A NEW OR IMPROVED DOCIMASTIC PROCESS AND METHODS FOR THE TREATMENT OF THE SIMPLE SULPHURETS, THE COMPLEX SULPHURETS, AND THE ARSENIO-SULPHURETS OF LEAD, ANTIMONY, COPPER, AND IRON, AS WELL AS COPPERY MATTS AND COPPERS CONTAINING PRECIOUS METALS IN ORDER TO EXTRACT SILVER AND GOLD THEREFROM
Year: 1870

page_text: ETTERS PATENT to Thomas James Smith, of the Firm of Robertson,
Brooman, and Company, of 166, Flect Street, in the City of
London, Patent Agents, for the Invention of "A NEW OR IMPROVED
DOCIMASTIC PROCESS AND METHODS FOR THE TREATMENT OF
THE SIMPLE
SULPHURETS, THE COMPLEX SULPHURETS, AND THE ARSENIO-SULPHURETS OF
LEAD, ANTIMONY, COPPER, AND IRON, AS WELL AS COPPERY MATTS AND
COPPERS CONTAINING PRECIOUS METALS IN ORDER TO EXTRACT SILVER AND
GOLD THEREFROM."-A communication from abroad by Cyprien Maric
Tessié du Motay, of 23, Boulevard de Strasbourg, Paris, France.
PROVISIONAL SPECIFICATION left by the said Thomas James Smith
at the Office of the Commissioners of Patents, with his Petition,
on the 25th March 1870.
I, THOMAS JAMES SMITH, of the Firm of Robertson, Brooman, and
Company, of 166, Fleet Street, in the City of London, Patent Agents,
do hereby declare the nature of the said Invention for "A NEW OR
IMPROVED DOCIMASTIC PROCESS AND METHODS FOR THE TREATMENT OF THE
SIMPLE SULPHURETS, THE COMPLEX SULPHURETS, AND THE ARSENIO-SULPHUEETS

page_text: OF LEAD, ANTIMONY, COPPER, AND IRON, AS WELL AS COPPERY MATTS AND COPPERS
CONTAINING PRECIOUS METALS IN ORDER TO EXTRACT SILVER AND GOLD THEREFROM,"
to be as follows:-
:-
This new or improved docimastio process and methods of heating the
simple sulphurets, the complex sulphurets, and the arsenio-sulphurets
of lead, antimony, copper, and iron, as well as coppery matts and
coppers containing precious metals in order to extract silver and gold
therefrom consist,―
Firstly. In roasting the simple or complex sulphurets, the antimonio-
sulphurets, and the arsenio-sulphurets containing silver or gold in the 1
presence of pure silica, of auriferous quartz, or terrous and metallic
silicates, adding in order to complete this roasting and to expel all the
sulphur contained in the minerals either lead, which is intended to
form oxide of lead, or litharge or minium or any other metallic oxido
capable of producing in contact with air or oxidizing flames peroxides 1
or silicates of peroxides.
· Secondly. In thus transforming into the state of very fusible basio
silicates the oxides of the desulphuretted metals.
Thirdly. In melting or running in the melted state the silicates of
this kind produced upon a matt of lead also melted, and in stirring or 2
agitating them either by paddles held in the hand, or by mechanical
means, or by means of gases mcohanically employed up to the moment
when the gold and silver are entirely dissolved in the melted load.
Fourthly. In separating the poor scoriae deprived of the precious
métals of the lead which has taken them up and to stir or agitate upon 2
the same mass of lead a fresh quantity of rich scoria.
Fifthly. In repeating this liquation an indefinite number of times
until the moment when the capacity of saturation of the lead for tho
precious metals, which is lessened by cach operation, no longer permits
the continuance of this mode of treatment.
Sixthly. In testing the lead saturated with silver or gold by the
methods of cupellation now in use in order to extract therefrom the
precious metal.
Seventhly. In removing from the poor scoriæ the oxides of lead,
antimony, and copper which for the most part are contained therein
by bringing back these oxides to the metallic state by the separate or
united action of charcoal and iron.
3

page_text: Eighthly. In separating by the special methods presently described
the copper and antimony from the lead with which they are united.
Ninthly. In re-employing either wholly or partly the purified lead in
the treatment by oxidation and silication of fresh quantities of mineral.
Tenthly. Lastly, in reducing either in reverberatory or cupola furnaces,
or in all other fusion furnaces, the basic silicates enumerated above by
the action of charcoal or iron when the latter are the produce of
minerals containing copper pyrites in considerable quantities.
The metallic matts thus obtained consist of an alloy of copper, of
lead, of silver, and of gold, or of copper, of lead, of antimony, of silver,
and of gold, free from sulphur, which may be all treated at once either
by docimastic methods in countries rich in combustibles, or by the
humid process in countries where mineral acids are low in price.
Having thus stated in a general manner my docimastic methods of
treating sulphuretted, antimonio-sulphuretted, and arsenio-sulphuretted
minerals containing precious metals, I proceed specially to describe the
new operations and reactions whereby they are essentially distinguished
from those at present employed for the same object.
These operations and reactions consist in the first place of the
roasting, the oxidation, and the scorification of the simple or complex
sulphurets, of antimonio-sulphurets, and of arsenio-sulphurets in the
presence of silica and oxides of lead, or of all other metallic oxidies
capable of passing into the state of peroxides or silicates of peroxides
in the oxidizing flames in order, firstly, to prevent the formation of the
oxysulphurets of lead, of antimony, and of copper, which in dissolving
with the silver or the gold in the lead cause afterwards the loss during
the cupellation of an appreciable quantity of the precious metals, which
are dissolved in this lead and render inapplicable for industrial purposes,
either the cupellated litharges or the lead proceeding by reduction from
the said litharges; secondly, to permit the complete dissolution in the
lead of the silver and gold contained in the basic silicates free from
sulphur without the antimony or the copper, which have passed from
the state of sulphurets into the state of silicates, being able to dissolve
in the lead, and consequently to injure it; thirdly, to obtain as the
final result from a series of successive liquations a testable (coupellable)
lead rich in precious metals; fourthly, to avoid a great number of
cupellations to obtain pure litharges transformable into lead of an equal

page_text: purity, and to thus diminish the net cost of the industrial extraction of
silver and gold by means of the cupel to a considerable extent.
The operations and reactions in the second place consist in the
reduction to puro lead or into an alloy of lead and antimony of lead and
copper, or of lead, of antimony, and copper, of the scoria deprived of
gold or silver in order, firstly, if the extracted lead is pure to make it
again serve by way of roasting for the oxidation of a fresh quantity of
sulphuretted, arsenio-sulphuretted, or antimonio-sulphuretted minerals;
secondly, if the lead is alloyed with antimony or copper or with both
these metals to separate it from one of these metals or both together in
order also to use it again after purification for the oxidation of a fresh
quantity of sulphuretted, arsenio-sulphuretted, or antimonio-sulphuretted
minerals.
The methods for separating the lead from the antimony or from the
antimony and copper united constitutes one of the greatest novelties, and
one of the most essential parts of this Invention. I therefore proceed to
describe separately the reactions peculiar to the separation of the metals
contained in the above-mentioned alloys. Taking, for example, an
alloy of lead, of antimony, the inventor submits it after having melted it
in a reverberatory furnace or a cupel furnace to the action of the nascent
steam produced by aërohydric or oxyhydric blow pipes fed by a mixture
in definite proportions of air or of oxygen and pure hydrogen or
carbonated hydrogen. The flame produced by these blow pipes should
be as free as possible from any trace of uncombined oxygen. It is even
preferred in order to prevent any oxidation of the lead that the flame
should contain a little hydrogen or free carbon. The nascent steam
may perhaps be mixed with the ordinary steam generated at 212°
Fahrenheit. The antimony, which decomposes water at a high
temperature, oxidizes in passing into the state of antimoniate of oxide of
antimony, one portion of which volatizes whilst the other remains
attached to the inner sides of the reverberatory or other furnace in this
operation, during which almost the whole of the antimony is separated,
and the lead which does not decompose water is but little or not at all
oxidized, but still retains traces of antimony with a strong affinitive
force; and in order to entirely purge it from this cristal it is necessary to
have recourse to sulphate of lead. This new reagent has the property of
becoming decomposed in oxido of lead, in free oxygen, and in sulphurous
acid by antimony, which by this decomposition taking up the oxygen
set at liberty acidifies and combines with the oxide of lead of the

page_text: decomposed sulphate. The lead is then completely purified and
rendered applicable for all industrial purposes. It follows as a matter
of course that the sulphate of lead can by itself without the previous
employment of steam in the nascent state separate the whole of the
antimony contained in an alloy of this metal with the lead, but in
many cases to employ it would cost too much. Terrous hydrates,
such as hydrates of lime and baryta, can also be efficaciously
employed instead of steam in a nascent state or of ordinary steam
from water in order to oxidize the antimony and to separate
it from the lead. But the Inventor prefers the steam generated by
acrohydric or oxyhydric blow pipes which furnish at the same time
the heat necessary for the fusion of the alloys and the reagent, which
partly or wholly removes from the lead the antimony which injures it.
When the lead is alloyed with copper and this alloy does not contain
antimony, I melt it with a quantity of sulphuret of lead rather more
than equivalent to the quantity of copper to transform into sulphuret;
this fusion is conducted away from any oxidizing action in a reducing
medium and proluces an immediate reaction by way of double exchange.
The sulphur combined with the lead acts upon the copper of the alloy
and thus substitutes metallic lead for the copper, which scorifies and
passes into the state of sulphuret. The lead thus deprived of copper
is pure and proper to be employed as indicated above, either for the
oxidation of fresh minerals or it may be sold for general purposes.
Alkaline, and alkalino-terrous, bisulphurets, and polysulphurets as well
as metallic sexqui-sulphurets, and bisulphurets, may be substituted for
the sulphuret of lead in order to remove the copper from the lead
by causing the latter metal to pass into the state of sulphuret. The
sulphuret of copper may after roasting be transformed into metallic
copper by the reducing processes at present employed. When antimonio.
sulphuretted argentiferous leads have been previously brought to the
metallic state by the methods of reduction at present employed the
Inventor submits them to the action of the same blow pipes, and when
the antimony which has passed into the state of oxide has been separated
from the lead in which the silver remains entirely dissolved this lead
is tested or cupellated and the precious metal extracted therefrom.
The chief points of novelty in this Invention may be stated as
follows:-
:-
First. The method of roasting and the silicatisation of the metallic,
simple or complex sulphurets. arsenio-suluhurete and autinnin

page_text: sulphurets containing silver or gold by means of the processes above
described.
Second. The method of liquation and fusion by successive series of
argentiferous and auriferous silicates upon one same bath of lead which
deargentises and deaurifies them, by which method the same object is
obtained by one cupellation which according to the best methods at
present in use requires several.
Third. The methods by which after the oxides of lead, antimony, or
copper contained in the silicates deprived of silver or gold have been
brought back to the metallic state, the lead is separated from the copper
with which it is united by the addition of an equivalent quantity of
sulphuret of lead or of one of the sulphurets enumerated above, and the
antimony by the action of the acrohydric or oxyhydric blow pipes
combined with the reaction produced by a small amount of sulphuret
of lead.
Fourth. Last, the application of the above-described methods to the
entire or partial treatment of copper matts, and argentiferous, and
auriferous coppers, of the minerals of antimoniferous lead, and of the
mineral of antimony containing silver and lead, or pure silver.
SPECIFICATION in pursuance of the conditions of. the Letters Patent,
filed by the said Thomas James Smith in the Great Seal Patent
Office on the 24th September 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JAMES SMITH, of the Firm of Robertson, Brooman, and Company, of
166, Fleet Strect, in the City of London, Patent Agents, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of March, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto mc, the said Thomas James Smith, Her special licence
that I, the said Thomas James Smith, my executors, administrators,
and assigns, or such others as I, the said Thomas James Smith, 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

page_text: 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 "A NEW OB
IMPROVED DOCIMASTIC PROCESS AND METHODS FOR THE TREATMENT OF THE SIMPLE
SULPHURETS, THE COMPLEX SULPHURETS, AND THE ARSENIO-SULPHURETS OF LEAD,
ANTIMONY, COPPER, AND IRON, AS WELL AS COPPERY MATTS AND COPPERS
CONTAINING PRECIOUS METALS IN ORDER TO EXTRACT SILVER AND GOLD THERE-
PROM," (communicated to me from abroad by Cyprien Marie Tessić du
Motay, of 23, Boulevard de Strasbourg, Paris, France,) upon the
condition (amongst others) that I, the said Thomas James Smith, my
exccutors 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 Thomas James Smith, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement thereof, that is to say :-
This new or improved docimastic process and methods of treating the
simple sulphurets, the complex sulphurets, and the arsenio-sulphurets of
lead, antimony, copper, and iron, as well as coppery matts and coppers
containing precious metals in order to extract silver and gold therefrom
consist,―
Firstly. In roasting the simple or complex sulphurets, the antimonio-
sulphurets and the arsenio-sulphurets containing silver or gold in the
presence of pure silica, of auriferous quartz, or terrous and metallic
silicates, adding, in order to complete this roasting and to expel all the
sulphur contained in the minerals, either lead, which is intended to form
oxide of lead, or litharge or minium or any other metallic oxide capable
of producing in contact with air or oxidizing flames peroxides or
silicates of peroxides.
Secondly. In thus transforming into the state of very fusible basic
silicates the oxides of the desulphuretted metals.
Thirdly. In melting or running in the melted state the silicates of this
kind produced upon a matt of lead also melted, and in stirring or

page_text: agitating them either by paddles held in the hand or by mechanical
means, or by means of gases mechanically employed up to the moment
when the gold and silver are entirely dissolved in the melted lead.
Fourthly. In separating the poor scoria deprived of the precious
metals of the lead which has taken them up, and in stirring or agitating &
upon the same mass of lead a fresh quantity of rich scoriæ.
Fifthly. In repeating this liquation an indefinite number of times
until the moment when the capacity of saturation of the lead from the
precious metals, which is lessened by each operation, no longer permits
the continuance of this mode of treatment.
Sixthly. In testing the lead saturated with silver or gold by the
methods of cupellation now in usc in order to extract therefrom the
precious metal.
]
Seventhly. In removing from the poor scoriæ the oxides of lead,
antimony, and copper which for the most part are contained therein by 1
bringing back these oxides to the metallic state by the separate or united
action of charcoal and iron.
Eighthly. In separating by the special methods presently described
the copper and antimony from the lead with which they are united.
Ninthly. In re-employing either wholly or partly the purified lead
in the treatment, by oxidation and silication of fresh quantities of
mineral.
Tenthly. Lastly, in reducing either in reverberatory or cupola furnaces
or in all other fusion furnaces the basic silicates enumerated above by
the action of charcoal or iron when the latter are the produce of
minerals containing copper pyrites in considerable quantities.
The metallic matts thus obtained consist of an alloy of copper, of
lead, of silver, and of gold, or of copper, of lead, of antimony, of silver,
and of gold free from sulphur, which may be all treated at once either
by docimastic methods in countries rich in combustibles or by the humid :
process in countries where mineral acids are low in price.
Having thus stated in a general manner my docimastic methods of
treating sulphuretted, antimonio-sulphuretted, and arsenio-sulphuretted
minerals containing precious metals, I proceed specially to describe the
new operations and reactions whereby they are essentially distinguished
from those at present employed for the same object.

page_text: These operations and reactions consist in the first place of the roasting,
the oxidation, and the scorification of the simple or complex sulphurets,
of antimonio-sulphurets, and of arsenio-sulphurets, in the presence of
silica and oxides of lead, or of all other metallic oxides capable of
passing into the state of peroxides or of silicates of peroxides in the
oxidizing flames, in order, firstly, to prevent the formation of the oxysul-
phurets of lead, of antimony, and of copper, which in dissolving with
the silver or the gold in the lead cause afterwards the loss during the
cupellation of an appreciable quantity of the precious metals which are
dissolved in this lead and render inapplicable for industrial purposes
either the cupellated litharges or the lead proceeding by reduction from
the said litharges; secondly, to permit the complete dissolution in the
lead of the silver and gold contained in the basic silicates free from
sulphur without the antimony or the copper which have passed from
the state of sulphurets into the state of silicates being able to dissolve
in the lead and consequently to injure it; thirdly, to obtain as the
final result from a series of sucessive liquations a testable (coupellable)
lead rich in precious metals; fourthly, to avoid a great number of
cupellations to obtain pure litharges transformable into lead of an equal
purity, and to thus diminish the net cost of the industrial extraction of
silver and gold by means of the cupel to a considerable extent.
The operations and reactions in the second place consist in the
reduction to pure lead or into an alloy of lead and antimony of lead
and copper, or of lead of antimony and copper of the scoriæ deprived
of gold or silver in order, firstly, if the extracted lead is pure to make
it again serve by way of roasting for the oxidation of a fresh quantity of
sulphuretted, arsenio-sulphuretted, or antimonio-sulphuretted minerals;
secondly, if the lead is alloyed with antimony or copper or with both
these metals to separate it from one of these metals or both together,
in order also to use it again after purification for the oxidation of a
fresh quantity of sulphuretted, arsenio-sulphuretted, or antimonio-sul-
phuretted minerals.
The methods for separating the lead from the antimony or from the
antimony and copper united constitute one of the greatest novelties,
and one of the most essential features of this Invention. I therefore
proceed to describe separately the reactions peculiar to the separation
of the metals contained in the above-mentioned alloys. Taking, for
example, an alloy of lead, of antimony, the Inventor submits it after

page_text: having melted it in a reverberatory furnace or a cupel furnace to the
action of the nascent steam produced by aĕrohydric or oxyhydric blow
pipes fed by a mixture in definite proportions of air or of oxygen and
pure hydrogen or carbonated hydrogen. The flame produced by these
blow pipes should be as free as possible from any trace of uncombined
oxygen. It is even preferred in order to prevent any oxidation of the
lead that the flame should contain a little hydrogen or free carbon.
The nascent steam may perhaps be mixed with the ordinary steam
generated at 212° Fahrenheit. The antimony which decomposes water
at a high temperature oxidizes in passing into the state of antimoniate
of oxide of antimony, one portion of which volatilizes, whilst the other
remains attached to the inner sides of the reverberatory or other furnace
in this operation, during which almost the whole of the antimony is
separated, and the lead which does not decompose water is but little
or not at all oxidized, but still retains traces of antimony with a strong
affinitive force, and in order to entirely purge it from this crystal it is
necessary to have recourse to sulphate of lead. This new reagent has
the property of becoming decomposed in oxide of lead, in free oxygen,
and in sulphurous acid by antimony, which by this decomposition
taking up the oxygen set at liberty acidifies and combines with the
oxide of lead of the decomposed sulphate. The lead is then completely
purified and rendered applicable for all industrial purposes. It follows
as a matter of course that the sulphate of lead can by itself without
the previous employment of steam in the nascent state separate the
whole of the antimony contained in an alloy of this metal with the
lead, but in many cases to employ it would cost too much. Terrous
hydrates, such as hydrates of lime and baryta, can also be efficaciously
employed instead of steam in a nascent state or ordinary steam from
water in order to oxidize the antimony and to separate it from the
lead. But the Inventor prefers the steam generated by aërobydric
or oxyhydric blow pipes, which furnish at the same time the heat
necessary for the fusion of the alloys and the reagent which partly or
wholly removes from the lead the antimony which injures it. When
the lead is alloyed with copper and this alloy does not contain antimony
the Inventor melts it with a quantity of sulphuret of lead rather more
than equivalent to the quantity of copper, to transform into sulphuret ;
this fusion is conducted away from any oxidizing action in a reducing
medium and produces an immediate reaction by way of double exchange.
The sulphur combined with the lead acts upon the copper of the alloy,

page_text: and thus substitutes metallic lead for the copper which scorifics and
passes into the state of sulphuret. The lead thus deprived of copper
is pure and proper to be employed as indicated above, either for the
oxidation of fresh minerals or it may be sold for general purposes.
Alkaline and alkalino-terrous, bi-sulphurets, and poly-sulphurets as well
as metallic sexqui-sulphurets and bi-sulphurets may be substituted for
the sulphuret of lead, in order to remove the copper from the lead by
causing the latter metal to pass into the state of sulphuret. The
sulphuret of copper may after roasting be transformed into metallic
copper by the reducing processes at present employed. When anti-
monio-sulphuretted argentiferous leads have been previously brought
to the metallic state by the methods of reduction at present employed
the Inventor submits them to the action of the same blow pipes, and
when the antimony which has passed into the state of oxide has been
separated from the lead in which the silver remains entirely dissolved,
this lead is tested or cupellated and the precious metal extracted there-
from.
And having now described the nature of the said Invention, and in
what manner the same is to be performed, I declare that I claim,―
First. The method of roasting and the silicatisation of the metallic,
simple or complex sulphurets, arsenio-sulphurets, and antimonio-sul-
phurets containing silver or gold by means of the processes above
described.
Secondly. The method of liquation and fusion by successive series of
argentiferous and auriferous silicates upon one same bath of lead which
deargentises and deaurifies them, by which method the same object is
obtained by one cupellation which according to the best methods at
present in use requires several.
Thirdly. The methods by which after the oxides of lead, antimony, or
copper contained in the silicates deprived of silver or gold have been
brought back to the metallic state, the lead is separated from the copper
with which it is united by the addition of an equivalent quantity of
sulphuret of lead or of one of the sulphurets enumerated above and the
antimony by the action of the aërohydric or oxyhydric blow pipes
combined with the reaction produced by a small amount of sulphuret of
lead.
Fourthly. Lastly, the application of the above-described methods to

page_text: auriferous coppers, of the minerals of antimoniferous lead, and of the
mineral of antimony containing silver and lead or pure silver.
In witness whereof, I, the said Thomas James Smith, have here-
unto set my hand and seal, this Twenty-fourth day of September
One thousand cight hundred and seventy.