IMPROVEMENTS IN OBTAINING COPPER AND OTHER METALS
Year: 1852

page_text: LETTERS PATENT to Alfred Trueman, of Swansea, in the County
of Glamorgan, Manager of Copper Smelting Works, for the
Invention of "IMPROVEMENTS IN OBTAINING COPPER AND OTHER METALS
Sealed the 19th February 1853, and dated the 7th October 1852.
PROVISIONAL SPECIFICATION left by the said Alfred Trueman at
the Office of the Commissioners of Patents, with his Petition, on
the 7th October 1852.
I, ALFRED TRUEMAN, of Swansea, in the County of Glamorgan,
Manager of Copper Smelting Works, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN OBTAINING COPPER AND OTHER
METALS FROM ORES OR MATTERS CONTAINING THEM" to be as follows:-
This Invention consists of acting on oxide ores (or sulphuret ores
after they are reduced to oxides by calcination) by digesting them in
acids, and afterwards applying muriate of lime and lime. If sulphuric
acid be used the copper alone will be dissolved, and is to be drawn off,
leaving sulphate of silver, which is to be washed out by hot water, and
added to the sulphate of copper previously run off. Common salt or
muriatic acid to be added to this solution to throw down the silver as
chloride; the solution of sulphate of copper is to be run off, and muriate

page_text: of lime added to it, forming muriate of copper and sulphate of lime
precipitated; the muriate of copper to be run off, and lime added to
it, to throw down oxide of copper, leaving muriate of lime in solution,
which is to be again used for the previous process. The oxide of copper
and chloride of silver to be treated in the usual way to obtain the metals.
The residue in the first tanks, after the copper and silver solutions
have been drawn off, is to be boiled in a solution of caustic alkali to
extract the oxide of tin, which may be obtained from the caustic solution
by various means. Or the residue may be smelted in the usual way to
obtain metallic tin. If muriatic acid be used the copper alone will be
dissolved out, and may be at once treated with muriate of lime and lime,
as before stated; the chloride of silver left in the first tank to be dissolved
out by a hot solution of common salt or of hyposulphite of lime, from
which the silver may be obtained by various means. The residue to be
treated as before. If nitric acid be used both silver and copper will be
dissolved; the silver may be obtained by the addition of salt or muriatic
acid, as from the sulphate of copper solution. The copper to be thrown
down from the solution by soda or potash, forming a solution of nitrate
of the substance used; the solution may be evaporated to obtain crystals.
The residue in the first tanks to be treated as before. I propose to
treat some of the slags obtained in the methods of copper smelting now
in use in a similar manner, that is, by digesting in acid. Also carbonates
of copper may be treated in the same manner, with or without calcina-
tion, that only being necessary when other metals are present which it
is desirable to separate from the copper by the calcination, some will
be peroxidized and rendered less soluble in acid, and others will be
driven off. Two or more acids may be used together, the after treat-
ment being varied accordingly.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred Trueman in the Great Seal Patent Office, 3
on the 7th April 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
ALFRED TRUEMAN, of Swansea, in the County of Glamorgan, Manager
of Copper Smelting Works, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of October, in the year of
our Lord One thousand eight hundred and fifty-two, in the sixteenth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Alfred Trueman, Her special licence that I,
the said Alfred Trueman, my executors, administrators,' and assigns,
or such others as I, the said Alfred Trueman, my executors, adminis-
trators, 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 OBTAINING COPPER AND OTHER METALS FROM ORES OR MATTERS CON-
TAINING THEM," upon the condition (amongst others) that I, the said
Alfred Trueman, by an instrument in writing under my hand and
seal, 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 Alfred Trueman, 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):
This Invention consists of acting on oxide ores (or sulphuret ores
after they are reduced to oxides by calcination) by digesting them in
acids, and afterwards applying muriate of lime and lime. If sulphuric
acid be used the copper alone will be dissolved, and it is to be drawn
off, leaving sulphate of silver, which is to be washed out by hot water,
and added to the sulphate of copper previously run off. Common salt
or muriatic acid to be added to this solution to throw down the silver
as chloride; the solution of sulphate of copper is to be run off, and
muriate of lime added to it, forming muriate of copper and sulphate of
lime precipitated; the muriate of copper to be run off, and lime added to
t, to throw down oxide of copper, leaving muriate of lime in solution,

page_text: which is to be again used for the previous process. The oxide of copper
and chloride of silver to be treated in the usual way to obtain the metals.
The residue in the first tanks, after the copper and silver solutions have
been drawn off, is to be boiled in a solution of caustic alkali to extract
the oxide of tin, which may be obtained from the caustic solution by
various means. Or the residue may be smelted in the usual way to
obtain metallic tin. If muriatic acid be used the copper alone will be
dissolved out, and may be at once treated with muriate of lime and
lime, as before stated; the chloride of silver left in the first tank to be
dissolved out by a hot solution of common salt or of hyposulphite of lime,
from which the silver may be obtained by various means. The residue
to be treated as before. If nitric acid be used both silver and copper
will be dissolved; the silver may be obtained by the addition of salt or
muriatic acid, as from the sulphate of copper solution. The copper to
be thrown down from the solution by soda or potash, forming a solution
of nitrate of the substance used; the solution may be evaporated to
obtain crystals. The residue in the first tanks to be treated as before.
I propose to treat some of the slags obtained in the methods of copper
smelting now in use in a similar manner, that is, by digesting in acid.
Also carbonates of copper may be treated in the same manner, with or
without calcination, that only being necessary when other metals are
present which it is desirable to separate from the copper by the cal-
cination, some will be peroxidized and rendered less soluble in acid,
and others will be driven off. Two or more acids may be used together,
the after treatment being varied accordingly. And in order that my
said Invention may be more fully understood I will proceed to describe
the means pursued by me.
TREATMENT OF SULPHURET ORES.
The ore is to be ground to fine powder and calcined at a gradually
increasing heat for about twenty-four hours in order to drive off the
sulphur, the last six hours the heat should be increased to and kept a
a good red, which will have the effect of peroxidizing the iron and any
tin that may be in the ore; the sulphur should be driven off' as nearly as

page_text: In some cases it may be found necessary or convenient to partially
calcine the ore before grinding to powder, in which (partially calcined)
state it is more easily ground, and after grinding may be again calcined
to finish the operation. After the calcination is completed the ore is
to be removed to tubs or vats or other suitable vessels, and acid added.
in proportion to the quantity of copper and other metals to be acted on
contained in the ore; the proportions are to consist of one equivalent
of acid to one of copper in the ore, and an additional quantity of acid
to act on the silver, if any in the ore. Water is then to be added to
the ore and acid in the vessel, so as to make an equal or greater weight
of water and acid as there is of orc, the whole to be boiled and well
stirred during the operation. The boiling should be continued during
several hours, at the end of which time the ore may be allowed to settle
and the supernatant solution drawn off into a tank N° 1, and then
fresh water added to the ore to wash out all the copper, which washings
may be added to the solution first drawn off. If the sulphuric acid has
been used for acting on the ore the water used for washing is to be hot;
if it is desired to obtain any silver in the orc by the use of hot water
the sulphate of silver previously formed will be dissolved, and this solu-
tion may be added to the first portion drawn off, to which must then be
added a muriate (common salt or muriatic acid are the most suitable)
sufficient to precipitate all the silver, which may be allowed to remain
at the bottom of the tank till a considerable quantity has accumulated;
the solution then containing copper, and, perhaps, a little iron, is to
be drawn off into another tank No. 2, and chloride of calcium added,
which will throw down sulphate of line, leaving chloride of copper,"
which is to be drawn off into another tank N° 3, and milk of lime
added to it, to throw down the copper as oxychloride; the solution and
precipitate in this tank should then be well boiled to concentrate the
precipitate; the liquor may then be drawn off and used for the previous
operation. The precipitate of oxychloride of copper may accumulate
in the bottom of tank till a foot or more in thickness, it should then
be removed and dried, and fused with carbon to obtain metallic copper.
The chloride of silver in N° 1, tank when a sufficieiit quantity has
accumulated may be treated in the usual way to obtain metallic silver.

page_text: If after boiling the ore with acid in the first vessel, and washing with
water, copper should then remain in the residue, a further quantity of
acid must be added and the boiling repeated; when all the copper has
been obtained the residue, if containing tin, is to be washed with water,
allowing of the particles to arrange themselves according to specific
gravity; the oxide of tin being heavier may thus be obtained nearly free
from oxide of iron and earthy matters, and may be reduced by carbon
in the usual manner. The residue in the first vessels may be treated
with a strong solution of caustic alkali which will dissolve out the oxide
of tin, which may be obtained from the solution by the addition of a
large quantity of water. This treatment, or that of washing, so as to
arrange the particles according to their specific gravities, may be used.
The acid I prefer to use is muriatic, which may be used in the following
way If silver is in the ore the acid should be sufficiently dilute to
prevent the chloride formed being dissolved, as it should remain in the
first vessel with the residue. The chloride of copper formed at the first
boiling and washing of the ore, after being run into N°1, tank, may
have milk of lime added at once, and after boiling in this tank the
solution of chloride of calcium may be allowed to run to waste, or, if
found of commercial value, may be crystalized. The precipitate of
oxichloride is to be treated as before directed. The residue in the first
vessel, if containing silver, is then to be treated with a hot solution of
common salt, or hyposulphites of lime or soda. I prefer the latter
salts, from which, after being drawn off into another tank, the silver
may be precipitated by placing in the solution pieces of iron or other
suitable metal. The residue may now be treated as before for tin.
Nitric acid may be used as well as either of the former acids, the solu-
tion of copper with which is to be precipitated by potash or soda,
which solution being drawn off from the precipitated oxide of copper
is to be evaporated and crystalized to obtain nitrate of soda or potash.
As the silver will have been dissolved in the first vessel by use of pure
nitric acid, it is advisable to use a very little muriatic acid mixed with
the nitric, which will cause the silver to remain in the first vessel with
the residue, which is to be treated as directed when muriatic acid has
been used. The slags produced by the present methods of copper

page_text: smelting I propose to treat in the same way as ore, if containing other
metal that it is desirable to obtain. The slag is to be ground to a fine
powder, and calcined the same as the ore, to oxidize the various metals
contained; the subsequent treatment will be the same as with ore.
Carbonates and oxides of copper may be treated in same way, either
with or without calcination, that only being necessary when other metals
besides copper are contained in the ore, and which it is desirable to
separate. Although I have proposed to separate the chloride of silver
from the residue by a solution of common salt, or of hyposulphite of
lime or soda, the separation may also be effected by the use of mercury,
as is well known. Also the copper may be precipitated from its solu-
tions by the insertion of another metal, as iron or zinc.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would remark that I am aware that
acid has before been used to separate small quantities of copper from tin
ores. I do not, therefore, claim the same; and I wish it to be under-
stood that what I claim is, the mode herein described of separating
copper from copper ores and slags. And I also claim the application
of earthy and alkaline hyposulphites for dissolving chloride of silver.
In witness whereof, I, the said Alfred Trueman, have hereunto set
my hand and scal, this Fifth day of April, in the year of our
Lord One thousand eight hundred and fifty-three.
ALFRED TRUEMAN. (L.s.)
Witness,
J. TREV. JENKIN,
Sol, and Master Extraordinary in Chancery,
Swansea.