IMPROVEMENTS IN THE TREATMENT OR PURIFICATION OF IRON, AND IN THE MANUFACTURE OF MALLEABLE IRON FROM CRUDE OR PIG IRON, ALSO IN THE MANUFACTURE OF CASTINGS, AND OF INGOTS SUITABLE FOR ROLLING INTO SHEETS, PLATES, AND OTHER FORMS, AND IN APPARATUS AND PROCESSES EMPLOYED IN SUCH MANUFACTURES." PROVISIONAL SPECIFICATION
Year: 1880

page_text: LETTERS PATENT to Sir Henry Bessemer, of Denmark Hill, in the County of
Surrey, Civil Engineer, and Alfred George Bessemer, of Oakfield, South
Dulwich, in the same County, for an Invention of "IMPROVEMENTS IN THE
TREATMENT OR PURIFICATION OF IRON, AND IN THE MANUFACTURE OF
MALLEABLE IRON FROM CRUDE OR PIG IRON, ALSO IN THE MANUFACTURE OF
CASTINGS, AND OF INGOTS SUITABLE FOR ROLLING INTO SHEETS, PLATES, AND
OTHER FORMS, AND IN APPARATUS AND PROCESSES EMPLOYED IN SUCH
MANUFACTURES."
PROVISIONAL SPECIFICATION left by the said Sir Henry Bessemer and
Alfred George Bessemer at the Office of the Commissioners of Patents on the
6th March 1880.
Sir HENRY BESSEMER, of Denmark Hill, in the County of Surrey, Civil Engineer,
and ALFRED GEORGE BESSEMER, of Oakfield, South Dulwich, in the same County.
"IMPROVEMENTS IN THE TREATMENT OR PURIFICATION OF IRON, AND IN THE
MANUFACTURE OF MALLEABLE IRON FROM CRUDE OR PIG IRON, ALSO IN THE
MANUFACTURE OF CASTINGS AND OF INGOTS SUITABLE FOR ROLLING INTO SHEETS,
PLATES AND OTHER FORMS, AND IN APPARATUS AND PROCESSES EMPLOYED IN
SUCH MANUFACTURES."
as
In the manufacture of mild steel or malleable iron by the "Bessemer process
now commonly practiced the carbon and silicon present in the molten crude iron
are wholly or almost wholly eliminated by the oxidation of those substances by
means of a blast of atmospheric air which is forced through the metal, but in so
doing a notable quantity of the iron operated upon also becomes oxidized and is
lost, while the quantity of oxygen absorbed by or occluded in the blown metal
causes it to boil or throw off much of the occluded gases while undergoing the
cooling and solidifying process in the ingot moulds, and which results in the
formation of ingots containing numerous bubbles or cells, the addition of
"spiegeleisen" or ferromanganese to the blown metal before pouring it into
the moulds has the effect of lessening this boiling action to some extent, as well as
of rendering the metal so alloyed more suitable for the after processes of hammering
or rolling, but-in-practice it has been found that this tendancy to boil in iron that
Price 8d 1
"
"

page_text: has been thoroughly decarburized by jets of atmospheric air is not entirely over-
come, even when large quantities of ferromanganese are employed; it therefore
happens that sound ingots of very small size cannot be made of such metal,
because there is not sufficient time for the escape of the occluded gas before the
solidification of the small ingot takes place. It must also be borne in mind that
the extremely high temperature at which decarburized iron solidifies does not
allow sufficient time for the division of a charge of several tons of "converted
metal" into a great number of small ingots. It has also been found that the
extremely high temperature of fluid decarburized iron causes so great a reduction
in bulk during its solidification and cooling as to produce those large central
hollows in steel ingots known as "piping," and which renders the upper end of so
many large ingots unsuitable for the purpose for which they are made, thus
increasing the quantity of "scrap or waste metal, and adding to the cost of the
more solid portions of the ingot. It will also be understood that the necessity of
forming large ingots for the reasons before stated entails a great expenditure of
mechanical force and skilled labor in reducing these heavy masses to such small
sections as "tin-plate-bar" or the small slabs from which other thin sheets are
usually rolled. We have thus pointed out several of the disadvantages connected
with the present mode of converting molten crude or pig iron into numerous small
ingots of malleable metal in order to show more clearly the distinctive character of
our present Invention, and in what manner and to what extent the combined
processes which we employ differ from the processes heretofore employed for such
purpose.
"
In carrying our improved processes into practical operation we prefer to employ
the ordinary "Bessemer convertor," which may be of such a size as to operate
conveniently on 5 or 6 tons of crude iron at each charge; the metal which we
employ may be supplied in a molten state direct from the blast furnace or from an
ordinary cupola or other remelting furnace.
We prefer to use for our Invention iron smelted wholly or in part from the
hoematite ores, but other crude or pig iron may be employed for this purpose,
provided that it is free or nearly free from phosphorous, or is dephosphorized by
the agency of lime, oxide of iron, or other matters prior to or during the refining
process.
As soon as the metal is tapped or run into what may be appropriately called the
refining vessel, we proceed to force air through it in the usual way until the work-
man superintending the process judges by the appearance of the flame and sparks
emitted from the mouth of the vessel, that the whole or nearly the whole of the
silicon originally present in the metal has been eliminated therefrom, and up to
which stage of the process, but very little of the carbon originally contained in the
iron has been removed, and only a comparatively small quantity of the iron
operated upon has been wasted by conversion into an oxide.
At this early stage of the process of refinement the metal is to be poured from
the vessel into what in the "Bessemer process" is employed as a casting ladle, but
which in our new process may be more appropriately called the mixing and
distributing ladle; and we desire it to be distinctly understood that the crude
metal which has been treated as hereinbefore described is not converted into a
malleable metal, but still remains a carburet of iron sufficiently rich in carbon to
be classed as cast iron or finery iron, but which is nevertheless wholly or almost
wholly free from an admixture or alloy of silicon, thus the process of refinement
which the crude metal has undergone in the vessel may be appropriately called
the desiliconization of crude iron, and consequently the metal resulting from
this process is hereinafter referred to as desiliconized iron. It is a metal suitable
for the production of castings which are to be rendered malleable by a subsequent
process of decarburation. In some cases it will be convenient to run the metal at
this time into moulds or channels to form pigs to be remeltd when required for use,
and sometimes before so doing we add to the metal a small proportion of
spiegeleisen or ferromanganese,

page_text: In cases where it is intended to produce sheets, plates, or other rolled forms it is
more convenient to proceed at once to cast the metal into small ingots, and we
shall proceed to describe the way in which we produce small ingots suitable for
rolling into sheets for the tin plate manufacture. Before pouring the desiliconized
iron from the refining vessel some small lumps of red hot spiegeleisen or ferro-
manganese are to be put into the mixing or distributing ladle, or the alloying
metal may be added in a fluid or a finely granulated state immediately after the
metal has been poured into the distributing ladle; in either case a thorough mixture
of these substances should be made by means of a revolving agitator after the
manner described in a Patent granted to Henry Bessemer, dated January the 31st,
1863, and numbered 114, or by other convenient means. A much smaller quantity
of ferromanganese than is generally employed in making Bessemer steel will
suffice, because in this partial refinement of a highly carburetted metal very little
oxygen will have combined with or become occluded in the metal, for it must be
borne in mind that the refined metal does not in this process attain the extremely
high temperature and furious state of ebulition accompanying the complete
decarburization of the metal. As soon as a thorough amalgamation of the ferro-
manganese and the desiliconized iron has taken place, the metal is to be transferred'
from the mixing or distributing ladle into the several casting ladles from which it
is run into the moulds. In order to facilitate the casting of numerous small ingots,
slabs, or plates of this desiliconized metal, we employ several casting ladles or
vessels, which we mount on wheels and which move on rails, so that each casting
ladle may be readily brought into a convenient position to be filled from the
distributing ladle by means of a valve and lever handle as commonly practiced in
the Bessemer process; these several ladles may be made of plate iron, and be lined
with moulded fire brick and loamed up in a manner well understood.
.
We prefer to provide each such ladle with a well fitted cover so as to prevent as
far as possible the escape of heat from the metal; we also prefer that these ladles
should be thoroughly heated prior to running the fluid metal into them, and each
such ladle as soon as filled may be wheeled away into the foundry where the ingots
are to be cast, and where iron moulds are provided of such sizes as are required to
form ingots for the several descriptions of plates, sheets, &c., into which the metal
is finally to be rolled, but in all cases ingots of a flat or thin section are preferred, as
the after process of decarburation to which they are subjected is greatly facilitated
by the thinness and extended surface of the ingots to be operated upon.
For example, when ingots are required for the manufacture of tin or black plates
we make them for the most part from 10 to 14 inches long, by 6 to 7 inches wide,
and from one half to three fourths of an inch in thickness, so that the ingots as
cast represent the short lengths of "tin plate bar" usually employed in the tin
plate manufacture.
Such ingots or pieces of tin plate bar may be cast in iron moulds constructed and
arranged in several different ways; one of the least complicated consists in making
a mould mainly in one piece capable of making, say, one hundred ingots in as many
compartments of the same mould. For this purpose we cast an iron wheel of about
six feet in diameter, formed somewhat like a spur wheel, in which the breadth of
the periphery is equal to the length of the ingots to be formed, while the depth and
breadth of the space between each tooth is equal to the breadth and thickness of
the intended bar or ingot.
This wheel is mounted on a horizontal axis, and has a ratchet wheel on the same
axis, or ratchet teeth may be formed upon the mould wheel, so that intermittant
rotatory motion may be communicated to it by means of a small crank, after the
manner in which the feed motion of planing machines and lathes are arranged.
Two cheek plates embrace the upper portion of the periphery and thus close the
ends of the grooves in which the metal is to be run; the top side of the moulds
thus formed-is-left-open-for-the-reception of the metal. In arranging a foundry on
this principle we prefer to place several such wheel moulds in a double line, with
a space between the two rows of moulds sufficient for the passage of the ladles

page_text: which are to be moved on wheels between the rows of moulds. These casting
ladles are mounted on a carriage with flanged wheels running on rails at such a
height as to convey the casting ladles at a short distance above the upper side of
the moulds.
The casting ladles are each provided with a valve and handle to regulate the
discharge of the metal from them in the manner commonly practised in casting
ingots by the Bessemer process, but the metal so liberated from the casting ladle
does not flow direct into the moulds, but is received into a basin which forms the
central part of an open or closed gutter or channel, which extends in both directions
across the space between the double row of moulds, and also across and above the
moulds. Near each end of the gutters or channels there are several small nozzles
arranged in one or two rows through which the fluid metal flows vertically into
one, or, preferably, two, of the compartments of each set of moulds, which are caused
to make a sudden movement when filled by the attendant putting in gear the
ratchet movement before referred to, and this continues until all the moulds in each
wheel are filled, or until the whole of the metal is run out of the ladle.
It may be mentioned that the spaces or grooves in which the small ingots are
formed may be slightly wedge shaped to facilitate the removal of the ingots.
The iron moulds employed in this process may be cooled either by the passage of
water through suitable channels formed in the metal so as to allow a continuous
circulation of water, or by means of jets projected against the moulds, or by
allowing the lower side of the moulds to move through a trough or tank of
water.
It will be readily understood that the division of the five ton charge of
desiliconized metal into five separate ladles, each of which is made to discharge its
contents through several nozzles into four separate ingot moulds at one time, and
thus simultaneously casting twenty ingots," will greatly facilitate the casting
operation, and as the metal will retain its fluidity owing to its high state of
carburation much longer than malleable iron or mild steel, it follows that ample
time is afforded for the formation of the whole five tons of desiliconized metal into
a large number of very small ingots. It will also be obvious that many other
forms of moulds may be employed; thus, for ingots of a larger size, say, from a foot
to fifteen inches square, by three fourths to an inch and a quarter in thickness, we
prefer to make a series of flat moulds having a hollow recess equal to the size of
the intended plate and half its thickness formed on each side, the surrounding
surface being planed true; such moulds may be stacked together on edge in large
numbers side by side, either on the floor of the foundry or on trucks moving under
the nozzles from which the metal is poured, and thus forming a series of moulds; or
they may be suspended in an iron frame by means of lugs or projections cast on
them for that purpose, and connected by links and pins, so that they may be separated
or opened out in such a way as to enable the ingots to be removed, and be then
made to slide or close up into close contact and be there held until they are again filled
with metal, with the same general arrangement of moveable casting ladle on wheels
and the gutters for the distribution of the metal as when a revolving or wheel
mould is employed.
The next stage of the process following the casting operation is the decarburation
of the desiliconized cast iron ingots, which may be effected by embedding them in
oxide of iron, manganese, or other metallic oxides or substances capable of absorbing
or removing the carbon therefrom.
This process of decarburation may be effected in moveable boxes in a manner
similar to that practised in making what are in the trade called malleable iron
castings; or the process of decarburation may be carried on in horizontal retorts
or chambers so constructed that a sufficient heat may be applied externally to the
said chambers to effect the decarburation; or in lieu thereof the decarburation of
the ingots may be effected in a long low roofed reverberatory furnace, on the bed
of which the ingots may be packed with metallic oxides between them, the upper
surface of the plates being protected by a thin covering from the direct action of

page_text: the flame. But in order to save labor, economise time, and to obtain uniform
results we prefer to decarburize the desiliconized iron ingots in vertical tubes or
retorts constructed and arranged after the manner shewn and described in a Patent
granted to us, and bearing date the 10th of October 1879, numbered 4110. We
prefer to use powdered hæmatite iron ore for this purpose, and also using the waste
gases of the blast furnace for heating such retorts when the process is carried
on at works where such gases are abundant.
The decarburized ingots of malleable iron so produced may be cleansed by
friction in a revolving box or cylinder; or they may be pickled in dilute sulphuric
acid and then he rolled into tin or black plate, or into other and larger sheets, bars,'
or rods by the ordinary or other improved processes of rolling.
Thus it will be understood that the combined processes of desiliconizing the
metal by blasts of air, the alloying it with as much manganese as is necessary to
make it work satisfactorily under the hammer or rolls, the casting of the metal
so treated into small ingots, the decarburation and conversion of such ingots while
in the solid state into malleable iron, and rolling the same into tin or black plates
and other sheets or forms, constitute a series and combination of processes, by
means of which crude or pig iron is converted into tin or black plates, or other
sheets or forms of malleable iron.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Sir Henry Bessemer and Alfred George Bessemer in the Great
Seal Patent Office on the 6th September 1880.
Sir HENRY BESSEMER, of Denmark Hill, in the County of Surrey, Civil Engineer,
and ALFRED GEORGE BESSEMER, of Oakfield, South Dulwich, in the same County.
"IMPROVEMENTS IN THE TREATMENT OR PURIFICATION OF IRON, AND IN THE
MANUFACTURE OF MALLEABLE IRON FROM CRUDE OR PIG IRON, ALSO IN THE
MANUFACTURE OF CASTINGS AND OF INGOTS SUITABLE FOR ROLLING INTO SHEETS,
PLATES, AND OTHER FORMS, AND IN APPARATUS AND PROCESSES EMPLOYED IN SUCH
MANUFACTURES."
In the manufacture of mild steel or malleable iron by the "Bessemer process,"
as now commonly practiced, the carbon and silicon present in the molten crude
iron are wholly or almost wholly eliminated by the oxidation of those substances
by means of a blast of atmospheric air, which is forced through the metal, but in
so doing a notable quantity of the iron operated upon also becomes oxidized and
is lost, while the quantity of oxygen absorbed by or occluded in the blown metal
causes it to boil or throw off much of the occluded gases while undergoing the
cooling and solidifying process in the ingot moulds, and which results in the
formation of ingots containing numerous bubbles or cells. The addition of "spiegel-
eisen" or "ferromanganese " to the blown metal before pouring it into the moulds
has the effect of lessening this boiling action to some extent, as well as of rendering
the metal so alloyed more suitable for the after processes of hammering or rolling,
but in practice it has been found that this tendancy to boil in iron that has been
thoroughly decarburized by jets of atmospheric air is not entirely overcome even
when large quantities of ferromanganese are employed. It therefore happens that
sound ingots of very small size cannot be made of such metal because there is not
sufficient time for the escape of the occluded gas before the solidification of the
small ingot takes place. It must also be borne in mind that the extremely high
temperature at which decarburized iron solidifies does not allow sufficient time for
the division of a charge of several tons of "converted metal" into a great number
of small ingots. It has also been found that the extremely high temperature of
fluid decarburized iron causes so great a reduction in bulk during its solidification
and cooling as to produce those large central hollows in steel ingots known as
'piping," and which renders the upper end of so many large ingots unsuitable for
the purpose for which they were made, thus increasing the quantity of " scrap or
waste metal and adding to the cost of the more solid portions of the ingot. It will
also be understood that the necessity of forming large ingots for the reasons before
stated entails a great expenditure of mechanical force and skilled labor in reducing
these heavy masses to such small sections as "tin plate bar," or the small slabs
from which other thin sheets are usually rolled. We have thus pointed out several
of the disadvantages connected with the present mode of converting molten crude
or pig iron into numerous small ingots of malleable metal in order to show more
clearly the distinctive character of our present Invention, and in what manner and
to what extent the combined processes which we employ differ from the processes
heretofore employed for such purpose.
tr
"
In carrying our improved processes into practical operation we prefer to employ
the ordinary Bessemer converter," which may be of such a size as to operate
conveniently on 5 or 6 tons of crude iron at each charge; the metal which we
employ may be supplied in a molten state direct from the blast furnace or from an
ordinary cupola or other remelting furnace.
We prefer to use for our Invention iron smelted wholly or in part from the
hæmatite ores, but other crude or pig iron may be employed for this purpose,
provided that it is free or nearly free from phosphorus or is dephosphorized by the

page_text: agency of lime, oxide of iron, or other matters prior to or during the refining
process.
As soon as the metal is tapped or run into what may be appropriately called the
refining vessel we proceed to force air through it in the usual way, until the
workman superintending the process judges by the appearance of the flame and
sparks emitted from the mouth of the vessel, that the whole or nearly the whole of
the silicon originally present in the metal has been eliminated therefrom, and up
to which stage of the process but very little of the carbon originally contained in
the iron has been removed, and only a comparatively small quantity of the iron
operated upon has been wasted by conversion into an oxide. At this early stage
of the process of refinement the metal is to be poured from the vessel into what in
the "Bessemer process" is employed as a casting ladle, but which in our new
process may be more appropriately called the mixing and distributing ladle, and we
desire it to be distinctly understood that the crude metal which has been treated
as herein before described is not converted into a malleable metal, but still remains
a carburet of iron, sufficiently rich in carbon to be classed as cast iron or finery
iron, but which is nevertheless wholly or almost wholly free from an admixture
or alloy of silicon; thus the process of refinement which the crude metal has under-
gone in the vessel may be appropriately called the desiliconization of crude iron,
and consequently the metal resulting from this process is hereinafter referred to as
desiliconized iron. It is a metal suitable for the production of castings which are
to be rendered malleable by a subsequent process of decarburation.
Such castings so decarburated may be employed for numerous purposes without
having undergone the process of hammering or rolling. This process of decar-
buration consists in embedding them in oxide of iron or other suitable matter in
close boxes, and exposing them for a considerable time to a red heat in the manner
already known and practised in the manufacture of what are known in the trade
as malleable-iron castinga, and which are usually made from white pig iron in the
crude state as run from the blast furnace. Instead of making such castings at
once from the metal as soon as it is desiliconized, in some cases it will be convenient
to run the metal into moulds or channels to form pigs or ingots to be remelted
when required for use, and sometimes before so doing we add to the metal a small
proportion of spiegel-eisen or ferromanganese.
In cases where it is intended to produce sheets, plates, or other rolled forms, it is
more convenient to proceed at once to cast the metal into small ingots, and we
shall proceed to describe the way in which we produce small ingots suitable for
rolling into sheets for the tin plate manufacture. Before pouring the desiliconized
iron from the refining vessel some small lumps of red hot spiegeleisen or ferro-
inanganese are to be put into the mixing or distributing ladle; or the alloying
metal may be added in a fluid or a finely granulated state immediately after the
metal has been poured into the distributing ladle; in either case a thorough
mixture of these substances should be made by means of a revolving agitator, after
the manner described in a Patent granted to Henry Bessemer, dated January the
31st, 1863, and numbered 114, or by other convenient means. A much smaller
quantity of ferromanganese than is generally employed in making Bessemer steel
(say one half) will suffice, because in this partial refinement of a highly carburetted
metal very little oxygen will have combined with or become occluded in the
metal, for it must be borne in mind that the refined metal does not in this process
attain the extremely high temperature and furious state of ebullition accompanying
the complete decarburization of the metal. As soon as a thorough amalgamation
of the ferromanganese and the desiliconized iron has taken place, the metal is to
be transferred from the mixing or distributing ladle into the several casting ladles
from which it is run into the moulds. In order to facilitate the casting of numerous
small ingots, slabs, or plates of this desiliconized metal we employ several casting
ladles or vessels which we mount on wheels-and-which move on rails, so that
each casting ladle may be readily brought into a convenient position to be filled
from the distributing ladle by means of a valve and lever handle as commonly

page_text: practiced in the Bessemer process; these several ladles may be made of plate iron
and be lined with moulded fire brick and loamed up in a manner well understood.
We prefer to provide each such ladle with a well fitted cover so as to prevent as
far as possible the escape of heat from the metal; we also prefer that these ladles
should be thoroughly heated prior to running the fluid metal into them, and each
such ladle as soon as filled may be wheeled away into the foundry where the
ingots are to be cast, and where iron moulds are provided of such sizes as are
required to form ingots for the several descriptions of plates, sheets, &c., into which
the metal is finally to be rolled, but in all cases ingots of a flat or thin section are
preferred, as the after process of decarburation to which they are subjected is
greatly facilitated by the thinness and extended surface of the ingots to be operated
upon.
For example, when ingots are required for the manufacture of tin or black plates,
we make them for the most part from 10 to 14 inches long by 6 to 7 inches wide,
and from one half to three fourths of an inch in thickness, so that the ingots as
cast represent the short lengths of "tin plate bar" usually employed in the tin
plate manufacture.
Such ingots or pieces of tin plate bar may be cast in iron moulds constructed and
arranged in several different ways; one of the least complicated consists in making
a mould mainly in one piece capable of making, say, one hundred ingots in as
many compartments of the same mould. For this purpose we cast an iron wheel of
about six feet in diameter formed somewhat like a spur wheel, in which the
breadth of the periphery is equal to the length of the ingots to be formed, while
the depth and breadth of the space between each tooth is equal to the breadth and
thickness of the intended bar or ingot.
This wheel is mounted on a horizontal axis, and has a ratchet wheel on the same
axis, or ratchet teeth may be formed upon the mould wheel so that intermittent
rotatory motion may be communicated to it by means of a small crank or a lever,
after the manner in which the feed motion of planing machines and lathes are
arranged. Two cheek plates embrace the upper portion of the periphery, and thus
close the ends of the grooves in which the metal is to be run; the top side of the
moulds thus formed is left open for the reception of the metal. In arranging a
foundry on this principle, we prefer to place several such wheel moulds in a double
line with a space between the frames, which support the two rows of moulds
sufficient for the passage of the ladles, which are to be moved on wheels between
the frames which support the rows of moulds. These casting ladles are mounted
on a carriage with flanged wheels running on rails, at such a height as to convey
the casting ladles at a short distance above the upper side of the moulds.
The casting ladles are each provided with a valve and handle to regulate the
discharge of the metal from them in the manner commonly practised in casting
ingots by the Bessemer process, but the metal so liberated from the casting ladle
does not flow direct into the moulds, but is received into a basin which forms the
central part of an open or closed gutter or channel, which extends in both directions
across the space between the double row of moulds, and also across and above the
moulds. Near each end of the gutters or channels there are several small nozzles
arranged in one or two rows through which the fluid metal flows vertically into
one, or preferably, two of the compartments of each set of moulds, which are caused
to make a sudden movement when filled by the attendant putting in gear the
ratchet movement before referred to, and this continues until all the moulds in each
wheel are filled, or until the whole of the metal is run out of the ladle.
It may be mentioned that the spaces or grooves in which the small ingots are
formed may be slightly wedge shape to facilitate the removal of the ingots.
The iron moulds employed in this process may be cooled, either by the passage
of water through suitable channels formed in the metal so as to allow a continuous
circulation of water, or by means of jets projected against the moulds, or by
allowing the lower side of the moulds to move through a trough or tank of water.
And in order that this particular arrangement of moulds may be more fully

page_text: understood, we have represented the same on the Sheet of Drawings annexed,
where Figure 1 is a vertical cross-section on the line A, B, of Figure 2, showing
one of the wheel moulds f* and the gutter y in elevation; Figure 2 is a side
elevation of the casting apparatus, shown broken off at both ends, and Figures 3, 4,
and 5 are details of the same on a larger scale. The general arrangement of the
wheel moulds as shown may be continued, so that the casting apparatus may be
made to include any desired number of moulds. In some cases we prefer to
employ ten pairs of wheel moulds in one framing, so that one set of five pairs may
be employed and cooled while the second set of five pairs are being used for
casting; thus, if each wheel mould will contain half a ton of small ingots, the set
of five pairs will suffice for a five ton charge of desiliconized metal, the other set of
five pairs allowing the process to be repeated while the ingots previously cast are
being removed and the moulds cooled.
In the annexed Drawing a, a, represents a portion of the main framing of the
casting apparatus; it is securely bolted to a solid foundation and may be extended
to any desired length in either direction, as shown by the broken off parts b, b.
A flanged rail c, c, is carried on upright supports d, d, bolted at their lower ends to
the main framing a, and steadied crosswise by stout stay rods e which extend from
one side to the other of the apparatus. The mould wheels f, f, form massive tyres
to the disc wheels g, g, the peripheries of which are fitted in between the raised
fillets f¹ and the boops n, which are bolted to the inside of the mould wheel f,
and thus allows the free expansion. and contraction of the moulds by change of
temperature. The wheels g, g, are supported on separate axes, one end of each of
which are supported on the outside plummer blocks h, h, and centrally in the
single plummer block i which rests on the central frame a*.
It will be seen that the mould wheels are formed into a series of deep grooves or
notches, each of which are planed or cut accurately; they are tapered slightly,
being narrowest at the bottom edge, so as to facilitate the removal of the ingots
from them; the sides of the mould-wheels are also truly turned, and the upper
parts of them pass between the two external frames ; and k, and also in contact
with a similar central frame The internal faces of these frames are bevilled at
jx and kx, and wedge shaped iron plates m are so placed as to come in close contact
with the bevilled part of the frame on one side, and with the mould-wheel on the
other, and thus close up the ends of the grooves and complete the mould. At that
part of the wheel where the casting operation is carried on two similar parallel
plates p, p, serve to close the opposite ends of the moulds; the pieces m and p are
made movable so as to be readily replaced when worn-out, and should be kept cool
either by circulation of water through small passages formed in them, or by means
of jets of water playing on them.
The ladler is supported on four flanged wheels, two of which 8, 8, move on
axes t, t, projecting from a hoop u which embraces the ladle. A second pair of
wheels v, v, are placed on an axis passing behind the ladle and running in bearings
which project from the hoop u. Both sets of wheels are placed above the centre
of gravity of the ladle, but the wheels 8, 8, are so near the centre of gravity
vertically as to allow the ladle to be easily tipped up on its axis t, t, and any slags
or other debris discharged therefrom after each casting operation, the wheels v, v,
in that case being lifted off the rails.
?"
The ladle is provided with a nozzle w and stopper x, as usual in the casting
ladles employed in the Bessemer process, and by means of which the workman
regulates the quantity of metal which flows from the ladle into the enlarged central
part of the gutter y, from which it flows in both directions to the small fireclay
nozzles z, and from them vertically in small quiet streams into the compartment
of the mould immediately beneath. The gutter y is made of plate-iron lined with
loam, and is supported by studs yx inserted in the top of the central frame !.
When the first casting ladle has been filled from the distributing ladle it-is-to be
wheeled along the rails c into the foundry and placed centrally over. the farthest
pair of wheel-moulds, and the process of casting at once commenced, while each

page_text: successive casting ladle as soon as filled is made to follow and be placed over the
next pair of mould-wheels in succession, and so on, until the distributing ladle is
emptied.
It will be observed that the disc wheels g, g, are provided with ratchet wheels 1
bolted firmly to them; a lever handle 2 moves on an axis 3 attached to a bracket 4;
the lower end of the lever 2 has a jointed pawl 5 kept up by a spring 6, so that
the movement backward and forward of the lever through the distance assigned to
it, between the studs 7, 7, will move the moulds the exact distance that their
centres are apart, and thus bring one after the other successively under the nozzles
from which the metal is flowing. By using two sets of nozzles, as shewn in
Figure 4, two moulds may be filled at one time in the same mould wheel, and thus
hasten the casting operation. A small truck, not shewn in the Drawings, may be
wheeled beneath the mould wheels to receive the ingots, which may be detached by
a slight blow of a hammer and chisel when vertically below the centre of the axis;
the mould wheel may then be cooled and the process of casting repeated from time
to time as required..
It will be readily understood that the division of the five ton charge of
desiliconized metal into five separate ladles, each of which is inade to discharge its
contents through several nozzles into four separate ingot moulds at one time, and
thus simultaneously casting twenty ingots, will greatly facilitate the casting
operation, and as the metal will retain its fluidity, owing to its high state of
carburation, much longer than malleable iron or mild steel, it follows that ample
time is afforded for the formation of the whole five tons of desiliconized metal into
a large number of very small ingots. It will also be obvious that many other
forms of moulds may be employed; thus, for ingots of a larger size, say, from a foot
to fifteen inches square by three fourths to an inch and a quarter in thickness, we
prefer to make a series of flat moulds having a hollow recess equal to the size of
the intended plate, and half its thickness, formed on each side, the surrounding
surface being planed true. Such moulds may be stacked together on edge in large
numbers side by side, either on the floor of the foundry or on trucks moving under
the nozzles from which the metal is poured, and thus forming a series of moulds;
or they may be suspended in an iron frame by means of lugs or projections cast on
them for that purpose, and connected by links and pins so that they may be
separated or opened out in such a way as to enable the ingots to be removed, and
be then made to slide or close up into close contact and be there held until they
are again filled with metal, with the same general arrangement of moveable casting
ladle on wheels and the gutters for the distribution of the metal as when a
revolving or wheel mould is employed.
The next stage of the process following the casting operation is the decarburation
of the desiliconized cast iron ingots, which may be effected by embedding them in
oxide of iron, manganese, or other metallic oxides or substances capable of absorbing
or removing the carbon therefrom.
This process of decarburation may be effected in moveable boxes in a manner
similar to that practised in making what, in the trade, are called malleable iron
castings; or the process of decarburation may be carried on in horizontal retorts or
chambers, so constructed that a sufficient heat may be applied externally to the
said chambers to effect the decarburation; or in lieu thereof the decarburation of
the ingots may be effected in a long low roofed reverberatory furnace, on the bed
of which the ingots may be packed with metallic oxides between them, the upper
surface of the plates being protected by a thin covering of such metallic oxide from
the direct action of the flame. But in order to save labor, economise time, and to
obtain uniform results, we prefer to decarburize the desiliconized iron ingots in
vertical tubes or retorts constructed and arranged after the manner shown and
described in a Patent granted to us, and bearing date the 10th of October 1879,
numbered 4110. We prefer to use powdered hoematite iron ore for this purpose,
and also to use the waste gases of the blast furnace for heating such retorts when
the process is carried on at works where such gases are abundant.

page_text: The decarburized ingots of malleable iron so produced may be cleansed by
friction in a revolving box or cylinder, or they may be pickled in dilute sulphuric
acid, and then be rolled into tin or black plate, or into other and larger sheets, bars,
or rods by the ordinary or other improved processes of rolling. Thus it will be
understood that the combined processes of desiliconizing the metal by blasts of air,
the alloying it with as much manganese as is necessary to make it work satis-
factorily under the hammer or rolls, the casting of the metal so treated into small
ingots, the decarburation and conversion of such ingots while in the solid state into
malleable iron, and rolling the same into tin or black plates and other sheets or
forms constitute a series and combination of processes by means of which crude or
pig iron is converted into tin or black plates, or other sheets or forms of malleable
iron.
Having thus described the nature of the said Invention, and the manner of
performing the same, we would have it understood that we claim,―
First. The purification of crude iron in such manner as to obtain a purified cast
iron suitable for making such castings as are to be rendered malleable by cementation
in the solid state by desiliconizing molten crude metal, and also in some cases
alloying the metal with manganese, substantially as described.
Second. The manufacture of tin or black plates, or other thin sheets of iron from
ingots, of desiliconized cast iron which have been decarburized and rendered
malleable by cementation, substantially as described.
Third. The manufacture of malleable iron ingots and castings by the, combined
processes of desiliconization with but partial decarburation of the molten crude
iron, the alloying the metal so treated with manganese, the pouring of the fluid
metal into moulds, and the subsequent decarburation and conversion of the ingots
or castings into malleable iron by cementation, substantially as described.
Fourth. The apparatus with circular or wheel moulds for casting ingots,
substantially as described.
In witness whereof, I, the said Sir Henry Bessemer, have hereunto set my'
hand seal, this Fourth day of September, in the year of our Lord One
thousand eight hundred and eighty.
HENRY BESSEMER. (L.S.)