IMPROVEMENTS IN THE MANUFACTURE OF REFINED IRON AND OF MALLEABLE IRON AND STEEL
Year: 1868

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, Cannon
Street, in the City of London, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF REFINED IRON AND OF MALLEABLE IRON AND
STEEL."
Sealed the 21st July 1868, and dated the 21st March 1868.
PROVISIONAL SPECIFICATION left by the said Henry Bessemor at
the Office of the Commissioners of Patents, with his Petition, on
the 21st March 1868.
I, HENRY BESSEMER, of Queen Street Place, Cannon Street, in the
City of London, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF REFINED IRON AND OF MALLEABLE IRON.
AND STEEL," to be as follows:-
My improvements consist in forcing or injecting into molten crude
iron, or re-melted pig iron, or other carburet of iron in a more or less:
refined state, streams or jets of fused or fluid nitrate of soda or nitate
of potash or other fused or fluid substances which contain or are capable
of evolving oxygen when brought in contact with fluid iron, such
substances, being used alone or in conjunction with oxides, peroxides,

page_text: or silicates of the peroxides of iron or manganese. The streams or jets
of fused or fluid matters are projected downwards at any desired angle
from nozzles or tuyeres, the orifices of which are situated above the
mean level or upper surface of the fluid iron to be operated upon, a
portion of the said fused or fluid matters, as well as a portion of the
cinder or oxides produced in the process, being again carried down into
the molten metal as an induced current caused by the passage of the
said jets or streams, which will pass downward through any fluid
matters floating on the surface and penetrate the fluid metal and be
there more or less decomposed, and operate upon the metal and the
impurities contained therein, and will more or less decarbonize and
refine the iron and convert it into steel, or into malleable iron, or
into a more or less refined cast iron, dependent on the quantity and
constituents of the fused or fluid matters injected therein. The iron
to be operated upon by the injection of the said fused or fluid matters
may be contained in a vessel mounted on trunnions similar to those
vessels known as "converters," and now generally employed in the
Bessemer process of manufacturing malleable iron and steel, or the
metal may be treated in a cylindrical or other fixed vessel or
chamber lined with fire-brick, "ganister," or other suitable refractory
material; or in lieu thereof the iron may be operated upon in the hearth
of a "finery furnace" similar to those generally employed in refining
crude or pig iron for puddling. When employing such a furnace for the
purposes of my Invention I arrange a set of air tuyeres along one side
thereof for melting the pig metal and partially refining the same, and
on the other side of the hearth I employ a separate set of tuyeres or
nozzles for the purpose of injecting the aforesaid fused or fluid matters
into the molten iron. The process in this finery furnace may be dis-
continued while the metal is in the condition of highly refined cast
iron approaching to steel, or it may be continued until a more or less
perfectly malleable metal is obtained suitable for melting in crucibles,
or otherwise to form steel, or the metal may be allowed to granulate or
assume a more or less solid condition, with or without manipulation
with an iron bar or rabble, and be removed from the finery furnace in
a condition to be formed into bars or blooms; or in lieu thereof the
process may be carried on in a reverberatory or puddling furnace
heated by solid fuel or by means of heated air and gas, in either of
which last-named cases it will be preferable to make the furnace much
larger and deeper in the hearth than is usual in ordinary puddling

page_text: furnaces. Mill scales, iron ore, or other matters now employed in
puddling iron may also be employed in this process. When the iron
to be treated by the means herein-before described contains much
phosphorus it will be preferable by regulating or stopping for a time
the jets of fused or fluid matters before named to allow such metal
during the process to pass into or assume a more or less pasty, granular,
or solidified condition, in order to its more readily parting with the
phosphorus it contains to the cinder or other fluid matters in contact
with the metal. When iron is so treated it may be taken out of the
furnace in a more or less solid state and be worked in a squeezer, or in
the rolls, or under a steam hammer, and be made at once into bars or
blooms, or in lieu thereof an addition may be made to it of some fluid
pig iron of a good quality (by preference containing manganese) before
removing the metal from the furnace or vessel in which it is treated,
and the whole may then be melted down together and run off in a fluid
state into a ladle and made into ingots or castings.
For the purposes of my present Invention I prefer to melt the said
nitrate of soda, nitrate of potash, or other fusible matters in a jacketted
iron vessel by means of highly heated atmospheric air or superheated
steam, and to use the pressure of such air or steam to act on the surface
of such fluid matters in order that they may thus be driven downward
upon the fluid metal with such force as to penetrate far into the molten
mass and put the same into rapid motion, and thus in turn bring all
parts thereof under operation. This motion in cylindrical vessels is.
best attained by placing the jet pipes at a tangent to their circum.
ference.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Bessemer in the Great Seal Patent Office
on the 21st September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of Queen Street Place, Cannon Street, in the City of London,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of March, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-

page_text: first year of Her reign, did for Herself, Her heirs and successors,
give and grant unto me, the said Henry Bessemer, Her special licence
that I, the said Henry Bessemer, my executors, administrators, and
assigns, or such others as I, the said Henry Bessemer, 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 MANUFACTURE OF REFINED IRON AND OF MALLEABLE IRON AND STEEL," upon
the condition (amongst others) that I, the said Henry Bessemer, 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 tho
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 Henry Bessemer, 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 thercof, that is to say:-
My improvements consist in forcing or injecting into molten crude
iron, or re-melted pig iron, or other carburet of iron in a more or less
refined state, streams or jets of fused or fluid nitrate of soda or nitrate
of potash, or other fused or fluid substances which contain or are capable
of evolving oxygen when brought in contact with fluid iron, such
substances being used alone or in conjunction with oxides, peroxides,
or silicates of the peroxides of iron or manganese. The streams or jets
of fused or fluid matters are projected downwards at any desired angle
from nozzles or tuyeres, the orifices of which are situated above the
mean level or upper surface of the fluid iron to be operated upon, a
portion of the said fused or fluid matters, as well as a portion of the
cinder or oxides produced in the process being again carried down into
the molten metal as an induced current caused by the passage of the
said jets or streams which, will pass downward through any fluid matters
floating on the surface and penetrate the fluid metal and be there more
or less decomposed and operate upon the metal and the impurities
contained therein, and will more or less decarbonize and refine the iron

page_text: <<
and convert it into steel, or into malleable iron, or into a more or less
refined cast iron, dependent on the quantity and constituents of the
fused or fluid matters injected therein. The iron to be operated upon by
the injection of the said fused or fluid matters may be contained in
a vessel mounted on trunnions similar to those vessels known as
"converters," and now generally employed in the Bessemer process of
manufacturing malleable iron and steel, or the metal may be treated in
a cylindrical or other fixed vessel or chamber lined with fire-brick,
ganister," or other suitable refractory material, or in lieu thereof the
iron may be operated upon in the hearth of a "finery furnace," similar
to those generally employed in refining crude or pig iron for puddling.
When employing such a furnace for the purposes of my Invention
I arrange a set of air tuyeres along one side thereof for melting the pig
metal and partially refining the same, and on the other side of the
of
hearth I employ a separate set of tuyeres or nozzles for the purpose
injecting the aforesaid fused or fluid matters into the molten iron; or
instead of this arrangement the finery furnace may have three ordinary
air tuyeres on each side thereof, with two small tuyeres for the injection
of the fluid matters on each side of the furnace occupying the spaces
between the air tuyeres. The process in this finery furnace may be
discontinued while the metal is in the condition of highly-refined cast
iron approaching to steel, or it may be continued until a more or less
perfectly malleable metal is obtained suitable for melting in crucibles,
or otherwise to form steel, or the metal may be allowed to granulate or
assume a more or less solid condition, with or without manipulation
with an iron bar or rabble, and be removed from the finery furnace in
a condition to be formed into bars or blooms; or in lieu thereof the
process may be carried on in a reverberatory or puddling furnace heated
by solid fuel, or by means of heated air and gas, in either of which last-
named cases it will be preferable to make the furnace much larger and
deeper in the hearth than is usual in ordinary puddling furnaces. Mill
scales, iron ore, or other matters now employed in puddling iron may
also be employed in this process. When the iron to be treated by the
means herein-before described contains much phosphorus it will be
preferable by regulating or stopping for a time the jets of fused or fluid
matters, before named, to allow such metal during the process to pass
into or assume a more or less pasty, granular, or solidified condition, in
order to its more readily parting with the phosphorus it contains to the

page_text: cinder or other fluid matters in contact with the metal. When iron is so
treated it may be taken out of the furnace in a more or less solid state
and be worked in a squeezer, or in the rolls, or under a steam hammer,
and be made at once into bars or blooms, or in lieu thereof an addition
may be made to it of some fluid pig iron of a good quality (by
preference containing manganese) before removing the metal from the
furnace or vessel in which it is treated, and the whole may then be
melted down together and run off in a fluid state into a ladle and made
into ingots or castings.
.
For the purposes of my present Invention I prefer to melt the said
nitrate of soda, nitrate of potash, or other fusible matters in a jacketted
iron vessel by means of highly-heated atmospheric air or superheated
steam, and to use the pressure of such air or steam to act on the surface
of such fluid matters, in order that they may thus be driven downward
upon the fluid metal with such force as to penetrate far into the molten
mass and put the same into rapid motion, and thus in turn bring all
parts thereof under operation. This motion in cylindrical vessels is
best attained by placing the jet pipes at a tangent to the circumference.
And in order that the mode in which I prefer to carry into practice
my Invention may be fully understood, I have hereunto annexed a
Sheet of Drawings, in which a fixed cylindrical vessel suitable for the
purpose is shewn in vertical section at Figure 1, and in horizontal section
at Figure 2.
a is the outer casing of plate iron with a thick lining of ganister or
other refractory material b, the vessel, is made in two parts united
together with a flange at c, so that the upper part may be lifted off the
lower one when desired, and thus give access to the interior; the upper
part of the vessel is domed and terminates in an opening d, through
which the sparks and gaseous products given off during the process may
escape; a large loop of iron e is jointed externally to the mouth of the
vessel so as to be moved from over the opening d; during the process
this loop serves to attach the upper part of the vessel to the crane when
it is to be removed. On two opposite sides of the vessel there are
tuyeres dipping downward at an angle and inclined toward a tangent
to the circumference of the vessel; these tuyeres consist of an outer
iron shell f, in which water may circulate as usual in water tuyeres;
a fire-clay nozzle n is fitted into the water tuyere, and into this nozzle

page_text: the injection pipe p enters, and is made tight by a ramming of loam r;
at s there is a screwed cap to give access to the injection pipe p, so that
it may be cleared out with a rod when necessary; a branch of the
injection pipe passes upwards into the chamber t, which contains the
fluid to be injected into the metal; this chamber t has an outer jacket u,
leaving a space between it and the chamber t for the circulation of
highly heated air or superheated steam, which is admitted by the pipe
and cock v, and escapes through a small nozzle w. On the upper part
of the jacket a stuffing box x is formed, through which a rod y passes;
this rod may be raised or lowered by any convenient lever arrangement,
or by a screw, as commonly employed in sluice valves, in the interior
of the chamber t; the rod y is made tubular, having numerous holes
to admit air or steam to its interior, as shewn at y*; the lower part of
this tubular rod is formed into a cone valve fitting into a seating g,
and by closing the orifice of the injection pipe prevents the passage of
h is an
any fluid from the chamber t so long as the valve is closed.
opening or screw plug, through which the nitrates or other matters
to be injected into the fluid iron are admitted to the chamber t, either
in a solid form and there to undergo fusion by the application of heated
air or steam, or they may be admitted to the chamber in a previously
fused or fluid state, and be merely retained in that condition until
required; a pipe and cock i supplies air or steam under pressure to the
interior of the chamber t for the purpose of acting powerfully on the
surface of the fluid, and causing it to be projected with such force on
to the surface of the fluid iron as to enter into and pass down to or
nearly to the lowest part of it; the jacketted chamber is supported
by a bracket to the casing of the vessel a, and a similar jacketted
chamber, not shewn in the Drawings, is also provided for each tuycre.
Before using the apparatus a coke fire may be made in the interior of
the converting vessel, which should be well heated; the fuel may be
supplied through the opening d and a current of air be allowed to enter
a hole in the door k, shown by dots, which hole, like that in an ordinary
founder's cupola, will also serve for the discharge of the converted
metal. I however prefer to urge the fire by a blast of air introduced
at the said opening by a moveable nozzle leading from a fan, or to provide
one or more small tuyeres in the lower part of the vessel for the
admission of the blast, and which tuyeres may be stopped up by a
plug of loam previous to the admission of the metal to the vessel; the

page_text: residue of the fuel after heating the vessel may remain in it, or it may
be removed through the door k, which must then be loamed up prior
to the admission of the metal to the vessel. The vessel having thus
been heated and the nitrates or other matters rendered fluid in the
chamber t, the fluid metal may be run into the vessel at the spout 1,
the aperture of which is then closed; air or steam under a pressure by
preference of not less than fifty pounds per square inch, and at a tem-
perature of about 50° Fahrenheit, above that at which the nitrate of
soda or other substance which is being used fuses is then admitted by
the cock to the chamber t; it will immediately rush. through the
openings and pass down through the hollow rod y and through the
injection pipe p, clearing the passage and heating the pipe and tuyere
through which the fluid will have to pass, the rod y may then be raised,
when the fluid nitrate or other matter contained in the chamber t will
be driven through the valve formed on the lower part of the rod y, and
passing down the pipe p will be driven into the fluid metal and be
diffused in a finely divided state through the metal, the tuyeres being
placed at a tangent will cause a rapid rotation of the metal, so that
all parts will be brought under the influence of the jets and be equally
acted upon.
When the metal has been thus treated to the desired extent
it
may be run out of the vessel or removed through the door k, or it
may be taken out by removing the upper part of the vessel; or in lieu
thereof a further portion of molten carburet of iron may be run into
the vessel and be mixed with the converted metal previous to running
it off.
The oxygen yielding material which I believe to be best suited for
use in the process above set forth I believe to be nitrate of soda. The
quantity employed will depend on the quality of the iron and of the
product desired, as is well understood. When oxides are used in con-
junction with the nitrates they may either be mixed therewith or placed
on the surfeace of the melted metal so as to be carried down into it
by the induced current.
Having thus described my Invention, and the manner in which it
may be carried into practical operation, I desire it to be understood
that what I claim as my Invention is, the forcing or injecting downwards
into molten crude iron or re-melted pig or other carburet of iron, streams
or jets of fused or liquid nitrate of soda, or nitrate of potash, or other

page_text: fused or liquid substances which contain or are capable of evolving
oxygen when brought in contact with liquid iron.
In witness whereof, I, the said Henry Bessemer, have hereunto
set my hand and seal, this Twenty-first day of September, in
the year of our Lord One thousand eight hundred and sixty-
eight.