IMPROVEMENTS IN THE SEPARATION AND EXTRACTION OF COPPER FROM ITS ORES
Year: 1857

page_text: LETTERS PATENT to Thomas Lewis, of Birmingham, in the County of.
Warwick, Mining Engineer, Heury Parrish, of the same Place, Gentle-
man, and Robert Martin Roberts, of Dolgelley, in the County of
Merioneth, Mining Captain, for the Invention of "IMPROVEMENTS IN
THE SEPARATION AND EXTRACTION OF COPPER FROM ITS ORES."
Sealed the 1st January 1858, and dated the 9th July 1857.
PROVISIONAL SPECIFICATION left by the said Thomas Lewis, Henry
Parrish and Robert Martin Roberts at the Office of the Commissioners
of Patents, with their Petition, on the 9th July 1857.
We, THOMAS LEWIS, of Birmingham, in the County of Warwick, Mining
Engineer, IIENRY PARRISH, of the same Place, Gentleman, and ROBERT
MARTIN ROBERTS, of Dolgelley, in the County of Merioneth, Mining Captain,.
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE SEPARATION AND EXTRACTION OF COPPER FROM ITS ORES," to be as follows:-
We take the ore as it comes from the mine, and having crushed or reduced
it by any of the known processes, the bulk is then calcined, after which the
residue is thrown into a bath containing a solution of sulphuric acid and iron,

page_text: by which solution a precipitate is formed. The bath solution is drawn off,
and the precipitate after being dried is melted in crucibles, or if preferred, in
a common furnace. The metal is then ready for the market, and the solution
sorres for many repetitions of the process.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Lewis, Ilenry Parrish, and Robert Martin Roberts
in the Great Seal Patent Office on the 8th January 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
LEWIS, of Birmingham, in the County of Warwick, Mining Engineer, HENRY
PARRISH, of the same Place, Gentleman, and ROBERT MARTIN ROBERTS, of
Dolgelley, in the County of Merioneth, Mining Captain, send greeting.
WHEREAS Iler most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of July, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
Thomas Lewis, Henry Parrish, and Robert Martin Roberts, Her special
license that we, the said Thomas Lewis, Henry Parrish, and Robert Martin
Roberts, our executors, administrators, and assigns, or such others as we, the
said Thomas Lewis, Henry Parrish, and Robert Martin Roberts, our 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 "IMPROVEMENTS IN THE SEPARATION AND EXTRACTION OF COPPER
FROM ITS ORES," upon the condition amongst others that we, the said Thomas
Lewis, Henry Parrish, and Robert Martin Roberts, by an instrument in
writing under our 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 Thomas Lewis, Henry Parrish, and
Robert Martin Roberts, do hereby declare the nature of our 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):-

page_text: Our Invention has for its object the chemical treatment of copper ores, so
as to obtain a greater per-centage of pure copper from the qualities of ore at
present employed, and also to render available refuse ore, so that that which
is now thrown aside as waste, by being treated according to our process, will
be made to yield pure copper in sufficient quantity to render its employment
profitable. We are thus enabled to dispense with many of the operations now
essential in the ordinary processes of extracting copper, avoiding considerable
delay, expense of fuel, and cost of freight and carriage upon the valueless
portions of the ore, whilst that refuse which now cumbers the mines and
works can also be profitably worked up.
The process is as follows:-The ore as produced from the mines is first
carefully assorted, and if in too large boulders, it is broken up into lumps of
about two or three inches cube; these lumps are then conveyed to a kiln or
furnace of any suitable description (that which we prefer being similar to a
drawing out lime kiln, slightly modified to suit our purpose, but many kinds
of furnace will answer for this operation; the ore is thus calcined, and is to be
kept at a dull red heat; the fuel employed may be coal, coke, peat, wood, or
other bituminous fuel, which is to be put with the ore into the kin in
sufficient quantity to keep the ore always at the same dull red heat. The
length of time which the ore is to remain in the kiln varies from three to twenty-
four hours, or even longer, according to the description of ore under operation,
whether it be copper pyrites, carbonates, or oxides, which can be previously
ascertained by inspection. After having been sufficiently roasted, the ore is
drawn from the kiln through a trap underneath, and instantly in the heated
state passed through two pairs of ordinary crushers, the first pair of which will
reduce it into small lumps, and the second will pulverize it into somewhat the
size of coarse gunpowder, or if preferred, this last process of crushing and
pulverizing may take place before the roasting. Whilst still hot, the reduced
ore is next plunged into a bath containing either sulphuric acid or muriatic acid,
or both, dissolved in water, a simple solution of sulphuric acid being preferred.
The strength of this solution must be determined by the kind of ore under
operation, as the quantity of acid may vary from one-third the weight of thic
ore to one-sixth of the weight; in some instances even a smaller quantity will
suffice. The bath or tank containing this solution should be made of lead, or
of slabs of slate selected to stand heat. This tauk is to be placed inside an
iron tank containing water, and fire being applied to the bottom of the water
tank, the solution is to be kept within a few degrees of boiling point for from
three to forty-eight hours, or more, according to the nature of the ore. Whilst

page_text: this operation proceeds, the orc must be kept frequently stirred in the solution,
and as some ore requires only three hours, whilst another description may take
the full time nanied, if it should be found in the latter case that the solution
is too much reduced, and copper crystals are beginning to form, add a
sufficient quantity of hot rain or river water. When the ore has remained
long enough in the bath for the solution to take up all the copper, which can
be ascertained by testing a portion of the ore with nitric acid, the solution
should be drawn off through a filter into a second tank, leaving the residue of
the ore and other precipitated matters behind. The second tank must contain
a sufficiency of iron to precipitate the copper held in the solution, and for this
purpose we prefer employing boiler plate iron, in plates from six to fifteen
inches wide, and from a quarter to half an inch thick; these are to be placed
in grooves, which are best formed of wood, and fixed edgeways from one side
of the tank to the other, at intervals of three or four inches apart, forming a
series of cells, the iron plates terminating at a few inches from the bottom of
the tank to give room for the precipitate. The tank is to be kept warm by a
slow heat under the bottom, to facilitate the operation. When the whole of
the copper has been precipitated (which may be ascertained by the liquor
again becoming clear, and also by dipping a bright iron rod into the solution,
which will come out unstained if no copper be left), the solution may be
carefully drawn off into another vessel, and is ready to be re-used after adding
fresh acid. The precipitate left in the tank is then to be thoroughly cleansed
with water to free it from the acid, after which it is to be laid upon a drying
stove, thoroughly dried, and it is then ready for melting. Ore which may
contain lime, or which may have been procured from lime strata, must first be
thoroughly freed from the lime by the first described operation of roasting, and
it should then be thrown into a bath of rain or river water containing a small
quantity of muriatic acid in solution. After thoroughly washing the ore, and
clearing it from the lime, the solution of sulphuric acid in rain water is to be
added at a boiling point, and kept hot in the manner already described. This
description of ore is then subjected to the same treatment and manipulation
which we have detailed with regard to other kinds of ore.
Having thus described the nature of our said Invention, and in what
manner the same is to be performed, we wish it to be understood that
we do not confine ourselves to these precise details, as the same may be
varied in many ways, but that which we claim and desire to have secured
to us by the herein-before in part recited Letters Patent is, the process
or processes herein described, or any mere modification of the same for

page_text: separating or extracting copper from its ores, as herein more fully set forth
and specified.
In witness whereof, we, the said Thomas Lewis, Henry Parrish, and
Robert Martin Roberts, have hereunto set our hands and scals, this
Sixth day of January, One thousand eight hundred and fifty-eight.
THOMAS LEWIS.
HENRY PARRISH.
(L.S.)
(L.S.)
ROBERT MARTIN ROBERTS. (L.S.)