IMPROVE- MENTS IN THE MANUFACTURE OF ZINC, COPPER, TIN, AND ANTIMONY
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDOUARD
JOSEPH FRANCOIS DUCLOS, late of Samson, in the Kingdom of Belgium, now of
the Parish of Oystermouth, in the County of Glamorgan, in the Principality
of Wales, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Thirty-first day of May, in the first year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Edouard
Joseph Francois Duclos, Her especial license, full power, sole privilege and
authority, that I, the said Edouard Joseph Francois Duclos, my exors, admors,
and assigns, or such others as I, the said Edouard Joseph Francis Duclos,
my exors, admors, or assigns, should at any time agree with, and no others,
from time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF ZINC, COPPER, TIN, AND ANTIMONY;" in which
said Letters Patent is contained a proviso that I, the said Edouard Joseph
Francois Duclos, shall cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, to be inrolled in
Her said Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said in part recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the said
Edouard Joseph Francois Duclos, do hereby declare the nature of my In-
vention is fully described and ascertained in and by the following statement
thereof, reference being had to the Drawings hereunto annexed, and to the
figures and letters marked thereon, that is to say:
In order more clearly to point out my improvements, I will shortly state the
nature of the processes which have heretofore been resorted to, and will then
describe my improvements. I will first, however, remark, that when the ore
to be operated on according to my Invention consists of minerals termed
sulphurets, I convert those sulphurets of metals into sulphates by various
modes of oxidation. From the sulphates so obtained I separate the metals
from the sulphuric acid, either by bringing them into oxides or by such other
means as I shall hereafter point out, and from which I obtain the metallic
produce by modes of reduction adapted to the peculiar properties of each
metal. When the metals are mineralized with other substances, I convert
them into oxides by modes already known and practised, or by such peculiar
modification of the processes as I shall hereafter describe. As the modes of
treatment of the particular ores and, metals to which my Invention relates
vary from their different chemical and physical natures, I will confine myself
to the treatment of each ore and metal separately as now practised, and then
proceed to describe the modes of manufacture pursued by me.
In the manufacture of zinc as at present practised, the ore from which the
metal is extracted is most generally that of a sulphuret of zinc, commonly
known as "blende" or "black jack," and which is generally found incorporated
with other sulphurets and earthy matters. Zinc is also manufactured from
the impure carbonate and silicate of zinc, known by the name of "calamine"
or "lapis calaminaris." The mode of treatment in the extraction of the
metal as heretofore practised, consists in the first instance of calcination of
the ores, which is effected in an ordinary reverberatory or calcining furnace,
with a view of converting them into oxides, but which is, however, but
imperfectly effected. The ore having been calcined is then mixed with ground
coals and small coke, which mixture is then introduced into a large pot set
in a furnace (similar to that employed in the manufacture of glass), the ore
and coal being introduced by a shoot in the side of the furnace communicating
with an opening in the top of the pot, which aperture is then hermetically
closed by a cover of clay. An iron pipe descends from the under side of the
pot, and passes through the lower part of the furnace on which the pot
rests. On a sufficient heat being communicated from the furnace to the pot
reduction begins, and the metal becomes converted into vapour, the distillation

page_text: of which is produced; the vapour passing down the pipe already mentioned
passes into a receiver. By this process of manufacture much ore and fuel
is consumed in producing a given quantity of the metallic zine.
Having thus stated the general features of the mode at present adopted,
I will now proceed to describe the nature of my Invention. I take any
quantity of sulphuret of zinc, which is in small particles, in the state in
which the ore is generally dressed at the mine. I mix with it hydrate of
lime (slack lime) in a sufficient quantity to render it adhesive, the proportion
being about two fifths (of quick lime) of the weight of the blende or zinc ore,
and mould the compound into blocks or bricks, the object being, by the addition
of lime to the blende, to separate the sulphur therefrom, and also to prevent
the metal (zinc) from combining with other foreign matters which may be
contained in the ore. Having dried the bricks so made, I place them in
an ordinary brick kiln, where they are submitted to the action of a gradually
increasing heat for twenty-four hours. When the bricks are in a state of
redness, they are left in the kiln for forty-eight hours, without the communi-
cation of any additional heat, combustion being maintained for a portion of
the time by the absorption of the oxygen of the external air by the sulphur
and metals contained in the blocks or bricks. After being removed from the
kiln, they are broken into small pieces, and in that state placed in a reverberatory
furnace, and submitted to calcination for from twelve to twenty-four hours,
carbonaceous matter, such as coal, being added thereto, in the proportion of
twelve to fifteen per cent. of the weight of the material introduced. The coal
or other carbonaceous matter is put into the furnace every four hours, in the pro-
portion of one and a half per cent. or thereabouts of the wight of the materials,
with which it is intimately mixed or stirred. In the last two hours of the
operation a further addition is however made, so that the entire quantity of
coal or carbonaceous matter used is equal in the whole to twelve or fifteen
per cent. of the mixture of blende and lime subjected to calcination. The
substances having been properly calcined are then submitted to the action of
a blast furnace, into which they are placed with the object of separating the
zinc in the form of vapours from the other foreign matters contained in the
calcined mixture. The blast furnace used for this purpose is shewn in Sheet 1
of the Drawings appended hereto. a is the body or interior of the furnace,
the top of which is covered by a dome in which is an aperture communicating
with a chamber 6, through which the material and coal, or other carbonaceous
matters, are introduced into the furnace. The top of the chamber b is sur-
rounded by a trough filled with sand or other material, into which passes the
cover c of the chamber 6, thereby forming an hermetical joint.. c' are two

page_text: sliding doors or valves, which pass through the side of the chamber 6, and on
which the material and coal, fall in their passage to the body of the furnace,
the two doors c¹ having levers for the purpose of readily withdrawing them
From the chamber 6 proceeds the flue d, which communicates with the
condensing chambers e. The bottom of the blast furnace is made after the
usual construction, the blast being introduced through the tuyere holes g, and
the overflow of the slag or scoria being emitted through the opening g'.
I will now proceed to describe the mode of working.-In order to intro-
duce the material and coal, or other carbonaceous matter, into the body of the
furnace, the cover c at the top of the chamber b being raised, the materials
will then fall upon the upper sliding valve c', the cover c.is then lowered into
the trough, after which the upper sliding door being withdrawn the materials
fall on the second or lower sliding door. The upper door being then closed
the lower one is withdrawn, and the materials pass at once into the body of
the furnace. By adopting these means I prevent the escape of any consider-
able portion of vapour from the furnace at the feeding place. The materials
being thus introduced into the body of the furnace and brought into a state of
fusion by any of the ordinary means of working blast furnaces (hot blast
being preferable for that purpose), the oxide of zinc becomes reduced and
the metal volatilized and rises to the upper portion of the furnace and
chamber b, from whence it passes along the flue d, into the condensing
chambers c, where it is condensed, the gases produced in the operation, after
having passed through all the chambers, being allowed to escape through an
aperture made for that purpose. The produce in the condensing chambers
being taken from them is then mixed with about fifteen per cent. or there-
abouts of charcoal or other carbonaceous matter, and placed in retorts made
of fire clay; these retorts are fixed in furnaces, as represented in the Drawing
Sheet 2. The retorts and the furnace being shewn in various views will
readily be understood. The two slides or frames of the furnace being of cast
iron, with a number of holes to receive the retorts; and there are also a
number of small holes having clay stoppers, the smaller holes being for the
purpose of looking into the furnace to observe whether the retorts are sound,
and to apply wet clay if cracked. (1) 1), are the holes for the retorts, and
(2) 2), are the smaller holes. The nature of the furnace will now be readily
traced, and it will be found to offer considerable facility for removing and
applying retorts. At the mouth of each of the retorts is placed a clay tube a,
and a conical wrought-iron vessel b, the inner surface being coated with a thin
layer of clay. This vessel slides on to the tube or neck of the retort, and is
thereby supported. When the vapours are coming out of the retorts the

page_text: metallic zinc will fall either into the vessel b, or on to the tube or neck of the
retort, from which the workman will continually rake the same by inserting a
small rake or other suitable instrument at the outer end of the conical
vessel b, and drawing the zinc into a crucible or other proper receiver. On
heat being applied to these retorts the oxide of zinc is reduced, and the
vapour of metallic zinc is forced through the small tube or pipe a, which
connects the retort with the receiver b, there having been a cover or stopper c
placed at the mouth of the retort where the materials are introduced. The
metal in its passage through the small pipe becomes partially condensed,
which operation is perfected on its arrival in the receivers b, from whence the
metal is taken and remelted into ingots, according to the modes now practised.
When the sulphuret of zinc is obtained in lumps or larger masses than those
already adverted to, it is at once placed into a furnace, as represented in
Figure A, Drawing Sheet 2, for the purpose of calcination, which being
completed the ore is then submitted to the action of the blast furnace, and the
subsequent treatment adopted, already described. When the carbonate or
silicate of zinc has to be treated, it is at once placed in the blast furnace,
accompanied by such flux (lime stone) as may be found necessary, according
to the chemical composition of the mineral, by which means the oxide of zinc
being obtained, it is subjected to the treatment described in the subsequent
operation, with respect to the sulphuret of zinc, as above explained.
I will now proceed to describe the second part of my Invention, which
relates to the manufacture of copper. The present process which is employed
in this country may be thus briefly described, it being first observed that the
copper ore, however rich in its produce, must necessarily be reduced so as to
yield not more than from eight to ten per cent. of metal. The ore being in
such case mixed with foreign matters, or with ore of poor quality, the process
not being adapted without such admixture to obtain the copper with advantage
from ores of rich quality. The ore containing with its admixture a produce
not exceeding ten per cent., is in the first instance placed in a reverberatory
furnace for the purpose of calcination, which being effected, the ore is then
carried to another reverberatory furnace for the purpose of separating the
copper regulus from the foreign matter, and which afterwards undergoes a
series of processes by reverberatory furnaces until a sulphuret of copper or
regulus is obtained, the iron passing off as silicate of iron or slag. This sul-
phuret of copper is again submitted to the action of other reverberatory
furnaces for further calcination until it is rendered pure enough to be refined
into metallic copper. According to my Invention, either rich or poor ores may
be treated without admixture. My first object is to extract a portion of the

page_text: sulphur from the ore by distillation, in order to render the ore fit for the
further process, taking care in the process of distillation to prevent atmo-
spheric air getting into the retorts or vessels containing the ore under operation,
and by distilling by heat a portion of the sulphur will be driven off, leaving
however a sufficient quantity combined with the mineral to convert it into
sulphates. To effect this I use the apparatus shewn in Figure B, Sheet 3.
a, a, are the retorts into which the ore is introduced. 6 the cover or plate
affixed to the mouths of the retorts. c is a pipe proceeding from the other
end of the retort which enters into the water contained in the trough d, the
pipe being for the purpose of conveying the vapours of sulphur into the
trough d. The coal is introduced into the chamber e by the openings f,
whereby the heat arising from the manufacture of coke is used or employed
in heating the retorts, the heat so obtained being well calculated for carrying
out this part of the operation. The carbonaceous matters which are evolved
during the combustion of the coal escape by an opening 9 in the arch of the
oven, and passes from thence into the flues h, where it comes in contact with
the heated air by which the combustion of it is effected, and escapes by the
chimney. Note, the heated air for the above purpose may be obtained by
passing air through two or more of the retorts and conveyed to the flucs by
pipes in any convenient manner. The tops of the flues h, h, are covered by a
series of cast-iron plates, on which rest leaden vats or troughs k, k, into which
the ore, after being submitted to the treatment in the retorts for eight to
twelve hours, is subsequently introduced in a hot state. To these troughs are
attached lids or covers which are made tight by water joints, as is clearly
skewn in the Drawing.
The object of the introduction of the ore into the leaden vats after being
taken from the retorts is for the purpose of converting the sulphurets into
sulphates, which may be effected by any mode whereby a sufficient quantity
of oxygen is obtained to combine with them to effect that end. The modes
which I consider best calculated to carry out this object is by the introduction
of steam, atmospheric air, or nitrous gas. The temperature generated in the
flues already described is found materially to assist the process of oxidation.
For the purpose of separating the sulphates from the remaining undecom-
posed mineral I introduce water through a pipe l, perforated in such manner
that the jets are directed on the material contained in the vats or troughs; by
this means the sulphates formed are dissolved, which operation being perfected
the solution is drawn off by means of the cock m into a leaden vessel for the
purpose of evaporation, the cock is then closed and the ores remaining in the
leaden vats are subsequently successively subjected to the treatment already

page_text: pointed out till the whole is dissolved, the earthy matters and insoluble
minerals remaining in the vats being afterwards removed. When the solution
taken from the vat is evaporated until it is in a state of concentration, holding
in solution from twenty-five to thirty per cent. of salts, I introduce, pure iron
in a state of crystallization, such as is obtained by the process of puddling
iron, and before it has been submitted to the action of the hammer, or by the
use of iron which may have been previously scoured by diluted acid so as to
render it sufficiently pure from any oxide which may have been upon it. To
insure the success of this manipulation it is necessary that the solution should
contain an excess of sulphuric acid. By the introduction of the iron already
referred to, the copper is precipitated in its metallic state, the sulphates
remaining in solution are then drawn off, and the precipitate is washed until
all [the soluble salts are completely separated from it. The copper is then
taken and submitted to fusion, taking care by a proper flux to prevent it from
becoming oxidized or carburetted in the operation. I would here remark,
that I am aware that at the present time copper precipitate is obtained from
the water taken from mines in a state of nature, which contains a solution
of sulphate of copper; this is effected by the introduction of iron into the
water so raised from the mine. By this means, however, the precipitation is
but imperfectly performed, and a portion only of the copper held in solution
is obtained; and further, in some cases where very poor ores are being treated,
the same having been roasted, is placed in large heaps, and by means of rain.
and the damp atmosphere the sulphates have been dissolved, and the waters
so obtained have been treated as above stated in respect to waters from the
mines, but which is an exceedingly slow process. In order to render my
process applicable to water impregnated with small quantities of copper
which may be raised from the mines or otherwise, I evaporate the water to
that state of concentration which I have already described, and then proceed
as before mentioned.
I will now proceed to describe the third part of my Invention, which
relates to the manufacture of tin. In the manufacture of tin, as at present
practised, the metal is generally obtained from ores which contain sulphurets
of iron, copper, and other minerals, in combination with woolfram. Tin is,
however, also obtained from alluvial deposits known by the name of "stream
tin" or oxide of tin. The reducing of the metal from the stream tin, as at present
effected, is by means of a blast furnace in which heat is developed by charcoal,
the metal descending in very nearly a pure state to the bottom of the furnace.
The only difference in my mode of treatment of stream tin is to introduce it
with charcoal or other carbonaceous matter into retorts. On sufficient heat

page_text: being applied externally of the retorts, the tin will run from the retorts, in
consequence of a slight inclination which I give to the retorts, and is received
into vessels placed for that purpose, whereby I am enabled to employ pit coal,
or other cheap fuel, for reducing the metal. In reducing tin from ores con-
taining sulphurets, as above mentioned, the mode now practised is to calcine
them, after which they are submitted to levigation, the produce remaining
after that process (being mixed with small coal) is then exposed to heat in a
reverberatory furnace, which reduces the tin to a state of fusion, when it is
drawn off and refined for any of the usual purposes. According to my
improved mode of manufacturing tin where sulphate of iron and other
minerals are combined, I successively submit them to the same processes as
those described in my improved mode of the manufacture of copper, up to
that point where I draw off the sulphates in solution, the tin and other
materials remaining in the troughs or vats must be removed from them and
submitted to levigation, which will carry off the earthy matters. The tin and
woolfram remaining I then introduce with charcoal or other carbonaceous
matter into retorts, and the metal is obtained from thence as described in my
mode of reducing the metal from stream tin.
I will now describe the fourth part of my Invention, which relates to
antimony. The sulphuret of antimony, the ore from which that metal is
commonly extracted, is, by the process at present in use, reduced by introducing
it mixed with iron or other substances into vessels, and then subjecting it to
heat, the metal separated from the sulphur being taken from thence, but in
an impure state, for any of the purposes for which it may be required. In
treating this mineral according to my improved method, I subject it to the
same processes of calcination, volatilization, and condensation, as those
already described in my improved mode of manufacturing zinc. The oxide
thus obtained I mix with coal or other carbonaceous material, and subject it
to beat in retorts, adding any of the substances as a flux (carbonate of soda or
potash), which are found to answer for reducing it into a metallic state. The
metal is then taken from the retorts and remelted, as already practised.
Having now described the nature of my improvements, and the manner of
carrying the same into effect, I would have it understood that the same may
be varied in some degree without departing from my Invention, and I would
have it understood that I make no claim to any of the apparatus or processes
employed other than is hereafter more particularly set forth and claimed as
my Invention.
And I would have it understood that what I claim as my
Invention is,―
First (in respect to the manufacture of zinc), the mode of manufacturing

page_text: zinc from the ores by applying lime, as above described, and also the employing
of blast furnaces with suitable condensers or receivers for separating the oxide
of zinc from the materials with which it is combined; and further, the mode
of distilling the metal in retorts or other vessels, whereby the metal is not
obliged to pass through the mass of materials contained in them, as above
described.
Secondly (in respect of copper), I claim the mode of manufacturing
copper from copper ores, by repeated oxidation of the sulphurets, and repeated
dissolution of the sulphates produced therefrom, and precipitating the metallic
copper by iron, and the concentration by heat of water containing copper, and
subsequently precipitating the copper by iron, as above described.
Thirdly (in respect to tin), I claim the mode of manufacturing tin above
described. And,
Fourthly (in respect to antimony), I claim the manufacture of antimony
above described.
In witness whereof, I, tho said Edouard Joseph Francois Duclos, have
herounto cot my hand and cool this Thirtieth day of Novembe
E. J. F. (L.S.) DUCLOS.
AND BE IT REMEMBERED, that on the Thirtieth day of November, in
the year of our Lord 1838, the aforesaid Edouard Joseph Francois Duclos
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 Thirtieth day of November, in the year of our Lord One
thousand eight hundred and thirty-eight.