IMPROVEMENTS IN THE MANUFACTURE OF THE SALTS, CAR- BONATES, AND HYDRATES OF BARYTA AND STRONTIA, AND ALSO FOR IMPROVED MODES OF MAKING BARYTA AND STRONTIA CAUSTIC
Year: 1874

page_text: LETTERS PATENT to Edward Thomas Hughes, of the Firm of Hughes
and Son, Patent Agents, 123, Chancery Lane, London, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF THE SALTS, CAR-
BONATES, AND HYDRATES OF BARYTA AND STRONTIA, AND ALSO FOR IMPROVED
MODES OF MAKING BARYTA AND STRONTIA CAUSTIC."-A communication
from abroad by Louis Gustave Ghilain Daudenart and Edmond
Verbert. of 34. Rue du Progrès. Schaerbeek. Brussels.
PROVISIONAL SPECIFICATION left by the said Edward Thomas Hughes
at the Office of the Commissioners of Patents, with his Petition, on
the 13th March 1874.
I, EDWARD THOMAS HUGHES, of the Firm of Hughes and Son;
Patent Agents, 123, Chancery Lane, London, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF THE SALTS, CARBONATES, AND HYDRATES OF BARYTA AND STRONTIA, AND ALSO FOR
IMPROVED MODES OF MAKING BARYTA AND STRONTIA CAUSTIC," being a com-

page_text: '
1
The chlorides of barium and strontium whether obtained by one of the
following ordinary methods:-First, by the action of hydrocloric acid
on the carbonates of baryta and strontia in their natural state; secondly,
by the action of the same acid on the sulphurets of barium and
strontium procured by the decomposition of the sulphates of these bases
by carbon; thirdly, by the reciprocal action, indicated by Mons". Kuhl-
mann, between the sulphates of baryta or strontia carbon and the
chloride of manganese, or by any other method by which they are
dissolved in water to 12 or 15 degrees Baumé. The solution thus
obtained, whether the chloride of barium or the chloride of strontium, is
mixed with hydrate of magnesia in any suitable apparatus which can
be afterwards closed. This mixture is kept in continual agitation in the
closed apparatus, and subjected to the action of a current of carbonic
acid, which gas is absorbed by the magnesia forming a carbonate of this
base. In principle the carbonate of magnesia decomposes the alkaline.
earthy chlorides, but the employment of an excess of carbonic acid
causes the decomposition to be more rapid, and at the same time the
carbonates of the alkaline earths are obtained, especially those of baryta
and strontia, free from carbonate of magnesia, a result that cannot be
.:

page_text: bonic acid, and thus a bicarbonate of magnesia is formed, and besides
this a double decomposition rapidly takes place between the alkaline
earthy chlorides and the bicarbonate of magnesia, carbonate of baryta
is precipitated, the carbonic acid is regenerated, and the liquor holds
in solution chloride of magnesium, as expressed by the following
notation:-
'
CI Bax (CO2) MgO × Aq. = CO² Ba O × CI Mg × CO² × Aq.
Carbonate of magnesia being but little soluble in carbonic acid, or in
other words the solubility in water of the bicarbonate of magnesia being
feeble, it was conceived that the current of carbonic acid should be made
to pass for a much longer time than would be required for the simple
carbonation of magnesia.
It is evident that the carbonation can be effected in any special or
distinct apparatus, and variations of minor importance may be made in
the manipulation, but the process before described is preferred on
account of its simplicity.
In practice the treatment of the alkaline earthy chlorides by magnesia
and carbonic acid should consist of two operations,-.
In the first the magnesia is in excess, which gives when the reaction is
terminated a liquor containing exclusively chloride of magnesium, which
is decanted and a precipitate obtained, consisting of a carbonate of the
alkaline earth and the magnesia employed in excess in a carbonated
state.
In the second operation an excess of alkaline earthy chloride is
found on the precipitate, that is, a quantity of the chloride equal to that
previously used augmented by a little in addition to what is necessary
for the neutralization of the excess of the carbonate of magnesia.
By the action of the carbonic acid the excess of the carbonate of
magnesia is transformed into chloride of magnesium, and is replaced in
the precipitate by an equivalent quantity of carbonate alkaline earth,
the final result being carbonate of baryta and strontia, which is obtained
in a pure state after a series of washings.
The liquor of the second operation is a mixture of chloride of mag-
nesium and of alkaline carthy chloride; the latter being in excess should

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward Thomas Hughes in the Great Seal Patent
Office on the 12th September 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
THOMAS HUGHES, of the Firm of Hughes and Son, Patent Agents,
123, Chancery Lane, London, send greeting.
:
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of March, in the year
of our Lord One thousand cight hundred and seventy-four, `in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Edward Thomas Hughes,
Her special licence that I, the said Edward Thomas Hughes, my
executors, administrators, and assigns, or such others as I, the said
Edward Thomas Hughes, 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 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 "IMPROVEMENTS IN THE MANUFACTURE OF THE
SALTS, CARBONATES, AND HYDRATES OF BARYTA AND STRONTIA, AND ALSO FOR
IMPROVED MODES OF MAKING BARYTA AND STRONTIA CAUSTIC," a communication
to me from abroad by Louis Gustave Ghilain Daudenart and Edmond.
Verbert, of 34, Rue du Progrès, Schaerbeek, Brussels, upon the con--
dition (amongst others) that the said
}
executors or administrators, by an instrument in writing under
or their, or one of their hands and scals, 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 imme-
diately after the date of the said Letters Patent.
·
NOW KNOW YE, that I, the said Edward Thomas Hughes, do hereby
declare. the nature of the said Invention, and in what manner the same

page_text: Hughes' Improvements in Preparations of Baryta and Strontia.
bonic acid, and th
a bicarbonate of magnesia is formed, and besides
this a double decomposition rapidly takes place between the alkalinė
carthy chlorides and the bicarbonate of magnesia carbonate of baryta
is precipitated, the carbonic acid is regenerated, and the liquor holds
in solution chloride of magnesium, as expressed by the following
notation:-
CI Ba + (CO2)2 Mg 0 + Aq. = CO³ Ba O + CI Mg + CO2 + Aq.
Carbonate of magnesia being but little soluble in carbonic acid, or in
other words the solubility in water of the bicarbonate of magnesia being
feeble, it was conceived that the current of carbonic acid should be made
to pass for a much longer time than would be required for the simple
carbonation of magnesia..
It is evident that the carbonation can be effected in any special or
distinct apparatus, and variations of minor importance may be made in
the manipulation, but the process before described is preferred on account
of its simplicity.
To practice the treatment of the alkaline.earthy chlorides by magnesia
and carbonic acid should consist of two operations,-
.
In the first the magnesia is in excess, which gives when the reaction
is terminated a liquor exclusively chloride of magnesium, which is
decanted and a precipitate obtained, consisting of a carbonate of the
alkaline earth and the magnesia employed in excess in a carbonated
state.
In the second operation an excess of alkaline earthy chloride is
found on the precipitate, that is, a quantity of the chloride equal to that
previously used augmented by a little in addition to what is necessary
for the neutralization of the excess of the carbonate of magnesia.
By the action of the carbonic acid the excess of the carbonate of
magnesia is transformed into chloride of magnesium, and is replaced in.
the precipitate by an equivalent quantity of carbonate alkaline earth,
the final result being carbonate of baryta or strontia, which is obtained
in a pure state after a series of washings.
:
The liquor after this second operation is a mixture of chloride of mag-
nesium and of alkaline earthy chloride; the latter being in excess should'
be again used, as it is superior to that employed in the first operation,

page_text: and by means of known reagents and tests it is to be ascertained, first
that the liquor of the alkaline earthy chloride employed the first time
contains only chloride of magnesium when the reaction has terminated;
and, secondly, that the precepitate after the second operation, washed
and dissolved in hydrochloric acid, does not contain any magnesia.
The liquors which only contain chloride of magnesium are con-
centrated by evaporating to 44 or more degrees Baumé, and are then
passed into the crystallizers, or if allowed to cool they become hard
masses, which are broken in picces to remove them, and, as will be seen,
the hydrochloric acid revivifies the magnesia according to the following
It is of importance to remark that the hydrated chloride of magnesium
calcined at a low red heat in a reverbatrory or in crucibles is not
completely decomposed, one-fifth escapes decomposition by the simple
disengagement of a part of the water it contains. Besides, all the
magnesia formed and submitted in this operation to a heat above
300 degrees centigrade is when cold in an unfavorable condition for
absorbing carbonic acid, and it is hydrated with such slowness as to be
incompatible with a rapid revivification, that the whole of our manu-
facture is based.
Hydrated chloride of magnesium submitted to the action of a current
of steam superheated to about 300 degrees centigrade without pressure
becomes completely decomposed, and is in the condition to be rapidly
hydrated and carbonated.
To manufacture caustic baryta and strontia from their carbonates by
our process we mix the carbonate of baryta or strontia with carbon or chalk,
and heat the mixture, whether subjected to the action of superheated
steam or not, in a regenerating or reverbatory furnace, which process is
applicable not only to the carbonates of baryta and strontia manu-
factured as before described, but also to the carbonates of baryta and
strontia in their natural state or produced in any other way, and we also
employ the furnaces for the decomposition of all salts that require a
high temperature, especially the sulphates of baryta and strontia mixed
with carbon. By these means we obtain such a temperature that the
carbonates of baryta and strontia, whether mixed with carbon or sub-

page_text: mitted to the action of superheated steam, are rapidly decomposed with
great facility and therefore economically.
Having thus described the nature of the said Invention, I claim the
improvements in the manufacture of the salts, carbonates, and hydrates
of baryta and strontia, and the improved modes of making baryta and
strontia caustic, substantially as herein described.
'
In witness whereof, I, the said Edward Thomas Hughes, have here-
unto set my hand and seal, this Twelfth day of September,
in the year of our Lord One thousand eight hundred and seventy-
four.
E. T. HUGHES. (L.S.)