Improvements in the Manufacture of Iron and Steel.
Year: 1893

page_text: Date of Application, 21st Apr., 1893
Complete Specification Left, 19th Jan., 1894-Accepted, 24th Feb., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Iron and Steel.
We, ALEXANDER SATTMANN and ANTON HOMATSCH, both of Donawitz near
Loeban, Styria in the Empire of Austro-Hungary, Mining Engineers, do hereby
declare the nature of this invention to be as follows:-
In the manufacture of iron and steel it has been usual first to produce crude pig
iron, in a blast furnace. This has been attended by the serious drawback that even
where the quantities of material have been comparatively small, it has required,
the consumption of expensive fuel, such as charcoal coke or anthracite. Such
fuel, in some cases has had to be brought from distant places and its employment
has made crude iron produced therewith, very expensive, such fuel as is to be
found in the vicinity of ore beds or deposits, being frequently unfit for use in a blast
furnace.
Now this invention is designed to enable fuel of inferior quality, and also
liquid or gaseous fuel, to be utilized in the production of crude iron and also
to effect the fining in a more efficient manner than by the fining process usually
carried out in reverberatory furnaces, the crude iron being in intimate contact
with gas jets thereby accelerating the fiuing and reducing the consumption of
fuel.
The manufacture of iron according to this invention comprises;-
1. Heating the ore and fluxes and, if necessary, roasting the ore by means of
gaseous fuel;
2. Reducing the ore and carburizing the spongy iron thus obtained by means of
reducing gases;
3. Melting down the carburized spongy iron by means of solid fuel; and
4. Fining the crude iron obtained after separation of the slag immediately after
melting, by means of oxidising gases, so as to obtain more or less decarburized
iron.
The first and second steps may be carried out by means of various kinds of
gases. Thus either natural gases or such as are obtained by the evaporation of
liquid fuel, by dry distillation or incomplete combustion of hydrocarbons or
carbonaceous material may be employed. Moreover the waste gases obtained from
a previous operation, may be utilized, this being advantageous in places where
natural gas is not available or where gases containing little nitrogen cannot be
obtained at a reasonable cost.
o
When it is desired to employ the waste gases produced in the process of reduction
of the ore and containing more oxygen and less nitrogen than atmospheric air; or
gases resulting from incomplete combustion; such gases must be allowed to pass
over a bed of incandescent coal for the purpose of being saturated with carbon in
proportion to the quantity or percentage of oxygen they contain, the result being
that their percentage of nitrogen will be proportionately reduced. If gases such
as these be employed several times over, and repeatedly subjected to the saturating
or restoring process just mentioned, as necessarily a portion of the gases is at the
gases will
same time burnt for the purpose of developing heat, the condition of the
become settled as it were, and in this condition they will be, if not quite free from,
yet a great deal poorer in nitrogen, than gases produced by incomplete combustion
would otherwise be.
The heat for reduction may be generated in some cases by the combustion of
solid fuel, in which case the quantity of nitrogen is still further diminished, and
consequently, the reducing power of the gases further increased. This will however

page_text: involve an increase in the consumption of the expensive fuel which ordinarily is
required only for melting.
By the employment of gases containing little nitrogen and a large quantity of
oxide of carbon the process of reduction is considerably accelerated, while on the
other hand the subsequent combustion of the gases for other purposes will
produce much more favorable results than before, as a less quantity of heat is
lost with the escaping products of combustion owing to the small quantity of
nitrogen present.
In roasting carbonate ores by means of the exhaust carbonic acid the gases become
richer in oxygen and as these gases are repeatedly re-saturated and utilised afresh,
a gas poor in nitrogen may at all times be relied on as a result.
By such gases the charge of material is heated, the ore being at the same time
roasted and reduced if necessary, and eventually the spongy iron is carburized.
The third phase of the process, viz. the melting of the ores by the reduction of
the spongy iron-obtained by means of the gases just referred to, is proceeded with
immediately after reduction, and for this purpose a hot non-oxidising gas jet or
current is used, which is produced by the combustion of solid fuel very rich in
carbon. As however the fuel, as it burns near the inlet of the blast, becomes
converted into carbonic acid, it is necessary that the layer of incandescent fuel
lying between the spongy iron and the tuyeres should be so proportioned that
the greater part of the carbonic acid produced may be reduced back to monoxide
of carbon on its way to the spongy iron. The temperature obtained during this
operation is quite sufficient for melting the spongy iron and the slag which has
formed.
In order to fine this crude iron, which may be made poor in carbon, silicon or
phosphorous as desired, when it has been freed from slag, it is brought into intimate
contact with a sufficiently hot flame or jet of oxidising gas, with the result that
whatever foreign bodies it may contain, which it is desirable to remove, are totally
or partially consumed.
If the temperature in the collecting chamber. during the fining operation is
maintained sufficiently high to keep the material in a liquid condition, more or less
refined crude iron, ingot steel or ingot iron will be obtained. By keeping the
temperature below the melting point however weldable iron or steel will be
obtained.
This process may be carried on either continuously or intermittently, and I
prefer to use plant such as illustrated in the accompanying drawings, in which
Figs. 1 and 2 represent a complete plant for intermittent operation in successive.
charges; the figures being respectively a sectional elevation and a plan.
The remaining figures are drawn to a
large scale.
Fig. 3 is a vertical central section, and
Fig. 4 is an end view partly in section of a furnace for the production of crude
iron adapted to operate intermittently.
Fig. 5 is an end view partly in section illustrating a fining chamber combined
with a furnace such as in Figs. 3 and 4.
Fig. 6 is a vertical section of a modified form of furnace for producing crude
iron which may also if desired be provided with a fining chamber similarly to the
forms shown in Figs. 1 and 4.
Figs. 7 and 9 shew in vertical section two modified forms of furnaces for the
production of crude iron, adapted for continuous working which may also be
combined with fining apparatus.
Figs. 8 and 10 are respectively cross sections on lines x x Fig. 7 and ¹¹
Fig. 9.
Referring to Figs. 1 to 4, a furnace for producing crude iron by intermittent
operation, .e. arranged to be fed by successive charges, consists of the charging
chamber a which receives the ores and fluxes, the melting chamber b, and the
space c in which the solid fuel is placed. This fuel-receiving chamber is arranged
on one side of the charging or feeding chamber and like the latter, has an orifice

page_text: provided with a suitable tight closing device. The chambers or compartments a
and c join below and form the melting chamber b. The charging chamber a has an
inclined floor or bottom upon which the ore is heaped up loosely.
Near the top of the fuel chamber c is situated the mouth of the gas conduit d
and near the top of the feeding chamber a, is arranged the escape or exhaust
channel. Into the melting chamber is inserted the wind tuyere or nozzle g¹ of
the wind or air conduit g. h is the slag hole. At the bottom of the melting
chamber is provided the outlet i for the discharge of the crude iron. k is an
opening provided for the purpose of facilitating the removal of any material
settling on the walls and also any repairs which the floor or bottom of the furnace
may require. If the furnace be combined with a fining chamber as illustrated in
Fig. 5 the connection is formed by the dam m and tymp n, as a substitute for the
discharge orifice i; the dam allowing the iron to flow into the fining chamber only
when it has reached a certain level, while the tymp prevents the slag from flowing
over. The fining chamber has a series of steps or off-sets and is connected, at the
top, with the escape channel f terminating above the dam, and below, with a
collecting chamber, while blast tuyeres ; lead into it from the side. In the
modification shown in Fig. 6 the fuel-receiving chamber c, adapted also to serve as
a melting chamber, is arranged below the charging chamber a and at its lower part
forms a pit in which the outlet i is arranged at a certain level above ground, the
slag mould being situated somewhat higher, and the blast tuyeres or nozzles g¹
higher still. Into the lower part of the charging chamber a also lead gas jets d¹
connected with the gas main or conduit d, and immediately above these jets, are
situated the nozzles g³ connected with the air main g.
When the waste gases are to be re-saturated or restored to the proper condition
for the purpose of being utilised again, the outlet pipe f, provided with a branch f¹
to carry off excess of gas so that it may be utilized elsewhere for other purposes,
is connected (see Figs. 1 and 2) with two recuperators in front of which is
arranged a steam jet o by which the gases are circulated. From each of these
recuperators or saturators the pipe d², which has suitable controlling valves, leads
to the gas conduit d, a branch pipe d³ being provided for conducting off surplus
gases to other parts for further utilisation.
The gases escaping through outlet pipe fare forced by the steam jet o into one of
the recuperators and caused to pass through the incandescent fuel bed, the carbonic
acid contained therein being in the process converted into monoxide of carbon,
while the gases leave the recuperator as reducing gases, and pass through the
pipe and the gas conduit d into the furnace. In the meantime air is admitted
through tuyeres into the other recuperator (which has been kept closed) whereby
the layer of coal spread therein is in its turu heated. This recuperator may,
therefore, be now started, while the operation of the other has to be stopped in
consequence of its having cooled down. It will thus be seen that the recuperation
or re-saturation of the gases may be carried on without interruption.
In using the form of furnace illustrated in Figs. 3 and 5, the process is carried
out as follows:-
The ores and fluxes are introduced into the chamber a and its charging orifice is
closed. Reducing gases are then admitted through the gas conduit d, and air is
admitted through the jets g¹.
The combustion of the gases is started in commencing to work the furnace, by
introducing incandescent fuel into the melting chamber; or if the furnace has been
in operation before, by the heat still retained from the preceding operation.
The gases, which according to the proportions in which they are mixed with air
are either neutral or oxidising, pass into the charging chamber, heat the ores and
fluxes therein, expel the carbonic acid, if there be any carbonates present, and
escape through the outlet pipe finto the recuperator.
When the ores have been thus sufficiently prepared for further treatment the
blast is wholly or partly cut off, and a reducing gas current is allowed to pass
through the charge of ore. If in consequence of the reduction any of the heat.be

page_text: lost, a portion of the gases that are admitted, or a certain amount of solid fuel is
burnt along with the air blast forced in. When the reduction is completed the
supplies of both gas and air are cut off and solid fuel is introduced into the
chamber b, unless this has already been done after the roasting. Air is now
again admitted and the hot gas current thus produced melts the spongy iron lying
at the bottom of the reduction chamber while the upper layer of the spongy iron
for the time being remains unmelted. The melted crude iron and the slag
combining with the cinder of the solid fuel are then discharged together into the
pit, such as is provided in the form of furnace illustrated in Fig. 3. The s
slag
constantly runs off through h while the crude iron, after the whole charge has been
melted down, is discharged into a proper receptacle, whereupon the furnace may be
charged afresh. During the melting the waste gases may, without being saturated
or recuperated, be used for other objects. If it be desired to refine the crude iron
obtained the furnace represented in Fig. 5 should be used. The gases are conducted
through the channel finto the fining chamber 1, and at the same time the blast is
admitted through the nozzles or tuyeres j, when the crude iron flowing over the
dam m and descending the step like arrangement in a finely divided condition
undergoes the desired refining action. As the waste or exhaust gases are burnt
together with the air, the crude iron is raised to a higher temperature propor-
tionately to its degree of decarburization. The crude iron and slag remaining in
the furnace is discharged through a special orifice.
The form of furnace illustrated in Fig. 6 is in the first place filled with a sufficient
quantity of solid fuel which, if the furnace be cold in the first instance, must be
introduced in a partly incandescent state. Over the fuel is spread a layer of ore
in small grains which layer should fill up the furnace up to a point just below the
gas jets d'. The rest of the charging chamber is filled with .ores and fluxes,
whereupon the receiving mouth or orifice of the furnace is closed.
Combustible gases are admitted through the gas jets d' and air for combustion
thereof through the blast jets g'. The preparation and, if necessary, the roasting
and reduction of the ores, take place in this form of furnace in the same manner
as in the arrangement illustrated in Figs. 3, 4 and 5, the air being admitted, for
the combustion of the gases through the upper blast tuyeres g³ and through the
lower tuyeres g' for the combustion of solid fuel.
In all the cases herein referred to, the nature or composition of the material to
be eventually produced may be altered at will, by more or less perfect reduction,
the maintenance of proper temperatures and the correspondingly accelerated or
retarded melting down of the ore.
If it be desired to carry on the process continuously, the four phases or
stages of operation being performed simultaneously and without interruption,
the two forms of furnaces shown in Figs. 7, 8, 9 and 10 may advantageously be
employed.
These furnaces have a charging chamber provided with a central outlet pipe f
and divided into a roasting compartment a, and a reducing compartment a¹ situated
underneath a. The melting chamber b and the fuel chamber c may be arranged
(see Fig. 7) in the same manner as in the forms shown in Fig. 3 or the melting
chamber may be arranged directly underneath the reducing chamber (Fig. 9) in
which latter case side feeding trunks c' are provided for the introduction of solid
fuel, it may be by means of a conveyor or feeding screws p.
From the air conduit g branch pipes lead to the nozzles or tuyeres g² and 9³,
the former of which terminate at a point between the roasting and the reducing
chambers, while the latter enter the furnace through the lower portion of the
reducing chamber. These tuyeres 9³ are arranged concentrically inside the gas
jets g of the gas conduit g.
In the furnace shown in Figs. 9 and 10 it may be advantageous to employ,
instead of one blast tuyere g' only, leading into the melting chamber b, as many
tuyeres or nozzles as there are feeding trunks c¹, to which the said tuyeres should
be placed at right angles.

page_text: The two forms of furnaces may, as has been set forth above, be utilised in
conjunction with recuperators with a view to the re-employment of the exhaust
gases, and also in combination with a fining chamber. The operation may be
summarised as follows:-
--
In the melting chamber b solid fuel is contained this fuel is consumed together
with the hot air blast supplied through the nozzles g' and is supplemented by
additional charges introduced either through the mouth of the fuel-receiving
chamber c or through the trunk c¹. The hot gas-current thus produced passes
through the layers of fuel, meets the spongy iron, which it melts together with
the slack forming in the meantime, and these molten materials run off into the pit,
absorbing the cinder or ashes at the same time.
The reducing gases generated during the melting process pass into the reduction
chamber a where they meet and mix with the gases forced in through the gas
jets g¹, and thereby reduce the material in the furnace. Through the blast
tuyeres 9 the air blast necessary for keeping up the combustion of a portion of the
gases is admitted.
When the gases enter the roasting chamber a a further portion of the same is
burnt at the same time as the air blast admitted through the nozzles 92 and the
heat produced is utilised in heating the charge roasting the carbonates and expelling
the water.
The gases passing away through the channel fand which, although cooled down,
are still perfectly combustible may be employed again for the same purposes as
those which they serve in furnaces arranged for intermittent operation. As the
spongy iron is melted away the material gradually sinks and makes room for
further charges of ores and fluxes.
In these furnaces arranged for continuous operation, in the same way as in the
furnaces arranged to operate intermittently, the nature or composition of the
final product may be determined and, controlled at will beforehand, especially in
the case of furnaces provided with fuel trunks c' which enable the quantity of
fuel introduced into them to be at any time increased or diminished as may be
required, so that to some extent the process is independent of the original com-
position of the ores, as well as of the quantity of moisture contained in the fuel
or any such incidental circumstances. The advantages afforded by the process
herein described and rendering it superior to the blast furnace process which has
been practised hitherto may be briefly stated as follows:-
1. The employment of inferior and less expensive fuel as a substitute for the
greater part of the expensive fuel required for the operation of ordinary blast
furnaces.
2. The diminished consumption of solid fuel and the corresponding diminution
of the quantity of slag formed; hence a saving of fluxes, heat and labor.
3. The possibility of dispensing with a special roasting or calcining furnace (if
it be at all necessary to roast the ore) the heat produced in roasting being utilized
for reduction.
4. The production of gases poor in nitrogen and possessing considerable heating
and reducing power by re-saturating or recuperating exhaust gases.
5. The saving realised in practice in the consumption of fuel as well as in the
cost of labor as compared to what is requisite for the ordinary blast furnace
process (where the fining is effected in a separate operation in a reverberatory
furnace) refining in the present arrangement being effected in conjunction with (or
more strictly immediately after) the melting operation.
Dated shie 00th d
A1 1902
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Iron and Steel.
We, ALEXANDER SATTMANN, and ANTON HOMATSCH, both of Donawitz near
Loeban, Styria, in the Empire of Austro-Hungary, Mining Engineers, do hereby
declare the nature of this invention and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
In the manufacture of steel and malleable iron it has been usual first to produce
crude pig iron in a blast furnace. This has been attended by the serious drawback
that even where the quantities of material have been comparatively small, it has
required, the consumption of expensive fuel, such as charcoal, coke or anthracite.
Such fuel, in some cases has had to be brought from distant places, and its
employment has made crude iron produced therewith, very expensive, the less
expensive kinds of fuel found in the vicinity of ore beds or deposits, such as coal of
inferior quality, brown coal, lignite turf or waste wood, being frequently unfit for
use in a blast furnace.
Now this invention is designed to enable fuel of inferior quality, and also liquid
or gaseous fuel, to be utilized in the production of crude iron by means of furnaces
of special construction, and also to effect the fining in a more efficient manner than
by the fining process usually carried out in reverberatory furnaces, the crude iron
being, according to this invention, in intimate contact with gas jets thereby
accelerating the fining operation and reducing the consumption of fuel.
The manufacture of iron according to this invention comprises :-
1. Heating the ore and fluxes, and, if necessary, roasting the ore, by means of
gaseous fuel;
2. Reducing the ore and carburizing the spongy iron thus obtained by means of
reducing gases.
3. Melting down the carburized spongy iron by means of solid fuel; and
4. Fining the crade iron obtained after separation of the slag and immediately
after melting, by means of oxidising gases, so as to obtain more or less decarburized
iron.
The first and second steps may be carried out by means of various kinds of
combustible gases. Thus either natural combustible gases, or such as are obtained
by the evaporation of liquid fuel, or by dry distillation or incomplete combustion
of hydrocarbons or carbonaceous material may be employed. Moreover the waste
gases obtained from a previous operation of this process, may be utilized, this being
advantageous in places where natural combustible gas is not available, or where
combustible gases containing little nitrogen cannot be obtained at a reasonable
cost.
When it is desired to employ the waste gases produced in the process of
reduction of the ore and containing more oxygen and less nitrogen than atmospheric
air, or gases resulting from incomplete combustion, such gases must be allowed to
pass through a bed of incandescent coal for the purpose of being saturated with
carbon in proportion to the quantity or percentage of oxygen they contain, the result
being that their percentage of nitrogen will be proportionately reduced. If gases
such as these be employed several times over, and repeatedly subjected to the
saturating or restoring process just mentioned, as necessarily a portion of the
gases is at the same time burnt for the purpose of developing heat, the condition
of the gases will become settled as it were, and in this condition they will be, if not
quite free from, yet a great deal poorer in nitrogen, than gases produced by
incomplete combustion would otherwise be.
The heat for reduction may be generated in some cases by the combustion of
solid fuel, in which case the quantity of nitrogen is still further diminished, and
consequently, the reducing power of the gases further increased.
This will

page_text: however involve an increase in the consumption of the more expensive fuel which
is otherwise required only for melting.
By the employment of such gases containing little nitrogen and a large quantity
of carbon monoxide, the process of reduction is considerably accelerated, while on
the other hand the subsequent combustion of the gases for other purposes will
produce much more favorable results than before, as a less quantity of heat is lost
with the escaping products of combustion, owing to the small quantity of nitrogen
present.
When the roasting process is carried on in the presence of carbonates, the evolved
carbonic acid will enrich the gases in oxygen and as these gases are repeatedly
re-saturated and utilised afresh, a gas poor in nitrogen may at all times be relied
ou as a result.
.
By such gases the charge of material is heated, the ore being at the same time
roasted and reduced if necessary, and eventually the spongy iron is carburized.
The third step of the process, viz. the melting of the spongy iron obtained by the
production of the ores by means of the gases just referred to, is proceeded with
immediately after reduction, and for this purpose a hot non-oxidising gas jet or
current is used, which is produced by the combustion of solid fuel very rich in
carbon. As however the fuel, owing to its burning near the inlet of the blast,
becomes converted to a large extent into carbon dioxide, it is necessary that
the layer of incandescent fuel lying between the spongy iron and the tuyeres
should be so proportioned that the greater part of the carbon dioxide produced
may be reduced back to carbon monoxide on its way to the spongy iron. The
temperature obtained during this operation is quite sufficient for niclting the spongy
iron and the slag which has been formed.
In order to fine this crude iron, which may be made poor in carbon, silicon or
phosphorous as desired, after it has been freed from slag, it is brought into intimate
contact with a sufficiently hot flame or jet of oxidising gas, with the result that
whatever foreign bodies it may contain, and which it is desirable to remove, are
totally or partially consumed.
If the temperature in the collecting chamber during the fining operation is
maintained sufficiently high to keep the material in a liquid condition, more or
less refined crude iron, ingot steel or ingot iron will be obtained. By keeping
the temperature below the melting point however, weldable iron or steel will be
obtained.
The process may be carried on either continuously or intermittently.
Plant suitable for carrying out the invention is illustrated in the drawings filed
with our Provisional Specification.
Figs. 1 and 2 of these drawings represent a complete plant for intermittent
operation with successive charges, the figures being respectively a sectional
elevation and a plan.
The remaining figures are drawn to a large scale.
Fig. 3 is a vertical central section, and
Fig. 4 is an end view, partly in section, of a furnace, adapted to operate inter-
mittently, for the production of crude iron.
Fig. 5 is an end view, partly in section, illustrating a furnace similar to that
shown in Figs. 3 and 4, but combined with a fining chamber.
Fig. 6 is a vertical section illustrating a modified form of furnace for producing
crude iron, and which may also if desired be combined with a fining chamber,
similarly to the forms shown in Figs. 1 and 4.
Figs. 7 and 9 show in vertical section two modified forms of furnaces for the
production of crude iron; they are adapted for continuous working and may also
be combined with fining apparatus.
Figs. 8 and 10 are cross sections on the lines xa of Fig. 7 and ¹¹ of Fig. 9
respectively.
The furnace shown in Figs. 1 to 4, which is adapted for producing crude iron by
intermittent operation, i.e. arranged to work by successive charges, consists of the

page_text: charging or feeding chamber a which receives the ores and fluxes, the melting
chamber b, and the space c in which the solid fuel is placed. This fuel-receiving
chamber is arranged on one side of the charging chamber and like the latter, has a
mouth provided with a suitable gas tight closing device. The chambers or
compartments a and c join below and form the melting chamber b. The charging
chamber a has an inclined floor or bottom, as shown, upon which the ore is heaped
up loosely.
Near the top of the fuel chamber c is situated the mouth of the gas conduit d,
and near the top of the feeding chamber is arranged the escape or exhaust
channel Into the melting chamber is inserted the air tuyere or nozzle g¹ of the
air conduit g. h is a slag hole. At the bottom of the melting chamber is provided
the outlet for the discharge of the crude iron. k is an opening provided for the
purpose of facilitating the removal of any material settling on the walls, and also
any repairs which the floor or bottom of the furnace may require. If the furnace
be combined with a fining chamber 1, as illustrated in Fig. 5, the connection is
formed by the dam m and tymp n, as a substitute for the discharge orifice ; the
dam allowing the iron to flow into the fining chamber only when it has reached a
certain level, while the tymp prevents the slag from flowing over.
The fining
chamber has a series of steps or off-sets as shown; it is connected at the top with
the escape channel which terminates above the dam, and below, with a collecting
chamber, while blast tuyeres lead into it from the side.
In the modification shown in Fig. 6, the fuel-receiving chamber c, adapted also to
serve as a melting chamber, is arranged below the charging chamber a, and at its
lower part forms the sump the outlet i being arranged lowermost, the slag hole h
being situated somewhat higher, and the blast tuyeres or nozzles g¹ higher still.
Into the lower part of the charging chamber a also lead gas nozzles d' connected
with the gas main or conduit d, and immediately above these nozzles, are situated
the nozzles g connected with the air main g.
When the waste gases are to be re-saturated or restored to the proper condition
for the purpose of being re-used, the outlet pipe f, provided with a branch f¹ to
carry off excess of gas so that it may be utilised elsewhere for other purposes, is
connected (see Figs. 1 and 2) with two recuperators or saturators in front of
which is arranged a steam nozzle o by which the gases are circulated. From each
of these recuperators or saturators, a pipe d², which has suitable controlling valves,
leads to the gas conduit d, a branch pipe d³ being provided for conducting off
surplus gases to other parts for further utilisation.
The gases escaping through the outlet pipe f are forced by the steam jet o into
one of the recuperators and caused to pass through a mass of incandescent fuel
therein, whereby the carbon dioxide present in the gases is converted into
carbon monoxide, the gases leave the recuperator as reducing gases, which pass
through the pipe d² and the gas conduit d and so into the furnace. In the
meantime air is admitted through tuyeres into the other recuperator (which has
been kept closed) whereby the mass of fuel therein is in its turn heated up to a
suitable temperature. When this has been done, this recuperator may be started,
while the operation of the other has to be stopped in consequence of its having
cooled down. It will thus be seen that the recuperation or resaturation of the
gases may be carried on without interruption.
In using the form of furnaces illustrated in Figs. 3, 4 and 5, the process is
carried out as follows:-
The ores and fluxes are introduced into the chamber a and its charging opening
then closed. Reducing gases are then admitted through the gas conduit d, and
air is admitted through the jets g¹.
The combustion of the gases is started in commencing to work the furnace, by
introducing incandescent fuel into the melting chamber; or if the furnace has been
in operation before, by the heat still retained from the preceding operation.
The gases, which according to the proportions in which they are mixed with
air are either neutral or oxidising, pass into the charging chamber, heat the ores

page_text: and fluxes therein, expel the carbonic acid, if there be any carbonates present, and
escape through the outlet pipe finto one or other of the recuperators.
turn.
When the ores have been thus sufficiently prepared for further treatment, the
blast is wholly or partly cut off, and a current of reducing gas caused to pass
through the charge of ore. If in consequence of the reduction, any of the heat
be lost, a portion of the gases that are admitted, or a certain amount of solid fuel
is burnt by means of the air blast forced in in order to compensate for such loss.
When the reduction is completed, the supplies of both gas and air are cut off, and
solid fuel is introduced into the chamber c, unless this has already been done after
the roasting. Air is now again admitted to the chamber b and the heat thereby
generated melts the spongy iron lying at the bottom of the reduction chamber
while the upper layer of the spongy iron gradually settles down and is melted in its
The melted crude iron and the slag combined with the ash of the solid fuel,
discharge together into the sump provided in the bottom of the furnace illustrated
in Figs. 3 and 4. The slag constantly runs off through the slag hole h, while the
crude iron, after the whole charge has been melted down, is discharged through the
lap hole into a suitable receptacle, whereupon the furnace may be charged afresh.
During the melting operation, the waste gases may, without being saturated or
recuperated, be used for other objects. If it be desired to refine the crude iron
obtained, the furnace represented in Fig. 5 is used. In this case the hot escaping
gases are conducted through the channel finto the fining chamber 1, and at the same
time a blast of air is admitted through the nozzles or tuyeres j, whereby the crude
iron flowing over the dam m and descending the step like arrangement in a finely
divided condition undergoes the desired refining action. As the waste or exhaust
gases are burnt together with the air, the crude iron is raised to the higher
temperature necessary for enabling it to be decarburized to the desired degree.
The crude iron and slag remaining in the furnace at the end of the process are
discharged through any suitable and convenient opening, not shown, and which is
normally closed.
When furnace illustrated in Fig. 6 is used it is first filled with a sufficient
quantity of solid fuel, which, if the furnace be cold in the first instance, must be
introduced in a partly incandescent state. Over the fuel is spread a layer of ore
in small grains, which layer should fill up the furnace up to a point just below
the gas nozzles d'. The rest of the charging chamber a is filled with ores and fluxes,
after which the charging opening of the furnace is closed.
Combustible gases are then admitted through the gas nozzles d' and air for
combustion thereof, through the blast nozzles g. The preparation, and if necessary,
the roasting and reduction of the ores, take place in this form of furnace in the same
manner as in the arrangement illustrated in Figs. 3, 4 and 5, air being admitted
through the upper blast tuyeres g² for the combustion of the combustible gases
admitted through the nozzle d' and through the lower tuyeres g' for the combustion
of the solid fuel.
In all the cases herein referred to, the nature or composition of the material to
be eventually produced may be altered at will, by more or less perfect reduction,
the maintenance of proper temperatures, and the correspondingly accelerated or
retarded melting down of the ore, combined when necessary with the fining
operation.
If it be desired to carry on the process continuously, the four phases or stages
of operation being performed simultaneously and without interruption, the two forms
of furnaces shown in Figs. 7 to 10 inclusive may advantageously be employed.
These furnaces each have a charging chamber a provided with a central outlet
pipe for the waste gases, and is divided into a roasting compartment a, and a
reducing compartment a¹ which is situated underneath a. The melting chamber b
and the fuel chamber c may be arranged (see Fig. 7) in the same manner as in the
form shown in Fig. 3, or the melting chamber may be arranged directly underneath
the reducing chamber (see Fig. 9) in which latter case, side feeding trunks c¹ are
B

page_text: Introduction of Sou fuel, it may be by invous
feeding screws p.
From the air conduit g branch pipes lead to the nozzles or tuyeres g³ and g³, the
former of which terminate at a point between the roasting and the reducing chambers,
while the latter enter the furnace through the lower portion of the reducing
chamber. The latter tuyeres g³, are arranged concentrically inside the gas nozzles d'
of the gas conduit d.
In the furnace shown in Figs. 9 and 10, it may be advantageous to employ instead
of one blast nozzle or tuyere g¹ only, leading into the melting chamber b, as many
nozzles or tuyeres as there are feeding trunks c', to which the said nozzle or tuyeres
should be placed at right angles.
The two forms of furnaces may be used in combination with recuperators, in the
manner hereinbefore explained, with a view to the re-employment of the exhaust
gases, and also in combination with a fining chamber. The operation of these
modified forms of furnaces, may be summarised as follows:-
:―
The solid fuel contained in the melting chamber b is consumed by the hot air blast
supplied through the nozzles g' and is supplemented by additional charges introduced
either through the charging opening of the fuel-receiving chamber c, or through
the trunks c. The current of hot gas thus produced passes through the layers of
fuel, meets the spongy iron which it melts, together with the slag forming in the
meantime, and these molten materials run off into the sump carrying with
them at the same time the cinder or ashes of the solid fuel employed.
The reducing gases generated during the melting process, pass into the reduction
chamber a where they meet and mix with the reducing gases forced in through the
gas nozzles d', and thereby reduce the material in the furnace. Through the blast
tuyeres go the air blast necessary for keeping up the combustion of a portion of the
gases is admitted.
When the gases enter the roasting chamber a, a further portion thereof is
burnt by the air blast admitted through the nozzles g², the resulting heat being
utilised in heating the charge, roasting the carbonates, and expelling moisture.
The gases passing away through the channel f and which, although cooled
down, are still combustible, may be employed again for the same purposes as
those which they serve in furnaces arranged for intermittent operation. As the
spongy iron is melted away the material gradually sinks and makes room for
further charges of ores and fluxes.
In these furnaces arranged for continuous operation, as in the furnaces arranged
to operate intermittently, the nature or composition of the final product may be
determined and controlled at will beforehand, especially in the case of furnaces
provided with fuel trunks c³, which enable the quantity of fuel introduced into
them to be at any time increased or diminished as may be required, so that to some
extent the process is independent of the original composition of the ores, as well as
of the quantity of moisture contained in the fuel or any such incidental
circumstances. The advantages afforded by the process herein described and which
render such process superior to the blast furnace process which has been practised
hitherto, may be briefly stated as follows:-
1. The employment of inferior and less expensive fuel as a substitute for the
greater part of the expensive fuel required for the operation of ordinary blast
furnaces.
2. The diminished consumption of solid fuel and the corresponding diminution
of the quantity of slag formed; hence a saving of fluxes, heat and labor.
3. The possibility of dispensing with a special roasting or calcining furnace (if
it be at all necessary to roast the ore), the heat produced in roasting being utilized
for reduction.
4. The production of gases poor in nitrogen and possessing considerable
beating and reducing power by re-saturating or recuperating exhaust gases.
5. The saving realised in practice in the consumption of fuel, as well as in the
cost of labor, as compared to what is requisite for the ordinary blast furnace

page_text: process, where the fining is effected in a separate operation in a reverberatory
furnace refining in the present arrangement being effected immediately after the
melting operation.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The manufacture or production of crude iron by heating, and if necessary
roasting, the ores and fluxes by gases poor in nitrogen, reducing the ores to
spongy iron, and melting the same without any preparatory cooling, by heat
produced by the combustion of solid fuel kept separate from the ores and fluxes
substantially as herein described.
2. The manufacture of iron or steel by heating, and if necessary roasting, the
ores and fluxes by gases poor in nitrogen, reducing the ores to spongy iron,
melting such spongy iron, without any preparatory cooling by heat produced
by the combustion of solid fuel kept separate from the ores and fluxes, and
fining the crude iron thus obtained, after separation of the slag and imme-
diately after melting, by means of oxidising gas so as to effect more or less
decarburisation of the crude irou substantially as herein described.
3. In the manufacture of iron and steel by the processes referred to in the
preceding claims, recuperating the exhaust gases escaping from the heating and
calcining chamber by passing them through incandescent fuel for the purpose of
converting them into combustible gases poor in nitrogen, substantially as herein
described for the purpose specified.
4. For carrying out the processes referred to in the preceding claims, apparatus
constructed arranged and operating substantially as hereinbefore described
with reference respectively to and shown in Figs. 1 to 4 inclusive or modified
according to Fig. 5; or to Fig. 6 ; in Figs. 7 and 8; and in Figs. 9 and 10 of
the drawings.
e drawings.
Dated this 19th day of January 1894.
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.