US1220843A - Production of metallic compounds from carbids. - Google Patents

Description

PAUL B. HERSHMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE MINERAL PRODUCTS COMPANY, OF NEW YORK, N. Y., A CORPORATION OF WEST VIRGINIA.

'rnonuc'rron or mar-name conroonns anon cnnnrns.

ea ers.

no Drawing.

To all whom it may concern Be it known that I, PAUL R. HERSHMAN, a citizen of the Empire of Austro-I-lungary,

residing in the city oi Chicago, county of,

, make and use the same.

The present invention is based upon the discovery that if aluminum carbid is heated (preferably under pressure) to a sufficiently high temperature, it will,-in .decomposing, yield metallic aluminum. It has been found further that the reaction is facilitated by the presence of oxids, sulfids, or chlorids of aluminum, or of some other suitable metal, such as copper, present in such proportions as to form with the aluminum the eutectic alloy of the two metals, that is to say, the alloy of definite compositionand definite physical properties having the lowest melting point of all the possible alloys of its constituent metals. Furthermore, the reduction is accomplished with additional facility in the presence of certain gases which do not tend to interfere with the decompositionv of the carbids or 'to'reconstruct the carbids after decomposition; such' gases being, for instance, hydrocarbons and particularly hy v drogen, which latter seems to have a catalytic efi'ect'in the general operation.

In carrying the invention into efiect, I preferably charge the aluminum carbid, in a compactmass into an electric furnace of the vertical type, that is to say, a furnace wherein the'electric' current traverses the charge from top'to bottom. With the aluminum carbid of the charge may be associated small quantities (say 10%20% by weight) of aluminum oxid, aluminum chlorid, or aluminum sulfid. The several ingredients may be brought into union in any suitable way, as, for instance, by subjecting them to a mixing and kneading operation in a suitable mixer.

The reducing operation as hereinbefore indicated, is preferably carried on under pressure, and with the introduction of a suitable gas, admitted under pressure into the interior of the'furnace. To this end, the electric furnace should be fitted with a cover 7 Specification of Letters Patent.

Patented Mar. 2?, 191W.

Application filed. December 21, 1914. serial Hatfield.

securely held in place thereon, and the gas may be admitted into the interior of the furnace in any convenient way, as, for instance, through hollow arcing electrodes, if the furnace is of the electric arc type, or through a hollow carbon resistance rod with a side entrance into the furnace chamber if the furnace is of the electric resistance type. The pressure developed in the electricfurnace chamber may be determined by providing the cover with a suitable vent, and the issuing gases may be burned as they take their exit from the vent; or, if desired, the issuing gas current may pass through a suitable safety valve, which will hold the contents of the furnace automatically under regulable pressure. In practice, I have found superatmospheric pressure of from 10 to 15 pounds to the square inch to give satisfactory results, but this pressure may be exceeded,

due regard being had to such precautions as 'willprevent the pressure from rising beyond the limits of safety in any particular instance.

In some instances, the charge may be inserted, either in a compact mass or in briqueted form within anelectric tube furnace, that is to say, a chamber of tubular form whose walls are heated electrically. In practice, I have found when such a tube furnace is brought to a temperature of 2200 'C. that the charge begins to melt quickly, whereuponfithe temperature may be lowered somewhat (say to 2100 C.) with theproduction of metallic aluminum.

When an oxid, chlorid, or a sulfid of another metal is employed, in admixture with the aluminum carbid, the ingredients thus added to the aluminum carbid should be present-in such roportion that there will result the eutectic alloy of the aluminum with the metal of the oxid, chlorid, or sulfid added, 'as hereinbefore specified. Thus, by way of example, the oxid, chlorid, .or sulfid of copper, may be em loyed in such proportion as to produce the eutectic alloy represented by area, of aluminum and 5.8% of copper and which has a tensile strength of about 30,000 pounds.

- What I claim is IL. The method of producing metallic aluminum from aluminum carbid which comprises heating the carbid in the presence of gases which do not tend to interfere with the decomposition of the carbids under super-atmospheric pressure, and to a tem:

perature sufficient to decompose the carbid and to produce metallic aluminum. 2. The method of producing metallic aluminum from aluminum' carbid which comprises heating .the carbid'to a 'te'mperature of about 2200 C.

4. he method (if producin metallic aluminum from aluminum 'car id which comprises heating the carbid with small quantities of an additional aluminum com pound facilitatin the decomposition to a temperature of a out 2200 C. until the char begins to melt and thereafter lowering t e temperature to about 2100 C. for further efl'ecting the decomposition of the carbid andthe formation of aluminum.

5. The method; of producing metallic aluminum from aluminum carbid which comprises heating the carbid in the presence of a gas containing does not tend to interfere-with the decomposition of the carbids under superatmos' hydrogen which pheric pressure, and to a tem rature sufficient todecompose the carbi and to produce metallic aluminum.

6. The method of producing metallic aluminum. from aluminum carbid which.

a. temperature suflicient to effect the decomposition of the carbids and the production of aluminum.

7. The method of producing metallic aluminum from aluminum carbid which comprises heating the carbid in the presence of gases which do not tend to interfere with the decomposition of the carbids under a super-atmospheric pressure of about ten to fifteen pounds to the square inch, and to a temperature sufiicient to decompose the carbid and-to produce metallic aluminum.

In testimony whereof I aifi'x my signature, in presence of two witnesses.

' PAUL R. HERSHMAN. Witnesses;

M. AMEB, M. A. BILL.