US1420512A - Process of producing graphite - Google Patents

Description

T., FpBAlLY. PROCESS 0F PRODUCING GRAPHITE.

APPLICATION `FILED JAN. 31,1922.'

Patented J une 2 0, 1922.

p 1921, Serial No. 45

' UNITED STATT-:s

PATENT OFFICE.

THADDEUS F. janny, or ALLIANCE, omo.

' risoenss or 'rRoDUoINe GRAPHITE Speciipcationof Letters Patent. Patented June 20, 1922.

. Application led January 31, 1922. Serial No. 533,083.

I To all lwhom t may concern Be it-known that I, THADDEUS. F. BAILY, a citizen of the United States, residin at Alliance, in the county of Stark and tate of Ohio, have invented new and useful Improvements in Processes of' Producing Graphite, of which the following is a specification; this application in part being a continuation of the common subject'matter of my former apppation filed March 19,

The invention relates to a method of producing graphite andmore particularly to a process by means of which articial graphite is extracted from super-heated iron which is substantially fully saturated with carbon.

The usual'method of producing artificial graphite has been by passing anA electric current through anthracite coal or similar carbon, bringing the same to an extremely high temperature, at which temperature the amorphous carbon-is converted into graphite and is then allowed to cool.

The objects of the present invention are to rproduce graphite containing less impurities than the aphite produced by the electro-thermal me hod above mentioned and at a considerably less cost than is possible in the production of graphiteby the electrothermal method.

It is well known that iron at the freezing temperature will retain only about 4.3% of carbon, ,and that as the iron-*is heated to a molten state, it is capable ofI absorbing amorphous carbon, the'capacity of the molten iron for absorbing carbon increasingas the temperature of the iron is increased.

This being the case, when molten iron at a high temperature is fully saturated with carbon and then allowed to cool all .of the surplus carbon which has been dissolved in the molten 'iron is thrown outof the cooling bath in the form of graphite iiakes or powder, only the residual 4.3% ,of carbon remaining in the iron.

In carrying out the process, ironis heated in a furnace to a temperature' at which` the above its freezingtemperature, which process willthrow out of the bath, in the form of. graphite, the excess dissolved vcarbon above the residual 4.3% which is retained 1n the iron .at its freezing temperature.

`Th1s cooling is preferably accomplished by pouring the molten iron i into a closed chamber, allowing the iron to cool to near.'

its freezing temperature, the carbon being thrown off' from the cooling chamber in the' form of graphite which collects inthe chamber, the iron being poured from the chamber while still in the molten state.

If desired, a' suction may be created in the coolin chamber to cause the iron to cool a more rapidly, or ,to remove the graphite from the cooling'chamber. The iron which A melting furnace of any suitable design is illustrated at 1, provided with a illin yopening 2, normally closed by adoor f3, and with an outlet openin 4 which is normally vclosed by a plug inl t e usual .manner andl which communicates with a pourin I spout has eliminated the surplus carbon is re ceived in a suitable receptacle as ,it passes' 5. For the purpose of the invention, 't vis -fur-4 nace is necessarily elevated and may be mounted upon an suitable structure such as the standards 6 w ich are braced by the cross bars 7.

`A cooling receptacle form of .an elongated, upright cyllnder, is .located in position to receivethe-molten iron from the pouring spout 5 of the furnace, and is provided at its upper end with the cuppedreceptacle 9, having a central reduced outlet cooling chamber 11, the lower end of which 1s lcut as at 12 and provided with a reduced outlet openinglS.

l 8, i preferably in the t 'opening 10 communicating with the inner ioo A pit 14 1s preferably providedbeneath x the cooling chamber and arranged to receive la bucket` or other receptacle 15, the cooling chamber being supportedv above said pit in any suitable manner. as bythe uprights '16, a bailie plate or guard 17 being preferably provided at the upper end of the cooling chamber to prevent the molten metal from spattering or splashing out of the receptaclel 9 as it is poured from the spout of the furnace.

A graphite collecting receptacle 18may be located adjacent to the cooling chamber, be-

, ing preferably supported above the Hoor as b the frame 19 and provided with the taper ed or conical lower. end portion 2O having an outlet opening 21 -therein which is v:normally closed by the slidin movablereceptacle 23 may e laced beneath the collector as shown to receie the graphite therefrom. 1

The upper portion of the cooling chamber communicates with 'the intermediate portion of the collector. by means of the pipe 24, a

pipe 25 extending from the upper end of the collector to the lower portion of the cooling. chamber, a blowing fan of any usual con` struction bei-n located in the fan casing 26 which is provided in said pipe between the collector and cooling chamber.

In'carryl'ing out the invention with the apparatus s own in the drawing, iron as indicated at A, is placed in the furnace through the opening 2, the bucket 15 being arranged to be carried up to said opening in any usual manner as by a crane or the like. The outlet opening 4 of the furnace is, of course, plugged to retain the iron therein.

T e iron is then heated in the furnace to a temperature at which it will absorb additional carbon. Coke or carbon in other form, in proper quantity to be absorbed by the molten iron, is then dissolved in the bath.`

The plug is then removed from the outlet opening 4, the bath being poured in its super- `heated and saturated condition through the` pouring vspout 5 of the furnace and into thereceptacle 9, passing in a thin stream through the openin, -10 and through the closed coolair. -v

As' the molten iron in its saturated con- `ditionv is passed in a thin stream, as shown,

thrcughthe cooling chamber 11, it will be cooled to slightly a'bove its freezing temerature by means of the circulation of an lnertnon-oxidizing gas forced through the cooling chamber by the fan, which processwill throw lout of the bath in the form of graphite Hakes or powder, the excess carbon door 22. A reabove the residual 4.3% which is retained in the iron at its freezing temperature.

The circulation of the inert or non-oxidizing gas caused by the fan, will draw graphite flakes or powder from the upper end of the cooling chamber and deposit them in the collector as shown4 in the drawing, a fine mesh screen 27 may, if desired, be placed at the inlet to the pipe 25 to prevent the graphite Hakes from being carried back into the cooling chamber.

The graphite mayV be removed from the collector fromjtime to time, by opening the door 22, allowing .the graphite to drop into the receptacle 23. The iron which has eliminated the surplus carbon is received in the bucket 15 as it passes from the cooling cha1 n ber and may 'be poured back into the furnace 1 and reheated and recharged with .carbon findeinitely, the `same process being carried through successively. p

If silica or similar impurities are present in the iron, it maybe desirable to first heat the iron up to the desired temperature and pour the same, allowing it to cool `when the silica and similar impurities will be thrown out of the bath, after which the iron maybe reheated and recharged with carbon indefinitely, the graphite flakes orpowder which are then thrown out of the cooling bath, be-

ingin the form of pure graphite.

he advantages of this method of producing graphite, over the existing method, are

vquite obvious. lThere i's no ungraphitized carbon present in the inished product, as `is the case in a charge of material in the electro-thermal process.

As the molten iron exercises a clarifying effect upon the carbon, eliminating certain impurities which would otherwise be present in the nished graphite produced by the electro-thermal method, a better and more pure product is obtained by the present method.

1. The method of producing artificial graphite which consists in saturating a bathv ofYsuper-heated molten iron with carbon, pouring the saturated molteniron into a closed cooling chamber, cooling the iron sufficiently to throw ,the surplus carbon out of the bath into said chamber in the form of graphite andl withdrawing the molten iron from the cooling chamber.

2. The method of producing artificial graphite which consists in saturating a bath of molten iron with carbon, pouring the-molten iron through a closed chamber in a thin stream, cooling. the iron suliiciently to throw 'the surplus carbon out otf said' stream into -the chamber in the form of graphite and withdrawing the molten iron from the cooling chamber.

3. The method of producing artificial graphite which consists in saturatingaa bath n of super-heated molten iron with carbon,y

to assist in the removal of the graphite froml the iron.

4. The method of roducing artificial graphite which consists 1n saturating a bath of super-heated molten iron with carbon, pouring the molten iron into a closed cooling chamber, cooling the iron sufficiently to throw the surplus carbon out of the Ibath into the 'chamber in the form of graphite, and passing an inert gas, through the cooling chamber to -assist in the removal of the vgraphite from the iron.

v5. The method of producing artificial graphite which consists in saturating a bath of' super-heated molten iron with carbon, pouring the molten ironV in a thin stream through a closed cooling chamber, allowing the iron to cool sufficiently to throw the surplus carbon out of the bath into the cooling chamber inthe form of graphite and conveying the graphite 'by suction to a collector chamber. i

6. The method of producing artificial vgraphite which consists in saturating a bath of super-heated molten iron with carbon, pouring the molten iron into a closed cooling chamber, cooling the iron sufiiciently to throw the surplus carbon lout of the bath into the cooling chamber in the form of graphite, withdrawing the molten` iron from the cooling chamber and reheating the molten iron and again saturating the super-heated iron with carbon.

7. The method of producing artificial graphite which consists in saturating a bath of superheated molten iron with carbon,

pouring the molten iron in a thin stream through a closed cooling chamber, cooling the iron sufficiently to throw the surplus carbon out of the bath into the cooling chamber in the form of graphite, conveying the graphite by suction tor a collector chamber and continuously withdrawing the molten iron from the coolin chamber.

THA DEUSfF. BAILY.-

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