CERTAIN NEW AND USEFUL IMPROVEMENTS IN PROCESS AND APPARATUS FOR THE REDUCTION OF IRON ORE
Year: 1882

page_text: LETTERS PATENT to William Edward Gedge, of N° 11, Wellington Street,
Strand, London, in the County of Middlesex, Patent Agent, for an Invention
of "CERTAIN NEW AND USEFUL IMPROVEMENTS IN PROCESS AND APPARATUS
FOR THE REDUCTION OF IRON ORE" A Communication to him from abroad
by Louis Durand and Dexter H. Walker, both of New York City, in the
United States of America
PROVISIONAL SPECIFICATION left by the said William Edward Gedge at
the Office of the Commissioners of Patents on the 19th October 1882.
WILLIAM EDWARD GEDGE, of N° 11 Wellington Street, Strand, London, in the
County of Middlesex, Patent Agent, "CERTAIN NEW AND USEFUL IMPROVEMENTS
IN PROCESS AND APPARATUS FOR THE REDUCTION OF IRON ORE" A Communi-
cation to me from abroad by Louis Durand and Dexter. H. Walker both of New
York City in the United States of America.
My Invention relates to the reduction of iron ores to the state of pulverulent
metal or sponge, and it consists, first, in a method of reducing the ore to the
metallic state by means of gaseous reducing agents exclusively; second, in the
production of steel direct from the ore as incident to the reduction of the ore to the
state of sponge iron, either or both of the said processes being effected by the use
of either vegetable or mineral fuel; third, in the latter case, the method of freeing
the reducing gases from the presence of constituents which would otherwise injure
the products; and, fourth, in the apparatus used, all substantially as hereinafter
set forth.
The reduction of the oxides of iron to the state of pulverulent metal or sponge,
whether by the laboratory processes of reduction through the action of hydrogen or
hydro-carbon gases upon the oxide, or, on a commercial scale by the action of solid
carbon upon the ore, has long been known and to some extent practiced, and various
processes for the production of sponge iron are described in the books and have
been made the subject of Letters Patent in England, France and the United
States.

page_text: While such reduction is theoretically feasible on a large scale, it has heretofore
not been practically and commercially successful and the failure has been due to
two principal causes, vis, structural defects in the apparatus and the use of other
than the proper reducing agent, or rather, the use of the proper reducing agent, if
at all unwittingly and under such conditions as to prevent the attainment of any
useful end whatever.
6
The agent to which I have reference carbonic oxide (CO) while being a product
of the incomplete combustion of carbonaceous matter, or of the action of carbonic
acid (00) (the product of complete combustion) upon carbon, is necessarily
produced in greater or less proportion, and is perhaps to that extent active, in all
or nearly all the well known processes for the reduction of iron ore to sponge; but,
as above stated the results which would have attended its use under proper
conditions, which is the pith of this invention, were either defeated entirely, or
were so masked by the admixture of solid carbon with, the ore, or by the main-
tenance of improper temperatures in the apparatus, that no good results have been 1
heretofore known as attending the presence of this gas, nor has its adaptability for
the purpose been recognized or admitted. The defects in processes heretofore
proposed or attempted for the reduction of ore by means of carbonic oxide have
been due to the fact that either the ore or gas or both were heated independently
of the heating attending the production of the gas, causing the sponge to agglomerate,
or else the ore was mixed with carbonaceous matter. In the process of this
Invention the ore is unheated' except by the gaseous reducing agent and it (CO)
has only its natural temperature, io, the temperature incident upon its production
For the purposes of this Invention an apparatus has been devised in which this
gas is produced in a state of purity, that is, in the sense of its freedom from
admixture with any agent which could have a deleterious effect upon its action
and which said apparatus is adapted as well for the production of the carbonic
oxide from vegetable as from mineral fuel, and, in the latter case, means are afforded
for eliminating impurities, such as sulphur from the gas.
The apparatus is adapted also for the conversion of the metallic sponge into
steel.
Proceeding now to a description of the Invention and referring to the accom-
panying Sheet of Drawing upon which
Figure 1 is a central vertical longitudinal sectional view of the furnace on the
line x, x, of Figure 2
Figure 2 is a horizontal view on the line zu, w, of Figure 1
Figure 3 is a vertical sectional view on the line a¹, ¹, of Figure 2
Figure 4 is a similar view on the line y, y, of Figure 2 and
Figure 5 is a similar view on the line z,,,of Figure 2.
A is the furnace constructed exteriorly of any suitable masonry such as brick-
work, and having its interior lined with fire brick. It consists by preference of
five vertical chambers B, C, C, D, D, the chambers CD' being counterparts,
respectively, of the chambers CD. Suitable tuyeres a, a, enter the chambers
D, D, near their bases, cach chamber having preferably, four tuyeres. The
chambers D, D' communicate with the chambers CC by means of channels b, b,
and the chambers CC have openings c, c, leading to the central shaft or chamber B,
'near its base.
The accompanying drawings are made to scale 15 millimetres to the metre, the
scale below Figure 2 being assumed to truly represent a deci-metre and its divisions,
and the apparatus is of a capacity to reduce ten tons of ore per diem.
The various chambers are provided with suitable apparatus for closing them
at the top which I have considered it unnecessary to illustrate and shall not
particularly describe, as such apparatus is old and well known.
Suffice it that it is only desirable that the closing device be of such construction
as to avoid loss of gas from the chambers while charging them.
The chambers DD constitute the gas generators and each is provided at its
base with a wedge shaped partition E extending entirely across the generator

page_text: parallel to the plane of the tuyères, and it has its apex or ridge one metre above
the bottom of the chamber or crucible.
This separation into two compartments at the bases of the generators is
important as facilitating the discharge of refuse.
In Figure 3 is shown a section of the central ore reducing chamber B on the
line x. x of figure 2. Into this chamber the ore is charged and at the bottom of
the chamber are two tubes F into which the sponge descends and which discharge
at the sides of the Furnace. These tubes are by preference made double and a
current of water is caused to flow between the walls in order to cool the coutents
of the tubes and prevent spontaneous combustion of the sponge when removed
therefrom.
GG are rotary taps whereby the metal may be removed without permitting
escape of gas from the stack.
His a wedge shaped block of masonry covered with fire-brick and arranged to
discharge the sponge into the tubes F, and serve as a support for the cast iron
plate & which supports them. Cast iron plates e, e, are built into the walls and
sustain the over-lianging portion.
In Figure 4 is shown a vertical section of the generators on the line y, y, of
Figure 2. Here a, a, are the tuyeres and f, f, the cast iron plates on which they
rest. The space below these plates is, in operation filled with cinders, and E, is the
wedge-shaped masonry structure which separates the base of the generator into
two compartments.
The lower portions of the generators are made larger than the upper, the design
being to prevent the fuel from settling down.
In Figure 5 is shown the chamber C (C¹) in section on the line 2, 2, of Figure 2.
These chambers increase in size from above downward and at the hottom are
wedge shaped walls I leading to lateral openings H which latter are provided with
doors that are luted air tight in operation.
The apparatus is designed, first, for the reduction. of the ore to sponge iron,
vegetable fuel alone being used for the production of the reducing agents carbonic
oxide and hydrogen; second, for the reduction of the ore as above, mineral fuel
being used and means being provided for the elimination from the gases of all
traces of sulphur whereby an iron is made equal in quality to that reduced by
vegetable fuel; third, for the reduction by vegetable fuel with either a total or
partial conversion of the product into steel; and fourth, for producing steel from
the ore, coal or coke being used as fuel
I shall describe the modus operandi in each of the before mentioned cases,
REDUCTION OF THE ORE BY THE USE OF VEGETABLE Fuel.
The ore is charged into the compartment B completely filling it, and the
chambers C C D D are filled with charcoal, the top openings of all being
hermetically sealed. The surplus gases from the compartment B are led away
through a pipe or pipes opening into it near its top as at m, to the hearth where
they are burned to heat the blast.
The various compartments are charged from time to time, the intervals never
being allowed to exceed three hours.
The air for supporting combustion is directed into the bases of the gene-
rators D D through the tuyeres a and the product of the complete combustion
at that point is carbonic acid (C O³) the temperature being theoretically 2200° C.
The carbonic acid generated is compelled to traverse the whole layer of charcoal
between the level of the tuyeres a and the orifices b, pending which transit it is
gradually converted into carbonic oxide (CO) by contact with the charcoal.
The heat which becomes latent in this conversion, theoretically lowers the

page_text: •
tomperature to 780° C, but practically this reduction is enhanced by radiation and
absorption to about from 620° C to 650° C.
"
Complete conversion of the CO2 into CO is essential to the proper working of
the apparatus, and, in order to insure it, the layer of charcoal, which the gases are
compelled to traverse, must be ample. There exists no theoretical principle for
determining a priori, the requisite volume of this layer, but practical experience*
has shown that about ton hectolitres per ton of charcoal consumed per diem is
sufficient. As the consumption by the furnace, under tho. conditions upon which
this assertion is based is 4000 Kilos for the reduction of ten tons of ore, the total
volume of the layer to be traversed by the gas must be 40 hectolitres, or 20 hecto-
litres for each generator.
This volume may well be increased without any possible deleterious result, and
in practice it is better to adopt say 22 to 24 hectolitres instead of 20, foreseeing &
case in which the fuel is of exceptional density, or in which it is desired to some-
what increase the daily production.
The dimensions in each generator shown in the drawings are as follows :—
1
Height
1.50
"
Whence we find the contents to be about 2,425 O M..or 24, 5 hectolitres for
each generator, which is ample for the complete conversion of the carbonic.acid
into carbonic oxide in cases of the consumption of four or even five tons of charcoal
per diem.
The gaseous mass, as it issues through the openings b, consists of carbonic oxide,
nitrogen and steam, the latter having been derived from the hygrometric water of
the charcoal, and in this state it enters the chambers C C. where it encounters, a
new layer of charcoal between the levels of the openings band c.
In this transit the carbonic oxide and nitrogen remain unaltered, because,
charcoal, at a red heat, has no action, upon either gas, but the steam decomposes
by the action of the carbon upon its oxygen the resultant products being carbonic
oxide and free hydrogen.
Inasmuch as the volume of watery vapour is small in comparison with that of
gas, the area of the chambers C C₁ between the levels b and c, necessary for the
complete conversion of the vapor into carbonic oxide and hydrogen need not exceed
a tenth of that of the generators, or, say, from 2 to 25 hectolitres for each com-
partment. But, as in the other case, excess does no harm, and I deem.it proper
to largely increase the necessary area in order to provide for other operations as
hereinafter set forth
The dimensions given in the Drawings are:-
Length perpendicular to section of Fig: 1
Width parallel to section of Fig: 1
Height
-
that is to say the cubical contents are about 0-897 C M.
compartment.
"
172 motres
0.58
0.90
"
"
= 9 hectolitres for eacli
This great excess is never harmful, and is in some instances useful to the extent
,of being absolutely necessary, as will hereinafter appear.
The gases which enter the base of the chamber B.are composed only of carbonic
oxide, hydrogen and nitrogen. The first two are energetically reductive, and the
latter absolutely inert. As the gaseous mass passes upward through the chamber B
it yields up to the latter a portion of its heat, until an equilibrium of temperature
is established, when the carbonic oxide and hydrogen take gradual possession of
the oxygen of the ore, reducing the latter to the state of metallic sponge.
The capacity of the compartiment B must be proportionate to the quantity of
,ore which it is desired to reduce every 24 hours, and which, in the present case, is

page_text: ten. tons. Reduction is not immediately effected by any means; the ore must
remain for a certain length of time exposed to the action of the reductive gases in
order to pass to the state of sponge.
We know that in the blast furnace the conversion is effected in sixteen hours
and about the same time is required in this apparatus.
The reduction of ten tons in 24 hours corresponds to 416-66 kilos per hour and
for sixteen hours the amount would be 6666 Kilos, therefore, the volume of the
chamber must be about four cubic metres.
The average dimensions of the chamber are:-
Length perpendicular to section of Fig: 1
Width, parallel to section of Fig: 1
Height, above entrance of gases
-
1.46 metres
-
0.86
22.
-
5,
32
Whence we find the contents to be about 6. C. M. from which about one fourth
must be deducted because the gases are taken from the compartment 1.20 m.
below the superior level and exert no influence upon the ore above that point.
The residual excess, 0,50 CM. is not injurious, and in some cases beneficial.
To obtain perfectly regular metallic sponge it is sufficient to regulate the intro-
duction of air through the tuyeres in such manner as to burn 4000 kilos of charcoal
per diem, or 116 kilos per hour, and at the same time to extract a volume of
metallic sponge equal to that of 417 kilos of ore gross weight, or say, 25 hectolitres.
The best device for the removal of the sponge is the rotary tap G which operates.
on the principle of an ordinary spigot, and at each complète revolution it discharges
the sponge which fills it. This amount, since there are two taps should be from
1.25 to 15 hectolitres.
It is essential that the sponge shall reach the taps cold, else spontaneous ignition
is liable to occur, and furtherinore it is desirable as insuring a free working of the
taps. This cooling may be effected by causing a current of water to circulate
between the walls of the tubes, F. The latter according to the dimensions shown,
contain each 1300 kilos of sponge, or in all 2600 kilos. The duration of the sojourn.
of the sponge in the tubes may be calculated from the proportion 10,000: 24::
26.00, whence we find the time to be about 6 hours.
4
This is ample for the cooling of the sponge even without the water jacket.
The material and important difference between coal or coke and charcoal for
the reduction of iron ores, consists in the presence of sulphur in the former, while
the vegetable carbon contains none.
This sulphur, if left in the gases used for reduction of the ore, would result
in the production of an iron which would be practically worthless, since as little
as one ten thousandth part of sulphur is enough to make the iron brittle and a
larger proportion renders it entirely unserviceable. It is therefore essential to
thoroughly eliminate all sulphur from the gases in case mineral fuel is used. If so
the chambers C C are filled with a mixture of charcoal and scrap iron instead of
charcoal alone as in the preceding case.
The conversion of the carbonic acid into carbonic oxide and the decomposition
of the hygrometric water are effected precisely as hereinbefore described, and the
charcoal mixed with the scrap iron effects the conversion of the steam into carbonic
oxide and hydrogen.
It is susceptible of demonstration that the gaseous mass obtained from coke must
be compelled to traverse a layer of scrap iron of a volume of one hectolitre per ton
of ore to be reduced -per diem, provided the average superficies of the particles of
scrap iron is two square centimetres.
The quantity of ore to be reduced being ten tons, the volume of the mass of scrap
must be ten hectolitres, ie, five for each chamber. The capacity of the chambers

page_text: being nine hectolitres each there remain four to be filled with charcoal, which is
more than sufficient, but the excess does no harm. The above figures are based
on the assumption that the coke contains seven Kilos of sulphur per ton, of
course an excess demands a corresponding increase in iron scrap.
The object of mixing charcoal with the scrap is to reduce any oxide of iron which
would be formed by the action upon the scrap of the steam and watery vapors
driven off from the fuel in the chambers D.
Were it not for the presence of the carbon the iron would become superficially
oxidized and its efficiency as a desulphurizing agent would be impaired.
The mixture of charcoal and iron, which latter is superficially converted into
sulphide, is gradually removed from the chambers through the openings H, the
charcoal is separated and the iron is thrown into water whereby the sulphuretted
portion is removed and the iron may be reused.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Edward Gedge in the Great Seal Patent Office on the
17th April 1883.
"
"
WILLIAM EDWARD GEDGE, of 11 Wellington Street, Strand, London, in the
County of Middlesex, Patent Agent, CERTAIN NEW AND USEFUL IMPROVEMENTS
IN PROCESS AND APPARATUS FOR THE REDUCTION OF IRON ORE A Communi-
cation to me from abroad by Louis Durand and Dexter H. Walker both of New
York City in the United States of America,
My invention relates to the reduction of iron ores to the state of pulverulent
metal or sponge, and it consists, first, in a method of reducing the ore to the
metallic state by means of gaseous reducing agents exclusively; second, in the
production of steel direct from the ore as incident to the reduction of the ore to
the state of sponge iron, either or both of the said processes being effected by the .
use of either vegetable or mineral fuel; third; in the latter case, the method of
freeing the reducing agents from the presence of constituents which would other-
wise injure the product, and, fourth, in the apparatus used, all substantially as
hereinafter set forth.
The reduction of the oxides of iron to the state of pulverulent metal or sponge,
whether by the laboratory processes of reduction through the action of hydrogen
or hydro-carbon gases upon the oxide, or, on a commercial scale by the action of
solid carbon upon the ore, has long been known and to some extent practiced, and
various processes for the production of sponge iron are described in the books and
have been made the subject of Letters Patent in England, France and the United
States.
While such reduction is theoretically feasible on a large scale, it has heretofore
not been practically and commercially successful and the failure has been due to
two principal causes, viz:, structural defects in the apparatus and the use of other
than the proper reducing agent, if at all unwittingly and under such conditions as
to prevent the attainment of any useful end whatever.
The agent to which I have reference carbonic oxide (CO) while being a product
of the incomplete combustion of carbonaceous matter, or of the action of carbonic
acid (C. O2) (the product of complete combustion) upon carbon is necessarily produced
in greater or less proportion; and is perhaps to that extent active, in all or nearly
all the well known processes for the reduction of iron ore to sponge; but, as above
stated the results which would have attended its use under proper conditions,
which is the pith of this invention, were either defeated entirely, or were so masked
by the admixture of solid carbon with the ore, or by the maintenance of improper
temperatures in the apparatus, that no good results have been heretofore known as
attending the presence of this gas, nor has its adaptability for the purpose been
recognized or admitted
The defects in processes heretofore proposed or attempted for the reduction of
ore by means of carbonic oxide have been due to the fact that either the ore or
gas or both were heated independently of the heating attending the production of
the gas, causing the sponge to agglomerate, or else the ore was mixed with carbon-
aceous matter. In the process of this invention the ore is unheated except by the
gaseous reducing agent and it (CO) has only its natural temperature, ie, the
temperature incident upon its production
For the purpose of this Invention an apparatus has been described in which this
gas is produced in a state of purity, that is, in the sense of its freedom from'
admixture with any agent which could have a deleterious effect upon its action and

page_text: which said apparatus is adapted as well for the production of the carbonic oxide
from vegetable as from mineral fuel, and in the latter case, means are afforded for
eliminating impurities, such as sulphur from the gas.
The apparatus is adapted also for the conversion of the metallic, sponge
into steel.
Proceeding now to a description of the invention and referring to the accom-
panying Sheet of Drawings upon which
Figure 1. is a central vertical longitudinal sectional view of the furnace on the
line X-X of fig: 2.
Figure 2. is a horizontal view on the line W-W of fig: 1."
Figure 3. is a vertical sectional view on the line X-X' of figure
Figure 4. is a similar view on the line Y-Y of fig: 2, and,
Figure 5. is a similar view on the line Z-Z of fig: 2.
A is the furnace, constructed exteriorly of any suitable masonry such as brick-
work, and having its interior lined with fire-brick. It consists by preference of
five vertical chambers B, C, C, D, D', the chambors C₁, D', being counterparts,
respectively, of the chambers C, D; Suitable tuyeres a, a, enter the chambers D, D',
near their bases each chamber having preferably four tuyeres. The chambers D, D¹,
communicate with the chambers O, C, by means of channels b, b, and the chambers
C, O, have openings cc, leading to the central shaft or chamber B, near its base.
The accompanying drawings are made to scale 15 inillimetres to the metre, the
scale below fig: 2 being assumed to truly represent a deci-metre and its divisions,
and the apparatus is of a capacity to reduce ten tons of ore per diem.
The various chambers are provided with suitable apparatus for closing them
at the top which I have considered it unnecessary to illustrate and shall not
particularly describe, as such apparatus is old and well known.
Suffice it that it is only desirable that the closing device be of such construction
as to avoid loss of gas froin the chambers while charging them.
The chambers D, D', constitute the gas generators and each is provided at its base
with a wedge shaped partition E extending entirely across the parallel to the plane
of the buyeres, and has its apex or ridge one metro above the bottom of the
chamber or crucible.
This separation into two compartments at the bases of the genèrators is
important as facilitating the discharge of refuse. In Gg: 3, is shewn a section
of the central or reducing chamber B, on the line X, X, of fig: 2. Into this
chamber the ore is charged and at the bottom of the chamber are two tubes F into
which the sponge descends and which discharge at the sides of the furnace. These
tubes are by preference made double and a current of water is caused to flow
between the walls in order to cool the contents of the tubes and prevent spontaneous
combustion of the sponge when removed thorefrom.
G, C, are rotary taps whereby the metal may be removed without permitting
escape of gas from the stack.
His a wedge shaped block of masonry covered with fire-brick and arranged to
discharge the sponge into tubes F, and serve as a support for the cast iron
plate d, which supports them. Cast iron plates c, e, are built into the walls and
sustain the overhanging portion
In fig:
is shown a vertical section of the generators on the line. Y-Y of
fig: 2. Here a, a, are tuyeres and the cast iron plates on which they rest.
The space below these plates is, in operation filled with cinders, and E, is the wedge-
shaped masonry structure which separates the base of the generator into two
compartments.
The lower portions of the generators is made larger than the upper, the design
being to prevent the fuel from settling down
In fig: 5, is shown the chamber C (0¹) in section on the line Z-Z of
fig: 2. These chambers increase in size from above downward and at the bottom
are wedge shaped walls I leading to lateral openings H, which latter are provided
with doors that are luted air tight in operation.

page_text: The apparatus is designed, first, for the reduction of the ore to sponge iron,
vegetable fuel alone being used for the production of the reducing agents carbonic
oxide and hydrogen; second, for the reduction of the ore as above, mineral fuel
being used and means being provided for the elimination from the gases of all
traces of sulphur whereby an iron is made equal in quality to that reduced by
vegetable fuel; third, for the reduction by vegetable fuel with either a total or
partial conversion of the product into steel; and fourth, for producing steel from
the ore, coal or coke being used as fuel.
Tchell describe the modere merandi in each of the before mentioned cases.
The ore is charged into the compartment B, completely filling it, and the
chambers C, C, D D' are filled with charcoal, the top openings of all being hermeti-
cally sealed. The surplus gases from the compartment B are led away through a
pipe or pipes opening into it near its top as at m, to the hearth where they are
burned to heat the blast.
The various compartments are charged from time to time, the intervals never
being allowed to exceed three hours.
The air for supporting combustion is directed into the bases of the generators
D D¹ through the tuyeres a and the product of the complete combustion at that
point is carbonic acid (CO2) the temperature being theoretically about 2200° C.
The carbonic acid generated is compelled to traverse the whole layer of charcoal
between the level of the tuyeres a and the orifices b, pending which transit it is
gradually converted into carbonic oxide (CO) by contact with the charcoal.
The heat which becomes latent in this conversion, theoretically lowers the tempe-
rature to 780° C, but practically this reduction is enhanced by radiation and
absorption to about from 620 C to 650° C.
Complete conversion of the C O' into CO is essential to the proper working of
the apparatus, and, in order to insure it, the layer of charcoal, which the gases are
compelled to traverse, must be ample. There exists no theoretical principle for
determining a priori, the requisite volume of this layer, but practical experience
has shown about ten hectolitres per ton of charcoal consumed per diem is
sufficient. As the consumption by the furnace, under the conditions upon which
this assertion is based is 4000 Kilos for the reduction of ten tons of ore, the total
volume of the layer to be traversed by the gas must be 40 hectolitres or 20
hectolitres for each generator.
This volume may well be increased-without any possible deleterious result, and
in practice it is better to adopt say 22 to 24 hectolitres instead of 20, foreseeing a
case in which the fuel is of exceptional density or in which it is desired to somewhat
increase the daily production.
-
The dimensions in each generator shown in the drawings are as follows:—
Length perpendicular to the tuyeres
Width opposite the tuyeres and at their level
Height
-
1.72 metres
-
0.94 " "
1.50 "
"
Whence we find the contents to be about 2,425 C. M. or 24,5 hectolitrės for
each generator, which is ample for the complete conversion of the carbonic acid
into carbonic oxide in cases of the consumption of four or five tons of charcoal
per diem
The gaseous mass, as it issues through the openings b, consists of carbonic oxide,
nitrogen and steam, the latter having been derived from the bydrometric water of
the charcoal, and in this state it enters the chambers C, C', where it encounters a
new layer of charcoal between the levels of the openings b and c
In this transit the carbonic oxide and nitrogen remain unaltered, because,
charcoal, at a red heat, has no action upon either gas, but the steam decomposes by

page_text: the action of the carbon upon its oxygen the resultant products being carbonic
oxide and free hydrogen.
.
Inasmuch as the volume of watery vapor is small in comparison, with, that of
gns, the area of the chambers C, C, between the levels b, and c, necessary for the
complete conversion of the vapor into carbonic oxide and hydrogen need not exceed
a tenth of that of the generators or, say, from 2 to 25 hectolitres for each compart-
ment. But, as in the other case, excess does no harm, and I deem it proper to
largely increase the necessary area in order to provide for other operations as
hereinafter set forth.
The dimensions vitezen in the Drawing are
The dimensions given in the Drawinge
Length perpendicular to section of fig: 1
Width parallel to section of fig:1
Height
-
-
1.72 metres
-
0.58 ".
- .0.90
"
that is to say, the cubical contents are about 0.897 C. M. = 9 hectolitres for each
compartment.
This great excess is never harmful, and is in some instances useful to the extent
of being absolutely necessary, as will hereinafter appear.
The gases which enter the base of the chamber B are composed only of carbonic
oxide, hydrogen and nitrogen, the first two are energetically reductive, and the
latter absolutely inert. As the gaseous mass passes upward through the chamber B
it yields up to the latter a portion of its heat, until an equilibrium of temperature
is established, when the carbonic oxide and hydrogon take gradual possession of the
oxygen of the ore, reducing the latter to the state of metallic sponge.
The capacity of the compartment B, must be proportionate to the quantity of the ore
which it is desired to reduce every 24 hours, and which, in the prosent case, is ten
tons. Reduction is not immediately effected, by any means; the ore must remain
for a certain length of time exposed to the action of the reductive gases in order
to pass to the state of sponge.
Wo know that in the blast furnace the conversion is effected in sixteen hours and
about the same time is required in this apparatus.
The reduction of ten tons in 24 hours corresponds to 416-66 kilos per hour and
for 10 hours the amount would be 6660 kilos, therefore, the volume of the chamber
must be about 4 cubic metres.
The average dimensions of the chambers are:
Length perpendicular to section of fig: 1
Width parallel to section of fig: 1
Height above entrance of gases -
-
1:46 Metres
-
0.80
"
3)
5- "
"
Whence we find the contents to be about 6 C. M, from which about one fourth
must be deducted because the gases are taken from the compartment 1.20 m below
the superior level and exert no influence upon the .ore above that point. The
residual excess, 0,50 C. M. is not injurious, and in some cases beneficial.
To obtain perfectly regular metallic sponge it is sufficient to regulate the intro-
duction of air through the, tnyeres in such manner as to burn 4000 kilos of
charcoal per diem, or 116 kilos per hour, and at the same time to extract à
volume of metallic sponge equal to that of 417 kilos of ore gross weight, or say,
2:5 hectolitres.
The best device for the removal of the sponge is the rotary tap G. which operates
on the principle of an ordinary spigot, and at each complete revolution it discharges
the-s
e-sponge which fills. it. This amount, since there are two taps should be from
125 to 15 hectolitres.
It is essential that tho sponge shall reach the taps cold, else spontaneous ignition
is liable to occur, and furthermore it is desirable as insuring a free working of the
taps. This cooling may be effected by causing a current of water to circulate
between the walls of the tubo F. The latter according to the dimensions shown
contain each 1300 kilos of sponge, or in all 2600 kilos. The duration of the sojourn

page_text: The material and important difference between coal or coke and charcoal for the
reduction of iron ores, consists in the presence of sulphur in the former, while the
vegetable carbon contains none.
This sulphur, if left in the gases used for reduction of the ore, would result in
the production of an iron which would be practically worthless, since as little
as one ten thousandth part of sulphur is enough to make the iron brittle and
a larger proportion renders it useless. It is therefore essential to thoroughly
eliminate all sulphur from the gases in case mineral fuel is used. If so, the
chambers CC are filled with a mixture of charcoal and scrap iron instead of
charcoal alone as in the preceeding case.
The conversion of the carbonic acid into carbonic oxide and the decomposition
of the hygrometric water are effected precisely as hereinbefore described, and
the charcoal mixed with the scrap iron effects the conversion of the steam into
carbonic oxide and hydrogen.
It is susceptible of demonstration that the gaseous mass obtained from coke
must be compelled to traverse a layer of scrap iron of a volume of one hectolitre
per ton of ore to be reduced per diem, provided the average superficies of the
particles of scrap iron is two square centimetres.
The quantity of ore to be reduced being ten tons, the volume of the mass of
scrap must be ten hectolitres, ie, five for each chamber. The capacity of the
chambers being nine hectolitres each there.remain four to be filled with charcoal,
which is more than sufficient, but the excess does no harm. The above figures are
based on the assumption that the coke contains seven kilos of sulphur per ton, of
course an excess demands a corresponding increase in iron scrap.
The object of mixing charcoal with the scrap is to reduce any oxide of iron
which would be formed by the action upon the scrap of the steam and watery
vapors driven off from the fuel in the chambers D.
Were it not for the presence of the carbon the iron would become superficially
oxydised and its efficiency as a desulphurizing agent would become impaired.
The mixture of charcoal and iron, which latter is superficially converted into
sulphide, is gradually removed from the chambers through the openings H, the
charcoal is separated, and the iron is thrown into water whereby the sulphuretted
portion is removed and the iron may be re-used.
C.
CARBURATION OF THE WHOLE OR A PART OF THE SPONGE TO MAKE STEEL,
CHARCOAL BEING USED AS A FUEL.
In this case the reduction of the ore and the decomposition of the steam take
place precisely as in the first case.
The compartments C C are filled with a mixture of two parts of carbon and
one part metallic sponge. The charcoal must be absolutely dry and the duration
of its contact with the sponge must be about four hours, this time is, however, only
approximate, practice soon shows the necessary duration which will depend
somewhat upon the nature of the ore.
Now inasmuch as the volume of carbon is double that of the sponge, and, in the
supposed case, there is a yield of 6 C. M. of sponge per diem, and the total bulk
of material for conversion into steel is 18 C. M, a greater capacity of the chambers
C, C; than that indicated is necessary. But this is on the supposition that the
whole yield of a furnace is to be converted into steel, which will rarely be the case.

page_text: DEPE
In this case a special desulphurizing chamber similar to C C' must be used,
through which the gases are passed before entering the carburating chamber, in
all other respects the operation is the same as in the last case.
The air is first passed through the chambers D D' for the production of carbonic
oxide, thence through C C which are filled with a mass of iron scrap and carbon,
whereby the gas is desulphurized, thence through a pair of chambers similar to tho
last and filled with a mixture of sponge and carbon, and finally through the
chamber B which is filled with ore.
I have considered it unnecessary to show this construction in the drawings,
since it involves a mere duplication of the chambers C CBy the described
processes, an iron or steel as the case may be, is produced of unexceptionable
quality, and the working of the process is very economical and is susceptible of
the nicest regulation.
Having thus described the invention communicated to me as aforesaid, what
I claim as new and as secured to me by the hereinbefore in part recited Letters
Patent is
1 The method herein described of producing sponge iron from the oro,
consisting in passing a current of atmospheric air through incandescent car-
bonaceous matter, converting the carbonic acid so produced, into carbonic oxide
by passage through a stratum of carbon sufficient to that end, and finally
conducting the carbonic oxide at the temperature incident upon its production
through the mass of ore unheated and unmixed with carbonaceous matter,
substantially as described.
2 The method herein described of producing sponge iron from the ore,
consisting in passing through the mass of unheated ore unmixed with carbonaceous
matter the gases resulting from the action of carbon upon the products of com-
bustion and upon the hygrometric moisture of the fuel, carbonic oxide and
hydrogen to wit; the said gases having the temperature incident upon their
production, substantially as and for the purpose set forth.
3rd The method herein described of producing sponge iron from the ore,
consisting in passing the gases produced by injecting a current of air through
incandescent mineral fuel and thence through a stratum of carbon to produce
carbonic oxide through a mass of scrap iron and carbon, and finally conducting
the said gases at the temperature incident upon their production through the body
of unheated ore unmixed with carbonaceous matter as set forth.
4th The method herein described of preparing steel from the ore, consisting in
passing through a mixture of unheated sponge iron and carbon the gases produced
by injecting atmospheric air into a mass of incandescent carbon and passing it
thence through a stratum of carbon sufficient to convert the carbonic acid and
steam into carbonic oxide and free hydrogen the said gases having the temperature
incident upon their production, substantially as set forth
5th The method herein described of preparing, at once, iron and steel from the
ore, consisting in passing a current of carbonic oxide gas at the temperature.
incident upon its production through a mixture of unheated sponge iron and
carbon and thence through a mass of unheated oro unmixed with carbonaceous
matter, substantially as set forth.
6th The method herein described of preparing at once; sponge iron and steel from
the ore, consisting in producing a current of reductive gas from mineral fuel,
desulphurizing the same by transit through a mass of scrap iron and carbon, and
conducting it thence through a mass of sponge iron and carbon and finally, through
the mass of ore, substantially as set forth.

page_text: 7th The apparatus herein described for the purposes set forth, consisting of a gas
generating chamber provided with tuyeres near its base, and an opening in its side
leading into the base of the second chamber from which a lateral opening below
the top of the chamber leads into the base of the reducing stack, whereby a space
is left in each chamber above the exit level of the gases which pass through the
series, and the contents of each chamber feed progressively downward to the zone
of chemical action.
8th The apparatus herein described for the coincident reduction of ore to the
state of sponge and the conversion of sponge into steel, consisting of one or more
gas generating chambers having tuyeres near the base and lateral openings b
leading into the base or bases of one or more converting chambers C C', the said
converting Chambers having lateral openings c leading into the base of the reduction
stack B, each chamber having a central wedge shaped wall at its base adapted to
discharge the contents laterally.
9th In combination with the gas generating chamber and the chamber C (Ơ')
having lateral openings below their tops, whereby the gases traverse but a portion
of each chamber, the reduction stack B; having a central wedge shaped wall at its
base adapted to discharge the contents of the stack into extended cooling tubes F
which terminate in air excluding taps G as set forth.
In Witness whereof I the said William Edward. Gedge have hereunto set
my hand and seal this Twelfth day of April in the year of our Lord one
thousand eight hundred and Eighty three
TIT T
2