IMPROVEMENTS IN THE PRODUCTION OF STEEL
Year: 1874

page_text: LETTERS PATENT to John Imray, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN THE PRODUCTION OF STEEL."-A communication from
abroad by Thomas Schoenberger Blair, of Pittsburg, Pennsylvania,
in the United States of America.
Sealed the 19th January 1875, and dated the 22nd July 1874.
PROVISIONAL SPECIFICATION left by the said John Imray at the
Office of the Commissioners of Patents, with his Petition, on the
22nd July 1874.
I, JOHN IMRAY, of No. 20, Southampton Buildings, Chancery Lane,
5 in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE PRODUCTION OF STEEL," to be as
follows:-
This Invention relates to a process for producing steel in the open
hearth furnace by the treatment of iron sponge, the chief object of the
O Invention being to secure a good quality of steel at a moderate cost.
For this purpose iron sponge, which may be that produced in the manner

page_text: described in the Specification of a Patent granted to me for a communi-
cation from the said T. S. Blair on the 14th June 1872, No. 1795, is
mixed with about 5 per cent. by weight of finely divided carbonaceous
matter, such as pulverised charcoal, and about one-half per cent. of an
agent such as yellow prussiate of potash, which has the effect of accele-
rating the carburisation of iron. The mixture while cold is compressed
into blocks or blooms, which are placed in a heating furnace and raised
in the first place to a red heat, and afterwards are more highly heated,
the iron, sponge being thus carburised. From the heating furnace the
heated blooms are charged into an open hearth melting furnace where
they are fused. The fused material is tested, and if necessary portions
of iron sponge are added when the mixture contains too much carbon,
or portions of the carburised iron sponge are added if the mixture
contains too little carbon. After the fused material has been thus
brought to the desired condition, spiegel eisen or ferro-manganese is added
in the usual way, and the material is run off into moulds as cast steel.
In carrying on this process the heating furnace after one set of blooms
have been removed from it to the melting furnace may be charged with
a fresh set of blooms, which can be heated while the former set are
undergoing treatment in the melting furnace, and thus the process may
be rendered continuous. By thus employing iron sponge as the material
for the production of cast steel the purity of the latter is secured, the
iron sponge being free from the deleterious ingredients which are often
introduced when steel is produced from pig metal.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said John Imray in the Great Seal Patent Office on
the 19th January 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
IMRAY, of No. 20, Southampton Buildings, Chancery Lane, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of July, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and

page_text: successors, give and grant unto me, the said John Imray, Her
special license that I, the said John Imray, my executors, admini-
strators, and assigns, or such others as I, thé said John Imray, 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 PRODUCTION OF STEEL," a communication to me from
abroad by Thomas Schoenberger Blair, of Pittsburg, Pennsylvania, in
the United States of America, upon the condition (amongst others) that
I, the said John Imray, my executors or administrators, by an instru-
ment 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 John Imray, do hereby declaré
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 thereof, that is to say :—
This Invention relates to a process for producing steel in the open
hearth furnace by the treatment of iron sponge, the chief object of the
Invention being to secure a good quality of steel at a moderate cost.
For this purpose iron sponge, which may be that produced in the manner
described in the Specification of a Patent granted to me for a communi-
cation from the said T. S. Blair on the 14th June 1872, No. 1795, is
mixed with about 5 per cent. by weight of finely divided carbonaceous
1 matter, such as pulverised charcoal, and about one-half per cent. of an
agent, such as yellow prussiate of potash, which has the effect of accele-
rating the carburisation of iron. The mixture while cold is compressed
into blocks or blooms, which are placed in a heating furnace and raised
in the first place to a red heat, and afterwards are more highly heated,
the iron sponge being thus carburised. From the heating furnace the
heated blooms are charged into an open hearth melting furnace, where
they are fused.
The fused material is tested, and if necessary portions
of iron sponge are added when the mixture contains too much carbon,

page_text: or portions of the carburised iron sponge are added if the mixture
contains too little carbon. After the fused material has been thus
brought to the desired condition spiegel eisen or ferro-manganese is
added in the usual way, and the material is run off into moulds as cast
steel. In carrying on this process the heating furnace after one set of
blooms have been removed from it to the melting furnace may
be charged with a fresh set of blooms, which can be heated while the
former set are undergoing treatment in the melting furnace, and thus
the process may be rendered continuous. By thus employing iron sponge
in lieu of pig metal as the material for the production of cast steel the
purity of the latter is secured, the iron sponge being free from the
deleterious ingredients which are often introduced when steel is produced
from pig metal.
Having thus described the nature of this Invention and in what
manner the same is to be performed, as communicated to me by my
foreign correspondent, I claim,-
First. The method, substantially as herein described, of producing
cast steel in the open hearth process by the treatment of iron sponge
with admixture of carbon and agents for accelerating carburisation.
Second. For the production of steel in the open hearth process, the
use of iron sponge carburised in the manner referred to above in lieu of
pig metal, substantially as herein described.
In witness whereof, I, the said John Imray, have hereunto set my
hand and seal, this Nineteenth day of January, in the year of
our Lord One thousand eight hundred and seventy-five.
TATTET TID T