Process for the Extraction of Pure Metals or Metallic Alloys and the Production of Carbides by Electric Heat.
Year: 1898

page_text: Date of Application, 28th Mar., 1898-Accepted, 9th July, 1898
Process for the Extraction of Pure Metals or Metallic Alloys and the
Production of Carbides by Electric Heat.
I, HEINRICH ASCHERMANN, of 5 Terrasse, Cassel, Germany, Doctor of Sciences,
do hereby declare the nature of this invention, and in what manner the same is
to be performed to be particularly described and ascertained in and by the fol-
lowing statement:―
My Patent No. 859 of the 12th January 1897, has given technical sciences
the means of utilizing the electric furnace much more advantageously than
hitherto for the reduction of metallic oxides. This method consists in producing
in the furnace, by adding a metallic sulphide, an auxiliary chemical energy
whose power considerably diminishes the expenditure of electric energy which
has hitherto been necessary to the process of reduction.
I have found that the process is capable of an important modification which
reduces the price of it considerably inasmuch as this modification allows of obtain-
ing at the same time carbides with the metal to be treated. For this purpose,
by adding carbon in sufficient quantity, to the mixture of
an oxide
and
a sulphide, the carbon will absorb by formation of carbide that
one of the two liberated metals which has the greater affinity for the
carbon while the other metal, according as it is fixed or volatile, collects at the
bottom of the matter in fusion, or in the canals by which the gas escapes.
In principle, the modification consists in subjecting, to electric heating, a mix-
ture of carbon with an oxide and a sulphide of metals having different affinities
for the carbon.
If, for example, a mixture, which is approximately formed of the desired
theoretic quantities of sulphide of iron (Fe S2), lime and carbon, is treated in
the ordinary electric furnace, metallic iron is obtained on one side, on the
other side, carbide of calcium, which gives an acetylene as pure as the carbide
prepared in the usual way, while the expenditure of electrical current is diminished
at least 40%
The practical value of this modification is evident, it procures in saving the
current, during the extraction of metals and metallic alloys, valuable carbides,
without any other expenditure than that of carbon, and makes thus out of the
reduction of the sulphides (especially the natural sulphide of technically impor-
tant metals) a process which is very advantageous from an economical point of
view.
It is evident that the method, according to the above-given example, can be
performed with all oxides, and carbonates as well as with the known metallic
sulphides (natural or artificial) suitable for the formation of carbide provided
that they be decomposable by electric heating.
Finally, it will be easily understood that by the simultaneous use of several
sulphides or oxides with the described method, metallic alloys can also be
obtained as well as pure metals.

page_text: Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what I
claim is:-
A modification of the process protected by Patent No. 859 of the 12th January
1897, consisting in the addition to the mixture of oxide and sulphide of carbon,
with a view to obtain at the same time carbide, substantially as above described.
Dated this 25th day of March 1898.
L. DUVINAGE,
Patent Agent, 8, Rue des Princes, Brussels, Belgium.