IMPROVEMENTS IN THE TREATMENT OF ORES OF METALS OF WHICH THE SULPHATES ARE SOLUBLE IN WATER
Year: 1866

page_text: LETTERS PATENT to Paul Emile de Wissocq, Civil Engineer, residing at
Rue Richepanse, No. 11, and Count Louis Krasinski, residing at Rue
de Pentbièvre, No. 22, Paris, in the Empire of France, for the Inven-
tion of "IMPROVEMENTS IN THE TREATMENT OF ORES OF METALS OF WHICH
THE SULPHATES ARE SOLUBLE IN WATER."
PROVISIONAL SPECIFICATION left by the said Paul Emile de Wissocq
and Count Louis Krasinski at the Office of the Commissioners of
Patents, with their Petition, on the 6th December 1866.
We, PAUL EMILE DE WISSOCQ, Civil Engineer, residing at Rue Richepanse,
No. 11, and Count LOUIS KRASINSKI, residing at Rue de Penthièvre, No. 22,
Paris, in the Empire of France, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE TREATMENT OF ORES OF METALS OF WHICH
THE SULPHATES ARE SOLUBLE IN WATER," to be as follows:-
Our process is designed to obtain various metals in the state of oxide.
With this view we commence by bringing the metals to the state of sulphates
in a reverberatory furnace, using a furnace with several beds which will be
described further on, and into which we inject water or vapour of water.
When we wish to produce sulphates in the reverberatory furnace from ores
which contain little or no sulphur we mix them with the persulphuret of iron.

page_text: We dissolve the sulphate in water; then we transform it by one of two
processes which we will presently describe into bydrochlorate, from which we
separate the metallic oxide by means of lime, which substitutes itself for the
oxide, and forms a hydrochlorate of lime, which is very soluble and remains
in the mother liquor. If the mineral produces several sulphates, as is the
case, for example, with the sulphuretted ores of copper, which are always
mixed with sulphuret of iron, there will result a mixture of the hydrochlorates
of which the oxides will precipitate, and may be collected successively according
to the inverse order of their affinity for the acid; but in this case it will be
often preferable to commence by precipitating from the mixture of sulphates
some of the oxides by means of oxide of iron; there will then remain a liquid
heavily charged with sulphate of iron, which can be transformed into hydro-
chlorate, and then by means of lime oxide of iron may be extracted, and
this oxile may be employed in the following operation
-
To transform a sulphate into a bydrochlorate the first means which we
propose is to mix it with hydrochloride of soda, and submit the mixture to a
cold of 7 or 8 degrees below zero centigrade, a double decomposition of the
salts then ensues, sulphate of soda is formed, which at that temperature is
completely insoluble, and in precipitating itself leaves a liquor which contains
the hydrochlorate which it is desired to obtain.
The second means consists in employing the hydrochloride of lime in place
of hydrochloride of soda; then and without its being necessary to submit the
mixture to a low temperature sulphate of lime precipitates in place of sulphate
of soda, and in either case a liquid is obtained containing in solution the
hydrochlorate which is required.
The reverberatory furnace which we employ to transform the sulphurets
into sulphates has several soles one above the other; the lowest sole only has
a fre-place, and is intended to heat the ores at the commencement of the
operation, and also to maintain the furnace at a suitable temperature when
the ore is so poor in sulphur that the combustion of this body is not sufficient
to maintain the temperature. Openings are also made in the furnace to admit
of the introduction of steam, which facilitates and hastens the formation of
sulphates, and renders the sulphates more stable, avoiding risk of their decom.
position should a careless workman allow the temperature of the furnace to
ise too high; this jet of steam also furnishes a means of regulating the
temperature of the furnace at pleasure, and of maintaining it constantly on
each of the soles at the degree which is most favorable for that sole; we
consider this introduction of steam very useful in the process of roasting
sulphurets into sulphates. The furnace that we propose is in fact a group of

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Paul Emile de Wissocq and Count Louis Krasinski in the
Great Seal Patent Office on the 4th June 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, PAUL
EMILE DE WISSOCQ, Civil Engineer, residing at Rue Richepanse, No. 11, and
Count LOUIS KRASINSKI, residing at Rue de Penthiévre, No. 22, Paris, in the
Empire of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of December, in the year of our
Lord One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said Paul Emile de Wissocq and Count Louis Krasinski, Her special licence
that we, the said Paul Emile de Wissocq and Count Louis Krasinski, our
executors, administrators, and assigns, or such others as we, the said Paul
Emile Wissocq and Count Louis Krasinski, our executors, administrators,
and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the 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 Inven-
tion for "IMPROVEMENTS IN THE TREATMENT OF ORES OF METALS OF WHICH THE
SULPHATES ARE SOLUBLE IN WATER," upon the condition (amongst others) that
we, the said Paul Emile de Wissocq and Count Louis Krasinski, our execu-
tors or administrators, by an instrument in writing under our or their hands
and seals, or under the hand and seal of one of us or them, should par-
ticularly 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 we, the said Paul Emile de Wissocq and Count
Louis Krasinski, 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:-
The object of our process is to obtain metals in the state of pure oxides, or
at least free from injurious bodies such as arsenic and antimony. To arrive

page_text: of water.
at this result we commence by bringing the metals into the state of sulphates
by roasting the minerals either in a heap or in a muffle furnace, or in an
ordinary reverberatory furnace, or in a furnace with a permeable bed, the air
to oxidize the mineral being admitted underneath and through this permeable
bed; or, lastly, it may be in a reverberatory furnace having several beds, and
such as is herein-after described, and into which we inject water or the vapour
We dissolve in water the sulphate produced by the roasting, then
we transform it by one of two processes which we will describe into hydro-
chlorate, from which we separate the metallic oxide by the means of lime
which takes the place of the oxide and forms a hydrochlorate of lime, which
being very soluble remains in the mother liquor. If the mineral has produced
several sulphates, as happens, for example, with sulphuret of copper minerals,
which are always mixed with iron, a mixture of the hydrochlorates will be
obtained from which the oxides are precipitated and collected successively
according to the inverse order of their affinity for the acids, or simultaneously
when these oxides have a great affinity the one for the other, as is the case
with the oxides of iron and copper; nevertheless, as the sulphate of iron is
decomposed at a comparatively low temperature, by raising the temperature
of the furnace above the degree at which this salt decomposes a mixture of
the oxid of iron with the other oxides may thus be avoided. The oxide
mains then in the insoluble residue in a minute state of division,"
which allows of its being readily separated, and it is collected for sale.
of iro..
To transform a sulphate into a hydrochlorate the first means which we
propose is to mix it with the hydrochlorate of soda and to submit the mixture
to a cold of 7 or 8° below zero centigrade; a double decomposition of the
salts then takes place, sulphate of soda is formed which is completely insoluble
at that temperature, and which on precipitating leaves a liquid which then
contains nothing but the bydrochlorate which it is desired to obtain.
The second means consists in employing the hydrochlorate of lime in place
of the hydrochlorate of soda; then and without there being any need to submit
the mixture to a low temperature sulphate of lime is precipitated in place of
sulphate of soda, and there remains as before a liquor containing in solution the
hydrochlorate which it is desired to obtain. The sulphate of soda or the
sulphate of lime which is collected always contains a certain quantity of water
mixed with it; this water is charged with metallic hydrochlorate which ought
not to be lost; to recover it the sulphate of soda or the sulphate of lime should
be washed.
The reverberatory furnace which we employ in transforming the sulphurets
into sulphates is represented in the annexed Drawings; it has several beds

page_text: placed one over the other, the lower bed only has a fire to heat the mineral
at the commencement of the operation and to maintain the furnace throughout
at a suitable temperature. Openings are made to allow of the vapour of
water being introduced into the several compartments which facilitates the
sulphatation and renders it much more rapid. The jet of steam also furnishes
a means of regulating at will the temperature of the furnace, and of main-
taining constantly on each bed the degree of heat which is most suitable for
it; the introduction of steam in this manner will be found very useful, and it
forms an important part of our process.
On examining the Drawings it will be seen that we substitute as it were a
group of small furnaces for the colossal furnaces which are now employed in
the roasting of minerals.
It has the advantage (partly in consequence of its form and also because
we work at a comparatively low temperature) not to require in its construction
materials of the first quality nor very skilful workmanship; this renders its
construction and repair much easier and more economical; it offers also a
more considerable advantage in that it renders the labour of the workman
less severe, and further it permits of the time during which the working doors
are kept open for emptying the furnace and raking over the material being
much reduced, so that without any inconvenience the material may be much
more frequently raked, which is very useful, especially on the upper bed where
the mineral freshly charged in has a tendency to agglomerate when it is very
sulphurous, an inconvenience which can only be remedied by very frequent
rakings.
The Invention then to which our Patent applies consists not only in the
separate employment of the processes which we have set forth, and of which
the most novel and important is the transformation of the sulphate into
the hydrochlorate, a transformation which renders possible and commercially
practicable the precipitation (attended with the complete separation of all
injurious substances) of metallic oxide by means of lime; but it consists
especially of the combined employment of several of these operations to obtain
a new result, to obtain at a small cost by precipitation metallic oxides in a
state of great purity, that is to say, separated from earthy matter and com-
pletely free from arsenic, antimony, phosphorous, and other matters which
injure the quality of the metal.
Our Invention also consists in the employment of a furnace with a porous
bed, through which air or the vapour of water is passed, which in permeating
amongst the mineral placed upon the bed converts the metals into sulphates,
or in the employment of a reverberatory furnaco with several beds placed the

page_text: one above the other, in the manner shown in the Drawing, and separated into
a number of compartments or little furnaces, which renders the labour of the
workman easier; it consists also in the employment which is made of the
vapour of water; it consists also when the minerals contain sulphuret of iron
in producing during the process sulphate of iron, which is again decomposed
during and especially near the end of the operation, and yields an oxide of
iron in a very fine state of division, and which may be used in place of
minium in painting, or may be otherwise usefully employed.
We would add to the description already given that as the first operation
of this process consists in the production of sulphate of the metal which it is
desired to obtain, the first thing to be done when the mineral does not
contain sufficient sulphur is to add it by mixing any very sulphurous mineral,
may be iron pyrites; also when from any cause whatever the mineral has
not been completely sulphated in the roasting it is necessary to complete the
sulphatation of the insoluble residue by treating it with a little sulphuric acid;
this will occasion a very slight expense, because the oxide of iron which
results from the decomposition of the sulphate of that metal having but very
slight affinity for the acid the other oxide will be attacked in preference, and
the quantity of acid employed to complete the sulphatation will always be
quite small.
In witness whereof, we, the said Paul Emile de Wissocq and Louis
Count Krasinski, have hereunto set my hand and seal, this Twenty-
fifth day of May, in the year of our Lord One thousand eight hundred
and sixty-seven.