IMPROVEMENTS IN THE MANU- FACTURE OF IRON AND STEEL
Year: 1863

page_text: LETTERS PATENT to Robert Mushet, of Coleford, in the County of Glou-
cèster, Metallurgist, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF IRON AND STEEL."
Sealed the 2nd September 1868, and dated the 25th June 1868.
PROVISIONAL SPECIFICATION left by the said Robert Mushet at the
Office of the Commissioners of Patents, with his Petition, on the 25th
June 1868.
I, ROBERT MUSHET, of Coleford, in the County of Gloucester, Metallurgist,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF IRON AND STEEL," to be as follows:-
When melted pig iron or cast iron is decarbonized by subjecting it to the
pneumatic process; it is usual át the close of the operation to add to the said
decarbonized and melted iron a quantity of melted spiegel eisen, in order to
improve the quality of the iron and steel prepared by decarbonizing the melted
pig iron or cast iron. The spiegel eisen or manganesic pig is either melted in
an air furnace or other furnace or in melting pots, and is then poured into the
melted decarbonized pig or cast iron contained in the pneumatic converting
vessel, so as to become mixed with the said decarbonized iron. Now I have
discovered that the addition to the melted decarbonized pig or cast iron of
some melted hematite pig iron, or Swedish charcoal pig iron, or other similar

page_text: pure hematite or charcoal pig iron, along with the melted manganesic pig
or spiegel eisen improves the quality of the iron or steel obtained from the
mixture and economises the cost of its manufacture. The hematite iron I
prefer to employ is that produced by smelting the red hematite iron ores of
Lancashire or Cumberland, or similar ores, in a blast furnace. I prepare the
hematite pig iron, or the Swedish charcoal pig iron, or other pure hematite or
charcoal pig iron for my purpose by melting them in an air furnace or rever-
beratory furnace or in melting pots along with the spiegel eisen intended to
be employed; or the said hematite pig iron, or Swedish charcoal pig iron, or
other pure hematite or charcoal pig iron may be melted separately from the
spiegel eisen, but for convenience sake I find it better to melt them together.
It is usual to add about one ton of melted spiegel eisen to from eight to ten
tons of melted decarbonised pig iron or cast iron; in place of this I melt
about half a ton of hematite pig iron, or of Swedish charcoal pig iron, or of
other pure hematite or charcoal pig iron, with half a ton of spiegel eisen, and I
pour the mixture of these substances, when melted, into the furnace, vessel, or
ladle, containing from eight to ten tons of melted decarbonized pig iron or
cast iron.
I do not, however, confine myself to the proportions of hematite pig.
iron, or of Swedish charcoal pig iron, or other pure hematite or charcoal pig
iron to spiegel eisen which I have herein-before set down, for these relative
proportions may be altered without departing from the nature of my Invention.
For instance, to eight or ten tons of decarbonized pig iron or cast iron there
may be added one half ton of melted spiegel eisen, and one ton or one ton and
a half of melted hematite pig iron, or melted 'Swedish pig iron, or other pure
hematite or charcoal pig iron, according to the result which it is required to
obtain. I wish it to be observed that the greater the proportion of melted
hematite pig iron, or of melted Swedish pig iron, or other pure hematite or
charcoal pig iron added to a given weight of melted decarbonized pig.iron or
cast iron the harder will be the quality of the iron or steel produced. When
the melted mixture of hematite or Swedish charcoal pig iron, or other. pure
hematite or charcoal pig iron, and spiegel eisen, has been added to the melted
decarbonized pig iron or cast iron, whether contained in a .ladle or in the
pneumatic converting vessel, I proceed to mix the melted ingredients .in. the
'usual manner, either by means of a blast of air or otherwise, and I then pour
the iron or steel obtained into moulds in the usual manner.
•
The essence of my Invention consists in adding to melted iron or steel
obtained from melted pig iron or cast iron decarbonized by the pneumatic
-process. a mixture of melted spiegel eisen with melted hematite pig iron, or

page_text: Swedish charcoal pig iron, or other pure hematite or charcoal pig iron, in
order to improve the quality of the said pueumatised iron or steel, and to
economise the manufacture of the said iron or steel.
SPECIFICATION in pursuance of the conditions of the Letters "Patent,
filed by the said Robert Mushet in the Great Seal Patent Office on the
24th December 1863.
.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
MUSHET, of Coleford, in the County of Gloucester, Metallurgist, send
greeting.
:
-`
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters.
Patent, bearing date the Twenty-fifth day of June, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Robert Mushet, Her special licence that I, the said Robert Mushet,
my executors, administrators, and assigns, or such others as I, the said Robert
Mushet, 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 Channe!
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF IRON AND STEEL," upon the condition (amongst others) that I, the said
Robert Mushet, 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 Robert Mushet, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and, ascertained in and by the following,
statement thereof, that is to say:-
When melted pig iron or cast iron is decarbonized by subjecting it to the.
process commonly called the pneumatic process, that is, by forcing a stream of
air through the said iron while the said iron is in a melted state, it is usual.
at the close of the operation to add to the said decarbonized and melted iron
a quantity of melted spiegel eisen or manganesic pig iron, in order to improve.
the quality of the iron and steel prepared by decarbonizing the melted pig

page_text: iron or cast iron. The said spiegel eisen
a manganesic pig iron made in
Rhenish Prussia, and well known in commerce by the name of spiegel eisen.
The spiegel eisen or manganesic pig iron is either melted in an air or other
furnace or in melting pots, and is then poured into the melted decarbonized
pig or cast iron contained in the pneumatic converting vessel, so as to
become mixed with the said melted decarbonized iron. Now I have dis-
covered that the addition to the melted decarbonized pig or cast iron of some
melted hematite pig iron, or Swedish charcoal pig iron, or other similar pure
hematite or charcoal pig iron along with the melted manganesic pig iron or
spiegel eisen improves the quality of the iron or steel obtained from the
mixture and economizes the cost of its manufacture. The addition of the said
melted hematite or Swedish pig iron to the melted decarbonized pig iron
in conjunction with the said spiegel eisen constitutes my Invention. The
hematite iron I prefer to employ in carrying my Invention into effect is that
produced by smelting the red hematite iron ores of Lancashire or Cumberland,
or similar ores, in a blast furnace. I prepare the hematite pig iron, or the
Swedish charcoal pig iron, or other pure hematite or charcoal pig iron for my
purpose by melting them in an air furnace or reverberatory furnace or in
melting pots along with the spiegel eisen intended to be employed; or the
said hematite pig iron, or Swedish charcoal pig iron, or other pure hematite
or charcoal pig iron may be melted and added to the decarbonized iron sepa-
rately from the spiegel eiser, but for convenience sake I find it better to melt
and add them together or simultaneously to the decarbonized pig or cast iron.
It is usual to add about half a ton of melted spiegel eisen to from four to six
tons of melted decarbonized pig iron or cast iron; in place of this I melt
about five hundredweight of hematite pig iron, or of Swedish charcoal pig
iron, or of other pure hematite or charcoal pig iron with five hundredweight
of spiegel eisen, and I pour the mixture of these substances, when melted,
into the furnace, vessel, or ladle, containing from four to six tons of the melted
decarbonized pig iron or cast iron.
I do not, however, confine myself to the proportions of hematite pig iron,
or of Swedish charcoal pig iron, or other pure hematite or charcoal pig iron
to spiegel eisen which I have herein-before set down, for these relative pro-
portions may be altered without departing from the nature of my Invention.
For instance, to four or six tons of decarbonized pig iron or cast iron there
may be added five hundredweight of melted spiegel eisen, and ten hundred-
weight to fifteen hundredweight of melted hematite pig iron, or melted Swedish
pig iron, or other melted pure hematite or charcoal pig iron, according to the
result which it is required to obtain. I wish it to be observed that the greater

page_text: the proportion of melted hematite pig iron, or of melted Swedish pig iron, or
other pure hematite or charcoal pig iron added to a given weight of melted
decarbonized pig iron or cast iron, the harder will be the quality of the iron or
steel produced. When the melted hematite or Swedish charcoal pig iron, or
other pure hematite or charcoal pig iron and spiegel eisen have been added,
either separately or in mixture, to the melted decarbonized pig iron or cast
iron, whether contained in a ladle or in the pneumatic converting vessel, I
proceed to mix the melted ingredients in the usual manner, either by means
of a blast of air or otherwise, and I then pour the iron or steel obtained into
moulds in the usual manner. As the processes of decarbonizing pig iron or
cast iron called the pneumatic process is well known and commonly practised,
I do not consider it necessary to describe the same; neither do I consider it
necessary to describe the vessels, furnaces, melting pots, and implements I
employ in carrying my Invention into effect, as they do not differ from those
commonly employed for like purposes.
The essence of my Invention consists in adding to melted iron or steel
obtained from melted pig iron or cast iron decarbonized by the pneumatic
process, a mixture of melted spiegel eisen with melted hematite pig iron, or
Swedish charcoal pig iron, or other pure pig iron from hematite iron ores, or
in adding the said spiegel eisen and hematite or charcoal pig iron separately,
in order to improve the quality of the said pneumatized iron or steel, and to
economize the manufacture of the said iron or steel.
In witness whereof, I, the said Robert Mushet, have hereunto set my
hand and seal, this Seventh day of December, in the year of our Lord
One thousand eight hundred and sixty-three.
Witnesses,
EDW. M. MUSHET,
Cheltenham.
B. MUSHET,
Cheltenham, Gloucestershire.
ROBERT MUSHET. (L.S.)