AN IMPROVED MODE OF REDUCING METALS FROM THEIR ORES, AND PURIFYING AND REFINING THE SAME
Year: 1873

page_text: LETTERS PATENT to Richard Werdermann, of Princes Street, in the
County of Surrey, Civil Engineer, for the Invention of "AN
IMPROVED MODE OF REDUCING METALS FROM THEIR ORES, AND PURIFYING
AND REFINING THE SAME.”
Sealed the 20th June 1873, and dated the 10th February 1873.

page_text: The reduction of iron ores may be effected either in the usual manner
in the melting furnace with carbonaceous matter, or in a reverberatory
furnace with some suitable flux only. The best ore for this purpose is
the hæmatite, because it is a good conductor of electricity. As soon as
the oxide begins to flow the reduction takes place, and all noxious
elements are eliminated in the following order, viz.,—
Valto.
By regulating in a suitable manner the electro-motive force and the
intensity of the electric current, and stopping it at the proper moment,
cast iron, wrought iron, or steel can be produced directly from the
furnace without any intermediate operations. This puddling by means
of an electric current will occupy from 10 to 15 minutes only, instead of
several hours as in the ordinary puddling by hand labor or machinery,
and consequently a great saving of time will be effected.
The entire liberation of the electro-negative elements is in some cases
not effected immediately, but an intermediate transformation of the ore
takes place. For instance, in treating the sub-sulphide of copper this
ore does not conduct electricity at the ordinary temperature, but at 230°
Fahrenheit it becomes a very good conductor; copper is then produced
at the negative electrode or pole, and at the positive pole. Sulphide of
copper is formed, which being a good conductor at a lower temperature
is now entirely decomposed, and converted into metallic copper. A
great difficulty in the reduction of plumbic oxide in the usual process
consists in the formation of silicate of lead due to the presence of
silicates mixed with the ore. This difficulty is entirely overcome by the
application of the electrical current for the formation of the silicate of
lead, which is readily fusible, is no obstacle, and all ores rich in
silicates, which could not be treated till the present time can now be
employed for the extraction of lead.
Instead of treating the sulphides and carbonates and other more com-
plicated combinations directly by the electrical current, such ores may
first be converted into oxides by roasting them in the usual manner for
some time in contact with atmospheric air or oxygen.

page_text: While the metal is being reduced all impurities and noxious elements
mixed or combined with it are eliminated, so that finally the metal is
collected perfectly purified and refined.
Having now described my said Invention, and the manner of per-
forming the same, I wish it understood that I claim, the application of
electric currents for the purpose of reducing metals from their ores with
without the aid of the ordinary chemical action of carbonaceous
matter, and for the purpose of purifying and refining the metal during
its reduction from the ores.
or
In witness whereof, I, the said Richard Werdermann, have here-
unto set my hand and seal, this Fourth day of February, in
the year of our Lord One thousand eight hundred and seventy-
three.
Witness,
WM. ROBT. LAKE,
8, Southampton Buildings,
London.
R. WERDERMANN. (L.s.)