IMPROVED PROCESSES FOR THE EXTRACTION OF IODINE
Year: 1873

page_text: LETTERS PATENT to Bristow Hunt, of Serlo Street, Lincoln's Inn,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVED PROCESSES FOR THE EXTRACTION OF IODINE."-A communi-
cation from abroad by Alvaro Francisco Carlos Reynoso, of Paris,
France.
Sealed the 12th August 1878, and dated the 5th March 1873.
PROVISIONAL SPECIFICATION left by the said Bristow Hunt at
the Office of the Commissioners of Patents, with his Petition, on
the 5th March 1878.
I, BRISTOW HUNT, of Serle Street, Lincoln's Inn, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVED PROCESSES FOR THE EXTRACTION OF IODINE" (a com-
munication to me from abroad by Alvaro Francisco Carlos Reynoso, of
Paris, France), to be as follows:-

page_text: mother waters of the treatment of "caliche" in the mother waters of
the purification of American nitrates, and other similar products.
First Process. Firstly acidulate the mixture containing the iodate by
means of sulphuric, nitric, or other acid added in a proportion relative
to the richness in iodate. Then cause an electric current to pass
through the same either by the employment of any electric pile, electro-
magnetic machine, or by other means capable of engendering an electric
current able to decompose the iodinic combination. This electric current
separates the iodide, which is partly precipitated, a small quantity
floats forming very thin scales, and a very slight quantity remains in
solution.
The precipitated iodide is to be separated, and the remaining liquid
agitated with one of the numerous solvents of iodine (such as benzine,
chloroform, sulphuret of carbon, and various volatile oils), and the
iodine may be separated from its solvent by means of evaporation
obtained by heat, or by a current of air, or by refrigeration. Instead of
separating this dissolved iodide the mixture may be agitated with
potash, soda, or other similar agent; and when thought desirable the
mixture of iodide and iodate thus obtained may be calcined in order to
obtain pure iodide.
Second Process. This consists in acidulating the mixture containing
the iodate with sulphuric acid in quantity relative to the proportion of
iodate, and then adding granulated zinc. The iodine is precipitated as
in the process above above described, and all the operations which havo
been described in the preceding case apply equally to this.
Third Process. The mixture is to be slightly acidulated with
sulphuric acid, and a current of sulphurous acid passed through the
same until not only the iodate is converted into iodide, but till a great
excess of sulphurous acid remains. Sulphate of copper is then added,
and thus a precipitate of cuprcous iodide is obtained, which should bo
washed and dried. This cupreous iodide must then be decomposed by
mixing it with oxide of iron, or of manganese, or copper, or simply by
the action of heat in the midst of a current of air, which is kept up
during the whole time of decomposition. Instead of free sulphurous
acid bi-sulphite of soda may be used.
(B.) Two processes for the extraction of the iodine contained in the

page_text: Firstly. Acidulate the mixture with a dose of sulphuric acid propor-
tioned to the richness in iodide, and then cause to pass through the same
an electric current obtained by a pile or by an electro-magnetic machine,
or by any other process. The iodine is in a great measure precipitated,
a small quantity floats, whilst another small quantity remains dis-
solved. The precipitated iodine is separated, and the liquor treated the
same as in cases 1 and 2 of (A).
Secondly. Sulphate of copper is added to the mixture containing the.
iodide, and the whole is then agitated with one of the solvents of iodine
(such as benzine, sulphuret of carbon, chloroform, or other, solvent), in
order to remove the free iodine. These solutions are collected and
treated in the same manner as the iodinic solutions in cases first and
second (A) and first (B).
The precipitate of cupreous iodide is collected, washed, dried, and
decomposed either by mixing with oxides of iron, manganese, copper, or
other oxide, or by simply heating them by an intense fire in the midst
of a current of air.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Bristow Hunt in the Great Seal Patent Office on
the 4th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BRISTOW
HUNT, of Serle Street, Lincoln's Inn, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of March, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Bristow Hunt, Her special license
that I, the said Bristow Hunt, my executors, administrators, and
assigns, or such others as I, the said Bristow Hunt, 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

page_text: Channel Islands, and Isle of Man, an Invention for "IMPROVED PROCESSES
FOR THE EXTRACTION OF IODINE" (a communication to me from abroad by
Alvaro Francisco Carlos Reynoso, of Paris, France), upon the condition
(amongst others) that I, the said Bristow Hunt, my executors 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 Bristow Hunt, do hereby declaro
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 in writing, that is to say:—
This Invention comprises the following processes:-
(A.) Processes for the extraction of the iodine contained in iodates,
applicable to the extraction of the iodine contained in the mother waters
of the treatment of "caliche."
First Process. Firstly acidulate the mixture containing the iodate by
means of sulphuric, nitric, or other acid added in a proportion relativo
to the richness in iodate. Then cause an electric current to pass through
the same either by the employment of an electric pile, electro-magnetic
machine, or by other means capable of engendering an electric current
able to decompose the iodinic combination. This electric current
separates tho iodino, which is partly precipitated, a small quantity floats,
forming very thin scales, and a very slight quantity remains in
solution.
The precipitated iodine is to be separated, and the remaining liquid
agitated with one of the numerous solvents of iodine (such as benzine,
chloroform, sulphuret of carbon, and various volatile oils), and the
iodine may be separated from its solvent by means of evaporation
obtained by heat, or by a current of air. The iodino may also bo
separated by the refrigeration of the solution, in which caso it is
deposited in a crystalized state. Instead of separating this dissolved
iodine the mixture may be agitated with potash or soda, and when
thought desirable the mixture of iodide and iodate thus obtained may
be calcined, in order to obtain pure iodide.

page_text: Second Process. This consists in acidulating the mixture containing
the iodate with sulphuric acid in quantity relative to the proportion of
iodato, and then adding granulated zinc, or stirring with a zino rod.
The iodine is precipitated as in the process above described, and all the
operations which have been described in the preceding case apply
equally to this.
Third Process.-The mixture is to be slightly acidulated with
sulphuric acid, and a current of sulphurous acid passed through the
same until not only the iodate is converted into iodine, but till an
excess of sulphurous acid remains. Sulphate of copper is then added,
and thus a precipitate of cupreous iodide is obtained, which should bo
washed and dried. This cupreous iodide must then be decomposed by
electricity, or by mixing it with ioxide of iron, or of manganese or
copper, and submitting the mixture to the action of heat in a suitable
apparatus, or the cupreous iodide may be decomposed simply by the
action of heat in the midst of a current of air, which is kept up during
the whole time of decomposition. Instead of free sulphurous acid
bi-sulphate of soda may be employed.
Fourth Process.-Firstly reduce a certain part of the iodate into
iodide by means of sulphurous acid or bi-sulphate of soda or potash, and
then mix this iodide with the iodate. The liquors being suitably
acidulated and mixed in proper proportions the iodine is precipitated.
(B.) Processes for the extraction of the iodine contained in the form
of iodide,―
Firstly. Acidulate the mixture with a dose of acid proportioned to
the richness in iodide, and then cause to pass through the same an
electric current obtained by a pile, or by an electro-magnetic machine,
or by any other process. The iodine is precipitated in a small quantity
whilst a large quantity remains dissolved. The precipitated iodine is
separated, and the liquor treated the same as in cases 1 and 2 of
process (A).
Secondly. The iodide is converted into iodate by means of chlorine or
hypochlorites, and the iodate then decomposed by an electric current or
by zinc in liquor acidulated by sulphuric acid.
Thirdly. Sulphate of copper is added to the mixture containing the
iodide, and the whole is then agitated with one of the solvents of iodine

page_text: (such as benzine, sulphuret of carbon, chloroform, or other solvent), in
order to remove the free iodine. Those solutions are collected and
treated in the same manner as the iodinic solutions in cases first and
second (A) and first (B).
The precipitate of cupreous iodide is collected, washed, dried, and 5
decomposed either by mixing with oxides of iron, manganese, copper,
or other oxide, or by (simply heating them by an intense fire in the
midst of a current of air in a suitable apparatus. The cupreous iodide
may also be decomposed by carbonate of potash or caustic potash, in
order to obtain iodide of potassium. It may also be decomposed by 1
electricity.
General Observations.-The solution of iodide in sulphuret of carbon
submitted to a very intense cold produced by a refrigerating mixture, or
by one of the numerous machines used for making ice, deposits the
iodine in a state of perfect crystallization, so that this method constitutes 1
a general process for purifying iodine, whatever may be the process
employed for obtaining it in the crude state. This process is preferable
in all respects to sublimation.
In witness whereof, I, the said Bristow Hunt, have hereunto
set my hand and seal, this Third day of September, in the 2
year of our Lord One thousand eight hundred and seventy-