IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN APPARATUS EMPLOYED THEREIN
Year: 1871

page_text: LETTERS PATENT to Arthur Warner, of Lee, in the County of Kent,
for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF IRON
AND STEEL, AND IN APPARATUS EMPLOYED THEREIN.
"
Sealed the 10th May 1872, and dated the 14th December 1871.
PROVISIONAL SPECIFICATION left by the said Arthur Warner at
the Office of the Commissioners of Patents, with his Petition, on
the 14th December 1871.
I, ARTHUR WARNER, of Lee, in the County of Kent, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF IRON AND STEEL, AND IN APPARATUS EMPLOYED THEREIN,'
be as follows: —
" to
This Invention has for its object the refining of cast iron, and the
conversion of iron so refined into steel or wrought iron.
In carrying out my improvements the first process is based upon and
is used in connection with a process described in the Specification of

page_text: a Patent granted to me dated 29th September 1860, No. 2363, in which
I claim the keeping of chemicals of any sort at the bottom of a receiver
until it is charged with molten metal, the heat of which will cause gases.
to be evolved from beneath and pass up through the metal, which will
be thereby purified.
I have found it easier to cure cold shortness than red shortness, which
I believe in cinder and hæmatite iron partly arises from the presence in
the metal of a varying quantity of particles of oxide which have not
been reduced in the blast furnace. In dealing with such classes of iron
I sometimes act upon them with tar, oil, pitch, rosin, coal, coke, charcoal,
or any other deoxidyzing agents, either alone and separately, or combined
with each other or other materials, not oxidyzing agents, as an oxidizing
and a deoxidizing agent if used together would neutralize each other.
In order to remove the silicon, sulphur, and phosphorus according to
my present improvements, I use a mixture of chalk, limestone, or any
other carbonate of lime, either alone or in connection with aluminous
clay, alumina, peroxide of manganese, or oxide of iron, or other oxidyzing
agent. The carbonate of lime may be sometimes replaced wholly or in
part by carbonate of manganese or carbonate of iron (spathose ore). The
carbonate of lime or other carbonate is decomposed by the heat of the
molten iron above it, and carbonic acid is evolved which oxidizes the
carbon and silicon.
When carbonate of manganese is used some of the protoxide formed
by the elimination of the carbonic acid will be easily reduced to the
state of metallic manganese by the action of the carbon in the iron;
in this state it will form an alloy with the iron, and greatly improve its
quality. The formation of this alloy may be helped by the addition of
tar, charcoal, or other carbonaceous matter to the peroxide.
When chalk is used it may be advisable to add a clay as free as
possible from silica, so as to form a double silicate of lime and alumina,
which is more fusible than simple silicate of lime.
The chalk or limestone will more readily part with its carbonic acid
when used in connection with an acid, such as sulphuric or hydrochloric
acids, and in some cases it is more desirable to use these acids, which
can be brought into contact with the chalk at the right moment by
the plan described in the Specification of my former Patent already
referred to..

page_text: When the iron is greatly charged with sulphur and phosphorus
according to this part of my Invention, I employ in addition hydro-
chloric acid, or the chlorides of sodium, iron, or manganese, or a
hypochlorite, such as bleaching powder, which will evolve chlorine
under the action of heat better than the before-mentioned substances.
If the two latter are used they may be conveniently applied in the
same vessel as the tar or deoxidizing agent, as they will not affect each
other.
I have found the alloys of potassium and sodium to change materially
the character of the iron, and are most beneficially used after the removal
of the silicon. Salts of ammonia also improve and toughen the iron.
All salts of the alkalis are beneficial, but those I prefer to use are the
carbonates, sulphates, and chlorides of potash, soda, and ammonia. I
also use small quantities of prussiate of potash, either alone or in con-
nection with the above-mentioned salts for the purpose of giving the
iron a steely character.
These materials are to be applied in the manner described in the
Specification of my previous Patent before referred to, or in any other
way by which the same result is arrived at, viz., that they are kept
down at the bottom, of a deep receiver until it is charged with molten
metal. But as I have found by experience that there is a difficulty in
keeping the metal hot a sufficient length of time for it to be acted upon
by the necessary quantity of chemicals, I use according to this part of
my Invention one or more receivers, at the bottom of each of which I
place the chemicals, and above these receivers I erect a cupola or other
furnace at such a height that the metal can run from it into each
receiver by means of a trough lined with loam, sand, or other materials.
The cupola is so constructed that there is a depth of red-hot coke, by
preference of not less than six or seven feet, and as much more as can
be conveniently obtained. The metal during its passage through the
coke will become much more fluid and heated than when it left the
blast furnace, and by properly regulating the blast may be highly
charged with carbon. From the cupola it runs by a loamed trough or
otherwise into one of the receivers lined with fire-bricks, which have
been by preference well coated with blacking, in order to prevent the
metal adhering to them, and at the bottom of which a certain quantity
of chemicals or materials have been placed and securely retained in
position. As soon as the action is over the iron can be if necessary

page_text: tapped out into the ladle hoisted up and passed through the cupola into
a second receiver, and so on. When the process is complete the iron
may be tapped out into the pig bed.
Besides using the cupola for the purpose before mentioned, according
to this part of my Invention, it is used for containing as well as coke or
charcoal any chemicals or ingredient which may be applied in the
following ways:-
First. Ingredients that do not melt easily, such as limestone, which
are broken up into pieces, and when the coke is well alight thrown in
on the top to a depth varying from two or three to seven feet or more,
according to the quantity of iron to be operated upon, and when this is
red hot the metal is run out of the blast furnace into a ladle, hoisted up
and tapped into the cupola, so that it percolates in thin streams through
the pieces of red-hot lime or other ingredients, and is acted upon by
them as well as the blast, the heat being kept up by the combustion of
the coke or charcoal below, which will still further heat the metal on
its passage through it.
Second. Fusible substances, such as oxides or clays of iron, manganese,
fluor spar, carbonates, sulphates, or chlorides of soda, potash, lime, or
barytes, may be used in the manner just described, or they are fused
and allowed to run down and form a bath at the bottom of the cupola.
The metal from the blast furnace is then hoisted up as before and run
into the cupola. By its passage through the coke it acquires an intense
heat, and drops in a finely divided state into the bath of ingredients at
the bottom, which will remove the impurities, as the iron being heavier
than the molten mass must pass through it. The iron is then tapped
out, and if necessary run into the ladle and passed one or more times
through the cupola.
These processes may be used separately, but I prefer to use them
together.
3
Volatile substances and liquids are introduced into the cupola by a
shoot just below the tuyers, by which means they can be inserted at any
stage of the process. This shoot may be also used for the introduction
of non-volatile chemicals or ingredients.
These processes may be modified according to my improvements by
using a cupola filled with lime, limestone, or chalk, either alone or mixed

page_text: with other infusible ingredients in lumps, and with or without the
bath of molten flux at the bottom, and the introduction of the volatile
ingredients or liquids, and with or without the addition of coke, which
may be rendered white hot by the introduction of mixed jets of gas and
air arranged at different heights from the bottom. There will thus
be presented a scrubber of white hot lime or other infusible materials
through which the iron will percolate, and be thus deprived of its
impurities.
Of course the beneficial effect of the limestone is not so great, as it
has been deprived of all its carbonic acid by the heat, but it will com-
bine with the silica to form a slag of silicate of lime, and will also unite
with the sulphur and phosphorus.
The iron to be refined may sometimes be melted in the cupola,
although I prefer to use it direct from the blast furnace, as before
described.
The second part of my Invention has for its object the conversion of
iron refined, as herein-before described, into steel or wrought iron.
In order to carry out this part of my Invention, I first granulate or
reduce to powder the iron which has been purified, and in that state
either oxidize it at the surface by preference by watering it with a
solution of chloride of lime, which will at the same time further tend to
remove any sulphur or phosphorus, or I mix a certain proportion of
powdered hæmatite or other oxide with the iron. I prefer, however,
the first plan. In this state I either throw it into a reverberatory
furnace similar to a puddling furnace, where, owing to its finely divided
state, it very quickly comes to a welding heat, when it is so well acted
upon by the intimately mixed oxide that it does not require to melt, but
may be balled up, squeezed, and rolled, as after the old mode of puddling,
saving much labour, time, and fuel. Or the mixture of granulated or
powdered iron and oxide can be melted together either in crucibles to
make steel, or in a furnace where a great heat can be obtained, such as
a Siemens' regenerating gas furnace, or Bessemer's furnace, for heating
under pressure, and then run out into ingot moulds ready for reheating
and rolling into rails, or for other purposes; or, secondly, I melt the
refined pigs in a suitable furnace, such as Siemens', Bessemer's, or other
furnace, and add either wrought, scrap, puddled bar, or the mixture of
powdered oxidized iron before referred to, but which has been previously

page_text: brought to a bright red heat in another furnace, where it has been
formed into a spongy wrought iron.
By melting these mixtures in crucibles or moulds, and allowing them
to remain closed until cool, the steel produced is of a softer and more
malleable quality.
The proportions of wrought and cast iron can be varied according to
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Arthur Warner in the Great Seal Patent Office
on the 14th June 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
WARNER, of Lee, in the County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of December, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Arthur Warner, Her special licence that
I, the said Arthur Warner, my executors, administrators, and assigns,
or such others as I, the said Arthur Warner, my executors, adminis-
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for " IMPROVEMENTS IN THE
MANUFACTURE OF IRON AND STEEL, AND IN APPARATUS EMPLOYED THEREIN,' upon
the condition (amongst others) that I, the said Arthur Warner, my
executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
"

page_text: NOW KNOW YE, that I, the said Arthur Warner, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, that is to say:-
:-
My present Invention has for its object the refining of cast iron, and
the conversion of iron so refined into steel or wrought iron.
In carrying out my Invention the first process is based upon and is
an improvement on a process described in the Specification of a Patent
granted to me, dated 29th September 1860, No. 2363, in which I claim
the keeping of chemical of any sort at the bottom of a receiver charged
with molten metal, the heat of which will cause gases to be evolved
from beneath and pass up through the metal, which will be thereby
purified. But I have found by experience that there is a great difficulty
in acting at once on all the impurities in iron, for this among other
reasons, that many impurities require to be acted upon by different
agents, which are of such a nature that if used at one and the same
time they would neutralize one another.
'
Accordingly in the first part of my Invention I use as herein-after
described 2 or more receivers, into which I place the requisite
chemicals, and treat them by successive operations having regard to the
impurities to be attacked.
As in the process described in the Specification of my said former
Patent I have found a difficulty in keeping the metal heated for a
sufficient length of time, and as this difficulty is greater in my present
Invention where I use more than one purifying receiver, I use one or
more reheating cupolas or furnace, which may be made to act also as
purifiers, and to carbonize the iron in the manner herein-after described.
I erect this reheating cupola or other furnace at such a height that the
metal can run from it into each receiver by means of a trough lined with
sand, loam, or other suitable material. The cupola is so constructed
that there is a depth of red-hot coke by preference of not less than six or
seven feet, and as much more as can be conveniently obtained.
The arrangement of apparatus, as shown in Figures 1 and 2, Sheet 1
of the Drawings hereunto annexed, is a convenient one for carrying this
part of my process into operation, although I do not confine myself to
the use of such an arrangement only.

page_text: A is a melting cupola, constructed on the Woodward steam jet
principle, as being the most economical, although any other description
of melting furnace may be employed. B, B, B, B, are 4 cast-iron
columns about 40 feet high, which support a pulley or pulleys D. A
chain is passed through this pulley over the drum C of a hoisting crab
or winch.. A hydraulic crane or lift may sometimes be substituted for
this mode of hoisting. The chain raises and lowers a cage or platform E
holding a ladle F on wheels (shown separately in Sheet 2 of the Draw-
ings), which can thus be run on and off the platform.
This ladle may
be made of sufficient depth and so constructed as to serve for one of the
purifying receivers. It is drawn to a larger scale in Sheet 2 of the
Drawings, and shows the man-hole "a" for introducing the chemicals,
and the tapping-hole b, which is used when it is not desired to pour the
metal out by means of the pouring gear. G is a cast or wrought-iron
trough for conveying the metal; it is balanced on a pivot H or a little
carriage, so that it can be turned into the position G when it is necessary
to raise or lower the cage. I is the reheating or purifying cupola (con-
structed by preference on the steam jet principle) with 4 or more rows
of tuyers instead of 2, in order to raise an intense heat in the cupola
at a short notice; it is covered in the case of the Woodward cupola,
with the cover M hung on a balance lever and weight N, so that it will
keep open when the metal is running in. The reheating cupola is
surrounded with a platform O, which runs also round the sides of the
hoist columns. There are 2 shoots L with tightly fitting covers which
serve for the introduction of chemicals or ingredients. The reheating
cupola is supported on an arched brickwork base P, and in the bottom
or near the bottom of the cupola there are one or more holes for the
admission of steam or purifying gases which are made to blow through
the cupola when the iron is not running down for the purpose of
removing any sulphur from the coke, and so prevent the iron from
absorbing any during its passage. S is a platform for the workman to
stand on when tapping out of the cupola. T¹, are 5 receivers of
strong wrought iron, which may be made of any convenient height.
As shewn in the Drawing they are about 11 feet high. The
deeper the receivers are in proportion to their length and breadth the
better. They are lined with fire-brick, and have some 18 or 20 inches
from the bottom a man-hole a with a cover made of fire-brick backed
with iron. These man-holes serve for the introduction of the ingredients
at the bottom of the receiver. b is a tapping out hole, from which the
8
, ' ,
34 5

page_text: metal is run into the pig bed when it is sufficiently purified. There is
also a tapping out hole on the other side, so that the iron can be tapped
back again into the ladle and hoisted up for a further purification if
required. Just above these receivers there is a chimney or funnel U to
carry away the gases and smoke from the receivers. This is supported
so as to swing over each receiver in turn by means of the cast-iron
clip V, which is supported by the wheels c, c, and f, f, running on the
rails d and g, which are supported by the stout cast-iron columns e, e, e.
Q is a moveable trough of cast or wrought iron supported on a little
carriage R, so that it can be pushed round to each receiver in turn. A
convenient arrangement is to have a crane by which each receiver can
be removed when the iron has been tapped out, and another receiver pre-
viously charged with chemicals put in its place, or the receivers may be
mounted on wheels and removed and replaced by means of a tramway.
When the coke in the purifying or reheating cupola contains too
large a per-centage of sulphur it may be purified by passing a current
of chlorine, hydrochloric acid gas, or steam for 10 or 20 minutes through
the cupola before the iron is poured down it. The steam should not be
passed through the reheating cupola during the pouring of the iron, as
it will tend to cool the coat which is required as hot as possible in
order to heat the iron and carbonize it, but there is no objection to the
passage of the chlorine and hydrochloric acid gases.
For the purpose of carbonizing the metal the hearth of the cupola may
be made of a sufficient size to hold the whole charge of iron, so that it may
remain for some time in contact with the coke before it is tapped out.
The operation is conducted as follows:-The charge of iron, by
preference not less than 5 or 6 tons, is tapped out of the blast furnace or
melting cupola A into the ladle or moveable receiver F (sunk below the
ground in a pit W), in which it is raised by means of the steam crab C
until it is sufficiently high, when it is poured or tapped into another
receiver, or into the top of the reheating cupola. (If desired the charge
may be melted in the reheating cupola I and thus dispense with a
separate melting cupola when the iron is not taken direct from the blast`
furnace.) The iron during its passage through the coke will become
much more fluid than when it left the blast furnace, and by properly
regulating the blast it may be highly charged with carbon. From the
heating cupola it runs by a trough or otherwise into another moveable
receiver, or into one of the fixed receivers T lined with fire-bricks which

page_text: will form an alloy with the iron and greatly improve its quality. The
formation of this alloy may be helped by the addition of tar, charcoal, or
other carbonaceous matter. When chalk is used it may be advisable to
add a clay as free as possible from silica so as to form a double silicate
of lime and alumina, which is more fusible than simple silicate of lime.
As this mixture is somewhat infusible it is sometimes advisable besides
or instead of retaining it at the bottom of the receiver until the latter is
filled with the molten metal to place it in a loose powder at the bottom,
or to feed it in at the same time as the iron by causing it to fall upon the
stream that is running into the receiver, or by feeding it in separately by
means of a hopper or screw, or any other well-known plan, so that the
iron may churn it up and well mix with it in the receiver. By allowing
the contents of the receiver to stand a short time the ingredients will
rise as a slag to the top and be separated from the iron. This separation
can only be properly effected in a deep vessel.
The plan hitherto adopted of applying chemicals in comparatively
shallow moulds or pans will not allow the impurities to separate
thoroughly before the metal solidifies, and although the impurities are
in a degree chemically separated from the iron they are mixed with it.
mechanically.
The chalk or limestone will more readily part with its carbonic acid
when used in connection with an acid such as sulphuric or hydrochloric
acids, and in some cases it is more desirable to use these acids which can
be brought into contact with the chalk at the right moment by the plan
described in the Specification of my former Patent already referred to.
When the iron is greatly charged with sulphur and phosphorus I
employ chloride of iron or a hypochlorite such as bleaching powder
which will evolve chlorine under the influence of heat.
I have found the alloys of potassium and sodium to change materially
the character of the iron, and are most beneficially used after the removal
of the silicon. Salts of ammonia also improve and toughen the iron.
All salts of the alkalies are beneficial, but those I prefer to use are the
carbonate of potash, soda, and ammonia, and chloride of ammonium. I
also use small quantities of prussiate of potash, either alone or in con-
nection with the above-mentioned salts, for giving the iron a steely
character.

page_text: Besides using the cupola for the purpose of heating the iron before
running into the receivers, as herein-before mentioned, it may in some
cases be used for containing as well as coke any chemicals or ingredients
that may be applied in the following ways:—
First. Ingredients that do not melt easily, such as limestone, which is
broken up into pieces and when the coke is well alight thrown in on
the top to a depth varying from 2 or 3 to 7 feet or more, accord-
ing to the quantity of iron to be operated upon, and when this is
red hot the metal is run out of the blast furnace into a ladle,
hoisted up and tapped into the cupola, so that it percolates in thin
streams through the pieces of red-hot lime or other ingredients, and is
acted upon by them as well as the blast, the heat being kept up by the
combustion of the fuel below, which will still further heat the metal on
its passage through it.
Second. Fusible substances, such as fluor spar, may be used in the
manner just described, or they may be fused and allowed to run down
and form a bath at the bottom of the cupola. The metal from the blast
or melting furnace is then hoisted up as before and run into the cupola.
By its passage through the coke it acquires an intense heat and drops in
a finely divided state into the bath of ingredients at the bottom, which
will remove the impurities, as the iron being heavier than the molten
mass must pass through it. The iron is then tapped out, and if
necessary run one or more times through the cupola.
These processes may be used separately, but I prefer to use them
together.
'Volatile substances and gases may be introduced into the cupola by a
shoot just below the tuyers, or by the tuyers themselves, by which
means they can be inserted at any stage of the process. This shoot may
be used for the introduction of non-volatile ingredients. These sub-
stances will however violently attack the lining of the cupola if made
of brickwork; when therefore I desire to use the cupola for these sub-
stances I make the hearth or bottom of the cupola of cast or wrought
iron water chambers coated thinly over with clay or loam, which will
not be so readily destroyed, as it is kept cool behind by the water.
When the iron is purified in this manner the charge should be by
preference not more than 2 or 3 tons.

page_text: These processes may be modified according to my improvements by
using a cupola filled with lime, limestone, or chalk (either alone or
mixed with other infusible ingredients in lumps, and with or without
the bath of molten flux at the bottom, and the introduction of the
volatile ingredients and with or without the addition of coke), which
may be rendered white hot by the introduction of mixed jets of gas and
air arranged at different heights from the bottom. There will thus be
presented a scrubber of white hot lime or other infusible material
through which the iron will percolate and be deprived of its impurities.
Of course the beneficial effect of the limestone is not so great, as it
has been deprived of its carbonic acid by the heat, but it will combine
with the silica to form a slag of silicate of lime, and will also unite
with some of the sulphur.
The iron to be refined may sometimes be melted in a cupola, although
I prefer to use it direct from the blast furnace.
The second part of my Invention has for its object the conversion of
iron refined in the manner herein-before described into steel or wrought
iron.
In order to carry out this part of my Invention I first granulate or
reduce to powder the iron which has been purified by the removal of the
silicon in the manner before described, and in that state either oxidize
it at the surface by preference by watering it with a solution of chloride
of lime, which will at the same time further tend to remove any sulphur
or phosphorous; or I mix a certain proportion of powdered haematite
or other oxide with the iron. I prefer however the 1st plan. In this
state I either throw it into a reverberatory furnace similar to a puddling
furnace, where owing to its finely divided state it very quickly comes to
a welding heat, when it is so well acted upon by the intimately mixed
oxide that it may be balled up, squeezed, and rolled in the ordinary
manner, thus saving much labor, time, and fuel. Or the mixture of
granulated or powdered iron and oxide can be melted together either in
crucibles to make steel or in a furnace where a great heat can be
obtained, such as a Siemens' regenerative gas furnace or Bessemer
furnace for heating under pressure, and then run out into ingot moulds
3 ready for reheating and rolling into rails or other purposes. Or,
secondly, I melt the refined pigs in a suitable furnace, such as a
Siemens' or Bessemer's furnace, and then add either wrought, scrap,

page_text: puddled, bar, or the mixture of powdered oxidized iron before referred
to, but which has been previously brought to a bright red heat in
another furnace where it has been formed into a spongy wrought
iron.
By melting these mixtures in crucibles or moulds, and allowing them
to remain closed until cold, the steel produced is of a softer and more
malleable quality.
The proportions of wrought and cast iron can be varied according to
the temper of steel required.
Having now described my Invention, and the way in which it is to
be carried out, I would state that the chemicals or ingredients herein
mentioned, as well as others, have been used to remove impurities
from iron. I therefore do not confine my Invention to the use of the
particular agents herein named, nor do I make any claim thereto, but
what I do claim is,―
First. The use of apparatus constructed as above described for treating
iron substantially in the manner set forth.
Second. The treatment of iron by successive operations by means of
the apparatus substantially as herein described.
Third. The conversion of iron refined in the manner herein described
into malleable iron or steel, substantially as set forth in the second part
my Invention.
of
In witness whereof, I, the said Arthur Warner, have hereunto
set my hand and seal, this Thirteenth day of June, in the year of
our Lord One thousand eight hundred and seventy-two.
Witness,
J. G. TONGUE,
Patent Agent,
ARTHUR WARNER. (L.s.)
34, Southampton Buildings,
Chancery Lane, W. C.