AN IMPROVED PROCESS FOR THE DIRECT EXTRACTION OF lODINE FROM SEA-WRACK AND SEA-WEED
Year: 1879

page_text: LETTERS PATENT to Edgar Edmonds, of the Firm of Robertson, Brooman, and
Company, of 166, Fleet Street, in the City of London, Patent Agents, for
the Invention of "AN IMPROVED PROCESS FOR THE DIRECT EXTRACTION OF
lODINE FROM SEA-WRACK AND SEA-WEED." A cominunication from abroad
by Firmin Jullien, of Lorient, Morbihan, Franco, Merchant.
Sealed the 8th June 1880, and dated the 9th December 1879.
PROVISIONAL SPECIFICATION left by the said Edgar Edmonds at the Office
of the Commissioners of Patents on the 9th December 1879.
EDGAR EDMONDS, of the Firm of Robertson, Brooman, and Company, of 166,
Fleet Street, in the City of London, Patent Agents.
"AN IMPROVED PROCESS
FOR THE DIRECT EXTRACTION OF IODINE FROM SEA-WRACK AND SEA-WEED."
(A communication from abroad by Firinin Jullien, of Lorient, Morbihan, France,
Merchant.)
The object of this Invention is a process for the extraction of the iodine from
sen-wrack and sea-weed either in a green state, a dry state, or when burnt to
ashes, without the necessity of elimination of the salts by the evaporation of the
waters or solutions resulting from lixiviation.
This mode of direct extraction consists essentially in treating the waters resulting
from the lixiviation of the sea-wrack with sulphate of copper and sulphate of iron
so as to precipitate the alkaline iodides in the form of insoluble iodide of copper,
and to submit the precipitate thus obtained to distillation.
Such is the principle of the treatment, the different phases of which will now be
explained.
Firstly. The sea-wrack or its ashes are first exhausted by the displacement
method with cold water. The sea-wrack is thrown onto screens or gratings in
tanks or receivers into which water is introduced by channels.
These tanks or receivers communicate with each other by a conduit and cock
which allows the passing of the waters or solutions from one tank to the other for
concentrating the solution.
Secondly. The lixiviation waters or solutions are approximately tested by
ascertaining their density, and they are then mixed with each other in another
tank or receiver.

page_text: Thirdly. In this tank or receiver the alkaline iodides contained in the waters or
solutions are transformed into insoluble iodides of copper by the admixture of
two parts of sulphate of copper and three parts of sulphate of iron for one part of
iodine.
The precipitate formed by this double decomposition is allowed to settle for one
or two hours, after which the supernatent waters which are deprived of all trace
of iodine are drawn off. The decantation is facilitated by cocks placed at different
heights above the channel or conduit which conducts the waters away.
remaining precipitate, which is in the form of sediment, is collected into a kind
of pit.
The
Fourthly. From there the sediment is pumped into small vats containing about
one cubic metre, in which the sediment rests on screens or gratings provided
with cloth; this produces a kind of filtration which removes the excess of water in
the mass.
Fifthly. This mass is then carried to the retorts of a distilling furnace.
This furnace as regards its hearth and its retorts is similar in arrangement to a
gas furnace. Under the action of the heat and by the effects of calcination, without
having recourse to any reagent, all the iodine is distilled and is deposited in con-
densation chambers, which communicate with the retorts; the insides of these
chambers are lined with faience or china tiles, and the upper part is composed of
panes of glass joined together by pasted or glued paper, and which may be easily
removed for the purpose of scraping off and obtaining the iodine deposited.
The reactions which take place during the calcination are the following:-
Sulphuric acid is produced at the expense of the sulphate of iron; the sulphuric
acid acts on the iodide of copper forming sulphate of copper and thus sets free the
iodine. It is only necessary to lixiviate the calcined residue to recover a con-
siderable quantity of deposited sulphate of copper.
In the process or treatment just explained the soluble salts of soda and potash
are lost, being carried away by the decantation of the waters, but these waters
may be treated for the extraction of the salts by the ordinary processes.
With very slight modifications the above described process is applicable to the
extraction of bromine. Instead of throwing away the supernatent waters in the
decomposing tank or receiver, the waters are in this case directed into another
vat and subjected to a current of chlorine. A solution of sulphate of copper and iron
is added to form insoluble bromide of copper which is treated by calcination in the
same way as in the preceding process.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edgar Edmouds in the Great Seal Patent Office on the 9th June
1880.
EDGAR EDMONDS, of the Firm of Robertson, Brooman, and Company, of 166,
Fleet Stroot, in the City of London, Patent Agents.
AN IMPROVED PROCESS FOR
THE DIRECT EXTRACTION OF IODINE FROM SEA-WRACK AND SEA-WEED." (A coin-
munication to me from abroad by Firmin Jullien, of Lorient, Morbihan, France,
Merchant.)
The object of this Invention is a process for the extraction of the iodine from
sea-wrack and sea-weed either in a green state, a dry state, or when burnt to ashes,
without the necessity of elimination of the salts by the evaporation of the waters or
solutions resulting from lixiviation. This mode of direct extraction consists
essentially in treating the waters resulting from the lixiviation of the sea-wrack
with sulphate of copper and sulphate of iron so as to precipitate the alkaline
iodides in the form of insoluble iodide of copper and to subinit the precipitate
thus obtained to distillation.
Such is tho principle of the treatment, the different phases of which will now be
explained with reference to the annexed Drawing, which represents in section the
apparatus employed.
Firstly. The sea-wrack or its ashes are first exhausted by the displacement
method with cold water. The sea-wrack is thrown onto screens or gratings in
tanks or receivers A and B, into which water is introduced by channels a, a, b, b.
These tanks or receivers communicate with each other by a conduit and cock C
which allows the passing of the waters or solutions from one tank to the other
for concentrating the solution.
The ashes may also be exhausted by displacement by operating in a large number
of vats, the bottoms of which are pierced with numerous holes, the said vats being
placed above a large cemented basin or tank.
Secondly. The lixiviation. waters or solutions are approximately tested by
ascertaining their density, and they are then mixed with each other in the
decomposing tank or receiver D.
Thirdly. In this tank or receiver the alkaline iodidles contained in the waters
or solutions are transformed into insoluble iodides of copper by the admixture of
two parts of sulphate of copper and three parts of sulphate of iron for one part
of iodine.
The precipitate formed by this double decomposition is allowed to settle for one
or two hours, after which the supernatent waters which are deprived of all trace
of iodine are drawn off. The decantation is facilitated by the cocks d, d, d, placed
at different hoights above the channel or conduit E which conducts the waters
away. The remaining precipitate which is in the form of sediment is collected
into a kind of pit F.
Fourthly. From there the sediment is pumped by a pump G into small vats
H, H, containing about one cubic metre, in which the sediment rests on screens or
gratings provided with cloth, this produces a kind of filtration which removes the
excess of water in the mass.
Fifthly. This mass is then carried to the retorts of a distilling furnace I. This
furnace, as regards its hearth and its retorts, is similar in arrangement to a gas
furnace. Under the action of the heat and by the effects of calcination without
having recourse to any reagent, all the iodine is distilled and is deposited in the
condensation chambers K, K, which communicate with the retorts. The insides of
these chambers are lined with "faience" or china tiles, and the upper part is
composed of panes of glass joined together by pasted or glued paper and which

page_text: may be easily removed for the purpose of scraping off and obtaining the iodine
deposited.
The reactions which take place during the calcination are the following:-
Sulphuric acid is produced at the expense of the sulphate of iron; the sulphuric
acid acts on the iodide of copper forming sulphate of copper and thus sets free the
iodine. It is only necessary to lixiviate the calcined residue to recover a con-
siderable quantity of deposited sulphate of copper.
In the process or treatment just explained the soluble salts of soda and potash
are lost, being carried away by the decantation of the waters, but these waters may
be treated for the extraction of the salts by the ordinary processes.
With very slight modifications the above described process is applicable to the
extraction of bromine. Instead of throwing away the supernatent waters in the
decomposing tank or receiver the waters are in this case directed into another vat
and subjected to a current of chlorine. A solution of sulphate of copper and iron is
added to form insoluble bromide of copper which is treated by calcination in the
same way as in the preceding process.
The liberation of the iodine vapours which are disengaged in the retorts may be
facilitated by arranging an extractor on the bottom which exhausts or withdraws
the vapours in the retorts or drives them into the condensing chambers.
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 on behalf of my foreign
correspondent, the process herein before described for the direct extraction of the iodine
from sca-wrack and sea-weed without the necessity, as at present, of the previous
elimination of the salts by the evaporation of the lixiviating waters, the said
process being characterized by the combination of the operations hereinbefore
described with reference to the annexed Drawings, of which the three following are
the principal:-
First. The exhaustion of the sea-wrack and sea-weed by the displacement
method.
Secondly. The precipitation in the form of iodide of copper of the ioduretted
salts contained in the solutions by means of a mixed solution of sulphate of copper.
and sulphate of iron; and
Thirdly. The distillation of these precipitates in a retort furnace for the collection
or recovery of the iodine, as hereinbefore described.
In witness whereof, I, the said Edgar Edmonds, have hereunto set my hand
and seal, this Eighth day of June, One thousand eight hundred and eighty.
EDGAR EDMONDS. (L.S.)