IMPROVEMENTS IN SEPARATING COPPER AND BISMUTH FROM ORES CONTAINING METALS EITHER SEPARATELY OR COMBINED WITH OTHER METALS
Year: 1869

page_text: LETTERS PATENT to George Wells, of Westminster, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN SEPARATING
COPPER AND BISMUTH FROM ORES CONTAINING METALS EITHER SEPARATELY
OR COMBINED WITH OTHER METALS."-A communication from abroad
by Thomas Young Cotter and Charles Lewis Dubois, of Adelaide,
Australia.
Sealed the 24th August 1869, and dated the 31st March 1869.
PROVISIONAL SPECIFICATION left by the said George Wells at the
Office of the Commissioners of Patents, with his Petition, on the
31st March 1869.
I, GEORGE WELLS, of Westminster, in the County of Middlesex, do
hereby declare the nature of the said Invention for "IMPROVEMENTS
IN SEPARATING COPPER AND BISMUTH FROM ORES CONTAINING METALS EITHER
SEPARATELY OR COMBINED WITH OTHER METALS," a communication to me from
abroad by Thomas Young Cotter and Charles Lewis Dubois, of Adelaide,
Australia, to be as follows:-
The Invention consists, firstly, in reducing sulphuret ores by means of
the sulphur they contain by converting the said sulphur into sulphurio
acid.

page_text: The following is the process I prefer to employ :-The ore is first
reduced to an impalpable powder mixed with a given quantity of
saltpetre (nitr. pot.), say 10 lbs. for every cwt. of sulphur present in the
ore; it is then placed in shallow pans supplied with a hood to retain
the vapour arising therefrom; heat is applied under the pans (the
temperature not being raised above 300° Fahrenheit), and when the ore
is well heated a small quantity of water or steam is introduced, so as to
keep the surface of the ore covered with vapour. The ore is kept
continually stirred, atmospheric air being freely admitted thereto, by
which means the sulphur is converted into sulphuric acid, which unites
with the copper in the ore and converts it into a soluble sulphate. The
roasting is generally completed in about two hours, and when complete
the ore is drawn off into a tank in which water is kept in a state of
agitation for a short time, then allowed to subside, and the sulphate of
copper drawn off, the copper being precipitated in the usual way with
iron in the form of scrap or otherwise.
Secondly. In extracting copper from ores containing that metal in the
form of oxides or carbonates by the use of sulphate of iron, the following
method being adopted therefor :-The finely crushed ore is mixed with a
given quantity of the sulphate of iron resulting from the foregoing
process, or with the ordinary sulphate of iron of commerce, in the pro-
portion of about 21 lbs. of sulphate of iron for every unit of copper
present in the ton of ore (14 units will require 294 lbs. of sulphate of
iron per ton of ore); water is added, if necessary, and the whole boiled
until the ore shews by the ordinary tests that the copper is all dissolved;
and I prefer wooden vats for this purpose heated by injected steam, but
any other mode of boiling will do; the ebullition is then allowed to
subside, and the supernatant liquor syphoned or drawn off, the ore washed
clean from the sulphate of copper, and removed to a vat adapted to the
purpose and briskly agitated in flowing water carrying the precipitated
iron with it, which is collected either by filtration or subsidence and
dried and converted into metallic iron in the ordinary way, if necessary.
Having allowed the solution of sulphate of copper time to deposit any
foreign matter that may be present, it is decanted into a vat and the
copper thrown down by metallic iron in the customary way. The solution
of sulphate of iron resulting therefrom is pumped into an evaporating
pan to be reduced to the necessary specific gravity, when it is again ready
to extract the copper from fresh ore, and so on ad infinitum, natural

page_text: waste only having to be made good by the addition of fresh sulphate of
iron. Should gold, silver, or bismuth be present the ore after having
been washed clean from the iron deposited out of the sulphate of iron
used as a solvent is dried and roasted in an iron or other retort (at a low
heat so as not to generate carbonic oxide) with carbon or carbonic acid
gas (however produced) until the salts of the metals present are reduced
to the metallic state, when they can be separated from the ore by
amalgamation in the usual way.
And, thirdly. In separating bismuth from its ores by means of amalga-
mation, for which process the following method is employed:-Having
obtained an amalgam of bismuth by the means herein-before stated, or
by any other suitable or known means, in the retort with the amalgam is
placed a small quantity of any substance that will produce carbonic acid
gas at a low heat, by which means we check or prevent the volatilisation
of the bismuth without having any effect upon the quicksilver. A cold
solution of sulphate of iron may be employed to extract copper from ores
containing it, but as the process is very slow I prefer the use of heat,
and I prefer putting dolomite into the retort with the bismuth amalgam,
that being the best substance for the purpose yielding carbonic acid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Wells in the Great Seal Patent Office on
the 29th September 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WELLS, of Westminster, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of March, in the year of
our Lord One thousand cight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George Wells, Her special licence that
I, the said George Wells, my executors, administrators, and assigns, or
such others as I, the said George Wells, my executors, administrators,
and assigns, should at any time agree with, and no others, from tune
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,

page_text: IN SEPARATING
SEPARATELY
and Isle of Man, an Invention for "IMPROVEMENTS
COPPER AND BISMUTH FROM ORES CONTAINING METALS EITHER
OR COMBINED WITH OTHER METALS," a communication to me from abroad
by Thomas Young Cotter and Charles Lewis Dubois, of Adelaide,
Australia, upon the condition (amongst others) that I, the said George
Wells, my executors or administrators, 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 George Wells, 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 (that is to say) :-
This Invention consists, firstly, in reducing sulphuret orcs by means of
the sulphur they contain by converting the said sulphur into sulphuric
acid.
The following is the process I prefer to employ :-The ore is first
reduced to an impalpable powder mixed with a given quantity of
saltpetre (nitr. pot.), say 10 lbs. for every cwt. of sulphur present in the
ore; it is then placed in shallow pans supplied with a hood to retain the
vapour arising therefrom; heat is applied under the pans, the temperature
not being raised above 300° Fahrenheit, and when the ore is well heated
a small quantity of water or steam is introduced, so as to keep the surface
of the ore covered with vapour. The ore is kept continually stirred,
atmospheric air being freely admitted thereto, by which means the
sulphur is converted into sulphuric acid, which unites with the copper
in the ore and converts it into a soluble sulphate. The roasting is
generally completed in about two hours, and when complete the ore is
drawn off into a tank in which water is kept in a state of agitation for a
short time, then allowed to subside, and the sulphate of copper drawn off,
the copper being precipitated in the usual way with iron in the form of
scrap or otherwise.
Or by another method the ore is pulverized very fine, then spread
evenly over the bottom of the roaster about three inches in thickness,
and the fire urged until it begins to give off strong fumes of sulphur,
care being taken never to heat the ore beyond the point at which the

page_text: sulphur burns, when the ore is stirred or raddled. When this point is
attained sufficient nitre is placed in a strong cast-iron basin and sulphuric
acid added to it in sufficient quantity to decompose the nitre; this is
placed on a suitable stand in the roaster and a jet of steam introduced
thereto every ten minutes, the ore being well stirred during each interval.
By this means the whole of the sulphur is converted into sulphuric acid,
which unites with the copper, forming soluble sulphate of copper, and
the process is complete when the ore ceases to give off blue flame
on being stirred. The ore is then raked into a cistern of water and
kept boiling by injected steam for two or three hours, and when all
the soluble salts are dissolved the ore is to be allowed to settle, and
the clear liquor (being a solution of sulphate of copper) drawn off
and the copper precipitated with iron in the usual way, and the
Should
resulting sulphate of iron used for carbonate or oxide ores.
the ore not contain sufficient sulphur to extract the copper a solution
of sulphate of iron must be used instead of water, according to the
quantity required. In stirring the ore while roasting care must be
used to prevent the escape of sulphur vapour as much as possible,
and for this reason it should be stirred after the injection of steam
and not before. The retort or roaster I prefer to use is 5 ft. wide,
10 ft. long, and 18 inches high, and is made of cast iron, the bottom
being lined with tiles of fire-clay, and the fire made to play evenly
under the bottom by means of flues. If the ore contains arsenic
a chamber may be connected with the top of the retort to condense
this injurious metal. Bismuth ores very foul with arsenic have been
rid of it in this way.
Secondly. In extracting copper from ores containing that metal in
the form of oxides or carbonates by the use of sulphate of iron, the
following method being adopted therefor :-The finely crushed ore is
mixed with a given quantity of the sulphate of iron resulting from the
foregoing process, or with the ordinary sulphate of iron of commerce,
in the proportion of about 21 lbs. of sulphate of iron for every unit
of copper present in to ton of ore (14 units will require 294 lbs. of
sulphate of iron per ton of ore); water is added, if necessary, and the
whole boiled until the ore shews by the ordinary tests that the copper
is all dissolved; and I prefer wooden vats for this purpose heated by
injected steam, but any other mode of boiling will do. The ebullition
is then allowed to subside, and the supernatant liquor syphoned or
drawn off, the ore washed clean from the sulphate of copper, and

page_text: removed to a vat adapted to the purpose and briskly agitated in
flowing water, carrying the precipitated iron with it, which is collected
together either by filtration or subsidence and dried and converted
into bloom or metallic iron in an ordinary Catalan forge, or by any
other known means. Having allowed the solution of sulphate of
copper time to deposit any foreign matter that may be present, it
is decanted into a vat and the copper thrown down by metallic iron
in the customary way. The solution of sulphate of iron resulting
therefrom is pumped into an evaporating pan to be reduced to the
necessary specific gravity, when it is again ready to extract the copper
from fresh ore, and so on ad infinitum, natural waste only having
to be made good by the addition of fresh sulphate of iron.
Or by another method the ores are pulverized as before and boiled
by means of injected steam in a solution of sulphate of iron obtained
from the preceding process or otherwise, taking about 4 lbs. of dry
sulphate of iron for every pound of copper. The mixture is then
boiled until all the copper is in solution, then drawn off, and the ore
washed clean with hot water, the copper precipitated with iron, and
the resulting sulphate of iron evaporated to the specific gravity required
for extracting the next batch of copper. The peroxide of iron which
has been left in the ore must be washed out by passing water up
through the ore, which is then filtered, dried, and metallized, when it
can again be used for the purpose of precipitating the copper. Should
gold, silver, or bismuth be present the ore after having been washed
clean from the iron deposited out of the sulphate of iron used as a
solvent is dried and roasted in an iron or other retort, at a low
heat so as not to generate carbonic oxide with carbon or carbonic acid
gas (however produced) until the salts of the metals present are reduced
to the metallic state, when they can be separated from the ore by
amalgamation in the usual way.
And, thirdly. In separating bismuth from its ores by means of amalga-
mation, for which process I employ the following method:-Having
obtained an amalgam of bismuth by the means herein-before stated,
or by any other suitable means, in the retort with the amalgam is
placed a small quantity of any substance that will produce carbonic
acid gas at a low heat, by which means the volatalization of the
bismuth is checked or prevented without having any effect upon the
quicksilver.

page_text: Another method for separating bismuth from the ore per se is to
place the crushed ore in a roaster or retort with sufficient carbon to
generate the necessary quantity of carbonic acid to reduce the salts
of bismuth to the metallic state, and having luted up all openings as
close as possible the charge is brought to a good red heat for three or
four hours, the fire is then allowed to go out, and when cool the charge
is drawn, the superfluous charcoal washed out, and the ore placed in an
amalgamator with the required quantity of mercury (say 6 lbs. for every
pound of bismuth). When all the bismuth is taken up it is washed
from the tailings and the quicksilver retorted off in the usual way, a
quantity of charcoal or other substance that will generate carbonic acid
being placed in the retort to prevent the vaporization of the bismuth.
Should the ore contain copper it is to be boiled with sulphate of iron
or sulphuric acid to extract the copper before roasting. A cold solution
of sulphate of iron may be employed to extract copper from ores
containing it, but as the process is very slow I prefer the use of heat,
and I prefer putting dolomite into the retort with the bismuth
amalgam, that being the best substance for the purpose yielding
carbonic acid.
Having now described the nature and particulars of the said Invention
I claim,-
First. Reducing sulphuret ores by means of the sulphur they contain
by converting the said sulphur into sulphuric acid, as herein described.
Second. Extracting copper from ores containing that metal in the
form of oxides or carbonates by the use of sulphate of iron, as herein
described.
Third. Separating bismuth from its ores by means of amalgamation,
as herein described.
In witness whereof, I, the said George Wells, have hereunto set my
hand and seal, this Twenty-seventh day of September, in the year
of our Lord 1869.