IMPROVEMENTS IN TREATING COPPER ORES AND SOLUTIONS OF COPPER TO OBTAIN COPPER THEREFROM
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by the said James Dickson at the
Office of tle Commissioners of Patents, with his Petition, on the 24th
July 1862
I, JAMES DICKSON, of 66, Tollington Road, Holloway, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN TREATING COPPER ORES AND SOLUTIONS OF COPPER TO OBTAIN
COPPER THEREFROM," to be as follows:-
99
My mode of treatment consists, 1stly, in obtaining aqueous acid, saline, or
other solution of copper from copper ores, and employing the said solution
when heated as negative electrolyte in a battery cell with appropriate positive
poles, or with positive electrolytes contained in a porous medium or cell, and
thereby precipitating or depositing its metallic copper from it.
2ndly. Copper ores which contain iron or other metals, are at once smelted
so as to reduce the copper together with the other metals that may be present,
the alloy or
alloys thus formed are then used as positive poles in the arrange-
hereafter mentioned, or as positive poles in many of the forms of the
battery,
for which I received Provisional Protection on or about the 18th day of
February 1862, numbered 340. The said solution of copper from its ore may
ments
be obtained by roasting ordinary copper pyrites in contact with atmospheric

page_text: air, so as to convert the sulphide of copper which it contains as far as possible
either into sulphate of copper or into oxide of copper, which substances are
subsequently dissolved in hot or cold aqueous acids; if sulphate of copper be
formed as described, this may be dissolved in water, or in hydrochloric,
sulphuric, or other suitable acids, or in common salt or other suitable salts
dissolved in water. Or if the ore of copper operated on contain in its natural
state oxide or dioxide of copper or carbonate of copper, these are dissolved in
sulphuric, hydrochloric, or other suitable acids. An improved mode by which
I obtain solution of copper for the above purpose is shewn in the following
example:-Any of the copper ores already alluded to are, if necessary, roasted
so as ultimately to convert them as much as possible into oxide or dioxide of
copper, and I prefer the latter oxide; the said roasted ore is then added to a
hot or cold solution of sulphurous acid in aqueous solution of common salt, sea
water, or in other suitable aqueous salt; the soluble portion of the said ore is
then to a large extent dissolved out by the said solution The positive poles
which I employ in the said porous cell are iron, zinc, tin, lead, or other
suitable metals or metallic substances. The positive electrdytes also employed
in the said porous cell with a carbon or other suitable positive pole are the
sulphides of the metals of the alkalies or sulphides of the metals of the
alkaline earths. I also employ in the said porous, cell aqueous solutions of
the alkalies or alkaline earths, either alone or impregnated with sulphur or
any suitable metallic oxides; or I employ in the said porous cell sulphurous
acid, or other suitable acids or salts.
To assist the said precipitation of copper in some or in all of the arrange-
ments alluded to, I unite them if necessary to a source of voltaic power, such
as many of the modifications of the voltaic battery for which I received
Provisional Protection on or about the 18th day of February 1862, numbered
340, which said modifications I use in preference, from their economy, to
ordinary batteries. Again I subject solutions of copper, whether dissolved in
acids, alkalies, or salts, in a decomposition cell, to the action of a current of
voltaic electricity; in this case I employ carbon or other suitable anodes, and
I dispense with a porous cell in some instances, but in using a porous cell I
employ therein any of those fluids or substances herein-before described, as
used or poured therein, which can be advantageously employed in assisting
the said voltaic precipitation of copper. I find that at a temperature of
about 212° Fahrenheit, or at still higher temperatures, the said precipitation
of copper may in most of the cases stated be very readily effected, but as
many of the said modifications of my own battery, already alluded to, are very
inexpensive sources of voltaic electricity, I can also by employing as sufficient

page_text: number of them produce with advantage a precipitation of copper in many of
the cases alluded to at temperatures much lower than that of 212° Fahrenheit.
3rdly, I also obtain copper from fused ores or compounds of copper, which
are sufficiently rich in copper, by passing a current of voltaic electricity through
the said fused ores or compounds, by means of carbon or other suitable anodes
and cathodes immersed therein and connected with the terminal poles of a
voltaic battery.
Any of the products formed during the coid
o SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Dickson, in the Great Seal Patent Office on the
24th January 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
DICKSON, of 66, Tollington Road, Holloway, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of July, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Dickson, Her special licence, that I, the said James
Dickson, my executors, administrators, and assigns, or such others as I, the said
James Dickson, 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 "IMPROVEMENTS IN
TREATING COPPER ORES AND SOLUTIONS OF COPPER TO OBTAIN COPPER THEREFROM,'
upon the condition (amongst others) that I, the said James Dickson, 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 James Dickson, do hereby declare the
nature of my 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:-
37

page_text: In stating the date of Letters Patent, No. 340, in the Provisional Specifi-
cation hereunto attached an error occurs in the words
on or about the
18th day of February 1862"; the said error in the date alluded to is herein-
after corrected and written as the 10th day of February 1862, instead of the
said 18th day of February 1862.
The terms "battery cell," "battery cells," used in this Specification are in
a general sense used to signify a charged battery cell, or charged battery cells
capable of yielding voltaic electricity.
By the method firstly to be described, sulphate of copper is dissolved in
sulphuric acid water of from specific gravity 1.52, to specific gravity 1-15, so
so as to form a saturated solution of sulphate of copper; this solution is then
to be conveyed into the negative compartment of the battery cell represented
in Figures 1 and 2, and heated therein to about 212° Fahrenheit.
5
A, A, A, A, in Figures 1 and 2, represent a glazed stoneware vessel or cell,
into which is placed a double porous cell or positive compartment p, p; the
inner and outer porous cells of the said double porous cell may each be fur-
nished with a short nozzle projecting downwards at their upper parts, the
nozzle of the inner porous cell being sufficiently short to be placed into the
nozzle of the outer porous cell, so that the said inner porous cell delivers into
the nozzle of the said outer porous cell, the nozzle of which latter delivers into
the pipe c; the pipe c delivers into the gutter g, whereby any fluid instead
of being siphoned off either from the said inner or outer porous cells, or from
the said negative compartment, may be conducted at separate intervals of
time into the said gutter g; k, k, k, k, represent the negative pole, which may
be formed of thin sheet copper or brass, the lower part of the said negative
pole is supported on rests as shewn in Figure 1, the said rests also support
the double porous cell at each of its lower ends; m, m, m, m, in Figures 1, 2,
and 3, represent an oblong shaped mass of glazed stoneware to be termed a
weight, suspended by copper wire ropes f, f, whose upper ends are attached to
the pulleys d, d, keyed on to a shaft e, e, which latter is actuated by motive
power, the said weight by a reciprocating motion of the pulleys is first raised
to its position represented in the said Figures, and then lowered to the lowest
part of the negative pole, when it returns again to its original position, this
motion is repeated as often as it is found necessary to detach from the surface
of the negative pole the long crystals of copper which are deposited thereon,
the said crystals of copper as they are detached fall to the bottom of the
battery cell which is inclined downwards towards the opening B as shewn in
Figure 1. A soft piece of deal board, as represented in Figure 1, is screwed
and bolted to the said opening so as to make a water-tight joint; the copper

page_text: crystals a, a, are removed, and collected in the gutter X by gradually loosening
copper drawn
the nuts and bolts at B, the said board is then removed, and the
out by a rake. Or, the said opening at B may be dispensed with, and by
introducing to the bottom of the said battery cell a perforated scoop having a
5 long handle, the crystals of copper may be drawn up to the level of the pipe c,
but in this case a wide overhanging lip is to be substituted for the said pipe c,
so as to allow the copper when drawn up to the said lip to be pushed over into
the gutter g, and at the end of the said battery cell abutting the said lip suffi-
cient space between the porous cells and the inside of the said battery cell
o must be allowed for the ready use of the said scoop. The solution of copper
described having been conducted into the said negative compartment, the said
outer porous cell when iron is the positive pole to be used, is charged with a
mixture of one volume of oil of vitriol with from ten to fifteen volumes of
water, and the said inner porous cell into which the iron positive pole is
5 placed is charged with aqueous solution of sulphate of soda, the whole arrange-
ment of the said battery cell is then maintained at a temperature of about
212° Fahrenheit. On connecting the said iron positive pole with the said
negative pole, metallic copper in a crystalline state is reduced on the said
negative pole. Any number of such battery cells charged as described, may
be united in single series, when the voltaic current which pervades the whole
arrangement will precipitate or deposit an equal quantity of copper on each
of the said negative poles of the said series of battery cells at the same
time that a powerful voltaic current is generated capable of being further
applied to the reduction of metallic copper from its various solutions. Instead
of iron as positive pole, zinc may be substituted in the said inner porous cell,
but with zinc a single porous cell need only be used; so also with an iron
positive pole, a single porous cell may be used if the acid water of the said
negative compartment contain sulphate of copper dissolved in acid water of no
greater density than 11; with either an iron or zinc positive pole the
respective protoxides (FeO, HO), (ZnO, HO,) of the last-named metals are
to be mixed or agitated with the said solution of sulphate of soda; for the
said
aqueous solution of sulphate of soda, sulphate of potash, or of ammonia
be substituted, so also with iron or zinc as positive poles, the respective
sulphates of iron (FeO, SO,,) or of zinc may be substituted for the said
sulphates, but I prefer to use sulphate of soda. Or instead of saturating the
sulphuric acid water of the negative compartment with sulphate of copper,
only so much of the said sulphate is added thereto as will cause, during battery
action, a brownish-red bulky deposit of copper on the said negative pole.
The said deposit is readily detached from the negative pole, either by the
may

page_text: mechanism already described, or by suddenly injecting at suitable intervals of
time a powerful jet or jets of steam against the surface of the said negative
pole. The said deposit is then readily drawn off with a portion of the
copperous solution by means of a tap affixed to the lower part of the said
battery cell or negative compartment; or this may be effected by means of
siphons immersed therein. The said deposit is allowed to subside to the
bottom of vessels, from which it is extracted; then washed with a small portion
of water and dried in an atmosphere of steam. It may then be pressed into
masses and fused, either in suitable crucibles or fused on the sole of a
reverberating furnace, from which atmospheric air is excluded just previous to
introducing the said masses; the said fused copper is then cast into ingots.
The crystalline deposit, already alluded to, is also to be collected, washed,
dried, and then fused, and may be cast as last described. The washings of the
said deposits of copper are conveyed to the tanks or vessels in which the
peroxidized copper ore or carbonate of copper are arranged for lixiviation.
When the sulphuric acid to be used in the negative compartment of the said
battery cell A, A, A, A, is of about specific gravity 1.52, a cast-iron vessel
may be employed of the form represented in Figures 1 and 2 ; but in this case
that portion of the upper and inner surface, as well as the flat rim of the said
battery cell which are above the level of the said fluid last described, are to be
first coated with sheet lead by soldering the said sheet lead on to the said
ianer surface of the said battery cell; the said sheet lead is also to be soldered
about two inches below the level of the said fluid. By these means the
action of the atmosphere is excluded from the inner surface of the said iron
vessel or battery cell. The pipe c may be formed of stout sheet lead, to be
also soldered or clamped water-tight to the surface of the said cast-iron
vessel, so as to carry off the fluids therefrom; in a similar manner the flanch
of the opening at B may be coated, as described, with sheet lead. Or,
instead of any of the fluids and positive poles already named, a carbon positive
pole is to be used in the said porous cell, into which latter aqueous solution of
either mono or bi-sulphide of sodium, or of potassium is to be used, but I
prefer the first-named sulphide. The battery arrangement thus formed is now
to be connected in single series, or otherwise used with any of the battery cells
already described, when copper is deposited on the said negative pole. The
said copper is collected, washed, dried, and fused, as before described. In
employing the said sulphides as positive electrolytes I prefer to use an inner
orous cell of thin wood veneer. Or, in the last-named arrangement, a porous
ell may be used, which is formed of finely-ground peroxide, or magnetic oxide
f iron, with which a portion of hydrate of either oxide or peroxide of iron is

page_text: mixed, or with which a portion of either molasses, or pitch, tar, or resin, are
mixed, and then heated out of contact of the atmosphere to a temperature of
about 700° Fahrenheit. Or, a porous cell composed entirely of carbonaceous
organic matter, which has been ignited to about 700° Fahrenheit, may be
5 employed. Or, instead of using the said solution of sulphate of copper as
negative electrolyte in the said battery cell, a hot saturated solution of the
said sulphate is added to hot aqueous solution of common salt until the whole
of the said sulphate of copper has become converted into sulphate of soda and
chloride of copper. The deep green chloride of copper thus formed is suffi-
0 ciently evaporated to allow the sulphate of soda when cooled to crystallize
out. The said green chloride may then be further evaporated, if desirable, so
as to precipitate any remaining portion of sulphate of soda which exists in it;
or the portion of the said sulphate last alluded to may be precipitated by
adding sufficient chloride of calcium or of barium to the said green
5 chloride after the first portion of sulphate of soda has crystallized out. The
sulphate of either lime or baryta, which precipitates is allowed to subside
and kept apart from the sulphate of soda. The said deep green chloride
may now be diluted with about its bulk of water, to which is to be added
common salt weighing from three to six times the weight of the copper which
the said green chloride of copper contains. It is necessary that excess
of common salt should be added to the said green solution of chloride
of copper to prevent
to prevent during
during battery action any precipitation of white
dichloride of copper on the negative carbon pole employed. The solution
of green chloride thus prepared is conducted into the negative compart-
ment of the battery cell A, A, A, A, (Figures 1 and 2,) which in this
case must be formed of glazed stoneware; a carbon negative pole is then
immersed into the said green chloride, and into the positive compartment or
porous cell is conducted aqueous solution of common salt, into which, as
positive pole, either iron, zinc, or lead are immersed, and the whole arrange-
ment is then heated to about 212° Fahrenheit. Or for the said aqueous
solution of common salt used with the said last-named metals as positive poles,
in the said porous cell are substituted a carbon pole, and the aqueous solution
of either mono or bi-sulphide of sodium, potassium, or of calcium, to which
latter is added common salt; or soda waste is to be used with a carbon
positive pole in the said porous cell. In using any of the sulphides of calcium
I prefer to keep their said aqueous solution briskly agitated during battery
action by means of a jet or jets of steam forced into their said solution. On
uniting in single series any required number of the battery cells charged as
described, a powerful voltaic current is producible; if the terminal battery

page_text: wires be united, the green chloride of copper speedily becomes of a dark
brown color, and by continued battery action is reduced to aqueous solution
of dichloride of copper in common salt. When the sulphates of soda and
potash are formed in the preparation of the said green chloride, the said
sulphates are to be converted into their respective mono-sulphides, which
latter are to be used as positive electrolytes with carbon as positive pole in
further assisting by voltaic agency the precipitation of metallic copper from
the said brown aqueous solution of dichloride of copper in common salt. The
said brown solution of dichloride of copper devoid of free hydrochloric or other
acid is conducted into an iron vessel, to be used as the negative compartment
and negative pole of a battery cell similar to that represented in Figures 1
and 2; into the single porous cell to be used in the said battery cell is to be
placed an iron positive pole, and aqueous solution of common salt is then
conducted into the said porous cell. The whole arrangement is then heated
to about 212° Fahrenheit; on uniting the said positive and negative iron poles
copper is deposited or precipitated on the said negative pole. Any required
number of such battery cells may be arrranged in single series with any of the
battery cells already herein-before described. For iron, any of the other
metals as positive poles may be substituted in the said fluid of the porous cell,
so also any of the said positive electrolytes may be used in the said porous
cell with carbon as positive pole; the battery cells thus producible being then
united in single series, as lastly described. Of the said positive electrolytes
last alluded to I prefer to use the mono or bi-sulphide of sodium. A portion
of hydrochloric or sulphuric acid may be added to the said brown solution of
copper, but then I prefer to use a glazed stoneware battery cell with a thin
copper or negative pole. It is here evident that when copper is dissolved as
a positive pole or anode in aqueous solution of common salt, as described in
my Invention for improvements in the manufacture of caustic soda and
carbonate of soda, No. 2044, dated on or about the 17th day of July 1862,
the said copper may be recovered in its metallic state from the said solution.
The copper precipitated as described from the said brown solution of copper is
collected, fused, and cast into ingots. In forming solution of
of copper to be used as already described, the sulphate of soda need not be
In forming solution of green chloride
crystallized out from the said solution before using the latter in the negative
compartment of the battery cell, the crystallization of the said sulphate may
be finally effected after the total extraction of the metallic copper from the
brown solution of copper already alluded to. Solution of
copper to be used in the negative compartment of the battery cells may
green chloride of
be formed by adding a sufficient excess of hydrochloric acid to sulphate of
also
$

page_text: copper as will prevent the precipitation of dichloride of copper on the negative
pole to be used in the said green chloride. If the sulphate of copper used in
these operations has been carefully crystallized, so as to avoid the other
metallic impurities of the ore from which the said sulphate is derived, the
5 copper furnished, as already described, will be sufficiently pure for commercial
purposes. To assist the precipitation of the copper in the foregoing or
subsequent operations herein specified, I connect in single series or otherwise
any of the most inexpensive or elegible forms of the voltaic battery (for which
I received Letters Patent No. 340, on or about the 10th day of February
o 1862,) with the battery cells or voltaic arrangements already specified. When
lead is used as positive pole, as already described, the said lead may be pre-
cipitated from its solution as oxide by lime, or by other suitable reagents, and
then reduced to its metallic state by the usual methods practised in its
reduction to the metallic state. I also recover lead and zinc from their
respective solution formed in these operations by the means to be described in
the Specifications of the Inventions for which I have received Provisional
Protection, viz., for "Improvements in Treating Zinc Ores and Solutions of
Zinc to Obtain Zinc therefrom," No. 2253, dated on or about 12th day of
August 1862, also for Improvements in Treating Ores and Solutions of Lead
to Obtain Lead therefrom," No. 2254, dated on or about 12th day of August 1862.
By the method 2ndly to be described, copper ores are reduced to crude
metallic copper by a rough smelting operation, whereby the copper of the said
ores is contaminated with other metallic impurities of the said ores; when the
said ores consist chiefly of oxide or dioxide of copper with peroxide of iron, they
are separated as far as possible from silicious gangue or earthy matters, and
are at once smelted for crude metallic copper, which is to be purified, as here-
after described. When the said ores consist chiefly of sulphides, such as iron
pyrites containing copper, or of such ores as purple copper, variegated copper,
copper pyrites, and any of those varieties of fahl-ore or grey copper, which
may be fit to be operated on, then any of the said ores are to be picked, sorted,
and separated from silicious or earthy impurities, and subjected to a furnace
operation, during which their sulphur and other volatile impurities are burnt
off by freely admitting the atmosphere to the said ores; in this state the said
ores are mixed with the necessary amount of carbonaceous matter, and are at
once reduced to the metallic state by a further furnace operation. Where
copper exists in small quantities in iron pyrites, I then prefer to burn or
oxidize the said pyrites, as described, and then smelt the burnt pyrites for iron
in a blast furnace, in the manner practised in smelting iron ores.
The crude copper or alloys of copper produced in smelting the said ores as

page_text: described, are to be purified by casting the said crude copper into bars, rods
in which either sulphate or chloride of copper have been described as used in
or plates, which are to be used as positive poles in the voltaic arrangements,
the negative compartment of the battery cells already alluded to; if, however,
the said crude metal contain so much copper as to be only slightly, or not at
all dissolved by immersion in sulphuric or hydrochloric acid, I use such crude
metal only as positive pole in either hydrochloric acid, or in aqueous solution
of common salt or other suitable chloride in the positive compartment with
either the solution of chloride of copper prepared as described, or with sesqui-
chloride of iron, oil of vitriol, sulphurous acid or other suitable negative
electrolyte in the said negative compartment; but when the said crude metal
is attackable by the said acids, as where it contains much iron and but little
copper, then such alloy is used as an iron positive pole would be in common
salt and water, or in other suitable fluids with the negative electrolytes last
alluded to; any required number of battery cells thus producible are heated to
about 212° Fahrenheit, and arranged in single series or otherwise with the
battery cells already specified as used in these operations, care being taken that
the surface of the battery poles is so augmented in the said battery cells, which
yield less "quantitative" energy than the more powerful battery cells with
which they are arranged, as to allow as far as possible the passage of the entire
battery current of the more powerful battery cells. To increase the quantitative
effect in any of the said battery cells, the positive and negative poles of each
battery cell instead of consisting of one large polar surface may be subdivided
into numerous smaller poles, each of which is insulated from the other, each
of the insulated positive poles in one battery cell A may then be connected to
a corresponding negative pole insulated in the manner described in another
battery cell B, and each of the insulated negative poles of the battery cell A is
then to be connected with its corresponding insulated positive pole in an
adjacent battery cell C; in this way a single series of battery cells
arranged on the multipolar system described. The crude copper metal formed
as described, dissolves as dichloride of copper when used as positive pole in
aqueous solution of a chloride (viz. Na C'), this occurs if great excess of
copper exist in the said crude metal, and at the same time there remains on
the surface of the said crude metal a portion of the insoluble metals or
substances which it may contain; if the said positive pole contain much iron S
and but little copper, the latter metal will exist as a dark substance on the
surface of the said positive pole during the battery action described. In either
case the crude metal used as positive pole may be made to revolve as a circular
plate, and is to be cleansed or scraped by means of apparatus already described
may
be

page_text: as used for a similar purpose in the Specification of my Patent No. 2044,
before stated, and I may here add that a similar revolving negative pole, or
plate, and the other parts of the said apparatus can be used as negative pole
to detach and collect the crystalline deposit of copper which occurs in the
5 operations before-described.
The solution of the said crude copper, formed as last described, is to be used
as negative electrolyte with iron or the other positive poles already named,
immersed in the appropriate aqueous solutions, and positive electrolytes with
which the said positive poles have been already described as used, and in this
0 case such arrangements, heated to 212° Fahrenheit are to be connected with
any of the battery cells or forms of the volatic battery described as used in the
preceding operations, copper is then precipitated on the negative pole or
poles immersed in the solution of dichloride of copper last alluded to; the said
copper is to be collected and treated as before described. Or the said hot
5 solution of dichloride of copper is conducted into proper vessels and stirred
with just sufficient sulphide of calcium diffused as a thin paste in water as will
precipitate all the copper as disulphide, and leave any chloride of iron in solution.
The said disulphide may now be digested with weak hydrochloric acid for a short
time, and is ultimately converted, by a furnace operation, into metallic copper.
Or a thin paste or cream of lime, as pure as possible, is gradually added, but
not in excess, to the said solution of dichloride, so as to precipitate all the
copper as dioxide of copper, which latter is then to be collected and dried or
heated in air, and sufficient dilute sulphuric acid is added thereto to convert
the said dioxide into metallic copper, and blue solution of sulphate of copper,
by these means half the copper of the said dioxide is at once obtained as a
fine red powder which is to be collected, dried and fused. The said blue
solution of sulphate of copper is then to be used as described in the battery
cells used in the preceding operations, when its copper is obtainable by the
battery action therein. Or the sulphate last alluded to is added to excess of
common salt so as to form chloride of copper, which latter is then used in the
battery cells as before described; the dichloride of copper which is then
formed may be treated for copper by either of the methods lastly described.
Where the copper ores already alluded to contain a larger per-centage of dioxide,
oxide, or carbonate of copper, these may be at once dissolved in sulphuric
or hydrochloric acid, and are then transferred to the battery cells, where dioxide
of
copper contained in the said copper ores is treated with sulphuric acid, a
portion of metallic copper is precipated, the said copper is to be separated
from other impurities either by washing its impurities away with water or by
fusing the said precipitate of copper.

page_text: Where in these operations it is desired to convert the copper or the solution
of dichloride of copper partly into black disulphide of copper, the said solution
of dichloride of copper (especially that in common salt), are to be mixed with
portion of sulphite of soda, formed in the negative compartment of thos
battery cells in which common salt and sulphurous acid are used as negative
electrolyte, such mixture is then heated and digested with sufficient sulphur t
precipitate the said copper as black disulphide, which may be treated fo
copper as before described. The supernatant fluid now contains hydrochlorid
acid in which latter protoxide of copper is to be dissolved to be used in the
battery cells as negative electrolyte.
is then
Solution of copper is obtained from its ores, which are sufficiently rich in
copper, in the following manner :-Oxide or dioxide of copper is prepared in
fine powder, either artificially or from the richest varieties of copper ore; or
carbonate of copper from which the carbonic acid has been expelled may be
used as fine powder; any of the last-named substances are added to aqueous
solution of common salt, in which is dissolved sulphurous acid prepared by
burning sulphur in excess of air; the said materials are to be constantly
agitated with access of air until the whole or greater portion of the cupreous
substances added are dissolved or converted into white dichloride of copper;
a sulphur salt of soda, probably sulphite of soda, is at the same time formed;
the said materials may be heated during the reactions described, and their
solution is to be used as negative eloctrolyte at about 212° Fahrenheit, with
either iron or other suitable positive poles and aqueous solutions, or positive
electrolytes already described as used in the operations given; copper
precipitated on the negative pole used and is to be collected and fused. In
this and other cases in which dichloride of copper (Cu², C¹) is decomposed by
battery action, about 64 lbs. of copper should be yielded for every 28 lbs.
of iron used to precipitate the said copper; the sulphite or other salt of
soda which ultimately remains in the negative compartment of the battery
cell or cells which are producible by the means of precipitating copper
described, is to be used for the formation of sulphide of sodium, or for the
manufacture of caustic soda or carbonate of soda. In all the cases in which
dichloride of copper in excess of common salt is formed, as herein described, a
portion of hydrochloric or sulphuric acid may be added thereto and the solution
gently heated, bars or rods of iron being at the same time immersed therein;
but this I avoid doing if the said dichloride contain sulphite of soda or of
potash. Dichloride of copper and sulphite or hyposulphate of soda are respec-
tively formed when sulphite of dioxide or of oxide of copper are added to
aqueous solution of common salt, when the said reaction is immediate; and if
last

page_text: at the same time the said solution be heated and fully saturated with the said
dichloride, the latter on cooling precipitates in numerous white crystals. The
sulphites of either oxide or dioxide of copper are to be formed and used in the
reactions last described by passing aqueous solution of sulphurous acid in
5 contact with the oxide or carbonate of copper, or in contact with the dioxide
of copper, any of which said substances should be in fine powder. By digesting
finely divided sulphur with any of the said last described solutions of copper in
which a sulphurous salt of soda exists, and heating the same, I precipitate the
copper therefrom as disulphide, which is to be treated as before described;
o the remaining acid liquor may now be used partly to dissolve out that portion
of the oxide of copper still remaining in the copper ores that have been treated,
as last described with aqueous solution of common salt and sulphurous acid;
the solution of copper thus dissolved out is conducted to the battery cells to be
further used therein.
Solution of sulphate of copper acidulated with sulphuric acid may be decom-
posed into copper and sulphuric acid in the following manner:-Into the
negative compartment of a glazed stoneware decomposition cell is poured the
said solution of copper, in which a porous cell is to be immersed; into the said
porous cell is then conducted sulphuric acid water (1 to 4), a carbon anode is
immersed into the said porous cell and connected with the negative pole of a
single series of the battery cells used in the foregoing operations; a copper
cathode is then immersed into the said solution of sulphate of copper, and is
connected with the positive pole of the said series of battery cells. The said
decomposition cell and its contents are now to be heated to about 212° Fah-
renheit, and sulphurous acid rapidly passed through the sulphuric acid water
in the said porous cell, copper is precipitated on the said cathode, and sulphuric
acid released and formed at the said anode, sulphate of copper is to be con-
stantly supplied to the said negative compartment. The sulphuric acid as it
accumulates in the said decomposition cell is to be used for the purpose of
dissolving out further portions of copper from the copper ores.
A porous cell may be dispensed with in the decomposition cell last alluded
to; but then, if the sulphurous acid be supplied to the fluid of the said decom-
position cell, disulphide of copper is precipitated on the said cathode, unless
the sulphate or oxide of copper be freely supplied to the said decomposition
cell; the said precipitation of disulphide of copper occurs principally when the
solution of the said sulphate is very dilute and contains excess of sulphurous
acid. The same remark applies when solution of dichloride of copper and
sulphurous acid are similarly used. Or, instead of acting as last described,
solution of dichloride of copper in common salt or hydrochloric acid is substi-

page_text: tuted for the said last-named solutions of copper in the said decomposition cell,
and in this case sulphurous acid or a porous cell may be used or dispensed
with, as it is required to vary the manner of precipitating copper or disulphide
of copper on the said cathode; the said copper is to be collected and fused, and
the said disulphide treated for copper as previously described.
For the said carbon anode an anode of impure or crude copper may be sub-
stituted in the said decomposition cell; the other additions, excepting the
employment of sulphurous acid in the said porous cell, are to be maintained.
nega-
By the method, thirdly, to be described, I obtain metallic copper by fusing
dichloride of copper in a porcelain or other suitable crucible, into which a
carbon or copper cathode is immersed; into the said fused dichloride is
immersed a porous tube containing fused common salt; into the said fused
common salt is then immersed either iron, zinc, impure or crude copper or
carbon to be respectively used as anodes, by connecting them with the
tive pole of a series of any of the battery cells already described; the said
cathode is then connected with the positive pole of the said series of battery
cells, when copper is reduced at the surface of the said cathode; the said
crucible is of course fitted accurately with a cover, into which the said porous
cell is to be also accurately fitted so as to prevent escape of the said dichloride;
through the said fused common salt, during battery action, a current of air may
be urged, so as to expel the chlorides formed therein, and a supply of fused
common salt is also to be regularly maintained in the said porous cell; the
volatile chlorides formed are expelled into a suitable chamber, in which they
may be condensed. When carbon or crude copper are used as anodes, the said
porous cell may be dispensed with; common salt may also be added to the
said fused dichloride.
Of the substances named or alluded to in my Provisional Specification, I
have now specified those on which I prefer to operate, the other of the said
substances I reject in the operations described.
In witness whereof, I, the said James Dickson, have hereunto set my
hand and seal, this Twenty-fourth day of January, in the year of our
Lord One thousand eight hundred and sixty-three.
JAMES DICKSON. (L.S.)