CERTAIN IMPROVED PROCESSES OR OPERATIONS FOR OBTAINING COPPER AND OTHER METALS FROM METALLIC ORES
Year: 1840

page_text: ISAAC COOKSON, of Newcastle-upon-Tyne, Esquire, send greeting.
WHEREAS Her present most Excellent Majesty hath granted unto me Iler
Letters Patent sealed at Westminster, the Fifth day of January, in the third
year of Her reign, for making, using, exercising, and vending, within that
part of the United Kingdom of Great Britain and Ireland called England, Her
Dominion of Wales, and Town of Berwick-upon-Tweed, my Invention of
"CERTAIN IMPROVED PROCESSES OR OPERATIONS FOR OBTAINING COPPER AND OTHER
METALS FROM METALLIC ORES," subject to the usual proviso, obliging me to
describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, and to cause the same to be enrolled in the High Court of Chancery
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Isaac Cookson, do hereby describe and ascertain the nature of my
said Invention, and in what manner the same is to be performed as follows,
that is to say-
My Invention is applicable to those metallic ores which contain copper, in
combination with sulphur, which, for the purpose of reference I call "sul-
phureous ores," and also to those which contain copper in combination with
oxygen, which, for the purpose of reference, I call "oxide ores," and it con-
sists in obtaining copper and other metals and sulphuretted hydrogen gas and

page_text: sulphurous acid from the "sulphureous ores," and in obtaining copper from
these "oxide ores" by the means herein-after described for such purposes.
The "sulphureous ores" herein-before mentioned contain iron in combi-
nation with sulphur, and sometimes small quantities of silver, and the "oxide
ores" herein-before mentioned, also sometimes contain small quantities of
silver.
In the processes herein-after described, which, for the purpose of reference,
I call "my first process," I use those "sulphureous ores" which contain a
large proportion of iron and sulphur and a small proportion of earthy matter,
and for the purpose of reference I call these ores "rich sulphureous ores;" I
reduce sulphuret of iron contained in these ores to protosulphuret by distilling
sulphur from such sulphuret. I then dissolve iron contained in the protosul-
phuret by muriatic acid or sulphuric acid, and thus obtain sulphuretted
hydrogen gas and iron in the state of muriate or sulphate of iron (as the case
may be). The sulphuret of copper and the silver (if the ore employed con-
tained silver) remain undissolved, and metallic copper may be obtained
from this sulphuret by the means usually employed to obtain metallic copper
from native copper ores, but by the means herein-after described for these
purposes, I obtain from the undissolved residuum metallic copper and sulphurus
acid, and also silver if the "sulphureous ore" employed contained silver.
In the processes herein-after described, which, for the purpose of reference, I
call "my second process," I roast the "sulphureous ores" at a bright red heat,
whilst they are exposed to the action of atmospheric air until the sulphurets of
iron and copper, which such ores contain, are converted into oxides, and by
mixing the roasted ores with muriatic acid, I dissolve the oxide of copper and
obtain muriate of copper, from which metallic copper may be obtained.
In the processes herein-after described, which for the purpose of reference,
I call "my third process," I also roast the "sulphureous ores" at a bright
red heat whilst they are exposed to the action of atmospheric air, but I dis-
continue this roasting when the greater part of the sulphuret of iron has been
converted into oxide. The copper remains in the state of sulphuret, and by
exposing the roasted ores to the action of atmospheric air at a suitable heat, I
convert this sulphuret into sulphate, and the remaining sulphuret of iron
becomes oxidised. I then separate the sulphate of copper by dissolving it,
and thus obtain oxide of iron (from which metallic iron may be obtained), and
sulphate of copper from which I obtain metallic copper and sulphurous acid.
In the processes herein-after described, which, for the purpose of reference,
I call my fourth process," I roast the "sulphureous ores," in the same
manner as in "my third process," until about one half of the sulphuret of

page_text: iron has been converted into oxide, no part of the sulphuret of copper being
converted into oxide; I then flux the roasted ores in mixture with carbo-
naceous matter, and thus obtain a regule containing sulphuret of iron in the
state of protosulphuret (capable of being decomposed by acids), and sulphuret
of copper and also silver (if the ore employed contained silver); I then
dissolve iron contained in the regule by muriatic acid or sulphuric acid, and
thus obtain sulphuretted hydrogen gas and muriate or sulphate of iron (as the
case may be). The sulphate of copper and the silver (if the ore employed
contained silver) remain undissolved, and metallic copper may be obtained
from the sulphuret by the means usually employed to obtain copper from native
copper ores, or this sulphuret of copper may be converted into sulphate of
copper and metallic copper, and sulphurous acid obtained therefrom by the
means mentioned for these purposes in describing "my third process, and in
such case silver the "sulphureous ore" employed contained. silver) may
be obtained from the residuum remaining after the sulphate of copper has
been dissolved. If the "sulphureous ore" employed did not contain silver, I
use the sulphuret of copper obtained in this "my fourth process," to mix
with sulphate of copper, as mentioned in describing "my third process,"
instead of converting it into sulphate.
"
The processes
herein-after described, which, for the purpose of reference, I
call "my fifth process," are applicable only to the "oxide ores." By digesting
these ores with muriatic acid or sulphuric acid, I dissolve oxide of copper and
obtain either muriate of copper, from which metallic copper may be obtained,
or sulphate of copper, from which metallic copper and sulphurous acid may
be obtained, by the means mentioned for that purpose in describing my third
process.
I will now describe more particularly the manner in which I carry my
several processes into effect. In carrying into effect the processes which, for
the purpose of reference, I have called "my first process," I put the "rich sul-
phureous ore," which I employ, into an oven or retort constructed of fire-bricks
or fire-clay, in a manner similar to the ovens or retorts constructed of such
materials which are used for distilling gas from coal, and I apply heat to such
oven or retort in the same manner as heat is applied in making coal gas. I thus
subject the ore to a red heat to distill off sulphur, but care must be taken to
5 avoid raising the heat to such a temperature as will cause the ore to become
fused, and I continue this heat until nearly the whole of the sulphuret of
iron contained in the ore is reduced to protosulphuret; I then withdraw the
ore from the oven or retort and put it into a vessel (which I prefer to construct
of lead or of wood) fitted with a gas tube for conveying off gas, and with

page_text: pipes for supplying steam and muriatic acid or sulphuric acid, and after I
have closed this vessel air-tight I introduce muriatic acid or sulphuric acid
into it, and I inject steam into the liquor to assist the action of the acid.
The protosulphuret of iron is decomposed by the action of the acid, sulphu-
retted hydrogen gas passes off through the gas tube into a gasometer, and I
obtain muriate or sulphate of iron (as the case may be) in solution. I then
draw off the solution and wash the residuum with water, to separate a further
quantity of muriate or sulphate of iron. This residuum contains sulphuret
of copper and also silver (if the "sulphureous ore" which I employed con-
tained silver), and metallic copper may be obtained from this sulphuret by the
means usually employed to obtain copper from native copper ore, or otherwise
metallic copper and sulphurous acid and also silver (if the "sulphureous ore'
employed contained silver) may be obtained from the residuum by the means
herein-after described for these purposes.
"
In carrying into effect the processes, which, for the purpose of reference,
1 have called "my second process," I put the "sulphureous ore" which I em-
ploy into an oven or furnace similar to the ovens or furnaces which are used for
roasting metallic sulphurets, in carrying into effect the Invention of Messrs. Hills
and Hadduck, for manufacturing sulphuric acid from metallic sulphurets, and
which have a current of atmospheric air passing through them, and I roast the
ore in this oven or furnace at a bright red heat. If the ore which I employ is
in powder I either continue the roasting until the sulphurets are completely
converted into oxides, or when a great portion of the sulphur contained in the
ore has been driven off, I remove the roasted ore to a common reverberatory
furnace, and complete this conversion in such furnace by the action of atmo-
spheric air at a red heat, but if the ore which I employ is not in powder, then
I find it necessary to pulverize the ore, when a great portion of the sulphur has
been driven off, and afterwards to complete the conversion of the sulphurets into
oxides by the means herein-before mentioned for that purpose. After the
sulphurets have been thus completely converted into oxides, I mix the roasted
ore with muriatic acid, and thus dissolve the oxide of copper; and I assist the
solution by frequently stirring the mixture; I then draw off the solution and
I obtain metallic copper from this solution, either by decomposing the muriate
of copper, which it contains, by metallic iron, or by other means herein-after
described for obtaining metallic copper from solutions of copper, by means of
lime. In carrying into effect the processes which, for the purpose of reference,
I have called "my third process," I roast the "sulphureous ore," which I
employ in the same manner as I have already mentioned in describing "my
second process," and I use a similar oven or furnace for that purpose,

page_text: but I withdraw the roasted ore from such oven or furnace when the greater
part of the sulphuret of iron contained in the ore has been converted into
oxide, and before any part of the sulphuret of copper is converted into oxide;
and if this roasted ore is not already in powder, I pulverize it; I then put
it into an oven or furnace, through which a current of atmospheric air is
passing, and heat it until it attains such a red heat, as is just perceptible. in
the absence of daylight, I thus cause the sulphuret of copper contained in
the ore to absorb oxygen from the current of atmospheric air passing
through the oven or furnace, and in order to promote this absorption
I frequently rake the ore during the operation for the purpose. of exposing
fresh surfaces to the action of the atmospheric air. I continue this operation until
the sulphuret of copper is converted into sulphate, and I then lixiviate the
product of the operation with water and thus dissolve the sulphate of copper,
and I draw off this solution and wash the residuum to separate a further
quantity of sulphate of copper. Metallic copper may be obtained from the
solution of sulphate of copper obtained by these means, either by precipitating
copper by means of metallic iron, or by precipitating oxide of copper from the
solution by means of cream of lime, and afterwards washing such oxide with
water to separate the sulphate of lime, and mixing the oxide thus washed with
carbon and then reducing the oxide into metallic copper by exposing this mixture
to a high temperature. But I obtain metallic copper and also sulphurous
acid from this solution of sulphate of copper. For this purpose I evaporate the
solution to dryness and mix the dry sulphate with half its weight of the sulphuret
of copper obtained by "my fourth process." I pulverize this mixture and expose
it to a red heat in a closed retort or oven (which I prefer to construct of fin
clay or fire-brick) and thus drive. off sulphurous acid suitable for the manu-
facture of sulphuric acid. The residuum in the retort or oven contains a great
proportion of metallic copper and some oxide of copper, and I separate oxide
by washing the residuum with water, or by dissolving oxide by muriatic acid or
sulphuric acid, and I afterwards melt the residuum with suitable fluxes to
obtain metallic copper, or otherwise I obtain metallic copper from this residuum
by fluxing it as it is taken from the retort or oven in mixture with carbonaceous
matter and suitable fluxes. If the ore is not heated in the operation of
converting sulphuret of copper into sulphate to a temperature exceeding such
a red heat as is above described, the sulphate will not become decomposed; but
if such ore is heated to a temperature much exceeding such red heat, a portion
of the sulphate will become decomposed and be converted into oxide of copper,
and in this case this oxide may be extracted from the residuum by dissolving
the oxide by muriatic acid, and metallic copper may be obtained from such

page_text: solution by precipitation with iron or by means of lime, in the manner herein-
before described for obtaining metallic copper from a solution of sulphate of
copper, by mcans of iron or lime. The residuum which remains after
dissolving and separating the sulphate of copper and the oxide of copper (if
any such oxide has been produced) contains oxide of iron, from which metallic
iron may be obtained by the means usually employed for obtaining metallic
iron from native oxide of iron.
In carrying into effect the processes which for the purpose of reference I
have called "my fourth process," I also roast the "sulphureous ore" which
I employ in the same manner as I have already mentioned in describing
"my second process," and I use a similar oven or furnace for that purpose,
and I withdraw the roasted ore from such oven or furnace before the sulphuret
of copper is converted into oxide; but I prefer to withdraw it as soon as about
one half of the sulphuret of iron has been converted into oxide of iron. I ascer
tain the proportion of iron which the roasted ore contains, and for every four
parts of iron contained therein, I add one part of powdered coke or coal, and for
the purpose of assisting the fluxing of the ore, I add fluxes to the powdered
coke or coal and roasted ore, and I regulate the quality and quantity
of the fluxes which I employ in the same manner and upon the same principle
as these are regulated in the ordinary operations of copper smelting, I mix
together the roasted ore, the coke or coal and the fluxes, and I put the mixture
into a furnace similar to the furnaces which are used for fluxing in the ordinary
operations of copper smelting, and I cause the mixture to become fluxed in the
same manner as fluxing is usually effected in these operations; I thus obtain a
slag or scoria consisting of the earthy matters which were contained in the ore
and a regule containing protosulphuret of iron (capable of being decomposed
by muriatic acid or sulphuric acid), and sulphuret of copper and also silver
(if the "sulphureous ore" employed contained silver); when the mixture has
been completely fluxed I cause the regule to be run off from the fluxing
furnace into water for the purpose of granulating it, and when it has been thus
granulated I prefer to powder it, and I put it into a vessel (which I prefer to
construct of lead or of wood) fitted with a gas tube for conveying off gas, and
with pipes for supplying steam and muriatic acid or sulphuric acid, and after I
have closed this vessel air-tight, I introduce muriatic acid or sulphuric acid
into it, and I inject steam into the liquid to assist the action of the acid. The
protosulphuret of iron is decomposed by the action of the acid sulphuretted
hydrogen gas passed off through the gas tube into a gasometer, and I
obtain muriate or sulphate of iron (as the case may be) in solution I then
draw off the solution and wash the undissolved residuum with water to

page_text: 66
separate a further quantity of muriate or sulphate of iron. This residuum
contains sulphuret of copper, and also silver (if the 'sulphureous ore
which I employed contained silver), and metallic copper may be obtained
from this sulphuret by the means usually employed to obtain copper from
native copper ores, but I prefer to convert sulphuret of copper thus
obtained into sulphate, and to obtain metallic copper and sulphurous acid
from such sulphate by the means which I have already described for these
purposes. In describing my third process," when the sulphuret of copper is
converted into sulphate, and this sulphate is dissolved and the solution
drawn off, the undissolved residuum contains such silver as was present in
the "sulphureous ore" employed, and silver in a metallic state may be
obtained from this residuum by some of the processes usually employed for
extracting silver from silver ores. If the "sulphureous ore" which I employ
in this "my fourth process" does not contain silver then I use the sulphuret of
copper, obtained in this process with dry sulphate as described in "my third
process."
In carrying into effect the processes which, for the purpose of reference, I
have called "my fifth process," I use only the "oxide ores." reduce the ore
which I employ to powder, and then mix it with muriatic acid or sulphuric
acid, and I assist the action of the acid employed by injecting steam into the
mixture; I thus dissolve the oxide of copper contained in the ore, and obtain
muriate or sulphate of copper (as the case may be) in solution. If muriatic
acid has been used I obtain metallic copper from the solution of muriate of
copper by means of iron or lime as mentioned, for the purpose of obtaining
metallic copper from solution of sulphate of copper by iron or lime in
describing "my third process," and if sulphuric acid has been used, I obtain
metallic copper and sulphurous acid from the sulphate of copper by the means
which I have herein-before described for obtaining metallic copper and
sulphurous acid from sulphate of copper in describing "my third process."
I have described certain apparatus which I consider most suitable to be
employed in carrying my Invention into effect, but I do not confine myself to
the use of the particular apparatus described, nor do I claim any exclusive
right to use such apparatus. I have also referred to certain processes by which
sulphur may be obtained by distillation from "sulphureous ores" and other
5 processes by which I drive off sulphur from sulphureous ores when exposed
to a current of atmospheric air, but these processes have been long in public
use. And I do not claim any of these as forming part of my Invention. I
have also described certain proportions in which I use some of the materials
herein-before mentioned, and which proportions I consider to be most

page_text: suitable, but I do not contine myself to the use of these materials in any
particular proportions.
I claim as my Invention,―
"
First, the processes or operations of reducing sulphuret of iron contained in
the "rich sulphureous ores' herein-before mentioned to protosulphuret
(capable of being decomposed by muriatic acid or sulphuric acid), by distilling
sulphur from such ores, and of obtaining sulphuretted hydrogen gas by means
of this protosulphuret, and of dissolving iron contained in such protosulphuret
by muriatic acid or sulphuric acid to facilitate the obtaining of copper and
silver from such ores.
Secondly, I claim the processes or operations of converting sulphurets of
copper and iron contained in the "sulphureous ores" herein-before mentioned
into oxides for obtaining muriate of copper capable of producing metallic
copper.
"
Thirdly, I claim the processes or operations of converting the sulphuret of
copper of the "sulphureous ores herein-before mentioned into sulphate of
copper (capable of producing metallic copper and sulphurous acid) by ex-
posing such sulphuret to the action of atmospheric air at a low red heat, or a
heat nearly approaching to redness, and of converting sulphuret of iron con-
tained in such "sulphureous ores" into oxide capable of producing metallic
iron.
Fourthly, I claim the processes or operations of reducing sulphuret of iron
contained in the "sulphurous ores "herein-before mentioned to protosulphuret
(capable of being decomposed by muriatic acid or sulphuric acid) by roasting
the ores, and then fluxing them in mixture with coke or coal, and of obtaining
sulphuretted hydrogen gas from this protosulphuret, and of dissolving iron
contained in such protosulphuret by muriatic acid or sulphuric acid to facili-
tate the obtaining of copper and silver from such ores.
Fifthly, I claim the use of the sulphuret of copper obtained by the decom-
position of the regule herein-before mentioned, for a decomposing sulphate of
copper obtained from the "sulphurcous ores" herein-before mentioned, for
obtaining sulphurous acid and metallic copper therefrom.
Lastly, I claim the use of muriatic acid and sulphuric acid for facilitating
the obtaining of copper from the "oxide ores" herein-before mentioned.
In witness whereof, I, the said William Isaac Cookson, have hereunto
set and affixed my hand and seal, this Thirtieth day of July, in the
year of our Lord One thousand eight hundred and forty.
WILLIAM I. (L.S.). COOKSON.

page_text: AND BE IT REMEMBERED, that on the Thirtieth day of July, in the
year of our Lord 1840, the aforesaid William Isaac Cookson came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Inrolled the Fifth day of August, in the year of our Lord One thousand
eight hundred and forty.