Improvements in the Manufacture and Purification of Iron, and in Means or Apparatus Employed therein.
Year: 1893

page_text: Date of Application, 30th Oct., 1893
Complete Specification Left, 30th Aug., 1894-Accepted, 30th Oct.,
1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture and Purification of Iron, and in
Means or Apparatus Employed therein.
We, WILLIAM JOHN CLAPP, of 33 York Place, Newport, in the County of
Monmouth, Surgeon, and SAMUEL. DICKINSON WILLIAMS, of 8 Faulkner Road,
Newport aforesaid, Engineer, do hereby declare the nature of this invention to be as
follows:-
In the following Specification it is to be understood that, to avoid repetition,
wherever the word furnace is used, the term cupola or other place or process
where iron is melted down in contact with carbon is included in reference to
our invention, with of course such modifications in its application as may be
obviously called for in any individual case.
In the smelting of iron ore in the furnace and the remelting of pig-iron in
the cupola, lime or limestone has always been used as a flux and a purifier in
the presence of incandescent fuel, but the method of using lime for this purpose
has hitherto been by loading lime or limestone in bulk at the top of the furnace
in the proportion sufficient for fluxing purposes and, in addition, charging in an
excess of lime or limestone, also in bulk, which to some extent eliminates or
washes out sulphur from the iron. This mode of manufacture, which hitherto
has been the one universally adopted, is well known to create this difficulty for
the manufacturer, viz.: that, on the one hand, the less lime that he charges
into the furnace at the top, the more sulphury the quality of the iron produced,
and on the other hand, the more lime that he thus charges into the furnace at
the top, forming as it does a highly infusible slag, the greater is the risk of
interfering with the work of the furnace by its "gobbing" up.
From the foregoing considerations the method of allowing the limestone or
line when charged into the top of the furnace to take its own chance of mixing
with the iron in its descent to the bottom of the furnace, is obviously a crude
and imperfect method in practice, inasmuch as, by this means, that mixture of
the lime and iron. which is required for the elimination of the sulphur cannot
be obtained. The theory of iron making requires that in smelting operations
generally, the best process would be one in which the lime and iron could be
brought together in intimate contact in the presence of a sufficiently high
temperature in a highly reducing atmosphere such as in the blast furnace, when
they are respectively reduced to the minutest particles.
In the first place our invention therefore consists in charging into the top of
the furnace, not an excess of lime or limestone, but only sufficient to bring
about the proper fluxing of the silicious and other earthy materials charged
into the furnace, and the excess of lime or limestone, instead of being charged
in bulk at the same point, we reduce by pulverization to the finest possible state
approaching, as nearly as physical particles can be brought thereto, to the
molecular or atomic condition so that they may float in suspense in the air like
a mist or fog and in that condition enter, by means of the blast through tuyeres,
into the furnace for the purpose of aiding the purification of the iron from
sulphur. We are aware that it has been proposed to introduce, through the
tuyeres, into the furnace many substances in the form of powder. According to
our invention however we propose to go much beyond this, as we attach every
importance to the degree of fineness to which the lime is reduced before using
the same in the manner described. In this respect we follow the reasoning that
as the sulphur is so intimately and thoroughly disseminated throughout the

page_text: mass of ore or metal, the purifying agent ought to be in such a state of extreme
subdivision and diffusion of its particles as to be capable of the most thorough
searching prolongation or intimacy of contact with the particles of iron.
According to one plan of our invention we provide that this contact takes
place at the moment when the iron, in'a highly fluid state, is trickling down in
fine streams through the coke bed to the hearth.
According to a second plan, which we work either by itself or in conjunction
with the one just previously mentioned, we provide that this contact takes place
at or in the hearth itself where the fluid metal is accumulating.
The condition, according to both our plans, either separately or in combination,
is thus set up which is most favorable for obtaining the best combination of the
lime with the sulphur in the iron. It is obvious however that, so far as any
mechanical method of pulverisation is concerned, there is a practical limit to
the subdivision of the lime.
In the second place therefore, our invention consists in reducing the lime to a
still finer state than that reached by the mechanical limit, by employing the
disruptive agency of heat or electricity whereby according to well known laws
such substance is brought into a condition in which it becomes susceptible of
being held in suspension in the air or in a gas, so that the lime thus practically
passes into the aeriform state. It is well known that soluble matters contained
in liquids are said to be held in solution, or in chemical suspension or diffusion,
and it is equally well known that matters, the particles or qualities of which
are infused into those of another, (when that other is a gas or any elastic medium
such as the atmosphere), are said to be held in suspension, and the condition of
things we create by our invention we wish to be understood as fully corresponds
to this latter description as anything said to be held in solution, or chemical
suspension, corresponds to the former description.
The state of subdivision into which, by mechanical, thermal or electrical
manipulation, separately or in combination, we bring the lime into suspension in
air or gas admits of our designating this combination in the case of gas as lime-
blast or lime-air, following the analogy of lime in solution in water being called
lime-water.
In giving practical effect to our invention we adopt any approved system of
pulverisation, but prefer one in which the process of separation of the finer
particles from the coarse oues is controlled by a self-contained fan which can
be regulated at will as to the degree of fineness required. We then, by suitable
means, pass the lime through pipes or chambers or containers heated, when
necessary, either by the resultant gases of the furnace or by other artificial
means as, for instance, in the case of a foundry cupola, by the application of a
gas jet or other flame, or in the case of a blast furnace, we utilise the hot blast
itself for this purpose in addition to using the same where required as a vehicle
for conveying the lime into the furnace, or by Cowpers or other stoves of greater
heating power, or by the application of the electric current. With the lime in
a state of exceedingly fine subdivision, we then impregnate or saturate air or a
gas such as nitrogen or carbonic oxide or carbonic acid or other gas or medium
favorable as mechanical vehicles for carrying the lime into the furnace, and
with this impregnated, saturated, elastic, volatile medium we load the blast itself
or otherwise carry the same into the furnace by any approved mechanical means,
such as an injector, or air compressor, whether operated by steam, air or other
motive power, working at a high pressure, whereby a maximum quantity of lime
is forced into the iron with a minimum quantity of air or other conveying
medium. The lime, in what may be considered as being an intermolecular com-
bination with the air or other gaseous vehicle, or as nearly so as may be is
thus capable of accomplishing the object of purifying or freeing the iron from
sulphur in a manner much more effective, economical, direct, continuous and
automatic than that which it is capable of effecting by the processes at present
in vogue, or methods which have been hitherto proposed.
.

page_text: We convey the loaded blast or gas or other carrying vehicle to a separate tuyere
or set of tuyeres. directed on to the molten iron on the hearth, and we also at such
other place or places as may be necessary according to the individual design of any
particular furnace-blow in at the ordinary tuyeres a lime saturated blast of a
neutral gas such as nitrogen, or preferably carbonic oxide or carbonic acid, for the
purpose of also freeing the fuel from sulphur.
In this connection our invention provides for the utilisation of the waste gases
given off during furnace work or products of combustion otherwise carried on.
Our invention it will be seen by obvious modifications and combinations of our
methods thus assists in the comparatively infusible slag containing an excess of
lime being continuously cleared out of the furnace, conjointly with a direct method
of eliminating sulphur from iron at a minimum expenditure and at a great saving
in the time and labour involved in the process of purification.
With regard to the mechanical means which we adopt for controlling the
introduction of the lime into the furnace, there are many descriptions of apparatus
which can obviously be applied, consisting of, amongst others, the closed hopper
and endless screw feed into the blast pipe or tuyeres, but our invention in this.
respect includes a new feature in the employment of a revolving tuyere carrying
radial arms with channels or blades, shaped screw or propellor fashion, which
dipping into a trough or container holding the supply of pulverised lime,
scoop up and deliver same at an orifice at their centre where, meeting with the
blast or other conveying vehicle, the same is carried into the furnace.
In the third place our invention provides for lining the furnace with a neutral
material or one non-absorbent in its character in regard to sulphur, and which in
addition exercises no antagonistic chemical action upon the particles of lime. For
such lining we sometimes use best Staffordshire fire brick, and when in position
with suitable degrees of heat and before charging the furnace for working we run
in a flux of borax and chloride of sodium or other flux such as bauxite, clay,
silicate of soda, or potash, or a suitable mixture of these, thus setting up a hard,
firm, glazed surface.
In the fourth place our invention provides that in order to maintain the heat in
the bottom of the furnace as also to furnish the necessary temperature for the
fusion of the refractory basic slag which is formed, we provide an approved means
for blowing in liquid fuel such as petroleum or carbonaceous matters, or solids
such as anthracite coal, separate or in combination with air or other gas or. other
bodies assisting in the combustion of fuel, such process as the foregoing being used
in combination where required with our other processes as described.
carbonaceous substances or compounds can be compressed or solidified into suitable
forms for the metallurgical processes indicated herein and other purposes
connected therewith.
The advantages of our invention in this respect are the following:
These
In the first place the lime or limestone charged into the top in bulk, being only
sufficient for the necessary amount of flux, enables the furnace to work without
irregularity and relieves the manufacturer from the risk of the furnace gobbing up
or other interference which is commonly met with.
In the second place the necessary excess of lime required for the elimination of
the sulphur from the iron reduced to the most finely divided form possible under
the circumstances and being introduced along with, and by means of, the main blast
brings about the purification of the iron from the sulphur, much more cheaply and
effectively than by processes hitherto in use.
It is obvious that one or other of the methods referred to herein may be worked
separately or in combination, but it is to be noted that the ones to which we attach.
importance are the combinations embracing
1. The loading of the furnace with the quantity of lime or limestone only
sufficient for fluxing.
2. The reduction of the excess of lime mentioned to the condition of fine

page_text: subdivision as described by mechanical, physical or electrical means, separately or
in combination.
3. The mixing of the same with air or other medium and thus transforming it
into practically a lime-mist or fog, or lime-air or lime-gas, or a highly volatile
medium, as the result of the high temperature or disruptive force, to which the
same has been exposed by one or other or all of the preceding methods.
4. The introduction of this into the furnace by means of the main or other blast,
injectors, air compressors, or other means as described, separately or in combination,
as also the separate blowing in upon the metal on the hearth.
5. The use of this lime-air similarly disintegrated or volatilized. and or in
combination with a suitable gas blown in upon the fuel at the same time as the
lime by one or other of the means methods or vehicles mentioned is blown in upon
the iron.
6. The lining of the furnace with a material non-absorbent as to sulphur or
non-absorbent as to lime.
By means of our invention we obtain the following advantages.
1. We more effectually free the iron from the sulphur and also produce an iron
of a better quality than hitherto known and at a less cost.
2. We make serviceable enormous quantities of sulphurous ores which are now
practically useless.
Dated October 30th 1893.
WILLIAM JOHN CLAPP,
SAMUEL DICKINSON WILLIAMS,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture and Purification of Iron, and in
Means or Apparatus Employed therein.
We, WILLIAM JOHN CLAPP, of 33 York Place, Newport, in the County of
Monmouth, Surgeon, and SAMUEL DICKINSON WILLIAMS, of 8 Faulkner Road,
Newport aforesaid, Engineer, 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 following Specification it is to be understood that, to avoid repetition,
wherever the word furnace is used, the term cupola, or other place or process where
iron is melted down in contact with carbon, is included in reference to our
invention, with of course such modifications in its application as may be obviously
called for in any individual case.
In the smelting of iron ore in the furnace, and the re-melting of pig-iron in the
cupola, lime or limestone has always been used as a flux and a purifier in the
presence of incandescent fuel; but the method of using lime or limestone for this
purpose has hitherto been by loading lime or limestone in bulk at the top of the
furnace in the proportion sufficient for fluxing purposes, and in addition charging
in an excess of lime or limestone, also in bulk, which to some extent eliminates or
washes out sulphur from the iron. This mode of manufacture, which hitherto has
been the one universally adopted, is well known to create this difficulty for the
manufacturer, viz.: that, on the one hand, the less lime or limestone he charges
into the furnace at the top, the more sulphury the quality of the iron produced,
and, on the other hand, the more lime or limestone that he thus charges into the
furnace at the top, forming as it does a highly infusible slag, the greater is the risk
of interfering with the work of the furnace by its "gobbing" up.
From the foregoing considerations the method of allowing the limestone or lime,

page_text: when charged into the top of the furnace, to take its own chance of mixing with
the iron in its descent to the bottom of the furnace, is obviously a crude and
imperfect method in practice, inasmuch as by this means that mixture of the lime
or limestone and iron which is required for the elimination of the sulphur, cannot
be obtained. The theory of iron making requires that, in smelting operations
generally, the best process would be one in which the lime or limestone and iron
could be brought together in intimate contact in the presence of a sufficiently high
temperature in a highly reducing atmosphere, such as in the blast furnace, when
they are respectively reduced to the minutest particles.
In the first place our invention, therefore, consists in charging into the top of
the furnace, not an excess of lime or limestone, but only sufficient to bring about
the proper fluxing of the silicious and other earthy materials charged into the
furnace, and the excess of lime or limestone, instead of being charged in bulk at
the same point, we reduce by pulverization to the finest possible state, approaching,
as nearly as physical or solid particles can be brought thereto, to the molecular or.
atomic condition, so that they may float in suspense in the air, like a mist or fog,
and in that condition enter, by means of the blast, through tuyeres into the furnace
for the purpose of aiding the purification of the iron from sulphur. We are aware
that it has been proposed to introduce through the tuyeres into the furnace, many
substances in the form of powder. According to our invention, however, we
propose to go much beyond this, as we attach every importance to the degree of
fineness to. which the lime or limestone is reduced before using the same in the
manner described. In this respect we follow the reasoning that, as the sulphur is
so intimately and thoroughly disseminated throughout the inass of ore or metal,
the purifying agent ought to be in such a state of extreme subdivision and diffusion
of its particles as to be capable of the most thorough searching prolongation or
intimacy of contact with the particles of iron.
According to one plan of our invention we provide that this contact takes place
at the moment when the iron, in a highly fluid state, is trickling down in fine
streams through the coke bed to the hearth.
According to a second plan, which we work either by itself or in conjunction
with the one just previously mentioned, we provide that this contact takes place at
or in the hearth itself, where the fluid metal is accumulating.
The condition, according to both our plans, either separately or in combination,
is thus set up which is most favorable for obtaining the best combination of the
lime or limestone with the sulphur in the iron. It is obvious, however, that, so
far as any mechanical method of pulverization is concerned, there is a practical
limit to the subdivision of the lime or limestone.
In the second place, therefore, our invention consists in reducing the lime or
limestone to a still finer state than that reached by the mechanical limit, by
employing the disruptive agency of heat or electricity, whereby, according to well
known laws, such substance is brought into a condition in which it becomes
susceptible of being held in suspension in the air or in a gas, so that the lime thus
practically passes into the aeriforin state. It is well known that soluble matters
contained in liquids are said to be held in solution, or in chemical suspension or
diffusion, and it is equally well known that matters, the particles or qualities of
which are infused into those of another (when that other is a gas or any elastic
medium such as the atmosphere), are said to be held in suspension, and the con-
dition of things we create by our invention, we wish to be understood, as fully
corresponds to this latter description as anything said to be held in solution or
chemical suspension corresponds to the former description.
The state of subdivision into which, by mechanical, thermal, or electrical
manipulation, separately or in combination, we bring the lime or limestone
into suspension in air or gas, admits of our designating this combination, in the case
of gas, as lime-blast or lime-air, following the analogy of lime in solution in water
being called lime-water.
In giving practical effect to our invention we adopt any approved system of

page_text: pulverization, but prefer one in which the process of separation of the finer
particles from the coarse ones is controlled by a self-contained fan, which can be
regulated at will as, to the degree of fineness required. We then, by suitable
means, pass the lime or limestone through pipes or chambers or containers, heated,
when necessary, either by the resultant gases of the furnace, or by other artificial
means, as, for instance in the case of a foundry cupola, by the application of a gas
jet or other flame, or in the case of a blast furnace, we utilize the hot blast itself
for this purpose, in addition to using the same, where required, as a vehicle for
conveying the lime or limestone into the furnace; or by Cowper's or other stoves of
greater heating power; or by the application of the electric current.
With the lime or limestone in a state of exceedingly fine subdivision, we then
impregnate or saturate air, or a gas such as nitrogen or carbonic oxide or carbonic
acid, or other gas or medium favorable as mechanical vehicles for carrying the
lime or limestone into the furnace, and with this impregnated, saturated, elastic,
volatile medium we load the blast itself, or otherwise carry the same into the
furnace by any approved mechanical means, such as an injector or air compressor,
whether operated by steam, air, or other motive power working at a high pressure,
whereby a maximum quantity of lime or limestone is forced into the iron with a
minimum quantity of air or other conveying medium. The lime or limestone, in
what may be considered as being an inter-molecular combination with the air or
other gaseous vehicle, or as nearly so as may be, is thus capable of accomplishing
the object of purifying or freeing the iron from sulphur in a manner much more
effective, economical, direct, continuous and automatic than that which it is capable
of effecting by the processes at present in vogue or methods which have been
hitherto proposed.
We convey the loaded blast or gas or other carrying vehicle to a separate tuyere
or set of tuyeres directed on to the molten iron on the hearth, and we also at such
other place or places as may be necessary, according to the individual design of
any particular furnace, blow in at the ordinary tuyeres, a lime saturated blast of
a neutral gas, such as nitrogen, or preferably carbonic oxide or carbonic acid, for
the purpose of also freeing the fuel from sulphur.
In this connection our invention provides for the utilization of the waste gases
given off during furnace work, or products of combustion otherwise carried on.
Our invention it will be seen, by obvious modifications and combinations of our
methods, thus assists in the comparatively infusible slag containing an excess of
lime being continuously cleared out of the furnace conjointly with a direct method
of eliminating sulphur from iron at a minimum expenditure and at a great saving
in the time and labour involved in the process of purification.
With regard to the mechanical means which we adopt for controlling the
introduction of the lime or lime-stone into the furnace, there are many descriptions
of apparatus which can obviously be applied, consisting of, amongst others, the
closed hopper and endless screw feed into the blast pipe or tuyeres, but our
invention in this respect includes a new feature in the employment of a revolving
tuyere feeding pipe carrying radial arms with channels or blades, shaped screw or
propellor fashion, which, dipping into a trough or container holding the supply of
pulverized lime or limestone, scoop up and deliver same at an orifice at their
centre, where, meeting with the air blast or other conveying vehicle, the same is
carried into the furnace.
When acting upon finely powdered lime or limestone by electricity we proceed
somewhat as follows. We employ an electric furnace constructed on any approved
principle and, having previously finely pulverized the lime or limestone, we feed it
in that condition between the electrodes of an electric circuit carrying a suitable
current, and as the particles pass into the arc, they become volatilized and the
resultant gas, which we call calcigen, we collect in a receiver. The feed of the
particles of lime or limestone into the electric are may be by process of gravity or
by the direction of concentration to a point which an injector or a directing nozzle
operated by a suitable propelling force would give to it. The resulting gas, or say

page_text: the "calcigen," thus produced, we transfer, by suitable conveying pipes and
directing and controlling valves, into the blast pipe, where, by means of the air
blast itself or by steam or vapour of petroleum or other of the known gases, it is
projected into the furnace and disseminated in the most thorough manner throughout
the contents of the same. The electric furnace may however be omitted as a
separate or preparatory stage, in which case the electric arc is arranged in direct.
connection with the blast pipe itself, and in such blast pipe we also arrange the
feeder or injector for transferring the pulverized lime or limestone into the blast.
In the path of the particles as thus borne along, is arranged the electric arc, which,
as they pass, volatilize them, and thus, in a molecular state, the resultant gas,
calcigen, is propelled by the blast into the furnace..
We also provide that in some cases lime or limestone reduced to the gaseous
form combined with air or other blast, is forcibly transported or impelled into the
furnace by means of any approved injector or piston or other blowing or forcing
apparatus.
A coil of metal placed inside the blast pipe near the tuyere can also be heated
by the electric current and used as a means of keeping the blast and lime or lime-
stone powder or calcigen hot, and the revolving tuyere feeder herein described may
be used in supplying the powdered lime or limestone required to produce the
resultant gas or calcigen.
In the third place our invention provides for lining the furnace with a neutral
material, or one non-absorbent in its character in regard to sulphur, and which in
addition exercises no antagonistic chemical action upon the particles of lime or
limestone. For such lining we sometimes use best Staffordshire fire brick, and when
in position, with suitable degrees of heat, and before charging the furnace for
working, we run in a flux of borax and chloride of sodium, or other flux such
as bauxite, clay, silicate of soda or potash, or a suitable mixture of these, thus.
setting up a hard, firm, glazed surface.
In the fourth place our invention provides that, in order to maintain the heat in
the bottom of the furnace, as also to furnish the necessary temperature for the
fusion of the refractory basic slag which is formed, we provide an approved means.
for blowing in liquid fuel, such as petroleum or carbonaceous matters, or solids.
such as anthracite coal, separate or in combination with air or other gas or other
bodies assisting in the combustion of fuel, such process as the foregoing being used
in combination where required with our other processes as described. These
carbonaceous substances or compounds can be compressed or solidified into suitable
forms for the metallurgical processes indicated herein and other purposes connected.
therewith.
The advantages of our invention in this respect are the following:
-
In the first place the lime or limestone charged into the top in bulk, being only.
sufficient for the necessary amount of flux, enables the furnace to work without.
irregularity and relieves the manufacturer from the risk of the furnace "gobbing
up or other interference which is commonly met with.
"
In the second place the necessary excess of lime or limestone required for the
elimination of the sulphur from the iron reduced to the most finely divided form
possible under the circumstances and being introduced along with, and by means.
of, the main blast brings about the purification of the iron from the sulphur, much
more cheaply and effectively than by processes hitherto in use.
The accompanying diagrammatic drawings, which are not made to any scale,
represent various arrangements of apparatus we employ in carrying our invention.
into practice.
Figure 1. is a sectional elevation representing a blast furnace provided with main
and supplemental blast pipes and tuyeres and revolving feeders for supplying
finely pulverized lime or limestone to the blast pipes.
Figure 2 is a plan of the circular blast pipes and tuyeres shown in Figure 1.
Figure 3 is a sectional elevation of the revolving feeder separately.
Figure 4 is a sectional elevation representing a blast furnace, main blast pipe,

page_text: circular blast pipes, and'tuyeres, similar to those shown at Figures 1 and 2, but
having a modified, arrangement of parts for delivering finely pulverized lime or
limestone to the circular blast pipes and tuyeres, and
Figures. 5 and 6 are sectional elevations representing respectively a cupola
furnace and a convertor provided with blast pipes, tuveres and apparatus for
supplying thereto finely pulverized lime or limestone, of similar arrangement to
those shown at Figures 1, 2 and. 3.
In all the figures like parts are indicated by similar letters of reference.
a represents the body of the blast furnace, cupola or convertor, the main blast
pipe, c the upper circular blast pipe, d the lower circular blast pipe, e the upper
tuyeres, and the lower tuyeres. The furnaces are provided with the usual-
charging holes a¹ and tapping holes a².
The tuyeres e fare preferably arranged as shown in plan at Figure 2; that is to
say, the tuyeres e are arranged intermediate of the tuyeres f, so as to cause every
part of the molten metal in the furnace to be acted upon by the blast and the finely
pulverized lime or limestone carried in therewith.
c' is a pipe connected with the main blast pipe. 6 and supplying the tuyeres e, and
d is a pipe connected with the main blast pipe b and supplying the tuyeres f.
In the furnaces and convertor represented at Figures 1, 2, 3, 5, 6, the finely
pulverized lime or limestone is supplied to hoppers g interposed between the pipes c
and c and between the pipes d and d¹. In connection with each hopper g is a
revolving tuyere feeding pipe c² or d³, carrying radial arms with channels or
blades and shaped somewhat screw or propellor fashion, the pipes 2 and d2 are
suitably mounted and revolved by bands passing around pulleys c³ d³.
.
The arms c, in their revolution, dip into the trough or container g and scoop up
and deliver the finely pulverized lime or limestone at a central orifice, where,
meeting with the air blast or other conveying vehicle, the same is carried through
the tuyeres into the furnace.
In the arrangement of apparatus represented at Figure 4, the pipes ² d² are
revolved as in the arrangement described with reference to Figures 1, 2, 5, for the
purpose of preventing the deposit of any lime or limestone powder in such tubes,
but the arms c are dispensed with, and in connection with the pipes c' d' we employ
hoppers g*, which, at their bottoms, open into the pipes c¹ d'.
In connection with the hopper g*, at the right of Figure 4, we have shown a
pulley which drives a stirrer at the bottom of the hopper to ensure the flow of
the finely powdered lime or limestone to the pipe g² connecting the hopper g* with
the pipe c', and a blast pipe g³ is shown connected with the lower part of the pipe g²
to blow the powdered lime or limestone into the pipe c¹ and to keep the outlet of
the hopper * clear.
The hopper g* at the left of Figure 4 has a blast pipe 93 passing through the
outlet to blow the finely pulverized lime or limestone into the pipe d¹ and keep the
outlet of the hopper clear. Any other convenient arrangement of apparatus may
however be employed for supplying the finely pulverized lime or limestone to the
tuyeres.
We prefer to apply in the upper part of the cupola furnace a superheater h
provided with a spray distributor to supply highly superheated steam for the
purpose of clearing the gases and making the cupola clearer for the elimination
process.
-In the blast furnaces represented in the drawings the upper tuyeres e open into
the furnace just below the coke bed, and the lower tuyeres f open into the hearth.
The full lines in Figures 1 and 4 show the blast furnaces with the hearth in the
usual place and form; we prefer however to employ a separate hearth connected to
the body of the blast furnace by a narrow neck, as shown by dotted lines at Figs. 1
and 4, and in such case the hearth may be placed immediately underneath the body
of the furnace, as shown at Fig. 1, or it may be at one side thereof as shown
at Fig. 4. In these forms of furnace the coke bed is immediately above the neck
leading to the hearth. By these constructions of furnace hearth the iron is

page_text: strained off from the slag and coke and the minutely divided lime or limestone is.
delivered by the blast on to the molten metal as it flows into and collects
within the hearth. The above arrangement of hearth is also applicable to other
furnaces.
In the convertor we have arranged a pedestal a³ at the bottom, so that the blast
entering the convertor by the tuyeres f will cause a rotary motion of the fluid
metal and thus obtain access to every part thereof. The tuyeres of the various
furnaces may be directed downwards as shown by the full lines, or they may be
horizontal as indicated by the dotted lines, in Figure 4, or they may be otherwise
directed as may be desired.
It is obvious that one or other of the methods herein referred to may be worked
separately or in combination, but it is to be noted that the ones to which we attach
importance are the combinations embracing:
.
1. The loading of the furnace with the quantity of lime or limestone, only
sufficient for fluxing.
2. The reduction of the excess of lime or limestone mentioned to the condition of
fine subdivision as described by mechanical, physical or electrical means, separately
or in combination.
3. The mixing of the same with air or other medium and thus transforming it
into practically a lime-mist or fog, or lime-air or lime-gas, or a highly volatile
medium, as the result of the high temperature or disruptive force to which the
same has been exposed by one or other or all of the preceding methods.
4. The introduction of this into the furnace by means of the main or other blast,
injectors, air compressors, or other means as described, separately or in combination,
as also the separate blowing in upon the metal on the hearth.
5. The use of this lime-air similarly disintegrated or volatilized and in com-
bination with a suitable gas blown in upon the fuel at the same time as the lime or
limestone, by one or other of the means, methods or vehicles mentioned, is blown in
upon the iron.
6. The lining of the furnace with a material non-absorbent as to sulphur or non-
absorbent as to lime.
By means of our invention we obtain the following advantages:
1. We more effectually free the iron from the sulphur and also produce an iron
of a better quality than hitherto known and at a less cost.
2. We make serviceable enormous quantities of sulphurous ores which are now
practically useless and we can also use sulphury or inferior coke.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. The herein described method of manufacturing and purifying iron which
consists in charging into the furnace a limited quantity of lime or limestone sufficient
for the proper fluxing of the silicious and other earthy matters and introducing the
excess of lime or limestone in a finely divided condition into the furnace for
purifying the iron from sulphur, substantially as set forth.
2. Purifying iron from sulphur by lime or limestone in a finely divided condition
carried into the furnace with a blast of air or other vehicle through tuyeres
substantially as set forth.
3. The method of purifying iron which consists in producing a vapour or aeriform
condition of lime or limestone and conveying the same into contact with the iron
through the medium of a blast of air or other vehicle and also supplying the same
to the fuel for purifying the latter substantially as set forth.
4. The method of purifying iron which consists in volatilizing lime or limestone
by the electric arc and introducing the "calcigen" thus produced into the furnace,
substantially as set forth.
5. The method of purifying iron which consists in feeding lime or limestone in a
finely pulverized condition between electrodes, collecting the resulting gas and

page_text: finely divided lime or limestone and introducing it into the furnace, substantially as
set forth.
6. The herein described revolving tuyere-pipe carrying radial arms with channels
or blades combined with a receptacle for finely powdered lime or limestone and
means for causing the lime or limestone to pass from said tuyere into the furnace,
substantially as set forth and for the purpose stated.
7. In the manufacture and purification of iron or steel from sulphurous ores the
lining of the furnace with a material non-absorbent as to sulphur and non-absorbent
as to lime in combination with the introduction of lime or limestone for fluxing and
finely divided lime for desulphurizing, substantially as set forth.
1004
W. J. CLAPP,
By Harris & Mills,
23, Southampton Buildings, London, Agents.