IM- PROVEMENTS IN THE MANUFACTURE OF BICHROMATE OF POTASH, AND IN THE MANUFACTURE OF IODINE AND BROMINE.
Year: 1875

page_text: LETTERS PATENT to Christian Heinzerling, of Glasgow, in the
County of Lanark, North Britain, for the Invention of "IM-
PROVEMENTS IN THE MANUFACTURE OF BICHROMATE OF POTASH, AND IN THE
MANUFACTURE OF IODINE AND BROMINE.'
"
PROVISIONAL SPECIFICATION left by the said Christian Heinzerling
at the Office of the Commissioners of Patents, with his Petition,
on the 28th July 1875
I, CHRISTIAN HEINZERLING, of Glasgow, in the County of Lanark,
North Britain, do hereby declare the nature of the said Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF BICHROMATE OF POTASH, AND IN
THE MANUFACTURE OF IODINE AND BROMINE," to be as follows, that is to
say:-

page_text: The chrome ore, and from twice to four times its weight of lime are
both pulverised and intimately mixed. Or instead of lime magnesia may
be used, or magnesian limestone, or the native carbonate of magnesia
known as magnesite, or sulphate of magnesia, or kieserite, or any other
convenient salt or compound of magnesia; or magnesia or its said salts
or its compounds may be used together with lime The infusibility of
magnesia and some of its salts is one reason why I use it, but the use
of the sulphite of magnesia has the recommendation of assisting the
oxidation of the chromic oxide into chromic acid or chromates
Thero may also be used instead of lime or magnesia, or together with
these substances, sulphur compounds of lime, such as "vat wasto,"
'gas lime," and "tank waste," the employment of which is -advan--
tageous for the reasons herein-after mentioned.
66
The pulverised mixture composed under either of the modes herein-
before set forth is moistened, and then highly heated for from 6 to 9
hours in a reverberatory furnace with an oxidising fire. After being
withdrawn from the furnace, the calcined mass is reduced to powder
and intimately mixed with ground kelp in the proportion of from three
to six parts by weight of kelp to one part by weight of the chrome ore
originally used in forming the calcined mixture. This mixture of kelp
with the calcined materials is heated in the furnace for from one hour
to an hour and a half. Tho temperature should be kept low during
this operation, not rising above a dull red heat in the mixture, in order
to avoid fusion of the material and loss of iodine or bromine by
volatilization. The mass after cooling is lixiviated, and the liquor
holding the soluble salts is run off from the deposit of lime, magnesia,
and other insoluble substances, which will settle down.
The bichromate of potash and the sulphates and other salts are
afterwards separated from the liquor under either of the following
modes:-
First. Sulphuric or other suitable acid may be added to the liquor
and the bichromate of potash obtained by crystallization in the first
instance, after which the sulphates and chlorides are separated in the
ordinary way by alternate evaporation and cooling.
Or, Secondly. The greater part of the sulphates and chlorides may be
separated in the first instance, and then, by addition of sulphuric or

page_text: other suitable acid to the mother liquor bichromate of potash is
obtained by crystallization. The quantity of sulphuric or other acıd
added in either case must not exceed what is necessary to convert the
neutral chromate into bichromate Such quantity may be ascertained
by determining the amount of chromic acid present in a small quantity
of the liquor, and from that calculating the requisite amount of acid to
be used. The mother liquor thus exhausted of the greater portion of
the salts which it contained is afterwards either distilled with the
addition of a sufficient quantity of sulphuric or other suitable acid to
liberate the iodine and bromine in the usual way, or the iodine and
bromine may be separated by precipitation according to any known
method.
It is not necessary to use peroxide of manganese along with the acid
before distilling, because there remains in the mother liquor a certain
quantity of bichromate of potash which cannot practically be entirely
crystallized out, and that serves as a substitute for the peroxide of
manganese as an oxidising agent.
I find that the alkaline sulphides, sulphites, and byposulphites which
are present, more or less, in all kelp exert a very beneficial influence in
promoting the conversion of chromic oxide into chromic acid by their
sulphur combining with the iron and setting the alkaline bases free so
as to induce the formation of chromates; the carbonates present in tho
kelp have also a similar influence through the libcration of their bases
by the expulsion of their carbonic acid. In this way that portion of
the chrome ore which escapes oxidation by roasting with lime is now
entirely or almost entirely oxidised by the action of the salts of the
kelp. For the same reason, in the first calcination of the chrome ore it
is advantageous to use the waste product of alkah manufactures known
as "vat waste" or the "tank waste" of gas manufacture in such pro-
portions as will present in the sulphides and other sulphur salts of
which these waste materials largely consist, sulphur in sufficient
quantity to the iron.
The decomposition of the sulphides, sulphites, hyposulphites, and
carbonates of the kelp by the chrome ore is also advantageous in the
subsequent production of iodine and bromine, as no use of sulphuric
acid is required beyond what is necessary to liberate the hydroiodic or
hydrobromic acid.
'

page_text: tr
The residues of lixivation contain a considerable proportion of pre-
cipitated sesquioxide of iron, which may be easily separated for use as
purple ore" where magnesia or any of its salts has been used instead
of lime. These residues also contain silicates of the alkalis, sulphate,
and oxide of lime, magnesia, and other substances besides the iron, and
may be utilised, whether the oxide of iron is separated from them or
not, as a flux in smelting iron ore, as a material for manufacturing
common bottle glass, as manure, or for other purposes.
If the kelp used be very poor in iodine and contain (as in that case it
generally will) a large quantity of the alkaline salts, particularly
sulphides, sulphites, and hyposulphites, it may be used without lime for
the production of bichromate of potash. But a higher temperature
than is herein-before set forth as applied to the kelp mixture is required
in order to oxidise the chrome orc in this case, and this might occasion
loss of iodine and bromine. I therefore do not recommend the
treatment of chrome ore with kelp alone, and without the previous
calcination of it with lime or-magnesia, especially if the production_of
iodine and bromine be an object. But the use of kelp, and especially of
kelp which is cheap because it is poor in iodine and bromine, and which
would not be chosen for the production of iodine and bromine, is found
very useful in the production of bichromate of potash, though it does
not yield or is not used for yielding iodine or bromine at all.
It is to be understood that besides kelp prepared in the ordinary
way the product obtained by treating seaweed with superheated
steam is included under the name of kelp for the purposes of this
Invention.
Instead of using kelp in the manner hercin-before described the
ashes of burned wood and other vegetable matters may be employed,
their liability to fuse the materials with which they are mixed when at
high temperatures being guarded against by keeping the temperature
below fusing point. This piccaution also applies to the use of kelp,
but it is found that both kelp and wood ashes may be used at tem-
peratures which, though below the fusing point, are still much higher,
than will occasion loss if the ultimate production of iodine or bromine
is an object in the manufacture, and they may therefore be employed
as a substitute for lime and magnesia, in which case the materials arc
submitted only once to the heat of the furnace.

page_text: The prior calcination with lime or magnesia at a high temperature,
and the subsequent treatment at a lower temperature wth kelp or wood
ashes is, however, the process preferred to be employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Christian Heinzerling in the Great Scal Patent
Office on the 21st January 1876
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHRISTIAN
HEINZERLING, of Glasgow, in the County of Lanark, North Britain,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of July, in
the year of our Lord One thousand eight hundred and seventy-
five, in the 39th year of Her reign, did for Herself, Her heirs and
successors, give and graut unto me, the said Christian Heinzerling, Her
special license, that 1, the said Christian Heinzerling, my executors,
administrators, and assigns, or such others as I, the said Christian
Heinzerling, my executors, administrators, or 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 BICHROMATE OF
POTASH, AND IN THE MANUFACTURE OF IODINE AND BROMINE," upon the
condition (amongst others) that I, the said Christian Heinzerling, by
an instrument in writing under my hand and seal, 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 Christian Heinzerling, 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, that is to say.
My said Invention has for its object to combine the manufacture of

page_text: Or, Secondly. The greater part of the sulphates and chlorides may be
separated in the first instance, and then by addition of sulphuric or
other suitable acid to the mother liquor bichromate of potash is obtained
by crystallization. The quantity of sulphuric or other acid added in
either case must not exceed what is necessary to convert the neutral
chromate into bichromate; such quantity may be ascertained by deter-
mining the amount of chromic acid present in a small quantity of the
liquor, and from that calculating the requisite amount of acid to be
used The mother liquor thus exhausted of the greater portion of the
salts which it contained is afterwards either distilled with the addition
of a sufficient quantity of sulphuric or other suitable acid to liberato
the iodine and bromine in the usual way, or the iodine and bromine may
be separated by precipitation according to any known method.
It is not necessary to use peroxide of manganese along with the acid
before distilling because there remains in the mother liquor a certain
quantity of bichromate of potash which cannot practically be ontirely
crystallized out, and that serves as a substitute for the peroxide of
manganese as an oxidising agent.
I find that the alkaline sulphides, sulphites, and hyposulphites which
are present, more or less, in all kelp exert a very beneficial influence
in promoting the conversion of chromic oxide into chromic acid by
their sulphur combining with the iron and setting the alkaline bases freo
so as to induce the formation of chromates; the carbonates present in
the kelp have also a similar in influence through the liberation of their
bases by the expulsion of their carbonic acid. In this way that portion
of the chrome ore which escapes oxidation by roasting with lime is now
entirely or almost entirely oxidised by the action of the salts of the
kelp. For the same reason in the first calcination of the chrome ore
it is advantageous to use the waste product of alkalı manufactures
known as "vat waste," or the "tank waste" of gas manufacture in
such proportions as will present in the sulphides and other sulphur
salts of which these waste materials largely consist sulphur in sufficient
quantity to the iron.
The decomposition of the sulphides, sulphites, hyposulphites, and
carbonates of the kelp by the chrome ore is also advantageous in the
subsequent production of iodine and bromine, as no use of sulphuric acid
is required beyond what is necessary to liberate the hydroiodic or hydro-
bromic acid.

page_text: The residues of lixivation contain a considerable proportion of pre-
cipitated sesqui-oxide of iron, which may be easily separated for use as
purple ore, where magnesia or any of its salts has been used instead of
lime. These residues also contain silicates of the alkalis, sulphate and
oxide of lime, magnesia and other substances besides the iron, and may
be utilised, whether the oxide of iron is separated from them or not, as a
flux in smelting iron ore, as a material for manufacturing common
bottle glass, as manure, or for other purposes.
If the kelp used be very poor in iodine, and contain (as in that case
it generally will), a large quantity of the alkaline salts, particularly
sulphides, sulphites, and hyposulphites, it may be used without lime for
the production of bichromato of potash. But a higher temperature than
is herein-before set forth as applied to the kelp mixture is required in
order to oxidise the chrome ore in this case, and this might occasion loss
of iodine and bomine. I therefore do not recommend the treatment of
chrome ore with kelp alone, and without the previous calcination of
it with lime or magnesia, especially if the production of iodine and bro-
mine be an object. But the use of kelp, and especially of kelp which is
cheap, because it is poor in iodine and bromine, and which would not
be chosen for the production of iodine and bromine is found very useful
in the production of bichromate of potash, though it does not yield or is
not used for yielding iodine or bromine at all.
It is to be understood that besides kelp prepared in the ordinary way
the product obtained by treating sea weed with superheated steam is
included under the name of kelp for the purposes of this Invention.
Instead of using kelp in the manner herein-before described the ashes
of burned wood and other vegetable matters may be employed, their
liability to fuse the materials with which they are mixed when at high
temperatures being guarded against by keeping the temperature below
fusing point. This precaution also applies to the use of kelp, but it is
found that both kelp and wood ashes may be used at temperatures wluch,
though below the fusing point, are still much higher than will occasion
loss if the ultimate production of iodine or bromine is an object in the
manufacture, and they may therefore be employed as a substitute for
lime and magnesia, in which case the materials are submitted only once
to the heat of the furnace.
The prior calcination with lime or magnesia at a high temperature,

page_text: and the subsequent treatment at a lower temperature with kelp or wood
ashes, is however the process preferred to be employed.
Having now described and particularly ascertained the nature of my
said Invention, and the system, mode, or manner in or under which
the same is or may be used or practically carried into effect, I would
observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the hercin-before
in part recited Letters Patent is,-
First. Combining the manufacture of bichromate of potash with the
manufacture of iodine and bromine, as herein-before described.
Second. The employment of magnesia and salts of maguesia instead
of or together with lime in the roasting of chrome oro in the said com-
bined manufacture, as herein-before described
Thurd. The use of kelp salts to complete the oxidation into chromic
acid of that portion of the chromic oxide, which is not oxidised by the
lime in the ordinary procoss, and the employment of kelp in the place of
lime, as herein-before described.
Fourth. The employment of chrome ore to decompose the sulphides,
sulphites, hyposulphites, and carbonates of kelp, which are in the
ordinary process of making iodine and bromine decomposed by sulphuric
or other acid before the iodine or bromine is obtained by distillation, as
herein-before described.
"
Fifth. Mixing the chrome ore with "vat waste" or gas waste"
instead of or together with lime or magnesia or compounds of magnesia
previous to roasting or calcination, as hercin-before described, in the
aforesaid combined manufacture.
Sixth The employment of the ashes of burned wood or other vegetable
matters instead of kelp in the said combined manufacture or in the
manufacture of bichromate of potash, as herein-before described.
In witness whereof, I, the said Christian Heinzerling, have here-
unto set my hand and seal, this Seventeenth day of January
One thousand eight hundred and seventy-six.
ΑΥΤΑ ΤΑΜΤ
•
CHRISTIAN HEINZERLING. (L.S.)