AN IMPROVEMENT IN THE MANUFACTURE OR TREATMENT OF PIG OR CAST IRON
Year: 1863

page_text: LETTERS PATENT to Robert Mushet, of Coleford, in the County of
Gloucester, Metallurgist, for the Invention of "AN IMPROVEMENT IN
THE MANUFACTURE OR TREATMENT OF PIG OR CAST IRON."
Sealed the 29th August 1868, and dated the 9th March 1863.
PROVISIONAL SPECIFICATION left by the said Robert Mushet at the
Office of the Commissioners of Patents, with his Petition, on the
9th March 1863.
I, ROBERT MUSHET, of Coleford, in the County of Gloucester, Metallurgist,
do hereby declare the nature of the said Invention for "AN IMPROVEMENT
IN THE MANUFACTURE OR TREATMENT OF PIG OR CAST IRON," to be as
follows:-
When pig iron or cast iron in a melted state is subjected to the pneumatic
process of refining or decarbonizing, that is, by passing air through the said
melted pig or cast iron, the said pig or cast iron is converted into a species of
steel or semi-steel or malleable iron, and when the pig iron or cast iron thus
operated upon is of good quality and nearly free from sulphur and phos-
phorous, the steel, semi-steel, or malleable iron obtained from the said pig or
cast iron possesses greater toughness and tenacity when cold than steel, semi-
steel, or malleable iron prepared by other processes, and I have also found that

page_text: the said steel, semi-steel, or malleable iron produced from pig iron or cast
iron decarbonized by the pneumatic process possess the property of communi-
cating to pig or cast iron, with which they are mixed and incorporated, great
strength, so as to render the said pig or cast iron peculiarly fitted for castings
where great strength is required.
My Invention consists in adding to and mixing with pig iron or cast iron
which it is intended shall be cast into castings or mouldings a quantity of
steel, semi-steel, or malleable iron obtained by refining or decarbonizing pig
or cast iron by the pneumatic process, in order by the mixture of these sub-
stances, namely, the pig or cast iron and the said steel, semi-steel, or malle-
able iron, to strengthen and improve the quality of the said pig or cast iron,
and thus to adapt it to purposes for which cast iron of great strength is required.
I effect the mixture of the pig or cast iron with the said steel, semi-steel, or
malleable iron when these substances are in a melted liquid state. The
quantity of the said melted steel, semi-steel, or malleable iron which I add to
a given weight of melted pig or cast iron may be varied at pleasure, but in
practice I find that from three to fifteen pounds of the said steel, semi-steel,
or malleable iron mixed with every one hundred pounds of melted pig or
cast iron afford excellent results, but I do not confine myself to these propor-
tions, which may be varied without departing from the nature of my
Invention. I prefer to obtain the said steel, semi-steel, or malleable iron
which I employ in my process from hematite pig iron of Cumberland or
Lancashire, or from spathose pig iron smelted from sparry ores or carbonates
of iron, or from charcoal pig iron, but other pig irons free or nearly free from
sulphur and phosphorous may be decarbonized or refined by the pneumatic
process in order to obtain the steel, semi-steel, or malleable iron which I
employ in my process. The pig or cast iron with which I prefer to mix the
said steel, semi-steel, or malleable iron is that kind which is termed foundry
iron or melting pig iron, but the said steel, semi-steel, or malleable iron may
also be advantageously mixed with grey forge pig iron. The melted pig or
cast iron may be mixed with the said melted steel, semi-steel, or malleable
iron in any convenient manner. For example, I take five tons of melted pig or
cast iron in a large foundry ladle suspended to and moved about by means of
a moveable crane, and I bring the said ladle containing the melted pig or cast
iron under the orifice or tapping hole of the pneumatic vessel or furnace
wherein the steel, semi-steel, or malleable iron has been prepared by refining
or decarbonizing pig or cast iron by the pneumatic process, and I then run
from three to fifteen hundredweights of the said steel, semi-steel, or malleable

page_text: iron into the melted pig or cast iron contained in the ladle. I then stir up the
mixture with a rod of iron or steel, and then proceed to cast or mould the
mixture in the ordinary manner practised by iron founders.
I do not claim the addition of malleable iron made by the puddling
process to pig or cast iron, and the melting of these substances together in
order to improve the quality of the pig or cast iron, for this, as I am aware,
has already formed the subject of a Patent claim.
The essence of my Invention consists in mixing with melted pig or cast iron
which it is intended to form into castings a quantity of melted steel, semi-
steel, or malleable iron, which said melted steel, semi-steel, or malleable iron
has been obtained by refining or decarbonizing melted pig or cast iron by the
pneumatic process, in order by this admixture to strengthen and improve the
quality of the said pig or cast iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Mushet in the Great Seal Patent Office on the
3rd September 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 Ninth day of March, in the year of our Lord One
thousand eight hundred and sixty-three, in the twenty-sixth 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 Channel
Islands, and Isle of Man, an Invention for "AN IMPROVEMENT IN THE
MANUFACTURE OR TREATMENT OF PIG OR CAST IRON," 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

page_text: 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
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
When pig iron or cast iron in a melted state is subjected to the pneumatic
process of refining or decarbonizing, that is, by forcing air through the said
melted pig or cast iron, the said pig or cast iron is converted into a species of
steel or semi-steel or malleable iron, and when the pig iron or cast iron thus
operated upon is of good quality and free or nearly free from sulphur and
phosphorous, the steel, semi-steel, or malleable iron obtained from the said
pig or cast iron possesses greater toughness and tenacity when cold than steel,
semi-steel, or malleable iron prepared by other processes, and I have found
that the said tough and tenacious steel, semi-steel, or malleable iron produced
from pig iron or cast iron decarbonized by the pneumatic process possesses the
property of communicating to pig or cast iron with which they are mixed and
incorporated great strength, so as to render the said pig or cast iron peculiarly
fitted for castings where great strength is required. The same effect is pro-
duced, but in an inferior degree, when melted steel or semi-steel or melted
malleable iron prepared by processes other than the pneumatic process is
mixed and combined with melted pig or cast iron.
My Invention consists. in adding to and mixing and combining with pig
iron or cast iron which it is intended shall be cast or moulded into castings or
mouldings a quantity of melted steel, semi-steel, or malleable iron obtained
by refining or decarbonizing pig or cast iron by the pneumatic process, or
melted steel or semi-steel or melted malleable iron prepared by processes
other than the pneumatic process, in order by the mixture of and combination
of the pig or cast iron with the said melted steel, semi-steel, or malleable
iron to strengthen and improve the quality of the said pig or cast iron, and
thus to adapt it to purposes for which cast iron of great strength is required.
I effect the mixture and combination of the pig or cast iron with the said
steel, semi-steel, or malleable iron when the pig iron or cast iron as well as
the steel, semi-steel, or malleable iron are in a melted liquid state. The
quantity of the said melted steel, semi-steel, or malleable iron which I add to
a given weight of melted pig iron or cast iron may be varied at pleasure, but
in practice I find that from three to fifteen pounds of the said melted steel,
semi-steel, or malleable iron mixed with every one hundred pounds of melted

page_text: pig iron or cast iron afford excellent results, but I do not confine myself to
these proportions, which may be varied without departing from the nature of
my Invention. I prefer to obtain the said steel, semi-steel, or malleable iron
which I employ in my process from hematite pig iron of Cumberland or
Lancashire, or from spathose pig iron smelted from sparry ores or carbonates
of iron, or from charcoal pig iron, but other pig irons free or nearly free from
sulphur and phosphorous may be decarbonised or refined by the pneumatic
process, in order to obtain the steel, or semi-steel, or malleable iron which I
employ in my process. The pig or cast iron with which I prefer to mix and
combine the said steel, semi-steel, or malleable iron is that kind which is
termed foundry iron or melting pig iron, but grey forge pig iron may also be
advantageously mixed and combined with the said steel, semi-steel, or mal-
leable iron. The melted pig iron or cast iron may be mixed with the said
melted steel, semi-steel, or malleable iron in any convenient manner. For
example, I take five tons of melted pig or cast iron in a large foundry ladle
suspended to a hook and chain, and moved about by means of a moveable or
travelling crane, and I bring the said ladle containing the melted pig or cast
iron under the orifice or tapping hole or spout of the pneumatic vessel or
furnace wherein the steel, semi-steel, or malleable iron has been prepared by
refining or decarbonising pig or cast iron by the pneumatic process, and I
then run from about three to about fifteen hundred pounds of the said steel,
semi-steel, or malleable iron into the melted pig or cast iron contained in the
ladle. I then stir up the mixture with a rod or paddle of iron or steel, and
then proceed to cast or mould the mixture or compound in the ordinary
manner practised by iron founders. Melted steel or semi-steel, or melted
malleable iron prepared by processes other than the pneumatic process, may
be employed to mix with melted cast iron, but I prefer to employ melted steel,
semi-steel, or malleable iron prepared by the pneumatic process, as cheaper
and more efficacious than steel, semi-steel, or malleable iron otherwise
prepared.
I do not claim the addition of malleable iron in the solid state made by the
puddling process to pig or cast iron, and the melting of these substances
together in order to improve the quality of the pig or cast iron, for this I am
aware has already formed the subject of a Patent claim.
The essence of my Invention consists in mixing and combining with melted
pig or cast iron which it is intended to form into castings a quantity of melted
steel, semi-steel, or malleable iron, which said melted steel, semi-steel, or
malleable iron has been obtained by refining or decarbonizing melted pig or

page_text: cast iron by the pneumatic process, or melted steel, semi-steel, or melted
malleable iron prepared by processes other than the pneumatic, in order by
this admixture and combination to strengthen and improve the quality of the
said pig iron or cast iron.
In witness whereof, I, the said Robert Mushet, have hereunto set my
hand and seal, this Twenty-eighth day of August, in the year of our
Lord One thousand eight hundred and sixty-three.
Witnesses,
EDW. M. MUSHET,
Cheltenham, Gloucestershire.
B. MUSHET,
Cheltenham, Gloucestershire.
ROBT. MUSHET. (L.B.)