IM- PROVEMENTS IN THE TREATMENT OF SPENT OXIDE OF IRON ARISING FROM THE PURIFICATION OF GAS OR THE SAID OXIDE WHEN PARTLY SPENT
Year: 1871

page_text: LETTERS PATENT to David Spence, of Manchester, in the County
of Lancaster, Manufacturing Chemist, for the Invention of "IM-
PROVEMENTS IN THE TREATMENT OF SPENT OXIDE OF IRON ARISING FROM THE
PURIFICATION OF GAS OR THE SAID OXIDE WHEN PARTLY SPENT."
Scaled the 30th June 1871, and dated the 19th April 1871.

page_text: sulphate or other salt of iron, and as the oxide is drawn from the puri-
fiers I apply the said solution thereto, a convenient method of effecting
which is to use a hose with an orifice similar to a garden rose. By
this treatment the workman is relieved of the influence of noxious
fumes and the ammoniacal vapour is fixed by the liberated sulphuric 5
acid and becomes sulphate of ammonia.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Spence in the Great Seal Patent Office
on the 19th October 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
SPENCE, of Manchester, in the County of Lancaster, Manufacturing
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of April, One thousand
eight hundred and seventy-one, in the thirty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said David Spence, Her special license that I, the said David Spence,
my executors, administrators, and assigns, or such others as I, the said
David Spence, 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 TREATMENT OF SPENT OXIDE OF IRON ARISING FROM
THE PURIFICATION OF GAS OR THE SAID OXIDE WHEN PARTLY SPENT," upon the
condition, amongst others, that I, the said David Spence, by an instru-
ment 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 imme-
diately after the date of the said Letters Patent.
KNOW NOW YE, that I, the said David Spence, do hereby declaro
the nature of my said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the
following statement, that is to say :-
My Invention consists in a method of treating oxide of iron arising
from the purification of gas, whereby I prevent the emission of noxious
fumes. In the purification of gas it is well known that sulphate of iron
is used in order to abstract sulphur, which enters into combination with
the metal and produces sulphide of iron, ammonia being also taken up
by the sulphuric acid of the salt. It is also well known that in other
cases native oxide of iron is placed in the purifiers in order in like
manner to abstract the sulphur. In both of these cases the sulphide
of iron thus formed is withdrawn from the purifiers and is spread out
exposed to the air in order that it may become oxidized so as to be
fit again for the purifying process, and these operations are repeated
until the amount of accumulated sulphur in combination with the
oxide of iron has increased the bulk so as to render the latter practically
uscless, after which a fresh charge of the sulphate or oxide of iron is
used. During the operations above described the purifying substance
has been exposed to the ammonia arising from the manufacture of gas,
and when a charge of the said substance is withdrawn it carries with
it mechanically a portion of the said ammonia, which being a volatile
substance gives off noxious fumes during the aforesaid oxidation, which
interfere materially with the labour of those engaged in the manufacture.
To obviate this I apply to the withdrawn charge a solution of sulphate
of iron, the acid of which by combining with the ammonia forms
sulphate of ammonia and arrests the fumes which would otherwise be
given off.
A convenient mode of applying the sulphate is to store it in
an elevated tank and to conduct a hose therefrom to any situation
required, the said hose being provided with an orifice similar to a garden
rose. The quantity of the solution at a given strength to be used for
a withdrawn charge will readily be ascertained by practice.
According to my Invention, as will be understood, sulphate of
ammonia is produced, which may be washed out when the oxide of
iron is rendered useless for further purifying processes, and used for
any known commercial or manufacturing purpose.
I have above spoken especially of the use of sulphate of iron for the
purposes of my Invention, but chloride or other soluble salts of iron
may in like manner be employed.

page_text: Having thus described and ascertained the nature of my said Inven-
tion, and the manner in which the same is to be performed, I desire
it to be understood that I claim as secured to me under the above in
part recited Letters Patent and for the purpose above set forth, the
application of sulphate or other salt of iron to the spent or partially
spent oxide of iron arising from the purification of gas.
In witness whereof, I, the said David Spence, have hereunto set my
hand and seal, this Eighteenth day of October, in the year of
our Lord One thousand eight hundred and seventy-one.