IMPROVEMENTS IN THE MANUFACTURE OF IRON
Year: 1856

page_text: LETTERS PATENT to Robert Mushet, of Coleford, in the County of
Gloucester, Metallurgist, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF IRON."
Sealed the 16th January 1857, and dated the 15th November 1856.
PROVISIONAL SPECIFICATION left by the said Robert Mushet at the
Office of the Commissioners of Patents, with his Petition, on the
15th November 1856.
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," to be as follows:-
My said Invention consists of a mode of reducing pig or cast iron into a
granular state, or powder.
I have found that when cast iron is heated to a temperature a little below
the melting point it is capable of being powdered or reduced to a granular
state by the application of mechanical force. If the iron to be operated upon
is cold or not sufficiently hot, I heat the pigs or pieces to a temperature
just below that which would melt them; and if the iron to be granulated is
in a melted state I allow it to cool down until it has begun to assume a solid
or pasty consistence. In either of these cases I take the iron in the heatedl
state above mentioned, and whilst it is in that state subject it to the action of
stamps, rollers, hammers, or other mechanical action, and thus reduce it to a
powder.

page_text: The cast iron thus powdered or granulated may t
then be subjected to further
processes or treatment, in order to convert it into cast steel or malleable
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
15th May 1857..
TO ALL TO WHOM THESE PRESENTS SHALL COME, ROBERT
MUSHET, of Coleford, in the County of Gloucester, Metallurgist, sends greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of November, in the year of our
Lord One thousand eight hundred and fifty-six, in the twentieth year of Iler
roign, did, for Herself, Her heirs and successors, give and grant unto him, the
said Robert Mushet, Her special licence that he, the said Robert Mushet, his
exccutors, administrators, and assigns, or such others as he, the said Robert
Mushet, his executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times. thereafter during tho
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, tho Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF IRON," upon the condition (amongst others) that he, tho said
Robert Mushet, his exccutors or administrators, by an instrument in writing
under his, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner tho samo
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 tho
date of tho said Letters Patent.
NOW KNOW YE, that I, the said Robert Mushet, 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:
My said Invention cousists of a mode of reducing pig or cast iron into a
granular state, or powder.
I have found that when cast iron is heated to a temperature a little below
that of its melting point it becomes softened, and its particles possess but
little coherence, and may bo powdered or reduced to a granular state by
stamping, crushing, or other mechanical force in any convenient manner.
If the iron to bo operated upon is cold or not sufficiently hot, I heat the

page_text: pigs or pieces to a temperature a little short of that of their melting point!;
or if the, cast iron to be granulated is in a fluid molten state, I suffer.it to
cool down until it begins somewhat to consolidate, and has assumed a soft
pasty consistency. In either, of these cases I take the cast iron in the heated
state I have described, and whilst it is in that state I subject it quickly to the
action of stampers, rollers, hammers, or other convenient mechanical powers
until it is pulverized and reduced to a powder. The cast iron thus granulated
may then be subjected to further processes or treatment, in order to convert
it into cast steel or malleable iron, or may be used for any other purpose for
which it may be applicable.
When my Invention is. to be used in reducing cold cast iron to a powder or a
granular state, I place lumps or pieces of cast iron of any convenient size (from
twenty pounds to thirty pounds weight each I have found sufficient) in a
common reverberatory furnace, such as an ordinary puddling furnace heated by
the flame of pit coal or in any other convenient and economical manner, and
I heat them until they become softened and brittle, which is easily ascertained
by touching them with an iron bar or rod, and the proper heat will also be
indicated by observing that the thin edges or projecting corners of the lumps
will begin to melt and drop upon the floor of the furnace. The lumps of
cast iron are now to be removed with a pair of tongs or on a shovel, or they
may be raked out and placed in large cast-iron mortars, wherein they are to
be immediately stamped and pulverized by workmen provided with pestles or
pounders of iron. As each lump is pounded the mortar is to be emptied of
its contents of pulverized metal, and another lump is then put in and similarly
treated. The granulated iron may then, if desired, be passed through a sieve
or riddle of any required capacity of mesh, and such lumps or pieces as may
not have been sufficiently pulverized for the intended purposes may be thus
separated from the other portions, and may be returned to the heating furnace
to be reheated and again pulverized in the mortar or other apparatus em-
ployed. I have found this method convenient and effectual in practice, but
the heated lumps of cast iron may be subjected to the action of stampers,
hammers, or rollers, worked by machinery in any convenient manner.
When I intend to operate upon cast iron which is in a melted state, I pour
it into ladles or vessels of a convenient size, and allow it to cool there until it
is a little consolidated, and then, whilst still sufficiently soft, I turn it out from
the ladles or vessels into mortars, and pulverize it in the manner I have before
described.
Having thus described the nature of my said Invention, and the manner in
which the same may be carried into practice, I declare that I do not claim

page_text: the granulation of cast iron by running it when melted into water, or by
projecting it into the air in streams or showers, neither do I claim the
stamping of pieces or scraps of cast iron in the cold state as any part of my
Invention; but what I do claim is, the reducing pig or cast iron into a
granular stato or powder by subjecting it to the action of mechanical force by
means of stampers, rollers, hammers, or other convenient apparatus whilst it
is in a heated state, as herein-before described.
In witness whereof, I, the said Robert Mushet; have hereunto set my
hand and seal, the Fourteenth day of May, One thousand eight hundred
and fifty-seven.
Signed, sealed, and delivered by the said
Robert Mushet, in the presence of
MAXWELL MUSIIET,
Coleford, Gloucestershire.
BROOKLYN MUSHET,
Coleford, Gloucestershire.
ROBT MUSHET. (L.9.)