t e molten light metal which rises from the cathode, and a water-cooled partition separating such chamber from the space surrounding the anodes.

2. An electrolytic ap ratus according to claim 1, having an an e chamber separated from such collecting chamber b such watercooled partition, and adapted or maintaining a layer of material floating upon the electrolyte and surrounding and protecting the anodes.

3. An electrolytic ap aratus for producing a metal lighter t an the bleotrol comprising a vessel for containing a mo ten fluorid bath, having an insulating layer of congealed salt on its bottom, a cathode rojecting upwardly through such layer into the vessel, anodes depending into the vessel out of vertical alignment with the cathode, a collecting hood above the cathode for re ceivingv the molten light metal which rises from the cathode, and means for cooling the upper portion of the bath located adjacent to the collecting hood, whereby to cong l in means, and thereby seal the intervening space. 4

4. An electrolytic apparatus accordin to claim 1, wherein the collectin h is formed by a hollow shell filled with insulating material.

5. An electrolytic apparatus accordin to claim 1, wherein the cathode pro ects through the bottom of the vessel, is enlarged beneath the latter to receive the weight of the vessel, and rests upon a conducting plate or bus-bar with which circuit connections are made, which plate in turn rests upon a supporting block.

6. An electrolytic apparatus for producing a metal lighter than the electrolyte, comprising a vessel for containing a molten bath, an anode and a cathode out of vertical alinement, the cathode being interposed between the anode and a wall of the vessel,

a collectin chamber above the cathode for receiving the molten light metal which rises therefrom, the inner side of the collecting chamber comprising cooling means to maintain a salt incrusted curtain.

.7. .An electrol ic apparatus for producing a metal lig ter than the electrol te,

comprising a vessel for contain bath, cathodes extending along sides of thevessel, anodes between the cathodes, collectin receiving the molten light metal which rises therefrom, the said chambers extending from the sides oi the vessel inward to a point between an anode and a cathode.

8. An electrolytic ap aratus for produc ing a metal lighter t the electrolyte, comprising a vessel for containing a molten bath, cathodes extending along the sides of 'the vessel, anodes between the cathodes, collectin chambers above the cathodes for receiving the molten light metalwhich rises therefrom, the said chambers extending from thesides of the vowel inward to a point between an anode and aeathode and coinprising cooling means on their inner sides to maintain a salt incrusted curtain.

9. An electrolytic apparatus for producing a metal lighter 'anthe electrol comprisinga vessel for a moteny tgea mo ten chambers above the cathodes for vessel, anodes between'the cathodes,- collecting chambers above the cathodes for receiving the molten light metal which rises therefrom, the said chambers extending from the sides of the vessel inward to a point between an anode and a cathode and comprisinga metal plate located near the surface of the bath, and means for counteracting radiation from the molten bath through the late; P 11. An electr lytic apparatus for producing a metal lig ter than the electrol comprising a vessel for containing a 1110 ten bath, an anode and a cathode out of vertical alinement, the cathode being interposed between the anode-and a wall of the vessel, a

collecting chamber above the cathode for receiving the molten light metal which rises therefrom, and comprisin a metal plate lo- GEORGE 01 .sawxnn.

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