IMPROVEMENTS IN THE MANUFACTURE AND TREATMENT OF IRON. AND IN THE MANUFACTURE OF STEEL."
Year: 1856

page_text: LETTERS PATENT to Henry Bessemer, of 4, Queen Street Place, in the
City of London, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
AND TREATMENT OF IRON. AND IN THE MANUFACTURE OF STEEL."
PROVISIONAL SPECIFICATION left by, the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the
10th November 1856.
I, HENRY BESSEMER, of 4, Queen Street Place, in the City of London, do
hereby declare the nature of the Invention for "IMPROVEMENTS IN THE MANU.
FACTURE AND TREATMENT OF IRON, AND IN THE MANUFACTURE OF STEEL," to be as
follows:-
In the manufacture of iron, as now generally. practised in Great Britain,
several varieties of the ores of iron are employed, which are distinguished by
names indicative of their peculiar properties or constituents; but notwith-
standing the general classification of the ores of iron, it is found that the ores
of almost every mine differ in the nature or proportion of the substances of
which they are composed; it is found that the crude iron which is obtained
in the process of smelting combines in a greater or less degree with the
heterogenous substances found associated with the ore, and to some extent
with the impurities contained in the fuel and fluxes used in the smelting
ГДнём

page_text: furnace; and hence in its conversion into malleable iron or steel the crude
metal requires to be treated in such a manner and in contact with such
substances as are found best adapted to remove the peculiar combination of
foreign substances which it is known to contain. Now, the object of my
present Invention is to separate from crude molten iron or from remelted pig
or refined iron, the whole or greater part of the matters alloyed or mixed
therewith, with the exception of carbon, which in some cases I prefer wholly
or in part to retain, and also in some cases to add to or combine with the iron,
carbon, manganese, or other substances, according as the quality of the iron or
steel so treated and purified may be required. For this purpose I construct a
vessel (by preference of wrought iron, of a cylindrical form, with hemispherical
ends), which 1 line with fire-brick, fire-stone, or other suitable refractory
substances. I mount the vessel in a horizontal position on a slide or on
suitable wheels, and I attach to one end of it the piston rod of a steam
engine, so that the vessel may be made to move rapidly backwards and
forwards, by means of its direct connection with the steam piston, or it may be
put in motion by a crank or other intermediate mechanism, as will be readily
understood. I mount the vessel on axes, so that it may be moved round
when required; it may also be detached from the piston rod or engine, so as
to be moved as desired on rails, by means of the wheels before named.
one end of the vessel I connect a pipe, moving in and out of a stuffing box,
so that air, steam, or other gaseous matters may be conveyed to the vessel
while it is in motion. In the vessel I make a manhole or opening, which
may be stopped with a fire clay or other stopper when required.
At
Previous to using this apparatus for the purification of crude molten iron,
I heat the interior lining, after which a charge of molten, crude, or remelted
iron is run or poured into it. I also run or pour therein a charge of fluid cinder
or slags, obtained from the blast furnace, or such slags as are produced in the
conversion of crude into malleable iron by currents of air or steam, as
described in my former Patents, or slags such as are obtained in the puddling
of iron. The different qualities of slags used for this purpose may be modified
by the admixture with them of lime, clay, silica, carbon, alkaline salts, and
carthy or metallic oxides, as may be found requisite to purify or act upon the
peculiar quality of crude iron under operation. It will be desirable that the
metal and slags should be run into the vessel at the highest temperature that
can be conveniently obtained; the manhole having been closed (with the
exception of a small hole for the escape of gaseous matters), the apparatus
is to be put in motion, which will have the effect of shaking the whole of
the materials, and bringing the fluid iron in a divided state in contact with

page_text: the fluid scoria or flux, which will have the effect of separating from the iron
a large proportion of the impurities which it contains; the more violent the
agitation the more completely will the metal be diffused throughout the liquid
fluxes, and the more rapid and perfect will be the action of these materials
upon the iron.
When thus treating iron that is intended to be used for
founding, it may be agitated in slags or fluxes, not containing a large quantity
of oxide of iron, so that the carbon may be retained in the iron; if, however,
too much carbon is driven off, an additional quantity may be given when
desired, by adding some carbonaceous substances to the charge. When,
however, it is intended to convert the crude molten metal into steel or into
malleable iron, a quality of slag, or flux, or ore, rich in oxide, should be used;
also iron scales or other metallic oxides may be added to the flux, combined
with chloride of sodium. The motion of the vessel being vigorously kept up
until the complete or the desired amount of decarbonization and purification
of the metal is effected by the action of the oxides and other substances
contained in the slags, after which the metal may be discharged from the
agitating vessel, the process of conversion having been effected without the
use of fuel, except that applied to smelt the iron or remelt the pigs, previous
to the commencement of my improved process. Or, in lieu of this particular
treatment, either of the following methods may be employed, namely, the
crude metal may be in part refined and its temperature considerably raised,
by means of currents of air or steam forced therein previous to running it
into the agitating vessel, in which its conversion into malleable iron or steel
by the action of slags or fluxes is to be effected, or the crude metal may
be first subjected to the action of slags or fluxes in the agitating vessel, and
be afterwards run into a suitable vessel, in which currents of air or steam
are forced into and below the surface of the metal, and whereby the complete
conversion of the metal will be effected. And here I would observe, that I
have found when converting crude iron into malleable iron or steel by means
of currents of air, steam, or other gaseous matters, forced into and below the
surface of the fluid metal, that the heat of such metal, while under operation,
is better retained, and the process facilitated by placing a floating fire tile or a
piece of fire stone or other suitable refractory substances on to the surface of
the molten metal, which will greatly assist in preventing the radiation of heat
therefrom. I have also found that the effect of the currents of air or steam
employed will be augmented by putting some of them at a higher level than
others, the upper ones assisting in mixing the slags with the iron, while the lower
ones keep up the temperature. Or, in lieu of either of the modes herein-before
described of treating molten crude iron or remelted pig iron, I adopt the following

page_text: process-Having fixed into the sides or ends of the agitating vessel suitable
tuyeres, I connect them to the end tube before named, by means of which air,
steam, or other suitable gaseous matters may be conveyed into the agitating
vessel, and be made to act upon the metal therein contained simultaneously
with the agitation of the fluid, or at alternate intervals, and whereby the
temperatures of the metal will most readily be kept up and the slags or fluxes
be made to thoroughly wash and cleanse the metal, while a blast of air, steam,
or other gaseous or solid matter, containing or capable of evolving oxygen, is
forced into the metal.
When fluid malleable iron is to be discharged from the vessel in which
it may have been obtained from crude iron, a great difference in the quality of
the bar or rolled iron produced therefrom may be effected by the way in which
the fluid metal is treated; if it is simply run into the mould it becomes
crystalline, and if powerfully stirred up before or in the act of solidfying, the
character of the grain will be considerably modified. But I have discovered
that a still greater change is given to the texture of the bar or rolled iron, by
diffusing, in the act of solidification, slags along with the fluid metal. The
mode by which I prefer to accomplish this, is first to run into the ingot mould
some fluid slags, and then proceed to run in the fluid metal. 1 place the
mould so far below the point where the metal is poured from, as to cause it to
fall in a shower of detached grains; or it may be divided by first falling on
to or against any suitable substance, capable of dividing or scattering the
stream, or a current of air or steam may be made to disperse the metal in a
shower, which falling through the fluid slags, will accumulate in a granular
mass in the mould; here it may be subjected to hydraulic pressure, or to a
powerful hammer, or it may simply be discharged from the mould, and be
conveyed to a furnace or oven, and there kept hot until it be required for
rolling. If this interval of heating the mass be prolonged, the slags contained
between the grains of metal will assist in their purification, while the rolled
metal produced from the granular ingot will be found to possess that peculiar
fibrous appearance considered essential to iron used for certain purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Bessemer in the Great Seal Patent Office on the
9th May 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, HENRY
BESSEMER, of 4, Queen Street Place, in the City of London, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of November in the year of our Lord One
thousand eight hundred and fifty-six, in the twentieth 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 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 AND TREATMENT
OF IRON, AND IN THE MANUFACTURE OF 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 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 Henry Bessemer do hereby declare the
nature of the said Invention, and in what manner the same is to performed,
to be particularly described and ascertained in and by the following state-
ment thereof, that is to say :-
In the manufacture of iron, as now generally practised in Great Britain,
several varieties of the ores of iron are employed, which are distinguished
by names indicative of their peculiar property or constituents, but notwith-
standing the general classification of the ores of iron it is found that the ores
of almost every mine differ in the nature or proportion of the substances of
which they are composed. It is found that the crude iron which is obtained
in the process of smelting combines in a greater or less degree with the
heterogeneous substance found associated with the ore, and to some extent
with the impurities contained in the fuel and fluxes used in the smelting
furnace, and hence in its conversion into malleable iron or steel, the crude
metal requires to be treated in such a manner and in contact with such
substances as are found best adapted to remove the peculiar combination of
foreign substances which it is known to contain.
Now the object of my present Invention is to separate from crude molten
iron, or from remelted pig or refined iron, the whole or greater part of the
matters alloyed or mixed therewith, with the exception of carbon, which in
some cases I prefer wholly or in part to retain, and also in some cases to

page_text: add to or combine with the iron, carbon, manganese, or other substances,
according as the quality of the iron or steel is treated and purified may be
required.
In the Specification of a Patent granted to me for "Improvements in the
manufacture of malleable iron and steel," and bearing date the Twelfth day
of February, One thousand eight hundred and fifty-six, I have described how
molten crude iron, or remelted pig or refined iron, may be rendered malleable
and yet remain fluid, and how the heat of such crude molten metal may be
retained or increased, by means of jets, or currents of air, or of steam forced
into and among the particles of molten metal, without the employment of any
furnace or fire for the purpose of heating the metal, the heat necessary for
the refinement, conversion, and retention of the fluidity of the metal being
derived from the chemical action or union of some of the constitutents of
crude iron with the oxygen which is forced therein. In the treatment of
iron according to the aforesaid patented process the jets of air or of steam,
by being forced into the fluid metal at a point below the surface thereof,
produce a heaving up or boiling of the fluid, whereby the metal is brought
more or less in contact with the fluid scoria or "cinder" which is produced
during the process, and which scoria for the most part floats upon the surface
of the molten iron, and hence does not present a very extended surface in
contact with the metal. In the course of working crude iron by the before-
named patented process I have discovered that fluid cinder" or fluxes exert
a powerful refining action on the metal, when kept presented to and in contact
with a very extended and changing surface of the metal, and that the metal
is thereby more readily refined, purified, and converted than when acted upon
by air or steam, in such manner as to present only a comparatively small
surface of the metal to the action of the fluxes. I have also discovered that
molten crude iron or remelted pig iron may be refined and purified without
further furnace heat, by bringing a sufficient extended and changing surface
thereof in contact with fluid scoria and fluxes without the forcing of air or
steam into the molten iron, the heat in the metal in such case being retained
for a sufficient period of time by the confinement of the metal in a close or
nearly closed vessel or chamber, lined with a slow or bad conductor of heat,
and by bringing the carbon of the iron and the oxygen in the metallic or
other oxides present into contact or union.
For this purpose I construct a vessel by preference of wrought iron, of a
cylindrical form, with hemispherical ends, which I line with fire-brick, fire-
stone, or other suitable refractory substances. I mount the vessel in a
horizontal position on a slide or on suitable wheels, and I attach to one end

page_text: of it the piston rod of a steam engine, so that the vessel may be made to
move rapidly backwards and forwards by means of its direct connection with
the steam piston; or it may be put in motion by a crank or other intermediate
mechanism, as will be readily understood. I mount the vessel on axes, so
that it may be moved round when required; it may be also detached from
the piston rod or engine, so as to be moved as desired on rails by means of
the wheels before named. At one end of the vessel I connect a pipe, moving
in and out of a stuffing box, so that air, steam, or other gaseous matters may
be conveyed to the vessel while it is in motion. In the vessel I make a
manhole or opening, which may be stopped with a fire-clay or other stopper
when required.
In order that the mechanical arrangements which I prefer to usc in carrying
into operation my present Invention may be fully understood, I have hereunto
annexed a Sheet of Drawings, on which is represented several different
modifications of the vessel or chamber in which the conversion of crude
iron into purified cast iron, refined iron, or into steel, or malleable iron, is to
be effected.
The first modification which I shall
describe is represented at Figures
1, 2, and 3, Figure 1 being a vertical cross section; Figure 2 a side elevation;
and Figure 3 a longitudinal section of the same. u, a, represents the shell
or case of the agitating vessel, constructed of plate iron and strengthened by
curved ribs b, b, one end of the ribs being joined to a circular sliding rod c, c,
and the other extremity of the rings being united to a flanged ring c*. The
shell a is made in two halves, which are united by bolts passing through the
flanges c*. A cast-iron bed plate d is supported on masonry, and carries on
its upper side the plummer blocks e, e, through which the sliding rod c is
free to move endwise, and when required to do so may be made to turn round
or partly round by means of the capstan ring W, which fits on to a feather or
key formed on the rod c, and is provided with holes around its outer edge into
which a lever may be put and the rod c forced round. is a coupling, by means
of which one end of the slide rod c of the agitating vessel is connected to a piston
rod g, which passes through the gland h of the steam cylinder i, where it is
connected to a piston of the usual construction. The steam may be admitted
by any suitable slide or valve into the cylinder i, so as to cause a reciprocating
motion of the piston, and consequently of the agitating vessel a, such slide
or valve being worked by a tapped or by rocking levers, actuated by the
reciprocating rod c or by other well known means. In consequence of there
being no crank or fly wheel used in this apparatus, I make the steam ports
at a few inches from each end of the steam cylinder, as shewn at j, Figure 2,

page_text: which represents one of them. From this position of the port it will be
readily understood that the piston on being propelled along the cylinder in
the direction shewn by an arrow will by its momentum be carried past the
port j, so that the steam occupying the space will not be able to escape, and
will consequently form a cushion and prevent the piston from striking the
cylinder cover; the force with which the mass is moving will be employed in
compressing the steam in the space 1, and as soon as the momentum of the
moving mass is thus absorbed, and the apparatus brought to a momentary
state of rest, the elasticity of the highly compressed steam occupying the space
between the piston and the cylinder cover will react upon the piston, and
cause it to start off at a high velocity in an opposite direction; it will thus
repass the port j, and be then impelled by a fresh supply of steam, which
will cause it to pass that port at tha opposite end of the cylinder, where it
will cushion, as before described, and in like manner be moved back by the
compressed steam, and in this manner it may be propelled with considerable
velocity backward and forward, carrying with it the agitating vessel.
The
The vessel a is shewn of the form I prefer, but the form may be varied.
It is lined with fire-bricks 2, moulded to a segmental form, and fitting as
near as may be to the interior of the vessel. In the upper part of the vessel
there is a small chamber m, through the opening into which the materials
to be operated upon may be put into or removed from the vessel a.
tile closes over the opening or manhole, so as to prevent the throwing out
of such portion of the metal and slags as may get into the upper chamber m.
An escape for sparks, flame, and gaseous matters arising from the agitated
materials is provided by a lateral opening p, as shewn in Figure 3. When
air or steam is to be forced into and among the particles of fluid metal in
the vessel a, I make the sliding rod c hollow, and fit thereto a tube r, which
slides freely into the rod c, and is secured from leakage by a backing ring
at. A pipes is connected to the hollow rod c, and is provided with a cross
piece and joint t, so that two short curved pipes are free to turn on this
joint, and thus have their extremities inserted into the outer ends of the
tuyeres or removed therefrom, as may be desired. In commencing to use
this apparatus for the purposes of my Invention I half fill the vessel with
coke, and ignite the same, and blow in air through the tuyeres until the
vessel a is well heated, after which the fuel is discharged from the vessel by
inserting a lever in the capstan ring w, and thereby turning the vessel round
until the opening is downwards. The vessel is then moved back into the
position shewn in the Drawings, when the molten iron, and the slags, scoria
cinder, metallic oxides, or other fluxes, or matters in a fluid or solid state

page_text: are introduced; the tile n is then placed, and secured by a suitable bar or
catch over the opening. Steam may then be admitted into the engine, and
the vessel a be made to reciprocate at a speed which I prefer to be from
100 to 200 double strokes per minute, the effect of which rapid motion will
be to dash the fluid metal and other matters confusedly together, and against
alternate ends or parts of the vessel a, according to its form, thus mechanically
mixing and bringing the metal in a divided state in contact with fresh portions
of the fluxes and matters, while the rapid breaking up and reunion of the
various parts of the scattered and divided mass will, present a constantly
changing surface of metal to be acted upon by fresh. surfaces of the fluxes or
other matters used for the purpose of assisting the réfinement of the metal.
. In some cases, particularly with the more highly carburetted classes of iron,
this action may be assisted, as hereafter explained, by the forcing in at the
tuyeres.hot or cold blast of atmospheric air or steam at its ordinary temperature,
or superheated or other gaseous matters, and other matters in a state of powder
may also be blown in at the tuyeres in a manner already known, and which
matters may be forced into and up, through and among the molten materials
contained in the vessel. When the metal is sufficiently, purified and refined
the reciprocating motion may be stopped by shutting off the steam from the
engine; the tile n may then be removed, and the vessel turned.partly round
on the. rod c, and the metal be discharged or removed therefrom.
When it. is
desired to refine very large charges. of metal, it may be found preferable to
give a somewhat less violent reciprocating motion to 'the vessel by causing its
movement to be regulated by a crank and fly wheel, or by other suitable
mechanical arrangements.
On the Sheet of Drawings hereunto annexed, I have shewn so much. of an
apparatus as is necessary to explain the manner in which this object may.be
accomplished, Figure 4 being a longitudinal section; 'Figure 5, an elevation,
and Figure 6, a vertical cross section of the same. A is. the agitating vessel,
formed of rivetted iron plates, and lined with fire-bricks B. It is supported on
trunnions C, so as to be tipped up on end when required by means of. the
winch or handle D, on the axis of which. is a pinion in gear with the spur
wheel E; this wheel is keyed on to the trunnion, and consequently carries the
vessel A round with it. The trunnions C rest in bearings formed. in the
frame F, which is supported on. flanged wheels G, resting on an iron curb
The
forming the upper angle of a pit, over which the apparatus moves.
frame F has a cross bearer, on which the stud H rests, and is there. held in a
clip.so as to retain the vessel in its required position during the agitating
process; at one end of the frame F is attached a connecting rod. I, shewn

page_text: broken off this rod may be connected to a crank, or to any suitable me-
chanism capable of imparting to the vessel and its carriage a reciprocating
motion. When air or other gaseous matters are to be forced into the vessel A,
a pipe J may be used for that purpose, jointed at J* to the hollow trunnion C*
and from thence the air may pass by a pipe K to a branch pipe L, on the ends
of which are jointed the tuyere pipes M, and by means of which the gaseous
or other matters may be driven through the buyeres N upward through the
metal, the upper end of the pipe J moving on a joint so as to allow it to
oscillate and follow the motion of the vessel; at P there is formed a spout for
the convenience of running out the metal when the vessel is tipped up. There
is also a larger aperture on the upper side, which allows the gaseous matters,
sparks, or flame arising from the metal and other matters to escape.
In order
to prevent the escape of metal during the agitating process, it will be found
useful to form the upper part of the vessel so that a portion of it may incline
downwards at each side of the escape aperture, as shewn at B*, whereby the
matters which pass up the ends and along the upper surface of the vessel may
be deflected downwards, and be prevented from passing through the aperture.
Or in lieu of this mode of preventing the escape of metal while allowing free
egress to the gaseous matters, I pass a short tube down into the vessel, as
shewn in Figure 7, which is a longitudinal section of an agitating vessel, of
the form represented at Figure 3. Q represents the tube open at both ends,
and secured by ramming loam between its exterior and the opening left in the
lining of bricks R for that purpose.
In carrying into practice my said Invention several modifications of the
mechanical arrangements may be employed; thus the vessel, instead of moving
on slides or on wheels, may be suspended on an axis, and be made to oscillate
like a pendulum, as represented at Figure S, which is an elevation of such an
arrangement, and at Figure 9, in which the vessel is shown in cross section.
The agitating vessel 1 is provided with trunnions 2, by which it is suspended
in the rocking frame 3; this frame oscillates on the axis 4. Two connecting
rods 5, 5, are attached to the trunnions at one end, and with a two-throw
crank at the other ends of them, by means of which a backward and forward
motion may readily be given to the vessel. A lever or handle 10, fastened to
one of the trunnions, will serve to turn up the vessel when required, and also
to retain the vessel in its required position during the process, by attaching the
upper end of the handle to the rocking frame by a suitable clip, as shewn
at 11. When air or other gaseous matters are to be used in the process, a
pipe 6 may be connected with the hollow trunnion of the vessel, the upper
end moving on a joint coincident with the axis on which the apparatus vibrates

page_text: the pipes 7 and 8, conveying the air or other gaseous matters into the tuyeres
at one end of the vessel; a manhole or door 9 is formed for the convenience
of gaining access to the interior of the vessel, or for the purpose of removing
the charge therefrom. After the process of refinement is completed, the door
may have a fire-lump fastened to its inner side, or a loose fire-clay stopper may
be placed in the aperture, and the joint around it be rammed with loam, the
iron door serving to secure the stopper in its place during the process.
And here I would observe, that it will be obvious that some parts or pecu-
liarities, shewn in one of these forms of apparatus, may be used with the other
modifications thereof, so also it will be understood that the number of tuyeres
and their position in the agitating vessel may be varied as may be desired.
Previous to using this apparatus for the purification of crude molten iron, I
heat the interior lining as above explained, after which a charge of molten
crude or remelted iron is run or poured into it; I also run or pour therein a
charge of fluid cinder or slags, obtained from the blast furnace, or such-slags-
as are produced in the conversion of crude into malleable iron by currents of
air or steam, as described in my former Patents, or slags such as are obtained
in the puddling of iron. The different qualities of slags used for this purpose.
may be modified by the admixture with them of lime, clay, silica, carbon,..
alkaline salts, and earthy or metallic oxides, as may be found requisite to
purify or act upon the peculiar quality of crude iron under operation. It will
be desirable that the metal and slags should be run into the vessel at the
The manhole-having
highest temperature that can be conveniently obtained.
been closed (with the exception of a small hole for the escape of gaseous
matters), the apparatus is to be put in motion, which will have the effect of.
shaking the whole of the materials, and bringing the fluid iron in a divided.
state in contact with the fluid scoria or flux, which will have the effect of
separating from the iron a large proportion. of the impurities which it contains ;.
the more violent the agitation the more completely will the metal be diffused
throughout the liquid fluxes, and the more rapid and perfect will be the action
of these materials upon the iron. When thus treating iron that is intended
to be used for founding, it may be agitated in slags or fluxes not containing a
large quantity of oxide of iron, so that the carbon may be retained in the
If, however, too much carbon is driven off, an additional quantity may
be given when desired by adding some carbonaceous substances to the charge.
The very highly carburetted irons will be found most suitable, and when the
iron has thus being refined and purified for foundry purposes, the metal will
quickly subside, and may be run direct into sand moulds and formed into
iron.

page_text: the article desired; or it may be made into pigs, and be remelted when
required.
When, however, it is intended to convert the crude molten metal into stee
or into malleable iron, a quality of slag, or flux, or ore rich in oxide should be
used; also iron scales or other metallic oxides may be added to the flux, com-
bined with chloride of sodium. The motion of the vessel being vigorously
kept up until the complete or the desired amount of decarbonization and
purification of the metal is effected by the action of the oxides and other
substances contained in the slags, after which the metal may be discharged
from the agitating vessel. The process of conversion having been effected
without the use of fuel, except that applied to smelt the iron or remelt the
pigs previous to the commencement of my improved process, and the metal
thus obtained may be afterwards treated by any suitable known processes,
whereby it may be converted into bars, rods, or plates. If the metal be
removed from the converting vessel in the form of fluid steel, it may be run
into an ingot mould, so as to form an ingot at once suitable for tilting or rolling
into bars; or it may be granulated for the convenience of remelting it in
crucibles at a future period; or if it be removed from the vessel in a semifluid,
or more or less solid state, the lumps of metal so obtained may be put into
crucibles, and be there melted and cast into ingots, as in the ordinary mode
of melting and making ingots of blister steel.
It has long been known that the crude irons obtained from spathose ores,
specular iron ore, and the purer description of hæmatite iron, or irons con-
taining manganese, as well as being like other irons applicable in making
malleable iron, are peculiarly adapted for the manufacture of steel, and I by
preference use such class of iron for the manufacture of steel by this process.
Or, in lieu of this particular treatment either of the following methods may be
employed, namely, the crude metal-may be in part refined, and its tempera-
ture considerably raised by means of currents of air or steam forced therein
previous to running it into the agitating vessel, in which its conversion into
malleable iron or steel by the action of slags or fluxes is to be effected. Or,
the crude metal may be first subjected to the action of slags or fluxes in
the agitating vessel, and be afterwards run into a suitable vessel in which
currents of air or steam are forced into and below the surface, and whereby
the complete conversion of the metal will be effected; and here I would
observe, that I have found, when converting crude iron into malleable iron or
steel by means of currents of air, steam, or other gaseous matters forced into
and below the surface of the fluid metal (contained in the converting vessels,

page_text: such as have been previously used by me, and described in my Patent of the
12th day of February 1856, and herein-before referred to), that the heat of
such metal while under operation is better retained, and the process facilitated
by placing a floating fire tile, or a piece of fire stone or other suitable
refractory substance on to the surface of the molten metal, which will
greatly assist in preventing the radiation of heat therefrom. I have also
found that the effect of the currents of air or steam employed will be
augmented by putting some of them at a higher level than others, the upper
ones assisting in mixing the iron and other matters, while the lower ones keep
up the temperature. The additional tuyeres thus used are for the purpose of
mixing the slags or scoria and fluxes with the iron, more effectually than has
hitherto been effected by the blowing or forcing of air, steam, or other gases
into the metal, and they may be placed at any convenient angle to the surface
of the metal most effective in disturbing the metal and slags, and mixing
them together; they may also be placed more or less at a tangent to the
circular vessel containing the metal, and at such a height as to act both on
the metal and fluxes, and cause them to become mixed in a greater or less
degree. The blast of air, steam, or other gaseous matters may also be
admitted vertically upwards through one central tuyere made at the lowest
part of a vessel, having a hemispherical or conical bottom, by which the blast
so introduced into the metal will have to traverse through a greater depth of
metal and materials, and will produce a more violent agitation thereof than
is effected by the use of several tuyeres acting horizontally or nearly so.
I have herein-before described how crude iron is to be refined by forcibly
agitating the fluid metal with suitable fluxes in a close vessel without furnace
heat, and also how the same may be effected when the iron has been previously
prepared for the process by in part refining, and by heating the same by means
of currents of air or steam forced into the fluid metal.
In lieu of either of the modes herein-before described of the treating
molten crude iron or remelting pig iron, I adopt the following process:-
Having fixed into the sides or ends of the agitating vessel suitable tuyeres,
I connect them to the end tube before named, by means of which air, steam,
or other suitable gaseous matters may be conveyed into the agitating vessel,
and be made to act upon the metal therein contained simultaneously with the
agitation of the fluid, or at alternate intervals, and whereby the temperature
of the metal will most readily be kept up, and the slags or fluxes be made to
thoroughly wash and cleanse the metal, while a blast of air, steam, or other
gaseous or solid matter containing or capable of evolving oxygen is forced
into the metal,

page_text: In the treatment of crude molten iron by this last-named modification of
my improved process, a great facility is afforded for the perfect refinement and
purification of the metal, by forcing into and among the particles of metal, air,
steam, or other gaseous or solid substances, containing or capable of evolving
oxygen the solid substances may be reduced to powder, and forced by the
gaseous matters along the blast pipe into the vessel, either when the convert-
ing vessel is in a state of rest, in which case the gaseous and other matters
will be forced into and below the surface of the metal, or the forcing in of
these may be effected while the converting vessel is in motion, in which case
the jets of air or other matters will be projected into and among the moving
particles of mixed slags and metal which are dashed about with considerable
force, by which the fluid metal will be mixed thoroughly with and disseminated
among the fluid cinder, fluxes, and matters used for its purification.
understood that by thus alternating the direction of the motion of the fluid
metal; that it will present a large extent of surface for chemical action, while
the rapidity with which the particles will be reunited, and again divided and
dispersed, will have the effect of constantly presenting new surfaces to the
chemical action of those matters which are introduced into the vessel, in order
to effect the refinement and purification of the metal.
It will be
Although I do not claim as part of my present Invention the use of any
particular substances or gaseous matters for purifying crude iron, it will never-
theless be obvious that any simple or compound substances or gaseous matters
hitherto known, and used in the purification or refinement or treatment of
iron or steel, in other processes of manufacturing iron or steel, may be used in
the purification and conversion of crude iron when in a fluid state by my
improved process; by forcibly agitating the metal along with such matters in
vessels having no furnaces or fires in connection therewith.
When fluid malleable iron is to be discharged from the vessel in which it
may have been obtained from crude iron, a great difference in the quality of
the bar or rolled iron produced therefrom may be effected by the way in
which the fluid metal is treated; if it is simply run into the mould it becomes
crystalline, and if powerfully stirred up before or in the act of solidifying,
the character of the grain will be considerably modified. But I have dis-
covered that a still greater change is given to the texture of the bar or
rolled iron by diffusing, in the act of solidification, slags along with the fluid
metal.
The mode by which I prefer to accomplish this is, first, to run into the
ingot mould some fluid slags, and then proceed to run in the fluid metal. I
place the mould so far below the point where the metal is poured from, as to

page_text: cause it to fall in a shower of détached grains, or it may be divided by first
falling on to or against any suitable substance capable of dividing or scattering
the stream, or a current of air or steam may be made to disperse the metal in
a shower, which falling through the fluid slags will accumulate in a granular
mass in the mould. There it may be subjected to hydraulic pressure or to a
powerful hammer, or it may simply be discharged from the mould and be
conveyed to a furnace or oven, and there kept hot until it be required for
rolling if this interval of heating the mass be prolonged the slags contained
between the grains of metal will assist in their purification, while the rolled
metal produced from the granular ingot will be found to possess that peculiar
fibrous appearance considered essential to iron used for certain purposes.
When employing moveable converting vessels, as herein described, for the
purpose of mixing the molten iron with the fluxes and other matters, the pro-
cess may be conducted in such manner as to cool or cause the metal to
assume the pasty or more or less solid state, in which condition of mechanical
combination with the cinder or fluxes the mass may be put into. ingot moulds,
or the metal in a more solidified form may be removed by a suitable implement.
But when it is desired to form an ingot or mass of metal in a granular form
from fluid malleable iron, I use by preference an apparatus such as is repre-
sented in a modified form at Figures 10 and 11, on the Sheet of Drawings
hereunto annexed; Figure 10 being a vertical section, shewing a portion of a
converting vessel 20, into the discharge orifice of which is inserted a fire-clay
tube 21, having a vertical passage crossing the end of the horizontal one,
which leads direct into the fluid metal. 22 is a blast pipe for the passage of
either air or steam. When the metal to be granulated is in a suitable condition,
one end of the tube 21 is forced through the stopping of loam into the fluid
iron or steel, and a powerful blast is allowed to rush out of the pipe 22, which
will carry the fluid metal rapidly downwards and disperse it in the form of
drops or small globules. At Figure 11 I have shewn a portion of a vessel
containing fluid iron or steel, having an open spout 23, along which the metal
is allowed to flow; the blast pipe 24 in this case acting on the stream at that
point where it leaves the spout, and thus separates and divides the metal into
small grains or globules.
Having thus described the nature of my Invention, and the manner of per-
forming the same, I would have it understood that I am aware that it is not
new to agitate fluid iron by machinery whilst heated in a reverberatory furnace,
and I am also aware that it is not new to cause melted iron to move whilst
heated in a reverberatory furnace (through which the heat and products of
combustion from a furnace or fire-place are passing) by rotating the body or

page_text: the bed of a reverberatory furnace. I do not; therefore, make any claim thereto,
and I would state that the peculiarity of my Invention consists in subjecting
fluid iron to agitation with fluxes and purifying agents, in vessels which are not
kept heated by heat and products of combustion passing through them from
furnaces or fire-places connected therewith and suitable for melting iron
therein. And I claim,―
First, the purification or refinement of molten crude iron, or melted..pig
or partially refined iron by causing the same to be 'mechanically mixed" and
agitated with slags and other suitable fluxes or purifying agents in' a vessel, as
herein described.
Secondly, I claim the purification or refinement or rendering malleable
molten iron that has previously been treated by means of jets or currents
of air, or of steam forced into the same, by agitating such iron with slags
and suitable fluxes or purifying agents in a vessel, as therein described.
Thirdly, I claim the subjecting of molten iron, which has been previously
agitated with other matters, as herein described, in a vessel to jets or currents
of air or of steam forced into and among the fluid metal.
Fourthly, I claim the purification and conversion of fluid, crude, or partially
refined molten iron into steel, or into malleable iron, by agitating and mechani-
cally mixing therewith fluxes or other matters, combined with the use of;
streams of air or steam in a vessel, as herein described, whether. the streams of
air or steam be used simultaneously with or before or after the mechanical
agitation of the said vessel.
And, fifthly, I claim the running in a divided state from a converting vessel
or apparatus, 'ifluid metal which has been treated by the action of streams of
air or steam into molten slag or scoria or purifying agents, as herein described.,
In witness whereof, I, the said Henry 'Bessemer, have hereunto set
my hand and seal, this Ninth day of May, in the year of our Lord
One thousand eight hundred and fifty-seven.
. Witness,
B. GOBEY,
-24, Southampton Buildings,
Chancery Lane.
HENRY BESSEMER. (L.S.).