IMPROVEMENTS IN THE SMELTING OF COPPER AND OTHER ORES
Year: 1847

page_text: SUSSEAD DEP
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCOIS
STANISLAS MELDON DE SUSSEX, of Millwall, in the County of Middlesex,
Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster the Twenty-third day-of March, Ono
thousand eight hundred and forty-seven, in the tenth year of Her reign, did
give and grant unto me, the said Francois Stanislas Meldon de Sussex, my
exors, admiors, and assigns, Der especial license, full power, sole privilege
and authority, that I, the said Francois Stanislas Meldon de Sussex, my
exors, adiñiors, or assigns, and such others as I, the said Francois Stanislas
Meldon de Sussex, my exors, adiñors, or assigns, should at any time agree
with, and no others, from time to time and at all times thercafter during the
term of years therein mentioned, should and lawfully might make, use, exer-
cise, and vend, within that part of Great Britain and Ireland called England,
Hor Dominion of Wales, and Town of Berwick-upon-Tweed, and also in the
Islands of Jersey, Guernsey, Alderney, Sark, and Man, and in all Her Colonies
and Plantations abroad, my Invention of "IMPROVEMENTS IN THE SMELTING OF
COPPER AND OTHER ORES;" in which said Lotters Patent there is contained a
proviso, requiring that I, the said Francois Stanislas Meldon de Sussex, shall
particularly 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 cause the same to be enrolled in ler said Majesty's High
Court of Chancery within six calendar months next and immediately after

page_text: .
the date of the said in part recited Letters Patent, as, reference being there-
unto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Francois Stanislas Meldon de Sussex, do hereby declare that the nature of
my Invention, and the manner in which the same is to be performed, are
particularly described and ascertained in and by this present instrument
in writing, as follows, that is to say :-
My said Invention consists of certain improvements in the process of
smelting copper and other ores, whereby the metal is obtained more readily
and more economically from said ores or gangues, and also. freeer from any
admixture of sulphur or arsenic, with which copper and other metals as they
are generally smelted at Swansea and elsewhere are always contaminated, to
the detriment of their malleability. These several improvements are appli-
cable according to my Invention to the various kinds of ore of copper, silver, and
other metals, such as the sulphurets, chlorides, oxides, and carbonates, which
are the most general kinds of ores to be met with in smelting works, and these
.said improvements are also applicable to the metallic salts of copper, silver,
and other metals which are not so generally met with in smelting works, such
as, for instance, the sulphates or other salts of copper, silver, and other metals.
Whatever kind of ore or metallic salts may be to be treated according to my
Invention, so as to obtain ultimately the metals therein contained, it will be
found that I always employ such means or use such matorials whereby an
interchange of elements may be effected, the acid, sulphur, or other admixture
contained in the ore or metallic salt forming a new combination with the sub-
stance made use of, according to my Invention, by the agency of heat or other-
wise, while the metal to be obtained is thus converted into an oxide and into
- metal.
I shall now describe successively the mode of treating the various metallic
combinations herein-before mentioned for the purposes of my Invention,
and will firstly explain that part of my said Invention, by which I obtain
copper from the sulphuret of that metal, wishing it to be understood that,
contrary to the present modes of smelting copper, whereby a certain
excess of sulphur must always be retained in the ore under operation, I
employ such means or substances as will cause an entire or complete disul-
phuration, and said means and substances having either such energy in
decomposing sulphurets or such affinity for the sulphur, much of the usual long
time occupied in smelting will thereby be saved; and by smelting only when
all the sulphur is entirely removed, the metal is necessarily obtained in a pure
state; but although I shall only describe as an example the mode of obtaining

page_text: copper from its sulphuret, it must be clearly understood that silver and other
metals will be obtained, according to my Invention, when the sulphurets of the
several metals respectively shall be treated, as will be herein-after described, in
the same manner as copper or its sulphurets. In order to disulphurate copper
ore, I use a furnace of the reverberatory kind, and having what is commonly
called sorted the ore, previously reduced into a fine powder and sifted in the
usual way, and so mixed rich and poor ore, that by analysis the quantity of
silica therein contained may be as nearly as possible in the ratio of sixty per
cent of silica, or instead of sorting the ore, I simply ascertain by analysis the
composition of the sulphuret to be smelted, and should the quantity of silica be
deficient, I then add to it so much sand as will be found necessary to form a
compound of sulphuret of copper and silica, containing from fifty to sixty per
cent. of the latter, and should, on the contrary, the proportion of silica be
ascertained to exceed fifty or sixty per cent., and the other components of the
ore be considered in too small a proportion, I then, proviously to subjecting the
pulverized ore to the process of disulphuration, add to it such proportions of
lime, fluor, spar, or other earths, as may be considered necessary, as it is at
present practised in smelting works, observing, however, that in smelting
copper according to my Invention, the proportions of silica, lime, or alumina
contained in the ore are not so important as in the usual mode of smelting the
slag, being otherwise rendered easibly fusible. I take about five hundred weight
of the powdered ore and mix intimately therewith about twenty-five pounds of
finely sifted charcoal, anthracite, coals, or other combustible matter free from
sulphur, or other quantities, in the same proportions, and then spread evenly
over the hearth of the reverberatory furnace the mixture of ore and com-
bustible matter, and allow the same to be exposed during three or four hours
to a temperature insufficient to fuse the metal or indeed to bring the ore to a
red heat; the arsenic and most of the sulphur will be thereby volatilized as
sulphuret of carbon; but I have observed that even after heating a sulphuret
in contact with carbonaceous matter, there is still invariably a certain
portion of sulphur remaining, and that owing to the draft of the furnace,
which brings air or oxygen in contact with the sulphuret; there are
also certain acids of sulphur formed, which are not easily separated from
the metal even after several roastings, and owing to the presence of such
remaining portion of sulphur, or to the combination of acids of sulphur with
the metal when the ore containing them is subject to the necessary tempera-
ture for causing fusion, the metal contained therein and the sulphur fuses
together, and the ingot is in that state unfit for any purposes to which copper
is applicable, and must be subjected to several subsequent refinings. To get

page_text: rid of these last portions of sulphur or acids of sulphur according to my Inven-
tion I employ one or the other of the two following modes:-
Firstly, having lowered the temperature by removal of fuel, I add to the ore
previously roasted with anthracite charcoal, or coals containing little or no
sulphur, about four or five per cent. of either alumina or magnesia or magne-
sian limestone, and, at the most, one per cent., of nitrate, of soda, nitrate of
potassa, or nitrate of lime, and mix the whole intimately by means of a rake,
during which time the flues of the furnace are shut by means of the damper,
to avoid as much as possible the small particles of the ore escaping while
being stirred; then I raise the temperature again, but not so as to cause fusion
of the material, but somewhat higher than before, by the addition of a small
portion of nitre and the treatment herein-before described. The sulphur
remaining in the ore will be wholly oxidized, and. thereby transformed into
sulphuric acid, which, together with the acids of sulphur already formed
during the operation of roasting, will combine with the magnesia or alumina,
according to which of these substances has been employed, and thus form sul-
phate of magnesia or alumina, which sulphates, having the property of yielding
their acid at a high temperature, will be decomposed. All the sulphur and
acid of sulphur being volatilized, and the copper being then wholly brought to
the state of oxide, and then said ore so desulphurated, is removed from the
reverberatory furnace, to be subsequently reduced into metal, as will be
herein-after described. This part of my Invention may be easily varied, as
will be shewn in the second method of desulphuration, or by adding magnesia,
or alumina, or magnesian limestone, in the first instance, with the ore and
anthracite, or other. carbonacious matter, but. I believe with less advantage,
and not so beneficial a result. The proportions herein-before given may be
altered and increased, should the quantity of sulphur existing in the ore be
found greater than three or four per cent., which will rarely be the case
whenever the process of roasting shall be. carried out with care, avoiding to
raise the temperature too high; and, lastly, the quantity of nitre may also be
varied, using more or less, in proportion to the sulphur existing in the ore, and
in the ratio of one of nitre to four of sulphur, or thereabouts; but I wish it to
be understood that any other oxidizing agent, such as maganise, or the maga-
nates of soda and potash, may be substituted for nitre, and that in case the
proportions of maganise, maganates, or other oxidizing agents should be regu-
lated by the quantity of oxygen they may respectively contain, and that so
inuch of either of said oxidizing agents should be employed as would contain
as much oxygen as there is in one part of nitre, which is employed, as herein-
before mentioned, for four parts of sulphur.'

page_text: Secondly, my other method or methods of disulphurating copper or other ores
is to be carried into practice in the following manner:-The powdered ore;
mixed with the same proportions as before-mentioned of anthracite, or other com-
bustible matter also reduced to powder being roasted in a reverberating furnace
during three or four hours, in the manner herein-before mentioned, is at the end of
that time to be removed from the furnace and subjected to the following mode
of removing the acid combinations of sulphur with the oro or the metal. Close
to the reverberatory furnace, assigned to the operation of roasting, is a tank
made of iron or other material, placed under ground, and containing alkaline
solutions, such as liquor of ammonia, solutions of soda, potash, magnesia, or
other alkaline carths forming soluble salts with acids of sulphur, but the most
economical substance and that I mean mostly to employ is ammonia, principally
in its caustic state, although carbonated alkalies would also answer. I thero-
fore pour into the tank from seventy-five to eighty pounds of liquor of ammonia,
of specific gravity 900, and add to it as much water as will be sufficient to
cover the whole quantity of ore previously roasted in the furnace, and cause
said quantity of roasted ore, five hundredweight, to be thrown into the tank
while still hot, stirring two or three times, and then allowing the ore to subside
at the lottom of the tank. I then draw off the clear liquor by means of a
syphon into another tank placed also under ground, but lower down than the
first tank, and now the ore precipitated in the first tank is to be removed
therefrom, it being now deprived of all the acid of sulphur it may have
previously contained, while the liquor drawn off into the other tank will be
found to contain sulphate of ammonia, if ammonia has been used, or sulphates
of soda, or of the other alkalies, if said other alkalies have been employed,
but should ammonia have been used, as herein-before described, and the con-
tents of the second tank be a sulphate of ammonia, I then add either in the
cold or at a temperature under the boiling point, as much lime as will be found
necessary to combine with the acid contained in the sulphate of ammonia, and
it will be found that twenty to twenty-eight pounds of lime will be amply
sufficient to combine with said acid forming an insoluble sulphate of limé,
which will soon. subside, while the ammonia will become caustic, and being
transferred into the first tank by means of a pump will serve the before-
mentioned purpose of removing all acid combinations of sulphur from other
charges of ore roasted in the reverberatory furnace in the manner- before
described, it being only. required to replace at each time the alkaline liquor;
it may be used over again, and the small quantity lost by being taken up by
the ore will be amply replaced by adding at each time six or eight pounds of
liquor of ammonia of specific gravity 900, the charge of ore being as before of

page_text: five hundredweight. In case soda, potash, or alkaline earth be used, the
proportions of soda at the most would be from twenty to twenty-five pounds,
dissolved in sufficient quantity of water to cover the whole produce of a charge
of five hundredweight of ore previously roasted, and should lime or magnesia
be substituted for soda or potash, the proportions to be used of either of the
said alkaline earths will not necessarily exceed twenty-eight pounds for the
same charge of the ore as before stated, but it will be found, I believe,
that the use of ammonia is in all respects preferable when it can be easily
procured. Thirdly, instead of adding any oxidizing agents, and principally
nitre, as I have described in my first mode of desulphuration, and instead
of treating the roasted ore, as I have also described in the second mode of
desulphuration, I may use a solution of nitrate of soda, or potassa, or lime,
using about six or seven pounds of nitre for five hundredweight of ore dissolved
in a sufficient quantity of water to moisten the whole quantity of said ore; the
whole being, as it will be herein-after described, subjected to the smelting
operation in that state of admixture with nitre, will be deprived of its remaining
portions of sulphur, but by no means so completely as by the second.mode
herein-before given for disulphurating metallic ores, since there would be a
sulphate of soda present, which, during the process of smelting, would neces-
sarily be transformed into sulphuret. And, as I have practically observed,
copper or the other metals cannot be obtained free from sulphur so long as
there is any sulphuret present while the metal enters into fusion when sub-
mitted to the necessary temperature, as will be fully herein-after described.
I will now describe that part of my Invention by which sulphates of copper
or other metals are to be treated, so as to obtain here also an oxide to be
subsequently reduced to the mettallic state, and I will take also as an ex-
ample a sulphate of copper, it being.always to be clearly understood that the.
other metallic sulphates will be treated in the same way as the sulphate of
copper. And in the manner following I take sulphate of copper, however
obtained, and dissolve it in a pan, having fire playing underneath or heated by
steam, and then add to said solution as much magnesia, alumina, or other
earths, preferring, however, to use magnesia or magnesian limestone, and for
every equivalent proportion of sulphate of copper, or for every forty pounds of
real sulphuric acid contained therein, I add to said solution one equivalent of
magnesia, or about twenty pounds. A decomposition soon takes place, the
acid combined with the oxide of copper passes to the magnesia and forms a
sulphate of magnesia, while the oxide of copper being insoluble subsides. I.
now draw off the clear liquor into another pan next to the former containing.
the precipitated oxide of copper, and cause said liquor to be evaporated to

page_text: dryness, the residue being a dry sulphate of magnesia, which being heated to a
red heat with a jet of steam, and after the manner specified in a Patent granted
to me under the Great Seal on the Nineteenth day of February, in the tenth
year of the reign of Her said Majesty, and intituled Improvements in the
manufacture of chlorine, hydrochloric acid, and nitric acid, &c., of which
the Specification was duly enrolled in the High Court of Chancery on or about
the Nineteenth day of August, in the eleventh year of the reign of Her said
Majesty, will he decomposed into an oxide of magnesiaum, and sulphuric acid
will be evolved and condensed as described in my Patent before mentioned.
Instead of alumnia, magnesia, or other alkaline earths, I could employ, ac-
cording to my improvements, soda, or potash, or ammonia, in decomposing
metallic sulphates in and after the method horein given as effectually but not
so economically.
I will now describe that part of my Invention applicable to chloridos, and will,
in this instance, describe the mode by which I treat the chloride of silver, as this
chloride is principally to be met with as a natural production. The said chloride
of silver being insoluble, is mixed according to my Invention with a due propor-.
tion of soda or potash, that is to say, for every one hundred and forty-four parts
by weight of tho said chloride contained in the ore thirty-two parts by weight
of real soda or forty-eight parts by weight of real potash are to be mixed with
the ore first reduced to powder, and about one hundred parts by weight at the
most of charcoal, anphracite, or such like carbonaceous matter are also to be
mixed with the chloride of silver and the above quantity of alkali; then as
much of the mixture as it may be found advisable to reduce is exposed in a
cruscible, or in any convenient furnace, to a temperature exceeding a red heat
whereby the silver will be reduced to the metallic state, aud form an ingot
easily separable from the slag, while the alkali used will be converted into a
chloride, and part of the combustible matter will be evolved in the state of
carbonic acid; but although soda or potassa will be found to answer the pur-
pose of obtaining silver from a chloride of that metal, I have found that instead
of soda or potash it is better to employ silicates of soda or potash, in which the
alkali is an excess, and thus for every one hundred and forty-four parts by
weight of real chloride of silver I use sixty-two parts by weight of said silicate
of soda or potash, or about the sanie proportion of aluminate of soda or potash,
or any other compound of alkali with the earths or alkaline earths, the process
being in all other respects the same as I have before described when soda or
potash alone are made use of. The chlorides of copper or other soluble chlo-
rides, however obtained, are treated according to my Invention in the following
manner; (that is to say,) the said chloridos, and taking the chloride of copper

page_text: as an example, are first dissolved in water, and a due proportion of magnesia,
lime, magnesian limestone, or any other earth or alkaline earths is to be added
to the solution, which it is better to treat so as to promote the decomposition,
and should magnesia be used, it will be found that twenty parts by weight
will be sufficient to decompose in the manner herein described about sixty-
eight parts by weight of dry chloride of copper, in this instance there will be
a precipitate of oxide of copper formed in the pan or apparatus in which the
chloride may have been dissolved and magnesia added, which oxide is to be
removed to be subsequently smelted, and the clear liquor being drawn off into
another pan, or any other convenient vessel, and evaporated, to dryness, it will
be found that the residue of the evaporation is a chloride of magnesia, from
which chlorine or hydrochloric acid may be obtained according to the process
described in the Patent granted to me as herein-before mentioned.
In the before-described improvements in the process of smelting copper and
other ores, with the exception of silver only, oxides have been obtained; but as
oxides of the various metals are also found in nature, I wish it to be understood
that I shall use in the following parts of my Invention either oxides produced
artificially according to the method or methods herein-before described, or those
oxidos or carbonates naturally formed, as the case may be, and will now in
accordance with said proviso proceed to the description of my improvements in
reducing oxides to the metallic state. In the following mode or modes of
smelting, I use a common reverberatory furnace of the kind generally adopted
in smelting works, without any difference whatsoever, and when the oxide has
been obtained from a sulphurate, or is otherwise mixed with silica and other
earths generally found in combination with ores, said silica and other earths
having by sorting been brought to certain relative proportions calculated to
render the slag already fusible. I proceed to the reduction in either of the
following ways:
Firstly, the complete separation of the 'metallic matter being in a great
measure dependent on the fusibility of the slag. I shall in the first mode of
smelting augment the fusibility of said slag, but without rendering the slag
soluble, and for the said purpose I mix. intimately with twenty-five hundred
weight of desulphurated ore of copper, or other metals containing about
tiventy per cent. of copper or other metals, about as much of powdered
anthracite coals, or any other carbonacious matter, and soluble silicate of soda
or potash, in the proportion of four parts to ten of the silica contained in
the above twenty-five hundredweight of disulphurated ore, and expose the
mixture in the smelting furnace to the temperature required to fuse copper or
the other metals, respectively stirring from time to time the material, princi-

page_text: pally when brought into fusion, which will occupy four or five hours, and by
means of the addition of the above-named proportion of silica, or a little moro
or loss of the same, it will be found that the whole of the slag has been
converted into glass of a great fluidity while in fusion, and that the metal hins
gathered into a mass at the bottom of the smelting furnace. The slag may
now be run off as usual into pigs or any other form in which such glass may
be rendered available, and the metal is afterwards allowed to run in the usual
way into moulds of sand or otherwise.
Secondly, I may use such proportions of alkali in its caustic or carbonated
stato, not only sufficient to render the slag very fusible, but so as to obtain a
soluble slag, the proportion of carbonacious matter remaining the same, and in
this case the quantity of alkali to be used with the ore previously disulphurated
must be at least equal to that of the silica and other earths taken together
contained in the orc, and said mixture of alkali and ore is afterwards. to bo
treated as herein-before described in my first mode of smelting; but the slag
thus obtained being soluble in water must be afterwards dissolved so as to
obtain the alkali combined therewith by the usual process of evaporation, but
I greatly prefer my first mode of smelting copper or other ores as being the
most economical. In reference to the pure oxides I may have obtained from
sulphates or chlorides of copper or other metals treated as herein-before
mentioned, I proceed to their reduction as follows:-I first prepare a flux
by mixing intimately together about one hundred parts by weight of powdered
anthracite or any other carbonacious matter, and ono hundred parts by weight
of flour spar, the flour spar being sometimes dispensed with and one hundred
parts by weight of silicate of soda containing at the most 20 per cent of alkali,
and mix said flux so composed with one hundred parts by weight. of said pure
oxide of copper or other ore, and proceed to the smelting in the manner
herein-before described, I proceed to the reduction of silver when mixed with
silica and other earths, and of the pure oxide, and indeed of other metals
according to the description given for obtaining copper, and I wish it to be
understood that when my process shall be applied to the reduction of other
metals, for instance, for obtaining from certain iron ores a finer kind of iron or
more malleable, all I have said of copper is to be applied to the reduction of
other metals; but I may, according to circumstances, vary more or less the
quantities and also the proportions of materials or the apparatus, so long as I
confine myself to the true spirit of my Invention.
Having now ascertained and described the nature of my said Invention, and
the manner in which the same is to be performed, I hereby declare that I
claim as my Invention for smelting copper and other ores,-

page_text: Firstly, the several methods of obtaining oxides of copper or of the other
metals freed from sulphur in and after the manner herein-before described.
Secondly, the mode or modes of obtaining oxides of copper, or of the other
metals, from the sulphates or chlorides of said metals respectively in and after
the manner herein-before described.
Thirdly, the mode or modes of obtaining silver from its chlorides in the
manner herein-before described.
Fourthly, the method or methods of fusion also herein-before described.
In witness whereof, I, the said Francois Stanislas Meldon de Sussex, have
hereunto set my hand and seal, the Twenty-third day of September,
in the year of our Lord One thousand eight hundred and forty-seven.