IMPROVEMENTS IN TREATING AND CONVERTING IRON ORES AND PIG METAL FOR THE PRODUCTION OF IRON AND STEEL, AND IN FURNACES AND APPARATUS EMPLOYED IN CONNECTION THEREWITH
Year: 1871

page_text: LETTERS PATENT to Charles William Siemens, of No. 3, Great George
Street, Westminster, in the County of Middlesex, for the Invention
of "IMPROVEMENTS IN TREATING AND CONVERTING IRON ORES AND PIG METAL
FOR THE PRODUCTION OF IRON AND STEEL, AND IN FURNACES AND APPARATUS
EMPLOYED IN CONNECTION THEREWITH,
"
PROVISIONAL SPECIFICATION left by the said Charles William
Siemens at the Office of the Commissioners of Patents, with his
Petition, on the 15th November 1871.
I, CHARLES WILLIAM SIEMENS, of No. 3, Great George Street, West-
minster, in the County of Middlesex, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN TREATING AND CONVERTING IRON OREB
AND PIG METAL FOR THE PRODUCTION OF IRON AND STEEL, AND IN FURNACES AND
APPARATUS EMPLOYED IN CONNECTION THEREWITH," to be as follows:-
In the Specification to my Patent dated 28th February 1870, No. 594,
I described a method of preparing iron ores for the production of cast

page_text: steel by fusing the ore in conjunction with fluxing materials and by
pouring the fused ore into moulds containing pieces of coke or other
solid carbonaceous substance for the purpose of effecting a partial or
complete reduction of the ore. Experience has proved however that the
reducing action of the pieces of coke ceases entirely from the moment of
solidification of the ore, and that the remaining unconsumed pieces of
coke are a hindrance to the subsequent process of steel melting. On the
other hand I have observed that the ore while in a fluid condition readily
attacks solid carbon, forming metallic iron in a dense form well suited
for carrying out my process of producing cast steel upon the open hearth
of a regenerative gas furnace.
According to my present Invention I effect the complete fusion of the
ore in a regenerative gas furnace of similar construction to that described
in my former Patent above alluded to. If the ore is a magnetic oxide
or a carbonate of iron its fusion will be effected without admixture of
carbonaceous matter, but if it is peroxide about five per cent. of coke,
anthracite, or coal should be mixed with it before charging it into the
feeding hopper. The fluxes used should bear a relation to the gangue
or earthy matter in the ore and also to the impurities in the pig. metal
which is to be acted upon by the converted ore in the steel melting
furnace. Thus if the ore contains much silica and there is little sulphur
or phosphorus either in the ore or in the pig metal it will suffice to use
ordinary limestone, and if it can be readily obtained, a certain proportion
of clay ironstone or clay; but if sulphur or phosphorus have to be
removed I prefer to resort to the stronger bases of potash or soda.
Manganese also, as oxide or carbonate, may be added with advantage to
such ore before fusion. If the ore contains little silica I prefer the use
of fluor spar as the fluxing material on account of its well-known action
upon sulphur and phosphorus. The fusion of the or ehaving been
effected I then add a certain proportion of carbonaceous matter, which
in being mixed thoroughly with the ore by stirring or otherwise converts
the same into a pasty mass consisting principally of reduced iron, which
is then formed into loaves or pigs to be used in the open hearth steel
melting furnace described in the Specification to my before-mentioned
Patent.

page_text: melting furnace with a trapdoor in the bottom plate of that part of the
furnace bed where the fluid ore accumulates, and I also provide a
stoppered aperture furnished with a hopper in the roof of the furnace
above the fluid bath, and whenever a sufficient mass of fluid ore has
accumulated I introduce small coke or anthracite powder into the fur-
nace through the feeding hopper, causing at the same time the fluid ore
to be agitated by stirring by means of rabbles introduced through side
doors. A powerful ebullition will ensue and the fluid ore will be speedily
converted into a pasty mass consisting in a great measure of reduced or
metallic iron. The quantity of carbonaceous matter necessary to effect
this conversion will be from 10 to 15 per cent. of the weight of fluid
ore, but has to be determined chiefly by experience. Before the
ebullition of the ore has ceased the trapdoor in the bottom of the
furnace is opened to discharge the boiling and pasty mass upon a pig
bed or divided hearth of fire-brick immediately below the furnace, where
it is allowed to solidify sufficiently for its removal in the shape of lumps
or pigs to be introduced into the bath of the steel melting furnaces while
still red hot if possible. The agitation of the fluid ore within the furnace
in mixing it with the carbon may be effected conveniently by a
mechanical rabble such as is used sometimes in puddling iron.
According to the second modification I provide a separate furnace for
effecting the mixing of the fluid ore with solid carbon with a view to
effecting its reduction. This mixing furnace consists of a hollow
chamber of a spherical or other suitable form, by preference of cast iron,
mounted upon a system of friction rollers actuated so as to impart rotary
motion to the chamber. This chamber is provided with two large
openings situated opposite each other around the horizontal axis of
rotation of the chamber. Through one of these openings a nozzle,
divided into two orifices by a fire-clay division wall, is introduced, which
orifices communicate with two pairs of brick regenerators for heated
combustible gas and air (of well-known construction) in such a manner
that the rotating chamber constitutes the combustion chamber of a
regenerative gas furnace with reversal of currents, the gas and air
passing into the chamber through the one orifice of the nozzle while the
gaseous products of combustion pass out through the other orifice. The
opening on the opposite side of the chamber serves for introducing the
necessary materials and for general access, the opening being usually
closed by means of a moveable door.

page_text: . An internal lining capable of resisting both intense heat and the
corrrosive action of fluid iron ores is provided for the chamber in the
following manner:-The ore melting furnace before referred to is
charged with titanic iron ore, chromate of iron, or other refractory
iron ore which is comparatively free from alkaline or other non-metallic
admixtures, and the heat of the furnace is raised sufficiently to fuse these
refractory materials. In the meantime moulds are provided for the
reception of the melted materials of such a shape as to produce lumps
of a conical or bevilled form, which if fitted together form a compact
arched lining to the rotating chamber before described. The refractory
nature of this lining may be further increased by calcination of the
lumps (whereby the magnetic oxide is converted into peroxide of iron),
and the lining when formed may be protected against fusion by the
internal heat by refrigerating the outer metallic shell of the chamber
either by casting iron pipes into it, through which water or air is made
to circulate, or by directing a current of water or air over the exterior of
the shell. This rotative protected chamber being heated internally
nearly to whiteness a ladle full or regulated stream of melted ore is
admitted through the working door, after which about 15 per cent. of
solid carbon is also introduced. The door is thereupon closed and the
chamber is made to rotate slowly, any suitable known means being pro-
vided for increasing the rotation gradually. With the rotation ebullition
will increase within the chamber until the mass becomes pasty. It
may thereupon be discharged through a trapdoor in the circumference
of the chamber by stopping the rotation of the same so as to bring the
trapdoor into the lowest position and over a pig bed of mould for the
reception of the semi-reduced mass. Or the reduction may be continued
in the rotating chamber until the particles of metallio iron have
agglomerated into a ball and separated completely from the liquid cinder
containing the earthy constituents of the ore. In this case the ball may
be more conveniently lifted out by means of any suitable known con-
trivances through the working door, and the liquid cinder alone be
discharged through a trapdoor or stoppered aperture in the circum-
ference of the vessel. The ball of reduced iron with some fluid cinder
adhering to it may be transferred forthwith to the bath of a steel melting
furnace, or it may be further consolidated in the first instance under a
shingling hammer or squeezers.

page_text: furnace with its adjunct near the steel melting furnace or furnaces in
order not to lose the heat of the lumps of partially or wholly reduced
metal, but in cases where the ore is found at a very great distance from
the steel works it may be more advantageous to place the furnace near
the mine, which will save cost of carriage, inasmuch as the lumps of
reduced metal weigh less than the ore used in their production.
The lumps taken from the rotating furnace when consolidated by
hammering or squeezing may also be passed through a rolling mill to
produce bars or plates of wrought iron for general application.
The said rotating furnace may also be used for puddling cast iron.
The pig metal should in that case be melted in a cupola or other separate
furnace, and after the introduction of a charge of melted pig metal into
the rotary furnace fluid ore in suitable proportion (being from 25 and
30 per cent. of the weight of the pig metal) should be admitted. In
giving rotation to the furnace, energetic ebullition will arise and a ball
of metal will soon be formed, which is taken out to be hammered and
rolled into any desirable shape, whereas the remaining fluid cinder is
discharged as before described. By this mode of working charges of
iron may be puddled in very rapid succession with great regularity and
with little expenditure of labour and fuel.
The lining of the rotating chamber will be liable to wear and will
have to be replaced by another lining from time to time, but in order
not to stop the working of the furnace for the sake of renewing or
repairing the lining of the rotary chamber the latter may be removed
bodily by means of a crane and another chamber with a proper lining
be substituted.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles William Siemens in the Great Seal Patent
Office on the 15th May 1872.
BO
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of No. 3, Great George Street, Westminster, in the
County of Middlesex, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Hér
Letters Patent, bearing date the Fifteenth day of November, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me; the said Charles William Siemens, Her special licence
that I, the said Charles William Siemens; my executors, administrators,
and assigns, or such others as I, the said Charles William Siemens, 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 TREATING AND CONVERTING IRON ORES AND PIG METAL FOR
THE PRODUCTION OF IRON AND STEEL; AND IN FURNACES AND APPARATUS EMPLOYED
IN CONNECTION THEREWITH,” upon the condition (amongst others) that I,
the said Charles William Siemens, 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 Charles William Siemens, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement thereof, reference being had to the
accompanying Drawings, and to the figures and letters marked thereon,
that is to say :-
In the Specification to my Patent dated 28th February 1870, No. 594,
I described a method of preparing iron ores for the production of cast
steel by fusing the ore in conjunction with fluxing materials, and by
pouring the fused ore into moulds containing pieces of coke or other
carbonaceous substance for the purpose of effecting a partial or complete
reduction of the ore. Experience has proved however that the reducing
action of the pieces of coke ceases entirely from the moment of solidi-
fication of the ore, and that the remaining unconsumed pieces of coke
are a hindrance to the consequent process of steel melting. On the
other hand I have observed that the ore while in a fluid condition

page_text: readily attacks solid carbon, forming metallic iron in a dense form, which
can be rolled or hammered and which is well suited for carrying out
my process of producing cast steel upon the open hearth of a regenerative
gas furnace.
According to my present Invention I effect the complete fusion of the
ore by preference in a regenerative gas furnace of similar construction
to that described in my former Patent above alluded. to. If the ore is a
magnetic oxide or a carbonate of iron its fusion will be effected without
admixture of carbonaceous matter; but if it is peroxide about five per
cent. of coke, anthracite, or coal should be mixed with it before charging
it into the feeding hopper. The fluxes used should bear a relation to
the gangue or earthy matter in the ore, and also to the impurities in the
pig metal which is to be acted upon by the converted ore in the steel
melting furnace. Thus if the ore contains much silica and there is
little sulphur or phosphorus it will suffice to use ordinary limestone,
and if it can be readily obtained a certain proportion of clay ironstone
or clay; but if sulphur or phosphorus have to be removed I prefer to
resort to the stronger bases of potash or soda. Manganese also, as oxide
or carbonate or iron ores containing manganese, may be added with
advantage to such ore before fusion. If the ore contains little silica I
sometimes use fluor spar as the fluxing material on account of its well-
known action upon sulphur and phosphorus. The fusion of the ore
having been effected I then add a certain proportion of carbonaceous
matter, which in being mixed thoroughly with the ore by stirring or
otherwise converts the same into a pasty mass consisting of reduced
iron mixed with cinder, which is then formed into loaves or pigs to be
used in the open hearth steel melting furnace described in the Specifi-
cation to my before-mentioned Patent, or which may be formed into
puddled balls and consolidated and cleared of cinder in the ordinary
way.
In carrying out the process I employ two different modifications of
furnaces, a stationary and a rotating furnace, which will be fully described
hereafter with reference to Drawings. The quantity of carbonaceous
matter, such as anthracite, or coke, or charcoal powder, necessary to effect
the precipitation or conversion of the iron varies from 10 to 20 per cent.
of the weight of the fluid ore according to its richness in iron, but has to be
determined chiefly by experience. Before the ebullition of the ore has
ceased the mixed mass of cinder and reduced iron may be discharged

page_text: through a trapdoor in the bottom of the furnace upon a pig bed or
divided hearth of fire-brick (which is in that case prepared immediately
below the furnace), where it is allowed to solidify sufficiently for its
removal in the shape of lumps or pigs to be introduced into the bath
of the steel-melting furnace while still red hot if possible. This mode
of proceeding is however applicable only to very rich and pure
ores, it being preferred generally to continue the operation until the
separation of the iron from the cinder is completed and a ball of
wrought metal is obtained. The agitation of the fluid ore within the
furnace in mixing it with the carbon may be effected conveniently
by a mechanical rabble such as is used sometimes in puddling iron,
and a tubular rabble may be used for the introduction of reducing gas
into the fluid mass.
According to another modification of my process I provide a separate
furnace for effecting the mixing of the fluid ore with solid carbon in
order to effect the precipitation of the iron. A rotary mixing furnace
is hereafter described in reference to the Drawings. The rotary furnace
being heated internally nearly to whiteness a ladle full or regulated
stream of melted ore is admitted to it, and from 15 to 20 per cent. of
solid carbon is also introduced. The door is thereupon closed and the
chamber is made to rotate slowly, any suitable known means being
provided for increasing the rotation gradually. With the rotation
ebullition will increase within the chamber until the mass becomes
pasty; but this chemical reaction may with advantage be accelerated by
rabbling during rotation. The agitation of the fluid mass is continued
until the particles of metallic iron have agglomerated into a ball and
separated completely from the liquid cinder containing the earthy
constituents of the ore. When this is the case the ball is lifted out by
any suitable known contrivance through the working door, and the
liquid cinder is discharged through a trapdoor or stoppered aperture in
the circumference of the vessel. The ball of reduced iron with some
fluid cinder adhering to it may be transferred forthwith to the bath of
a steel-melting furnace, or it may be further consolidated under a
shingling hammer or squeezers.

page_text: metal; but in cases where the ore is found at a very great distance from
the steel works it may be more advantageous to place the furnace near
the mine, which will save cost of carriage, inasmuch as the lumps of
reduced metal weigh less then the ore used in their production.
The lumps taken from the rotating furnace when consolidated by
hammering or squeezing may also be passed through a rolling mill to
produce bars or plates of wrought iron for general application. The said
rotating furnace may also be used for puddling cast iron. The pig
metal should in that case be melted in a cupola or other separate
furnace, and after the introduction of a charge of melted pig metal into
the rotary furnace fluid ore in suitable proportion (being from 25 to 30
per cent. of the weight of the pig metal) should be admitted. In giving
rotation to the furnace, which may be assisted by rabbling or by
injecting gases, energetic ebullition will arise, and a ball of metal will
soon be formed, which is taken out to be hammered and rolled into any
desirable shape, whereas the remaining fluid cinder is discharged as
before described. By this mode of working charges of iron may be
puddled in very rapid succession with great regularity and with little
expenditure of labor and fuel. The lining of the rotating chamber will
be liable to wear, and will have to be replaced by another lining from
time to time; but in order not to stop the working of the furnace for the
sake of renewing or repairing the lining of the rotary chamber the
latter may be removed bodily by means of a crane, and another chamber
with a proper lining be substituted.
Having thus described the nature of my Invention, I will now proceed
to describe the best means which I know of carrying the same into
effect, for which purpose I refer to the accompanying Drawings, and to
the letters and figures marked thereon.
Fig. 1, Sheet I., represents a longitudinal section; Fig. 2, Sheet I., a
transverse section; and Fig. 3, Sheet I., a sectional plan on the line Z, Z,
(Fig. 1) of a furnace constructed according to one modification for
carrying out the process of melting and converting. A. is the bed of the
furnace lined with refractory material, which may consist of a mixture
of carbon with argillacious matter, with or without iron oxides, either
rammed into its place or made into bricks and laid therein; or it may
consist of burnt limestone or of refractory iron oxides which have been
previously fused and cast into moulds so as to form bricks or blocks
which are laid in the furnace. Four flues B, B², and C, C³, open into

page_text: the back of the furnace, the two lower flues B, B¹, being used alternately
for admitting heated gas thereto and the two upper flues C, C¹, being
alternately used for admitting heated air. When the one pair of flues,
as B and C, are in use for the admission of the gas and air the other pair,
B and C, form exits for the products of combustion after they have
circulated in the furnace. Each of the four flues communicates with ȧ
regenerative chamber, one of which is represented at D in Fig. 1. For
a time two of these chambers. are heated by the passage of the waste
products of combustion through them, while the other two, which had
been previously heated, serve to heat the air and gas supplied to the
furnace. When the one pair of regenerators have been sufficiently
heated and the other pair cooled, the direction of the currents is reversed
by means of valves, so that the two flues which previously served as
inlets of gas and air are made now to serve as outlets of products of
combustion, and vice versa. This mode of using the regenerative system
of furnace for heating the gas and air by the waste heat of the products
of combustion is well known and understood; and I describe it here not
for the purpose of claiming it as part of my present Invention, but only
for more clearly explaining the action of the furnace to which in this
case it is applied. The heated gas and air admitted by the pair of flues
B and C, or B and C¹, produce a flame of intense heat in the furnace,
which beats upon the surface of the ore laid on the bed A. The ore
with its admixture of fluxing materials is introduced through the door E,
which can be opened for the purpose. The ore when fused is supplied
with the carbonaceous matter in the form of small coke or anthracite
powder, and is stirred by a rabble F introduced through a hole in the
side of the furnace or in the door. Instead of introducing solid car-
bonaceous matter and stirring the mixture by a solid rabble, I sometimes
introduce it in the form of carbonic oxide or of a rich carbonaceous gas
by means of a tubular rabble, which has the effect of at once agitating
the melted mass and giving it the supply of carbonaceous matter in a
minutely divided form; or I employ solid and gaseous carbonaceous
matter in conjunction.
Fig. 4, Sheet I., represents à section of an apparatus for generating
and enriching such carbonaceous gas. It consists of a furnace
G wherein slow combustion of coke, anthracite, or other fuel is main-
tained by the limited admission of air through the pipe H, carbonic
oxide and other combustible gases being discharged by the pipe I.
This pipe leads to a vessel J supplied with petroleum or other volatile

page_text: oils: The hot gases passing over the surface of the oil become enriched
with carbonaceous matter and are conducted by the pipe K to the
various tubular rabbles which it is intended to supply, and which are
connected by flexible pipes to branches on the pipe K: When by the
introduction of the solid or gaseous carbonaceous matter the fused ore
becomes deoxidized, metallic iron of great purity is precipitated, the
earthy constituents of the fluid mass forming a cinder which retains in
solution the bulk of silicon sulphur and phosphorus present. The inter-
mixture of the pulverulent carbon and the liquid ore is facilitated by
mixing the carbon with an equal weight or more of rich pulverulent
oxide of iron, such as hammer slag; or an ore rich in manganese may be
used with advantage for this purpose if it is desired that the iron pro-
duced should contain manganese, or if steel is to be produced. The
rapidity and completeness of this reaction depends chiefly upon the
temperature; which should exceed the welding heat; it also depends
however upon the presence of a sufficient proportion of fluxing materials
to combine with the silica contained in the orë, and upon a sufficiency of
carbon present, which latter may be added from time to time if necessary.
Under favorable conditions a rapid precipitation of the metallic iron
ensues, which latter may thereupon be separated from the fluid cindër
by balling it in the manner usual in puddling iron. Before completing
the balling a portion of the fluid cinder may be removed by tapping it
in order to clear the iron, which may thereupon be removed, hammered,
and rolled in the usual manner; or it may be transferred while still hot
to a steel melting furnace, as described in my Patent above referred to,
in order to be there dissolved in a bath of pig metal: It may be readily
understood that the formation of cast steel may be completed in the
same furnace if a lining of lime or argillaceous matter has been applied,
by discharging all the cinder from the furnace after the ball or balls are
formed; and by introducing the pig metal in a heated or fluid condition.
A portion of the pig metal supplied (if not all) should contain manganese.
Before tapping the metal samples should be taken out and tested by
observing the fracture when chilled in water, in order to see that the
per-centage of carbon or the temper of the steel is such as may be
desired.

page_text: being effected in one furnace and the conversion in another. Fig. 4,
Sheet II., represents a plan, and Fig. 5, Sheet II., an elevation shewing
the general arrangement of furnaces for this purpose. Fig. 6, Sheet II.,
represents a transverse section of the fusing furnace; Fig. 7, Sheet II.,
a longitudinal section of the converting furnace, and Fig. 8, Sheet II.,
a section through the throat of the converting furnace. The fusing
furnace L consists of a trough-shaped bed arched over by the crown of
the furnace, through which there are openings L, L,formed at each
side and surmounted by hoppers. The ore to be fused, mixed with about
5 per cent. of carbonaceous matter, is supplied to the hoppers and sinks
down through the openings into the bed of the furnace, forming a
-sloping heap at either side. For certain ores, such as hematite con-
taining silica, limestone should be added in proportions suited to the
amount of silica, such. proportions being determined chiefly by ex-
perience. Or, it is preferable to mix such hematite with spathic ore
containing limestone, magnesia, or manganese, to which may be added
an argillacious ironstone, the object being to produce by such mixture a
fusible slag without adding separate fluxing materials. Fluor spar may be
used with advantage as a fluxing material if the ores contain phosphorus
without much silica. Or stronger alkaline bases, such as potash or soda,
may be added with advantage when impure ore containing both silica and
phosphorus or sulphur is used. It is to be understood that these directions
as to fluxing apply when the single furnace is used as already described.
The flame enters the bed by one of the end openings M, and after
circulating through the furnace and playing on the ore, issues by the
other opening M, as indicated by the arrows in Fig. 6, Sheet II. These
openings communicate with regenerative chambers which are alternately
employed for heating the air and gas and for being heated by the waste
products of combustion, suitable valves being employed for the purpose
. of reversing the direction of the currents through the openings M, M².
The ore acted on by the flame is fused and the liquid ore collects in the
basin formed in the middle of the furnace between the two side heaps of
ore. When a sufficient quantity of liquid ore has collected carbonaceous
matter in powder may be introduced, as before described, and the mass
being well stirred a trapdoor N may be opened and the fused matter in
a pasty condition allowed to run into moulds or on to a pig bed below so
as to form bricks, ingots, or pigs, to be treated in a bath of melted pig
for the production of cast steel in another furnace. Or the fused ore

page_text: may be tapped from time to time so as to issue by a tap hole in the
front of the furnace, whence it runs by a moveable gutter O to the
converting furnace P.
Fig. 9, Sheet II., represents a transverse section of the gutter O, which
consists of a metallic casing lined and covered with refractory material,
and which should be internally heated by a gas flame before it is used.
The converting furnace P is preferably of globular or polygonal shape
mounted on rollers, on which it can be made to revolve. At the one
end of the axis of rotation is a throat into which four flues Q, R, and
Q', R¹, open. The two lower flues Q, Q', are used alternately for the
admission of the heated gas and the two upper flues R, R¹, for the
admission of heated air; the other two of the four flues being then
employed as outlets for the waste products of combustion. All
these flues communicate with regenerative chambers, one of which
is shewn at S, and the direction of the currents through the flues is
made to alternate by suitable valves, as already described with reference
to the furnace represented in Sheet I. The heated gas and air entering
by a pair of the flues form an intense flame, which beats upon the
material in the rotating chamber and after circulating therein issues by
the other pair of flues. Opposite the furnace throat there is an orifice,
which is closed by means of a door T. This door is suspended by a chain
over a pulley t, and can be raised and lowered by means of a crab
wheel. A spy hole Tu in the door T serves to introduce a rotating or
gas rabble, as shewn in Figs. 10 and 11 respectively, when the door
itself is down and the furnace at work. The door T is supported
laterally by two vertical guide bars T, and it is so suspended as to
lean against the circumference of the mouth or orifice of the rotating
chamber.
The lining of the rotating chamber is formed by preference of bricks
of fused refractory ore of conical shape put in cold and consolidated
when heated in their places by pouring other fused or semi-fused ore
over them in rotating the apparatus. The latter method is also
employed from time to time for mending the lining. Or a lining of
argillaceous brickwork may be introduced in the first instance, and a
ferrugenous inner lining be formed by the introduction of pure or
semi-fused iron ores, which should be rich oxides such as roll cinder
or haematites. Having thus prepared the furnace lining and raised the
internal temperature of the chamber to a white heat I introduce into

page_text: the same through the open door T a certain quantity of coke or
anthracite powder mixed intimately by preference with an equal or
double weight of pulverulent iron ore. In giving rotation to the chamber
this mass is well heated, and the partial reduction of the iron ore
effected, which owing to the high specific gravity prevents the carbon
from rising bodily to the surface of the fluid ore when that is introduced
and facilitates the process of intermixture.
If it is desired that the iron to be produced should contain manganese
it is found advantageous to mix ore rich in manganese with the carbon
powder, when it will be reduced in a great measure into the metallic
condition.
The process may also be varied by moistening the mixture of ore and
carbon and forming it into bricks or lumps before introducing it into
the rotating furnace. Or the inner lining may be formed of such
consolidated mixture of ore and carbon, in which case an argillaceous
ore or argillaceous matter in a separate form should be added. The
rotating furnace being thus prepared the door T is raised, the heated
gutter adjusted between it and the melting furnace, and the latter
tapped, whereby a stream of fluid ore is directed into the chamber.
The quantity of fluid ore to be admitted for one charge should bear a
proper proportion to the amount of carbonaceous matter charged and
the working capacity of the apparatus, and can be judged pretty nearly
by the time of flow or by the interval of time since the previous tap of
the melting furnace. The gutter is thereupon removed, the door T
closed, and the chamber put into rotation. The chemical reaction:
between the materials may now be further accelerated by the intro-
duction of the rotating or the gas rabble as before described. During
the continuance of this operation additional solid carbon may be added
either separately, or mixed with oxides, or combined with iron ore into
bricks or lumps. If the ores employed contain much gangue or foreign
matter it will be found advantageous to discharge the liquid cinder
before the ball of iron is quite formed. This liquid cinder will carry
with it nearly all the phosphorus and sulphur present, and it is
possible by this process to produce very pure iron from ores and fuel
containing those hurtful materials in large quantities.
Instead of mixing the solid carbonaceous matter used with pulverulent
ore it may be charged separately before or even after the fluid ore has
been introduced into the rotative chamber, and energetic rabbling may

page_text: be resorted to to effect a speedy precipitation of the metallic iron.
It must however be borne in mind that high temperature is an essential
condition for effecting the reaction, and that if a white beat is not
maintained a considerable proportion of iron will remain in the oxidized
condition with the cinder. The temperature being maintained at a
sufficient elevation the deoxidation of the ore depends upon the amount
of carbonaceous matter added (a small per-centage only of the oxide
of iron remaining in combination with the cinder). When the car-
bonaceous matter is added in excess steely iron or natural steel is the
result. When the conversion of the material is effected in P the iron
produced is balled, and the ball is removed through the doorway T and
dealt with by hammering or squeezing in the usual way. The fused
cinder left in the chamber P is run out through a tap hole P¹ formed in
one part of the periphery, the chamber being turned round so as to
3 bring that hole to the bottom.
It is to be understood that the exterior of the rotative chamber may
be cooled by the application of water either upon its surface or in
circulating tubes according to any known method. Also the rotative
chamber might be supplied with fused ore from a cupola or other
description of furnace applicable for that purpose, though the furnace L
already described is considered the most suitable for the purpose.
It is convenient to arrange one such globular converting furnace
between two fusing furnaces with a framing to support an overhead
travelling crane, by which the rotating chamber can be removed in order
to be relined or repaired and replaced.
In Figs. 4 and 5, Sheet II., are shewn the relative positions of the
rotating chamber P and the one fusing furnace L, another such fusing
furnace being supposed to be placed on the other side of P. A jib
crane V may be mounted on the framing for removing the ball from the
rotating chamber, and the rotation of the chamber may be effected by
means of a small engine W situated below the working floor. A
framing and set of rollers X may be provided at each end of the furnace
range for the reception of a rotative chamber under repair, and it is
convenient to have two rotative chambers, one in use for converting
while the other is under repair.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I would have it understood that I

page_text: do not claim generally the use of regenerative gas furnaces in the
production of iron and steel, nor do I claim the use of a tubular rabble
whereby gas can be introduced into melted matter while it is being
agitated by the rabble, nor do I claim generally the use of a rotating
chamber for the purpose of puddling; but I do claim,―
First. The process substantially as herein described of producing
wrought iron and natural steel by fusing iron ore and agitating the fluid
mass in contact with carbonaceous matter under the influence of intense
heat.
Second. The process substantially as herein described of producing
cast steel by fusing iron ore, agitating the fluid mass in contact with
carbonaceous matter under the influence of intense heat, balling and
tapping off the fluid cinder, and then dissolving the balled matter
in a bath of fluid pig either in the same or in a different
furnace.
Third. The use for the manufacture of iron and steel of a rotating
furnace constructed with the inlet for flame and outlet for products of
combustion arranged at one throat of the furnace, substantially as
described with reference to Figs. 7 and 8, Sheet II.
Fourth. The mode substantially as herein described of applying 1
regenerators to a rotating furnace for the production of iron and steel by
dividing the throat of such furnace into four passages, each communi-
cating with a regenerative chamber.
Fifth. The arrangement of fusing and converting furnaces in combi-
nation for successive operation, substantially in the manner and for the
purposes described in reference to Figs. 4, 5, 6, and 7, Sheet II.
In witness whereof, I, the said Charles William Siemens, have
hereunto set my hand and seal, this Fifteenth day of May, in
the year of our Lord One thousand eight hundred and seventy-
two.
C. WILLIAM SIEMENS. (L.S.)

page_text: In the Matter of Letters Patent granted to OHARLES WILLIAM
SIEMENS, of No. 8, Great George Street, Westminster, in the
County of Middlesex, for an Invention of "IMPROVEMENTS IN
TREATING AND CONVERTING IRON ORES AND PIG METAL FOR THE PRO-
DUCTION OF IRON AND STEEL, AND IN FURNACES AND APPARATUS EMPLOYED
IN CONNECTION THEREWITH," bearing date at Westminster, the
Fifteenth day of November, in the year of our Lord One
thousand eight hundred and seventy-one, No. 3077.
ISCLAIMER AND MEMORANDUM OF ALTERATION as proposed to
be entered by the said Charles William Siemens, pursuant to the
Statutes in that case made and provided.
WHEREAS Her Majesty Queen Victoria, by Her Letters Patent,
nder the Great Seal of the United Kingdom of Great Britain and
eland, bearing date at Westminster; the Fifteenth day of November,
he thousand eight hundred and seventy-one in the thirty-fifth year of

page_text: Her reign, did give and grant unto the said Charles William Siemens,
his executors, administrators, and assigns, the sole privilege of making,
using, exercising, and vending the said Invention for "IMPROVEMENTS IN
"TREATING AND CONVERTING IRON ORES AND PIG METAL FOR THE PRODUCTION OF
" IRON AND STEEL, AND IN FURNACES AND APPARATUS EMPLOYED IN CONNECTION
THEREWITH," within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, for and during the term of
fourteen years thence next ensuing:
66
And whereas in pursuance of a proviso in the said Letters Patent the
said Charles William Siemens did, within six calendar months thenee next
ensuing after the date of the said Letters Patent, cause a Specification
in writing, under his hand and seal, purporting to describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, to be duly filed in the Great Seal Patent Office:
And whereas since the filing of the said Specification, I, the said
Charles William Siemens, have discovered that part of the said Invention
as claimed in the said Specification may be objected to on the ground
that it was not entirely new, and that the claim having reference thereto
should be more precise in order to limit it to that which was actually
new in the said part of the Invention.
NOW KNOW YE, that by and with the leave of Her Majesty Attorney-
General, I, the said Charles William Siemens, do hereby disclaim and
alter part of the third claiming clause of the said Specification, so as
not to extend the claim thereby expressed in manner following, that is
to say:
-
In page 16, of the Queen's Printer's copy of the Final Specification,
between the word "rotating" at the end of the 16th line, and the word
"furnace" at the beginning of the 17th line, I insert the words " re-
generative gas." In the 18th line, between the words "at" and
I insert the word "the," and between the words "one" and "throat" I
18th
A
one
"
insert the words "end or," also in the same line, after the word
"furnace" I insert the words "and a working door at the opposite end."
And the said Specification, when disclaimed, altered, and amended, will
read as follows:-
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of No. 3, Great George Street, Westminster, in the

page_text: WHEREAS Her. most Excellent Majesty Queen. Victoria, by Her
Letters Patent, bearing date the Fifteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-one, in
the thirty-fifth year of Her reign, did, for Herself, Her heirs. and suc-
3 cessors, give and grant unto me, the said Charles William Siemens,
Her special licence that I, the said Oharles William Siemens,, my
executors, administrators, and assigns,. or such others as I, the said
Charles William Siemens, 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 Ohannel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN TREATING AND CONVERTING IRON ORES
AND PIG METAL FOR THE PRODUCTION OF IRON AND STEEL, AND IN FURNACES AND
“APPARATUS EMPLOYED IN CONNECTION THEREWITH," upon the condition
(amongst others) that I, the said Charles William Siemens, 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 caused 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.
66
NOW KNOW YE, that I, the said Charles William Siemens, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in, and by
the following statement thereof, reference being had to the accompanying
Drawings, and to the figures and letters marked thereon, that is to say:―
In the Specification to my Patent, dated 28th February 1870, No. 594,
I described a method of preparing iron ores for the production of cast
steel by fusing the ore in conjunction with fluxing materials, and by
pouring the fused ore into moulds containing pieces of coke or other
carbonaceous substance for the purpose of effecting a partial or complete
reduction of the ore. Experience has proved however that the reducing
notion of the pieces of coke ceases entirely from the moment of solidifica-
tion of the ore, and that the rema ing unconsumed pieces pieces of coke
ire a hindrance to the consequent process of steel melting. On the
other hand I have observed that while the ore while in a fluid condidition
readily attacks solid carbon, forming metallic iron in a dense form, which
in
A

page_text: can be rolled or hammered, and which is well suited for carrying out my
process of producing cast steel upon the open hearth of a regenerative
: gas furnace.
According to my present Invention I effect the complete fusion of the
ore, by preference in a regenerative gas furnace of similar construction
to that described in my former Patent above alluded to. If the ore is a
magnetic oxide or a carbonate of iron its fusion will be effected without
admixture of carbonaceous matter; but if it is peroxide, about five per
cent. of coke, anthracite, or coal should be mixed with it before charging
it into the feeding hopper. The fluxes used should bear a relation to the
gangue or earthy matter in the ore, and also to the impurities in the pig
metal which is to be acted upon by the converted ore in the steel
melting furnace. Thus if the ore contains much silica, and there is
little sulphur or phosphorus, it will suffice to use ordinary limestone,
and it can be readily obtained, a certain proportion of clay, ironstone, or
clay; but if sulphur or phosphorus have to be removed I prefer to
resort to the stronger bases of potash or soda. Manganese also, as oxide
or carbonate or iron ores containing manganese may be added with
advantage to such ore before fusion. If the ore contains little silica I
sometimes use fluor spar as the fluxing material on account of its well-
known action upon sulphur and phosphorus. The fusion of the ore
having been effected, I then add a certain proportion of carbonaceous
matter, which in being mixed thoroughly with the ore by stirring or
otherwise, converts the same into a pasty mass consisting of reduced iron
mixed with cinder, which is then formed into loaves or pigs to be used
in the open hearth steel melting furnace described in the Specification to
my before-mentioned Patent, or which may be formed into puddled balls,
and consolidated and cleared of cinder in the erdindary ordinary way.
In carrying out the process I employed two different modifications of
furnaces; a stationary and a rotating furnace, which will be fully described
hereafter with reference to Drawings. The quantity of carbonaceous
matter, such as anthracite or coke, or charcoal powder, necessary to effect
the precipitation or conversion of the iron, varies from 10 to 20 per
cent. of the weight of fluid ore, according to its richness in iron, but
has to be determined chiefly by experience. Before the ebullition of
the ore has ceased the mixed mass of cinder and reduced iron may be
discharged through a trap door in the bottom of the furnace upon a pig
bed or divided hearth of fire-brick (which is in that case prepared imme-

page_text: diately below the furnace), whereby it is allowed to solidify sufficiently for
its removal in the shape of lumps or pigs to be introduced into the bath
of the steel melting furnace while still red hot if possible. This mode
of proceeding is however applicable only to very rich and pure ores, it
being preferred generally to continue the operation until the separation
of the iron from the cinder is completed, and a ball of wrought metal is
obtained. The agitation of the fluid ore within the furnace in mixing
it within the carbon may be effected conveniently by a mechanical rabble,
such as is used sometimes in puddling iron; and a tubular rabble may be
used for the introduction of reducing gas into the fluid mass.
According to another modification of my process I provide a separate
furnace for effecting the mixing of the fluid ore with solid carbon, in order
to effect the precipitation of the iron. A rotary mixing furnace is hereafter
described in reference to the Drawings. The rotary furnace being
heated internally nearly to whiteness, a ladle full or regulated stream
of melted ore is admitted to it, and from 15 to 20 per cent. of solid
carbon is also introduced. The door is thereupon closed, and the chamber
is made to rotate slowly, any suitable known means being provided for
increasing the rotation gradually. With the rotation ebullition will
increase within the chamber until the mass becomes pasty; but this
chemical reaction may with advantage be accelerated by rabbling during
rotation. The agitation of the fluid mass is continued until the particles
of metallic iron have agglomerated into a ball, and separated completely
from the liquid cinder containing the earthy constituents of the ore. When
this is the case the ball is lifted out by any suitable known contrivance
through the working door, and the liquid cinder is discharged through a
trap door or stoppered aperture in the circumference of the vessel. The ball
of reduced iron with some fluid cinder adhering to it may be transferred
forthwith to the bath of a steel melting furnace, or it may be further
consolidated under a shingling hammer or squeezers.
It will generally speaking be advantageous to place the ore-reducing
furnace, with its adjunct, near the steel-melting furnace or furnaces, in order
not to lose the heat of the lumps of partially or wholly reduced metal; but
in cases where the ore is found at a very great distance from the steel works
it may be more advantageous to place the furnace near the mine, which
will save cost of carriage, inasmuch as the lumps of reduced metal
weigh less than the ore used in their production. The lumps taken from
the furnace when consolidated by hammering or squeezing may
rotating
A

page_text: also be passed through a rolling mill to produce bars or plates of
wrought iron for general application. The said rotating furnace may
also be used for puddling cast iron. The pig metal should in that case
be melted in a cupola or other separate furnace, and after the intro-
duction of a charge of melted pig metal into the rotary furnace fluid ore
in suitable proportion (being from 25 to 30 per cent. of the weight of
the pig metal) should be admitted. In giving rotation to the furnace,
which may be assisted by rabbling or by injecting gases, energetic
ebullition will arise, and a ball of metal will soon be formed which is
taken out to be hammered and rolled into any desirable shape, whereas
the remaining fluid cinder is discharged as before described. By this
mode of working charges of iron may be puddled in very rapid suc-
cession with great regularity, and with little expenditure of labor and
fuel. The lining of the rotating chamber will be liable to wear, and
will have to be replaced by another lining from time to time; but in
order not to stop the working of the furnace for the sake of renewing or
repairing the lining of the rotary chamber the latter may be removed
bodily by means of a crane, and another chamber with a proper lining
be substituted.
Having thus described the nature of my Invention I will now proceed
to describe the best means which I know of carrying the same into effect,
for which purpose I refer to the accompanying Drawings and to the
letters and figures marked thereon.
Fig. 1, Sheet I., represents a longitudinal section; Fig. 2, Sheet I., a
transverse section; and Fig. 8, Sheet I., a sectional plan on the line Z, Z,
(Fig. 1) of a furnace constructed according to one modification for
carrying out the process of melting and converting. A is the bed of
the furnace lined with refractory material, which may consist of a
mixture of carbon with argillaceous matter with or without iron oxides,
either rammed into its place or made into bricks and laid therein; or it
may consist of burnt limestone or of refractory iron oxides which have
been previously fused and cast into moulds so as to form bricks or blocks
which are laid in the furnace. Four flues, B, B', and C, O¹,
open into
the back of the furnace, the two lower flues B, B¹, being used alternately
for admitting heated gas thereto, and the two upper flues C, C, being
alternately used for. admitting heated air. When the one pair of flues
as B and C are in use for the admission of the gas and air, the other pair
B₁ and C¹ form exits for the products of combustion after they have

page_text: circulated in the furnace. Each of the four flues communicates with a
regenerative chamber, one of which is represented at D in Fig. 1. For
a time two of these chambers are heated by the passage of the waste
products of combustion through them, while the other two, which had been
previously heated, serve to heat the air and gas supplied to the furnace.
When the one pair of regenerators have been sufficiently heated and the
other pair cooled, the direction of the currents is reversed by means of
valves, so that the two flues which previously served as inlets of gas
and air are made now to serve as outlets of products of combustion, and
vice versa.. This mode of using the regenerative system of furnace for
heating the gas and air by the waste heat of the products of combustion
is well known and understood, and I describe it here not for the purpose
of claiming it as part of my present Invention, but only for more clearly
explaining the action of the furnace to which in this case it is applied.
The heated gas and air admitted by the pair of flues B and C or B¹
and C¹, produce a flame of intense heat in the furnace, which beats upon
the surface of the ore laid on the bed A. The ore with its admixture of
fluxing materials is introduced through the door E which can be opened
for the purpose.
The ore when fused is supplied with the carbonaceous
matter in the form of small coke or anthracite powder, and is stirred by
a rabble F introduced through a hole in the side of the furnace or in the
door. Instead of introducing solid carbonaceous matter and stirring the
mixture by a solid rubble, I sometimes introduce it in the form of
carbonic oxide or of a rich carbonaceous gas by means of a tubular
rabble, which has the effect of at once agitating the melted mass and
giving it the supply of carbonaceous matter in a minutely divided form,
or I employ solid and gaseous carbonaceous matter in conjunction.
Fig. 4, Sheet I., represents a section of an apparatus for generating
and enriching such carbonaceous gas; it consists of a furnace G, wherein
slow combustion of coke, anthracite, or other fuel is maintained by the
limited admission of air through the pipe H, carbonic oxide and other
combustible gases being discharged by the pipe I. This pipe leads to a
vessel J supplied with petroleum or other volatile oils; the hot gases
passing over the surface of the oil become enriched with carbonaceous
matter, and are conducted by the pipe K to the various tubular rabbles
which it is intended to supply, and which are connected by flexible pipes
to branches on the pipe K. When by the introduction of the solid. or
gaseous carbonaceous matter the fused ore becomes deoxidized, metallic

page_text: iron of great purity is precipitated, the a earthy constituents of the fluid
mass forming a cinder which retains in solution the bulk of silicon, sul-
phur, and phosphorus present. The intermixture of the pulverulent carbon
and liquid ore is facilitated by mixing the carbon with an equal weight
or more of rich pulverulent oxide of iron, such as hammer slag, or an ore
rich in manganese may be used with advantage for this purpose if it is
desired that the iron produced should contain manganese, or if steel is to
be produced. The rapidity and completeness of this reaction depends
chiefly upon the temperature which should exceed the welding heat; it
also depends however upon the presence of a sufficient proportion of
fluxing materials to combine with the silica contained in the ore, and
upon a sufficiency of carbon presente, which latter may be added from
time to time if necessary. Under favorable conditions a rapid precipi-
tation of the metallic iron ensues, which latter may thereupon be
separated from the fluid cinder by balling it in the manner usual in
puddling iron. Before completing the balling, a portion of the fluid
cinder may be removed by tapping it in order to clear the iron, which
may thereupon be removed, hammered, and rolled in the usual manner,
or it may be transferred while still hot to a steel melting furnace, as
described in my Patent above referred to, in order to be there dissolved
in a bath of pig metal. It may be readily understood that the formation
of cast steel may be completed in the same furnace if a lining of lime or
argillaceous matter has been applied, by discharging all the cinder from
the furnace after the ball or balls are formed, and by introducing the
pig metal in a heated or fluid condition. A portion of the pig metal
supplied (if not all) should contain manganese. Before tapping the
metal samples should be taken out and testedg by observing the fracture
when chilled in water, in order to see that the per-centage of carbon or
the temper of the steel is such as may be desired.
The Figures on Sheet II. represent the arrangement and construction
of furnaces according to another modification, the fusing of the ores
being effected in one furnace, and the conversion in another. Fig. 4,
Sheet II., represents a plan; and Fig. 5, Sheet II., an elevation shewing
the general arrangement of furnaces for this purpose; Fig. 6, Sheet II.,
a longitudinal section represents a transverse section of the fusing furnace;
Fig. 7, Sheet II., a longitudinal section of the converting furnace; and
Fig. 8, Sheet II., a section through the throat of the converting furnace.
The fusing furnace L consists of a trough shaped bed arched over by the

page_text: ་
-
crown of the furnace, through which there are openings L', L, formed at
each end side and surmounted by hoppers. The ore to be fused mixed with
about 5 per cent. of carbonaceous matter is supplied to the hoppers and
sinks down through the openings into the bed of the furnace forming
a sloping heap at either side. For certain ores, such as haematite
containing. silica, limestone should be added in proportions. suited to .
the amount of silica, such proportions being determined chiefly by
experience. Or, it is preferable to mix such hematite with spathic
ore containing limestone, magnesia, or manganese, to which may be
added an argillacious ironstone, the object being to produce by such
mixture a fusible slag without adding separate fluxing materials. Fluor
spar may be used with advantage as a fluxing material if the ores
contain phosphorus without much silica. Or stronger alkaline bases,
such as potash or soda may be added with advantage when impure ore
containing both silica and phosphorus or sulphur is used. It is to be
understood that these directions as to fluxing apply when the single
furnace is used as already described. The flame enters the bed by one
of the end openings M, and after circulating through the furnace and
playing on the ore issues by the other opening M², as indicated by.
the arrows in Fig. 6, Sheet II. These openings communicate with
regenerative chambers which are alternately employed for heating the
air and gas, and for being heated by the waste products of combustion,
suitable valves being employed for the purpose of reversing the direction
of the currents through the openings M, M'. The ore acted on by the
flame is fused and the liquid ore collects in the basing formed in the
middle of the furnace between the two side heaps of ore.
sufficient quantity of liquid has collected, carbonaceous matter in powder.
may be introduced as before described, and the mass being well stirred in
a trap door N may be opened and the fused matter in a pasty condition
allowed to run into moulds or on to a pig bed below, so as to form
bricks, ingots, or pigs to be treated in a bath of melted pig for the
production of cast steel in another furnace. Or the fused ore may
be tapped from time to time so as to issue by a tap hole in the front of
the furnace, whence it runs by a moveable gutter O to the converting
fisemane D
When a

page_text: is used. The converting furnace P is preferaby of globular or polygonal
shape mounted on rollers on which it can be made to revolve. At the
one end of the axis of rotation is a throat into which four flues Q, R,
and Q¹, R', open. The two lower flues Q, Q', are used alternately for the
admission of the heated gas, and the two upper flues R, R³, for the
admission of heated air; the other two of the four flues being then
employed as outlets for the waste products of combustion. All these
flues communicate with regenerative chambers, one of which is shown at
S, and the direction of the currents through the flues is made to
alternate by suitable valves as already described with reference.to the
furnace represented in Sheet I. The heated gas and air entering by a
pair of flues form an intense flame which beats upon the material in the
rotating chamber, and after circulating therein issues by the other pair
of flues. Opposite the furnace throat there is an orifice which is closed by
means of a door T. This door is suspended by a chain over a pulley't,
and
4
and can be raised of lowered by means of a crab wheel f¹. A spy hole
T in the door T, serves to introduce a rotating or gas rabble, as shewn
in Figs. 10 and 11 respectively when the door itself is down and the
furnace at work. The door T is supported laterally by two vertical
guide bars T, and it is so suspended as to lean against the circumference
of the mouth or orifice of the rotating chamber.
The lining of the rotating chamber is formed by preference of bricks
of fused refractory ore of conical shape put in cold, and consolidated
when heated in their places by pouring other fused or semi-fused ore
over them in rotating the apparatus. The latter method is also
employed from time to time for mending the lining; or a lining of
argillaceous brickwork may be introduced in the first instance, and a
ferrugenous inner lining be formed by the introduction of pure or semi-
fused iron ores which should be rich oxides such as roll cinder or
haematites. Having thus prepared the furnace lining and raised the
internal temperature of the chamber to a white heat, I introduce into
the same through the open door T a certain quantity of coke or
anthracite powder mixed intimately by preference with an equal or
double weight of pulverulent iron ore. In giving rotation to the
chamber this mass is well heated and the partial reduction of the iron
ore effected, which owing to the high specific gravity prevents the carbon
from rising bodily to the surface of the fluid ore when that is introduced,
and facilitates the process of intermixture.

page_text: If it is desired that the iron to be produced should contain man-
ganese, it is found advantageous to mix ore rich in manganese with
the carbon powder, when it will be reduced in a great measure into the
metallic condition.
The process may also be varied by moistening the mixture of ore and
carbon and forming it into bricks or lumps before introducing it into
the rotating furnace. Or the inner lining may be formed of such con-
solidated mixture of ore and carbon, in which case an argellaceous ore
or argillaceous matter in a separate form should be added. The rotating
furnace being thus prepared, the door T is raised, the heated gutter
adjusted between it and the melting furnace, and the latter tapped,
whereby a stream of fluid ore is directed into the chamber. The
quantity of fluid ore to be admitted for one charge should bear a
proper proportion to the amount of carbonaceous matter charged, and
the working capacity of the apparatus, and can be judged pretty nearly
by the time of flow or by the interval of time since the previous tap
of the melting furnace. The gutter is thereupon removed, the door T
closed, and the chamber put into rotation. The chemical reaction
between the materials may now be further accelerated by the intro-
duction of the rotating or the gas rabble, as before described. During
the continuance of this operation additional solid carbon may be added
either separately or mixed with oxides, or combined with iron ore into
bricks or lumps. If the ores employed contain much gangue or foreign
matter, it will be found advantageous to discharge the liquid cinder
before the ball of iron is quite formed. This liquid cinder will carry with
it nearly all the phosphorus and sulphur present, and it is possible by this
process to produce very pure iron from ores and fuel containing those
hurtful materials in large quantities.
Instead of mixing the solid carbonaceous matter used with pul-
verulent ore it may be charged separately before or even after the
fluid ore has been introduced into the rotative chamber, and energetic
rabbling may be resorted to to effect a speedy precipitation of the
metallic iron. It must however be borne in mind that high tem-
perature is an essential condition for effecting the reaction, and that
if a white heat is not maintained a considerable proportion of iron will
remain in the oxidized condition with the cinder. The temperature being
maintained at a sufficient elevation the deoxidia deoxidation of the ore
depends upon the amount of carbonaceous matter added (a small per-

page_text: centage only of the oxide of iron remaining in combination with the
cinder); when the carbonaceous matter is added in excess, steely iron
or natural steel is the result. When the conversion of the material
is effected in P the iron produced is balled, and the ball is removed
through the doorway T and dealt with by hammering or squeezing in 5
the usual way.
The fused cinder left in the chamber P is run out
through a tap hole P¹ formed in the one part of the periphery, the chamber
being turned round so as to bring that hole to the bottom.
It is to be understood that the exterior of the rotative chamber may
be cooled by the application of water either upon its surface or in cir- 1
culating tubes, according to any known method. Also the rotative
chamber might be supplied with fused ore from a cupola or other
description of furnace applicable for that purpose, though the furnace L
already described is considered the most suitable for the purpose.
It is convenient to arrange one such globular converting furnace 18
between two fusing furnaces with a framing to support an overhead
travelling crane, by which the rotating chamber can be removed in order
to be relined or repaired and replaced.
In Figs. 4 and 5, Sheet II., are shewn the relative positions of the
rotating chamber P and the one fusing furnace L, another such fusing 20
furnace being supposed to be placed on the other side of P. A jib
crane V may be mounted on the framing for removing the ball from the
rotating chamber, and the rotation of the chamber may be effected by
means of a small engine W situated below the working floor. A framing
and set of rollers X may be provided at each end of the furnace range 2:
for the reception of a rotative chamber under repair, and it is convenient
to have two rotative chambers, one in use for converting while the other
is under repair.
Having thus described the nature of my Invention, and in what manner
the same is to be performed, I would have it understood that I do not 3
claim generally the use of regenerative gas furnaces in the production of
iron and steel, nor do I claim the use of a tubular rabble whereby gas
can be introduced into melted matter while it is being agitated by the
rabble, nor do I claim generally the use of a rotating chamber for the
purpose of puddling; but I do claim,-
First. The process, substantially as herein described, of producing
wrought iron and natural steel by fusing iron ore and agitating the fluid
3

page_text: mass in contact with carbonaceous matter under the influence of intense
heat.
Second. The process, substantially as herein described, of producing
cast steel by fusing iron ore, agitating the fluid mass in contact with
carbonaceous matter under the influence of intense heat, balling and
tapping off the fluid cinder, and then dissolving the balled matter in a
bath of fluid pig, either in the same or in a different furnace.
Third. The use for the manufacture of iron and steel of a rotating
regenerative gas furnace, constructed with the inlet for flame and outlet
for products of combustion arranged at the one end or throat of the
furnace, and a working door at the opposite end, substantially as described
with reference to Figs. 7 and 8, Sheet II.
Fourth. The mode, substantially as herein described, of applying
regenerators to a rotating furnace for the production of iron and steel by
dividing the throat of such furnace into four passages, each communi-
cating with a regenerative chamber.
Fifth. The arrangement of fusing and converting furnaces in com-
bination for successive operation, substantially in the manner and for the
purposes described in reference to Figs. 4, 5, 6, and 7, Sheet II.
In witness whereof, I, the said Charles William Siemens, have
hereunto set my hand and seal, this Fifteenth day of May, in the
year of our Lord One thousand eight hundred and seventy-two.
And I, the said Charles William Siemens, do hereby further declare
that the above Disclaimer is not, nor is any part thereof, intended to
extend the exclusive right granted by the said Letters Patent, and
that these Presents shall not extend the said exclusive right in any way
whatever.
In witness whereof, I, the said Charles William Siemens, have
hereunto set my hand and seal, this Twenty-fifth day of July,
in the year of our Lord One thousand eight hundred and seventy-
Witnessed the signature,
CHARLES UNDERWOOD.
C. WILLIAM SIEMENS. (L.8.)

page_text: To the Commissioners for Patents for Inventions.
I hereby grant my fiat giving leave to the above-named Charles
William Siemens to file in the Great Seal Patent Office, with the
Specification to which the same relates, the above-written Disclaimer
and Memorandum of Alterations.
J. D. COLERIDGE,
5th Nov. 1872.
Attorney-General.