IMPROVEMENTS IN THE TREATMENT OF MINERALS AND ORES
Year: 1870

page_text: LETTERS PATENT to Henri Adrien Bonneville, of the British and
Foreign Patent Offices, 18, Chaussée d'Antin, Paris, in the Empire
of France, and 10, Sackville Street, Piccadilly, in the County of
.Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN
THE TREATMENT OF MINERALS AND ORES." -A communication .from
Outhenin Chalandre, senior, acting as Administrator of the
Company known as "La Société Anonyme des Anciennes Salines
Domaniales de l'Est, residing at Rue Bergére, Paris, aforesaid.
COMPLETE SPECIFICATION filed by the said Henri Adrien Bonneville
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 9th August 1870, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRI
ADRIEN BONNEVILLE, of the British and Foreign Patent Offices, 18,
Chaussée d'Antin, Paris, in the Empire of France, and 10, Sackville
Street, Piccadilly, in the County of Middlesex, Patent Agent, send
greeting.

page_text: 66
WHEREAS I am in possession of an Invention for “IMPROVEMENTS IN THE
TREATMENT OF MINERALS AND ORES," a communication to me from Outhenin
Chalandre, senior, acting as Administrator of the Company known as
'La Société Anonyme des Anciennes Salines Domaniales de l'Est,"
a person resident at Rue Bergére, Paris, aforesaid, and have petitioned
Her Majesty to grant unto me, my executors, administrators, and assigns,
Her Royal Letters Patent for the same, and made solemn Declaration that
it is a communication.
NOW KNOW YE, that I the said Henri Adrien Bonneville, do
hereby declare that the following Complete Specification, under my hand
and seal, fully describes and ascertains the nature of the Invention, and
the manner in which the same is to be performed, that is to say :—
This Invention, communicated to me, relates to a certain new and
improved treatment of ore or minerals enclosing metals combined with
sulphur, arsenic, and antimony with the view of extracting either the
metals themselves or the sulphur, arsenic, or antimony.
This process is based principally upon the property that has been
found to possess in a multitude of cases ferric chlorure in conjunction
with the atmospheric air and water of attacking with energy the
metallic sulphides, the metallic alligations of arsenic and of antimony,
such as pyrites of iron and of copper, blende ore, plumbago, cynabra, sul-
pharseniures of cobalt and of nickel, sulphantimoniures of lead and silver,
sulphide of antimony and other similar metallic sulphides. The reaction
takes place at an ordinary temperature as at a higher one. The ferric
chlorure is reduced to a ferrous state, whilst the metals pass to the state of
chlorures of iron, of copper, of lead, of nickel, of cobalt, of antimony, of
arsenic, of zinc, of mercury, of silver, some naturally soluble in water, as
the chlorures of iron, of copper, of cobalt, of arsenic, of zinc, and
slightly that of lead, others as the chlorure of mercury becoming soluble
by surchloridization, others as especially the chlorure of antimony, of
silver, of lead, becoming soluble in chlorure of sodium or in the
hyposulphite of soda. But when once the ferric chlorure (Cl³ Fe) is
re-established in the ferrous state (Cl² Fe²) the reaction would cease
if the contact with the air did not exist with its tendency to make the
ferrous salt return to the state of ferric salt, and thus render to it its g
original energy. If there be only a few sulphures, and especially if only
a few pyrites present, it will be necessary or at least advantageous
to add from time to time a free acid, preferably muriatic acid, which

page_text: facilitates the reconstitution of the ferric chlorure, and prevents the
formation of insoluble under salts: Sulphuric acid could also be used
(or even sulphurous acid or solutions of sulphurous acid which passes
rapidly in the atmosphere to the sulphuric acid state), but then a
corresponding quantity of chlorure of sodium or mother water salt
must be added to the sulphuric acid, in order that by double decom-
position sulphate of soda and muriatic acid or ferric chlorure may be
produced. In presence of pyrites of iron, or of copper, or in general of a
sulphurated ore, which is much the more frequently the case, the
addition of acid becomes useless. For by the action of the ferric chlorure
and of the air the sulphur itself oxydizes and passes to the state of
sulphuric acid. It is thus that the pyrite 2(Fe S2) under the
influence of the ferric chlorure is transformed gradually into ferric
sulphate 3SO³ Fe² O³, and into sulphuric acid SO³.
2(Fe S2)+015 3S0³ Fe³ 0³+SO³.
But under the influence of chlorure of sodium and water the ferric
sulphate is transformed into ferric chlorure, and the free sulphuric acid
into muriatic acid, giving existence to a corresponding quantity of
sulphate of soda.
3SO³ Fe² O³+SO3 + HO+4C1 Na=3SO³ Na 0+SO³ NaO+CI³ Fe²+IICI.
Consequently under the influence of pyrites and of chlorure of sodium.
the salt is transformed into sulphate of soda, and the oxygen of the air is
energetically absorbed. By burning pyrites alone it is possible to
disengage therefrom sulphurous gas, which is caused to be absorbed by a
fall of water, and this solution of sulphurous gas passes rapidly to the
state of sulphuric acid when on the masses of ore. A mixture of pyrites
and of salt may also be roasted under the influence of steam water.
Corrents of muriatic acid are disengaged that may also be absorbed, so
that even when far from any manufactory of chemical produce it is
rigourously possible to obtain sulphuric and muriatic acids in cases where
their use is indispensable. But in almost all cases an addition of a
certain quantity of oxydible pyrite suffices for the regular working, of the
operations..
It is to be noticed that the execution of this process is one of the
most economical ways of manufacturing sulphate of soda by means of
pyrites and chlorure of sodium, or in other words, it permits of the pro-
duction of sulphate of soda with matters of no commercial value, so to
speak, such as the residue of pyrites or roasted pyrites, having served in
1

page_text: .
the manufacture of sulphuric acid. Roasted pyrites are at present
generally thrown away; they are piled up in inconvenient heaps
exposed to the air and damp; roasted pyrite still possesses from 1 to
5 and 6 per cent. of sulphur, often more even, after a certain time a part
of this sulphur or rather of this rest of pyrite is converted into ferrous
sulphate or ferric sulphate. It is seldom the oxydization of the pyrite is
complete, even after a prolonged interval, in consequence of the slight
solubility of ferric basic sulphate and of the tendency of ferric sulphate
to form basic salts. Even the ferrous sulphate in the interior does not
continue to oxydize very rapidly; it is no longer the same if a solution
of chlorure of sodium be introduced; then by a double decomposition
the ferric sulphate is transformed along with the chlorure of sodium
into sulphate of soda and ferric chlorure, and this latter reacts again
very energetically on the remnant of sulphur or of pyrite not as yet
attacked.
For an example we will give with the requisite details the manner in
which the operation should be effected. The piles of roasted pyrites,
known as ash pyrite, after an exposure in the air of some months (the
operation can always be made on the piles which are to be found in too
great abundance near all manufactories of chemical matters, where
pyrites are roasted for the manufacture of sulphuric acid) are changed and
arranged in piles of a few cubic metres on an impenetrable clayey soil.
In arranging these piles care must be taken to leave spaces in order to
allow for the circulation of the air in the interior with sufficient ease.
All round these piles canals of a few decimetres in depth are dug in
order to receive the washings or solutions which could run off. The
piles are then watered with a solution moderately concentrated with
chlorure of sodium. The quantity of salt to be used is proportional to
the quantity of sulphur still existing in the roasted pyrites (quantity
already known or to be determined by an analysis). If any of the
liquid runs off into the canals it must be again poured gradually on to
the pile. After a few weeks (the time depends on the permeability and
the porosity of the piles) all the sulphur and all the iron is oxydized,
and the whole or nearly the whole of the chlorure of sodium is con-
verted into sulphate of soda. In dry weather this latter shoots out in
abundance on the piles and may be taken off the same. The next
process is the lixiviation of the pile. This operation may be executed either
with pure water or with a weak solution of chlorure of sodium, it should

page_text: be done regularly in order only to have concentrated liquids and at the
same time to lixiviate the whole completely. The apparatus and process
of lixiviation as now used for the lixiviation of oxydized buck ash and for
the preparation of yellow leg may be very suitably employed. The fresh
piles might be simply lixiviated with weak washings taken from a pile
half or nearly exhausted...
If it is desired to free the roasted pyrites from every trace of sulphur
(which enables them to be used as iron ore in blast furnaces to convert
them into excellent cast and wrought iron) it will be well to finish the
lixiviation not with salted water or pure water, but with a very weak
solution of muriatic acid so as to dismiss every trace of ferric bassic sul-
phate which may still remain. The liquids resulting from the lixiviation,
charged with sulphate of soda, are still ferruginous in order to disengage
the iron therefrom and obtain a pure sulphate of soda. There are two
manners of proceeding. Either these washings are warmed by a stream
of steam and lime white is poured thereon in sufficient quantity for the
acid or under ferric salt to be precipitated, which arrives very rapidly,
and then they are allowed to settle, and the clear limpid solution of
sulphate of soda is drawn off and concentrated for the crystalization
of the Glauber salt.. Or the solution of sulphate of ferruginous soda is
evaporated to dryness, and the residue of this evaporation is roasted in a
reverberating stove. The iron thus becomes soluble, and the roasted
matter re-dissolved in water at 40° (centigrade), and filtered and drawn
off from the insoluble residue furnishes a Glauber salt perfectly pure.
The mother waters serve again in the manufacture.
The treatment of ores is similar. Piles of more or less considerable
proportions, according to the value and richness of the ore, are con-
structed on an impermeable soil with surrounding canals, and first a
watering is performed with ferric chlorure or with the liquid resulting
from the lixiviation of the piles of oxydized pyrites under the influence
of the salt and of a little ferric chlorure with acid added to commence
and initiate the reaction. From time to time the pile is watered with a
solution of salt, when the reaction progresses favorably an elevation of
heat in the interior of the piles is very clearly noticed; if the heat
becomes too great it must be watered more frequently. From time:
to time it is lixiviated with a weaker solution of salt. The washing
running into the canals will contain, according to the ores, solutions of
chlorure of copper, of zinc, of cobalt, of nickel, of arsenic, of antimony,

page_text: -
and even of silver, especially if an excess of solution of chlorure of
sodium is used, the chlorure of silver dissolving in the chlorure of
sodium. To precipitate the copper iron is employed, and cementation
iron will be obtained. To precipitate zinc, cobalt, nickel, antimony, and
arsenic, it is proposed to use sulphure of sodium in aqueous solution.
This sulphure can be prepared at little expense by the red calcination
with coal of the sulphate of impure soda (obtained in the same reactions).
Silver will also be precipitated by the same reaction. In the event of
treating silver ore the sulphure of sodium transforming itself gradually
into hyposulfite will much facilitate the dissolution of the silver. It may
happen that the silver be reduced to the state of metals in the piles
under the influence of the sulphate or of the ferrous chlorure, in such
cases recourse may be had to extraction by amalgamation.
•
In all cases the pure metallic sulphures precipitated by the sulphure
of sodium will constitute an original matter of the greatest richness,
and to which the metallurgic processes, properly so called, could always
be then applied.
In many cases, either in consequence of the small richness of ores, or
of the particular circumstances in which they are worked, no metallurgic
treatment, properly so called, can be applied, that is to say, neither the
roast, the fusion, the cupellation, or the liquation.
All these operations generally demand a considerable expense of fuel,
and very often the produce obtained in consequence of the great quantity
of foreign matters that must be melted at the same time and caused to
pass over the dross would not cover the expense of separating either the a
metal or the substances with which it is combined. In these conditions
these ores could very frequently be treated by this new process, which
may be denominated a chemical metallurgical process.
This process
is more especially applicable when the gangue is of a quartz nature
and difficult to be attacked by chemical reactions, and this is very;
frequently the case. In this process no substance is employed but what
may be purchased at an excessively low price and almost everywhere,
these substances being, as seen above, sulphate and ferric chlorure,
chlorure of sodium, or mother water salt, sulphurous, sulphuric, and
muriatic or hydrochloric acids.
Having thus described the said Invention, and the manner of per-
forming the same, I would have it understood I do not confine myself.
to. the precise details herein indicated, as these may obviously be
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page_text: modified without departing from the principle of the said Invention;
out what I claim and desire to secure by the said Letters Patent is, the
ransformation of the metallic sulphures by means of the addition of a
solution of chlorure of sodium into soluble chlorures of the same metal,
and the extraction of the metal itself from the same.
Also the reduction of the sulphure to the state of sulphate of soda.
In witness whereof, I, the said Henri Adrien Bonneville, have
hereto set my hand and seal, this Sixth day of August, in
the year of our Lord One thousand eight hundred and seventy.