IMPROVEMENTS IN REVERBERATORY, BLAST, AND OTHER FURNACES FOR SMELTING ORES, AND IN THE MEANS OF EXTRACTING THE PRECIOUS METALS THEREFROM
Year: 1866

page_text: LETTERS PATENT to John Thomas, of Battersea, in the County of
Surrey, Ironfounder, and Alexander Prince, of No. 4, Trafalgar Square,
Charing Cross, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN REVERBERATORY, BLAST, AND OTHER FURNACES FOR
SMELTING ORES, AND IN THE MEANS OF EXTRACTING THE PRECIOUS METALS
THEREFROM."
Sealed the 30th October 1866, and dated the 1st May 1866.
PROVISIONAL SPECIFICATION left by the said John Thomas and
Alexander Prince at the Office of the Commissioners of Patents, with
their Petition, on the 1st May 1866.
We, JOHN THOMAS, of Battersea, in the County of Surrey, Ironfounder,
and ALEXANDER PRINCE, of No. 4, Trafalgar Square, Charing Cross, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN REVERBERATORY, BLAST, AND OTHER FURNACES FOR.
SMELTING ORES, AND IN THE MEANS OF EXTRACTING THE PRECIOUS METALS THERE-
FROM," to be as follows:-
This Invention relates, firstly, to improvements in the construction of
furnaces, whether reverberatory, blast, or otherwise for smelting ores of
copper, or other ores containing the precious metals; and, secondly, in the

page_text: means or extracting such precious metals from the ores when smelted in suc
furnaces.
The exterior of the furnace may be of iron, brick, or stone, and the interio
of a refractory material, such as Stourbridge fire-clay or bricks to withstand
the heat; the furnace may be a reverberatory air furnace, or a blast furnace
or otherwise as may be most suitable to the ores to be operated on; but in
the bottom of the furnace a well is to be formed having a tap hole at the
bottom thereof; another tap hole is formed in the bottom of the furnace above
the level of that in the well. Or, in some cases, the well may be dispensed
with, and two tap holes formed in the bottom of the furnace, but on different
levels. The well is to be filled or partly filled with lead, or alloys of lead, or
other alloys which in a molten state have an affinity for the precious metals.
The lead well may be charged through an opening near the bottom if a blast
furnace is used; or if a reverberatory furnace is used the charge may be
placed in the well through an opening made for such purpose; or the lead or
alloys may be mixed with the ores to be smelted, or may be thrown on the
melted mass of ores while in the fused state in the furnace; in either case the
lead or alloy will gravitate to the lowest part of the furnace and into the lead
well. If the ores smelted contain any precious metals, such metals will
gravitate to and mix with the melted lead or alloy. If the precious metals
are combined with ores or earths that have a tendency to hold the same in
combination we then mix with the ores either before they are put in the
furnace or after the charge is melted a small quantity of litharge, which will
percolate or run down through the whole charge into the lead or alloy
carrying with it in its passage the precious metals. If the ores to be operated
on are copper ores the tap hole for the copper matt or regulus must be so
far above that for the lead or alloy that in running off the copper or other
product it may not disturb the lead or alloy. The lead or alloy is to be run
off through the tap hole at the bottom of the well after the copper (or other
product according to the ores smelted) is run off from the upper tap hole.
If the lead or alloy is not rich enough in precious metals by the smelting of
one charge of the ores containing them it may be allowed to remain in the
well for so many successive charges as will make it rich enough, all depending
op the amount of precious metals contained in the ores operated on. After
the lead or alloy is withdrawn from the furnace it may be refined or sub-
jected to heat in a cupel in the ordinary way to obtain the precious metals.
The process is the same where no lead well is employed, the arrangement of
the tap holes enabling the separation of the smelted metal from the lead or
alloy to be effected with facility,

page_text: It is not intended to claim the combining or alloying precious metals with
lead or alloys in order to obtain such precious metals, but the novel con-
struction or improvement of the bottom of the furnace where the lead or
alloys having an affinity for the precious metals may lie undisturbed at the
bottom of the furnace without in any way interfering with or deteriorating
the smelting or the product of the other metals operated on.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Thomas and Alexander Prince in the Great Seal
Patent Office on the 1st November 1866.
t
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
THOMAS, of Battersea, in the County of Surrey, Ironfounder, and ALEXANDER
PRINCE, of No. 4, Trafalgar Square, Charing Cross, in the County of Mid-
dlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of May, in the year of our Lord One
thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said John Thomas and Alexander Prince, Her special licence that
we, the said John Thomas and Alexander Prince, our executors, adminis-
trators, and assigns, or such others as we, the said John Thomas and
Alexander Prince, our executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "IMPROVEMENTS
IN REVERBERATORY, BLAST, AND OTHER FURNACES FOR SMELTING ORES, AND IN THE
MEANS OF EXTRACTING THE PRECIOUS METALS THEREFROM," upon the condition
(amongst others) that we, the said John Thomas and Alexander Prince, our
executors or administrators, by an instrument in writing under our, 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 we, the said John Thomas and Alexander Prince,
do hereby declare the nature of our said Invention, and in what manner the

page_text: same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This Invention relates, firstly, to improvements in the construction of
furnaces, whether reverberatory, blast, or otherwise for smelting ores of
copper, or other ores containing the precious metals; and, secondly, in the
means of extracting such precious metals from the ores when smelted in such
furnaces.
The exterior of the furnace may be of iron, brick, or stone, and the interior
of a refractory material, such as Stourbridge fire-clay or bricks to withstand
the heat. The furnace may be a reverberatory air furnace, or a blast furnace,
or otherwise as may be most suitable to the ores to be operated on; but in
the bottom of the furnace a well is to be formed having a tap hole at the
bottom thereof; another tap hole is formed in the bottom of the furnace above
the level of that in the well. Or, in some cases, the well may be dispensed with,
and two tap holes formed in the bottom of the furnace, but on different levels.
The well is to be filled or partly filled with lead, or alloys of lead, or other
alloys which in a molten state have an affinity for the precious metals. The
lead well may be charged through an opening near the bottom if a blast
furnace is used; or if a reverberatory furnace is used the charge may be
placed in the well through an opening made for such purpose; or the lead or
alloys may be mixed with the ores to be smelted, or may be thrown on the
melted mass of ores while in the fused state in the furnace; in either case
the lead or alloy will gravitate to the lowest part of the furnace and into the
lead well. If the ores smelted contain any precious metals, such metals will
gravitate to and mix with the melted lead or alloy. If the precious metals
are combined with ores or earths that have a tendency to hold the same in
combination we then mix with the ores either before they are put in the
furnace or after the charge is melted a small quantity of litharge, which
will percolate or run down through the whole charge into the lead or alloy
carrying with it in its passage the precious metals. If the ores to be operated
on are copper ores the tap hole for the copper matt or regulus must be so far
above that for the lead or alloy that in running off the copper or other
product it may not disturb the lead or alloy. The lead or alloy is to be run
off through the tap hole at the bottom of the well after the copper (or other
product according to the ores smelted) is run off from the upper tap hole.
If the lead or alloy is not rich enough in precious metals by the smelting of
one charge of the ores containing them it may be allowed to remain in the
well for so many successive charges as will make it rich enough, all depending
on the amount of precious metals contained in the ores operated on. After

page_text: the lead or alloy is withdrawn from the furnace it may be refined or cupeled
in the ordinary way to obtain the precious metals. The process is the same
where no lead well is employed, the arrangement of the tap holes enabling
the separation of the smelted metal from the lead or alloy to be effected with
facility.
The Drawing represents a longitudinal vertical section of a reverberatory
furnace with the application of the well.
a is the brickwork; b, the fire-grate; c, the ash-pit; d, the fire; e, e, the doors,
and f, the chimney; 9 is the well; h, the lower tap hole for the lead and
precious metals; i, the upper tap hole for the copper or other metals smelted;
the lines k, l, m, indicate respectively the assumed levels of the lead or alloy
and precious metals, the level of the copper or other metal smelted, and the
level of the scoria or slag. The Invention is equally applicable to ordinary
blast furnaces. The furnace well would be substantially the same to all
intents and purposes.
Having now described the nature of our said Invention, and the manner
in which the same is to be performed, we would remark that we do not limit
ourselves to any special form or construction of furnace well, as the same may
be varied without departing from the principles of the Invention. We do not
claim the mere combining or alloying precious metals with lead or alloys in
order to obtain such precious metals; but we claim the novel construction and
improvement of the bottom of the furnace, and the construction and appli-
cation of the furnace well, where tho lead or alloys having an affinity for the
precious metals, such as silver and gold in the molten state, may lie undis-
turbed at the bottom of the furnace without in any way interfering with or
deteriorating the smelting or the product of the other metals operated on.
We prefer to use lead, but claim to use other metals or alloys having the
required affinity for the precious metals in conjunction with the improvements
in the furnaces, substantially as herein specified.
In witness whereof, we, the said John Thomas and Alexander Prince,
have hereunto set our hands and seals, this Twenty-seventh day
of October, in the year of our Lord One thousand eight hundred and