IMPROVEMENTS IN EXTRACTING COPPER FROM ORES
Year: 1860

page_text: LETTERS PATENT to Friederich Wilhelm Daehne, of Swansea, Glamorgan-
shire, Gentleman, for the Invention. of "IMPROVEMENTS IN EXTRACTING
COPPER FROM ORES."
Sealed the 19th March 1861, and dated the 26th September 1860.
PROVISIONAL SPECIFICATION left by the said Friederich Wilhelm Daehne
at the Office of the Commissioners of Patents, with his Petition, on the
26th September 1860.
I, FRIEDERICH WILHELM DAEHNE, of Swansea, Glamorganshire, Gentle-
man, do hereby declare the nature of the Invention for "IMPROVEMENTS IN
EXTRACTING COPPER FROM ORES," to be as follows:-
The ore is first to be pulverized. In case of its containing sulphur the
latter must be totally expelled by calcination; but in the event of the ore
being free from sulphur contents this preliminary process need not of course
be adopted. After the completion of this process the ore is mixed with
somewhere about 8 per cent. of sulphate of iron, (which falls as a waste
product in the subsequent extraction of the copper by cementation,) and is
subjected to a short calcining process at a low temperature until such time as
is required to decompose the sulphate of iron into peroxide of this matter, the
sulphuric acid combining instead of it with the copper contents of the ore in
the shape of sulphate of copper. The ore is now withdrawn from the calciner,.
and allowed to cool, afterwards put into proper kind of vessels, and lixiviated
with hot water, which will extract the now soluble copper produce wholly or
nearly so.

page_text: In case of failure this process of treatment with sulphate of iron may be
repeated a second time over. The leavings after washing out of the copper
will in many cases, more especially when a clean iron pyrites has been the ore
under treatment, form a most valuable material for the iron furnaces, as this
process has been found to clean the ore of all its sulphur contents.
the copper ore should contain slate as gangue, or if it should be mixed up
otherwise with large proportions of alumina, the foregoing process may be
modified somewhat. The ore is to be pulverized and calcined, so as to expel
the sulphur completely, after this the ore is withdrawn from the calciner,
allowed to get cold, and is mixed with such a proportion of sulphuric acid as
will thoroughly damp it. This mixture is now allowed to stand in heaps for
24 hours. It is afterwards put into the calciner and subjected to a slow calci-
ning fire until such time as will nearly expel all visible fumes of sulphuric acid
and until the iron of the ore, which has been transferred into a sulphate is
again decomposed into a peroxide, and has become insoluble. The ore thus
calcined with sulphuric acid is now washed out with water, as in the previous
case to remove the copper, which is soluble. In both instances the
precipitation of the copper is effected by any of the known and practised
methods.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Friederich Wilhelm Daehne in the Great Seal Patent Office
on the 26th March 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRIEDRICH
WILHELM DAEHNE, of Swansea, Glamorganshire, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of September, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign
did, for Herself, Her heirs and successors, give and grant unto me, the said
Friedrich Wilhelm Daehne, Her special licence that I, the said Friedrich Wilhelm
Daehne, my executors, administrators, and assigns, or such others as I, the said
Friedrich Wilhelm Daehne, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN EXTRACTING COPPER PROM ORES," upon the condition (amongst
others) that I, the said Friedrich Wilhelm Daehne, my executors, or adminis-

page_text: trators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Friedrich Wilhelm Daehne, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
My Invention consists in improved methods of extracting copper from ores
containing more or less sulphur, either in their raw state or with the sulphur
partially expelled as burnt ores or after treatment for other purposes in
chemical works, as well as from ores containing copper in a metallic state or
oxidized.
To facilitate the processes which it is to undergo, the ore is first to be
pulverized, if it has not already been reduced by grinding, stamping, or
otherwise, and if it contains sulphur this is to be expelled by dead calcination.
If the ore has not contained slate as gangue, or been otherwise mixed up with
large quantities of alumina, it is to be mixed with about 8 per cent of sulphate
of iron, and subjected to a short process of calcining at a dull low red heat
until the sulphate of iron is decomposed into peroxide of iron. The sulphuric
acid combining with the copper instead of with the iron as sulphate of copper.
The ore now taken from the furnace is allowed to cool, and is then lixiviated
with hot water which will extract nearly all the soluble salts of copper.
In case of an imperfect result in the operation the process of treatment
with sulphate of iron may be repeated. In many cases especially when the
ore is a clean iron pyrites the leavings after washing out the copper will form
a most valuable material for the iron furnace as the ore loses nearly all its
sulphur particles. If the ore contains slate as gangue, or has been otherwise
mixed up with large quantities of alumina, the process may be modified as
follows:-After the sulphur, if any, has been expelled, the ore withdrawn from
the calciner is allowed to cool, and is mixed with the common sulphuric acid
of commerce in a quantity sufficient to thoroughly damp it. This mixture is
allowed to stand in heaps for 24 hours, and is then put into the calciner, and
is subjected to a slow calcining fire until nearly all visible fumes of sulphuric
acid are expelled, and until the iron of the ore, which has been transformed
into a sulphate is again decomposed into a peroxide and has become insoluble in
water. The ore thus calcined with sulphuric acid is then withdrawn from the

page_text: furnace, and when cold is washed with water in the same manner and for the
same purpose as in the other process. The precipitation of the copper in both
cases is effected by any of the known methods.
In witness whereof, I; the said Friedrich Wilhelm Daehne, have hereunto
set my hand and seal, this Twenty-first day of March, in the year of
our Lord One thousand eight hundred and sixty-one.
FRIEDRICH WILHELM DAEHNE. (L.S.)