IMPROVEMENTS IN THE MANUFACTURE OF IODIDE of POTASSIUM AND OF BROMIDE OF POMAGGIE
Year: 1872

page_text: LETTERS PATENT to Edward Sonstadt, of Ramsey, Isle of Man, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF IODIDE of
POTASSIUM AND OF BROMIDE OF POMAGGIE"
Sealed the 8th October 1872, and dated the 10th April 1872.
PROVISIONAL SPECIFICATION left by the said Edward Sonstadt at
the Office of the Commissioners of Patents, with his Petition, on
the 10th April 1872.
I, EDWARD SONSTADT, of Ramsey, Isle of Man, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF IODIDE OF POTASSIUM AND OF BROMIDE OF POTASSIUM," to be as follows:-
I free the mother liquors resulting from the treatment of seaweed
or of kelp from organic matter by first melting the same, then dissolving
in water, and separating carbon and insoluble impurities by filtration
or decantation. If the solution contain sulphides it should be boiled
with lime, taking care not to continue the boiling after the sulphides
have disappeared from the solution. Sufficient caustic or carbonated

page_text: alkali, preferably soda, is added to bring the proportion of free alkali
in the liquid up to five atoms for each atom of iodide of potassium or
of sodium present in the liquid if the alkali used is caustic, or if
carbonated alkali is used, up to ten atoms, and proportionably if a
mixture of caustic and carbonated alkali is employed. Chlorine is then
passed through the liquid until the iodide present is oxidised into iodate,
when a solution of a soluble barium salt, preferably chloride, is added
as long as a precipitate forms, or in sufficient quantity to precipitate the
whole of the iodic and sulphuric acids present as iodate and sulphate
of barium. This precipitate after proper washing is digested best hot
with solution of sulphate of potassium taken in sufficient quantity to
decompose the iodate of barium. When the reaction is complete the
solution of iodate of potassium thus obtained is decanted or filtered
from the precipitate and boiled down to dryness, or, if preferred, the
iodate may be crystallized out by successive boilings and crystallizations,
and the resulting iodate is heated sufficiently to form iodide of potassium,
charcoal, sawdust, or other like matter being added towards the end of
the operation, if desired, to ensure complete decomposition. The melted
iodide may then be dissolved and crystallized in the usual way to obtain
pure crystallized iodide.
Permanganate of sodium or of potassium, or a hypochlorite, such as
bleaching powder, may be used in place of chlorine to oxidise the iodide
in the mother liquors into iodate, taking care that sufficient alkali is
present to prevent separation of iodine. If permanganate is used the
decanted or filtered solution containing the iodate may be precipitated
by a barium salt as before, but if bleaching powder is used a difficultly
soluble iodate of calcium is formed mixed with lime and carbonate of
calcium, which mixture may be treated, though less advantageously
than the barium salt, by sulphate of potassium at boiling heat. Car-
bonate of potassium may replace, if desired, the sulphate either in
treatment of the calcium or barium iodate, but the use of pure sulphate
of potassium is much to be preferred.
The iodide in the liquors may also in presence of alkali be transformed
into iodate by a current of electricity, applied as is usual in electrolysis,
but I do not find this method applicable to the formation of bromates.
The iodide in the mother liquors may also be oxidised by boiling the
liquors down with an atom of chlorate of sodium or of potassium for
cach atom of iodide present, and heating the dried mass carefully until

page_text: the iodide is oxidised, taking care not to carry the heat high enough
to decompose the iodate when that is once formed. The mass may then
be dissolved and treated as described. When the oxidation is directly
effected in this manner no alkali need be added to the mother liquor,
which should however be first freed from sulphides.
After the mother liquors have been freed from iodine by the transfor-
mation of the iodides into iodates and separation of the iodic acid as
described, the filtered or decanted liquid may be treated to obtain
bromide of potassium in like manner, except that the permanganate
process is not applicable, since the bromide of an alkali metal, unlike
the iodide, is not oxidised into an oxygen salt by permanganic acid in
presence of excess of alkali, neither as already stated is the process by
an electric current applicable. Also it must be mentioned that whether
an alkali or calcic bromate is first formed the bromic acid should in
either case be precipitated by a soluble barium salt, the bromate of
barium being decomposed by solution of sulphate of potassium in like
manner as described for the iodate and the resulting bromate of potassium
decomposed by heat, also in like manner as described for the iodate.
Although only the mother liquors derived from seaweed have been
referred to yet the process may be modified to suit the case of any
commercial products containing iodine or bromine or both.
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said Edward
Sonstadt in the Great Seal Patent Office on the 30th October
1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
SONSTADT, of Ramsey, Isle of Man, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of April, in the year of our
Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Edward Sonstadt, Her special licence
that I, the said Edward Sonstadt, my exccutors, administrators, and
assigns, or such others as I, the said Edward Sonstadt, my executors,

page_text: 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 IODIDE OF POTASSIUM AND OF BROMIDE OF POTASSIUM,"
upon the condition (amongst others) that I, the said Edward Sonstadt,
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 Edward Sonstadt, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement :-
I free the mother liquors resulting from the treatment of seaweed
or of kelp from organic matter by first melting the same, then dissolving
in water, and separating carbon and insoluble. impurities by filtration or
decantation. If the solution contains sulphides it should be boiled
with lime, taking care not to continue the boiling after the sulphides
have disappeared from the solution. Sufficient caustic or carbonated
alkali, preferably soda, is added to bring the proportion of free alkali
in the liquid up to five atoms for each atom of iodide of potassium or
of sodium present in the liquid if the alkali used is caustic, or if car-
bonated alkali is used up to ten atoms, and proportionably if a mixture
of caustic and carbonated alkali is employed. Chlorine is then placed
through the liquid until the iodide present is oxidised into iodate, when
a solution of a soluble barium salt, preferably chloride, is added as long
as a precipitate forms, or in sufficient quantity to precipitate the whole
of the iodic and sulphuric acids present as iodate and sulphate of
barium. This precipitate after proper washing is digested best hot
with solution of sulphate of potassium taken in sufficient quantity to
decompose the iodate of barium. When the reaction is complete the
solution of iodate of potassium thus obtained is decanted or filtered
from the precipitate and boiled down to dryness, or if preferred the
iodate may be crystallized, out by successive boilings and crystalli-

page_text: zations, and the resulting iodate is heated sufficiently to form iodide of
potassium, charcoal, sawdust, or other like matter being added towards
the end of the operation if desired to ensure complete decomposition.
The melted iodide may then be dissolved and crystallized in the usual
way to obtain pure crystallized iodide.
Permanganate of sodium or of potassium or a hypochlorite, such as
bleaching powder, may be used in place of chlorine to oxidise the
iodide in the mother liquors into iodate, taking care that sufficient
alkali is present to prevent separation of iodine. If permanganate is
used the decanted or filtered solution containing the iodate may be pre-
cipitated by a barium salt as before, but if bleaching powder is used
a difficultly soluble iodate of calcium is formed mixed with lime and
carbonate of calcium, which mixture may be treated though less advan-
tageously than the barium salt by sulphate of potassium at boiling
heat. Carbonate of potassium may replace if desired the sulphate,
either in treatment of the calcium or barium iodate, but the use of pure
sulphate of potassium is much to be preferred.
The iodide in the liquors may also in presence of alkali be transformed
into iodate by a current of electricity applied as is usual in electro-
lysis. But I do not find this method applicable to the formation of
bromates.
The iodide in the mother liquors may also be oxidised by boiling the
liquors down with an atom of chlorate of sodium or of potassium for
each atom of iodide present, and heating the dried mass carefully until
the iodide is oxidised, taking care not to carry the heat high enough to
decompose the iodate when that is once formed. The mass may then
be dissolved and treated as described. When the oxidation is directly
effected in this manner no alkali need be added to the mother liquor,
which should however be first freed from sulphides.
After the mother liquors have been freed from iodine by the trans-
formation of the iodides into iodates, and separation of the iodic acid
as described, the filtered or decanted liquid may be treated to obtain
bromide of potassium in like manner, except that the permanganate
is not applicable since the bromide of an alkali metal unlike the iodide
is not oxidised into an oxygen salt by permanganic acid in presence
of excess of alkali, neither as already stated is the process by an electric
current applicable. Also it must be mentioned that whether an alkali
or calcic bromate is first formed the bromic acid should in cither case

page_text: as
be precipitated by a soluble barium salt, the bromate of barium being
decomposed by solution of sulphate potassium in like manner
described for the iodate, and the resulting bromate of potassium decom-
posed by heat also in like manner as described for the iodate.
Although only mother liquors derived from seaweed have been referred
to, yet the process may be modified to suit the case of any commercial
products containing iodine or bromine, or both.
Having now described and particularly set forth the nature of this
Invention, and the manner in which the same is or may be carried into
effect, I would observe in conclusion that I do not confine or restrict
myself to the precise details or arrangements which I have described or
referred to, as variations may be made therefrom without deviating from
the principles or main features of this Invention; but what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is, the manu-
facture of iodide of potassium and of bromide of potassium, substantially
as herein described.
In witness whereof, I, the said Edward Sonstadt,, have hereunto
hand and seal, this Ninth day of October, in the. year of
our Lord One thousand eight hundred and seventy-two.
set
my