IMPROVEMENTS IN THE MANUFACTURE OF IRON
Year: 1856

page_text: LETTERS PATENT to Andrew Barclay, of Kilmarnock, in the County of
Ayr, North Britain, Engineer, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF IRON."
Sealed tho 15th March 1857, and dated the 15th November 1856.
PROVISIONAL SPECIFICATION left by the said Andrew Barclay at the
Office of the Commissioners of Patents, with his Petition, on the 15th
November 1856.
I, ANDREW BARCLAY, of Kilmarnock, in the County of Ayr, North Britain,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF IRON," to be as follows, that is to say:-
This Invention relates to the manufacture or production of cast and wrought
iron from the metallic ore by a process which involves both economy in
manufacturing expenses, and a superior yield of merchantable iron. In carrying
out this Invention in practice a species of compound reverberatory furnace is
employed. This furnace or reduction apparatus consists of a fire-place or fuel
chamber of the ordinary kind, a molten metal or puddling recess, an inclined
hearth for the calcined ore, a reverberatory arch, and a vertical draught
chimney.
The raw ore as it comes from the mine is first of all calcined or roasted, as

page_text: is usual in the primary preparation of iron ores, except that in this calcining
process a large quantity of coal is added to the mass, in proportion sufficient to
give to the ore a superior amount of carbon. The roasted or calcined ore thus
prepared is deposited upon the inclined hearth of the reverberatory furnace,
which is at one end of the furnace structure, and slopes downwards towards
the puddling recess, or the shallow chamber which receives the molten metal
as it flows from the ore. At the upper end of the inclined hearth an entry
passage is made through the wall of the structure, for the purpose of
admitting whatever flux, such as lime, salt, and other matters, may be needed
for admixture with the roasted ore upon the hearth. When the firo is
lighted in the furnace, the flame and heat of the fuel therein being directed
upon the inclined hearth, the ore is gradually reduced, and the iron slowly
trickles or flows down the incline until it falls into the recess at its base.
As the process goes on, the reverberatory action of the furnaco causes the
heat and flame to strike downwards, both upon the molten metal in the
puddling recess and upon the hearth where the oro is placed. As the molten.
metal collects in a pasty mass in the puddling recess, the cinder, scoria, and
foreign matter is skimmed off, and the metal is either run off into pigs or moulds,
or is puddled in the usual manuer. Tho puddling is performed in the usual
way by a side door in the furnace, and the blooms are removed and hammered,
rolled, or otherwise treated, in the ordinary manner common to the malleable
iron manufacture.
The raw ore may either be calcined in the ordinary way, or it may be
roasted in the reverberatory furnace. And in order still further to economise
the process, a separate calcining chamber may be fitted up in connection with
the vertical chimney of the furnace, so as to employ the otherwise waste beat
of the furnace for roasting the ore, and when roasted, the ore along with a
suitable flux may be pushed from its hearth, so as to fall down upon the
inclined hearth beneath for final reduction. It is to be understood that in this
process of manufacturing iron the roasted ore is always highly charged with
carbon, and the metal is brought away from the ore in a gradual manner, and.
so as to leave the natural good qualities of the iron as little changed as
possible. The ore is preferred to be highly charged with carbon, but tho
nietal may be separated from some ores without a preliminary caleining
process when a furnace of the kind herein-before described is used. Common
pig iron may also be treated in this class of furnace, so as to be very econo-
mically converted into either refined iron or malleable iron. A second charge
may be undergoing a heating process whilst the first is being worked off.
The metal may be very economically decarbonised by a current of heated

page_text: air from the furnace whilst running down the incline towards the puddling
chamber. This metal may be retained in a separate chamber until the first
charge is worked off, when it may be let into the puddling chamber in a melted
condition. By adopting this process the ordinary refining furnace may bo
dispensed with. Pig iron may also be melted in an ordinary cupola, and
poured through a sieve or grating through a current of air in a shaft into a
cistern of water or other fluid, or into a puddling furnace, and then worked in
such puddling furnace; or the iron thus prepared may be puddled in an
ordinary puddling furnace. Instead of using a reverberatory furnace, a blast
arrangement of any kind may be adopted.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Andrew Barclay in the Great Seal Patent Office on the
15th May 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ANDREW
BARCLAY, of Kilmarnock, in the County of Ayr, North Britain, Engineer, send
greeting.
WHEREAS Iler most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of November, in the year of our
Lord One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Andrew Barclay, Her special license that I, the said Andrew Barclay, my
executors, administrators, and assigns, or such others as I, the said Andrew
Barclay, my executors, administrators, or 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 MANT-
FACTURE OF IRCN," upon the condition (amongst others) that I, the said
Andrew Barclay, by an instrument in writing under my hand and seal, should
particularly describe and ascertain the nature of the said Juvention, and
in what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Andrew Barclay, do hereby declare the
nature of my said Invention, and in what manner the same is to be performed,

page_text: to be particularly described and ascertained in and by the following statement
in writing, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
When
My said Invention relates to the manufacture or production of cast and
wrought iron from the metallic ores by a process which involves both
economy in manufacturing expences, and a superior yield of merchantable iron.
In carrying out this Invention in practice a species of compound rever
beratory furnace is employed. This furnaco or reduction apparatus consists of
a fire-place or fuel chamber of the ordinary kind, a molten metal or puddling
recess, an inclined hearth for the calcined ore, a reverberatory arch, and a
vertical draught chimnoy. Tho raw ore as it comes from the mine is first of
all calcined or roasted, as is usual in the primary preparation of iron ores,
except that in this calcining process a large quantity of coal is added to the
mass, in proportion sufficient to give to the ore a superior amount of carbon.
The roasted or calcined ore thus prepared is deposited upon the inclined hearth
of the reverberatory furnace, which is at one end of the furnace structure, and
slopes downwards towards the puddling recess, or the shallow chamber which
receives the molten metal as it flows from the ore. At the upper end of the
inclined hearth an entry passage is made through the wall of the structure, for
the purpose of admitting whatever flux, such as lime, salt, and other matters,
may be needed for admixture with the roasted ore upon the hearth.
the fire is lighted in the furnace, the flame and heat of the fuel therein being
directed upon the inclined hearth, the ore is gradually reduced, and the iron
slowly trickles or flows down the incline until it falls into the recess at its base.
As the process goes on, the reverberatory action of the furnaco causes the heat
and flame to strike downwards, both upon the molten metal in the puddling
furnace and upon the hearth where the ore is placed. As the molten metal
collects in a pasty mass in the puddling recess, the cinder, scoria, and foreign
matter is skinned off, and the metal is either run off into pigs or moulds, or
is puddled in the usual manner. The puddling is performed in the usual way
by a side door in the furnace, and the blooms are removed and bammered,
rolled, or otherwise treated, in the ordinary manner common to the malleable
iron manufacture. The raw ore may either be calcined in the ordinary way,
or it may be roasted in the reverberatory furnace. And in order still further
to economise the process, a separate calcining or heating chamber may be
fitted up in connection with the vertical chimney of the furuace, so as to
employ the otherwise waste heat of the furnace for roasting the ore, and when
roasted, the oro along with a suitable flux may be pushed from its hearth, so
as to fall down upon the inclined hearth beneath for final reduction. It is to

page_text: be understood that in this process of manufacturing iron the roasted ore is
always highly charged with carbon, and the metal is brought away from the
ore in a gradual manner, and so as to leave the natural good qualities of the
iron as little changed as is possible. The ore is preferred to be highly charged
with carbon, but the metal may be separated from some ores without a pre-
liminary calcining process when a furnace of the kind herein-before described
is used. Common pig iron may also be treated in this class of furnace so as
to be very economically converted into either refined iron or malleable iron.
A second charge may be undergoing a heating process whilst the first is being
worked off. The metal may be very economically decarbonised by a current
of heated air from the furnace whilst running down the incline towards the
puddling chamber. This metal may be retained in a separate chamber until
the first charge is worked off, when it may be let into the puddling chamber in
a melted condition. By adopting this process the ordinary refining furnace
may be dispensed with. Pig iron may also be melted in an ordinary cupola,
and poured through a sieve or grating through a current of air in a shaft into
a cistern of water or other fluid, or into a puddling furnace, and then worked
in such puddling furnace; or the iron thus prepared may be pudilled in an
ordinary puddling furnace. Instead of using a reverberatory furnace, a blast
arrangement of any kind may be adopted.
And in order that my said Invention may be properly understood, I shall
now proceed to describe the illustrative Figure on the explanatory Sheet of
Drawings which I have hereunto appended, for the purpose of showing one
modification under which my improvements may be judiciously carried out in
practice.
The Figure on my Sheet of Drawings is a longitudinal vertical section of a
furnace suitable for the manufacture of iron, and arranged according to one
modification of my improvements. In the arrangement shown in the
Drawing, the furnace is of a compound description, that is to say, it partakes
of the character of a reducing and a puddling furnace. It consists of a fire-
place or furnace A. The roof of the furnace gradually rises upwards, and then
descends, forming a reverberatory chamber B of the usual arched form. At
the back of the fire bars C the brickwork is built to form a bridge D, and
behind this bridge the floor of the reverberatory chamber B is hollowed out to
form a kind of chamber or recess E for the reception of the molten metal.
Beyond the hollowed part or chamber E, the brickwork is carried upwards;
and forms an inclined plane F, terminating in an aperture G made in the
brickwork, forming the exterior of the furnace. In a vertical direction above
the lower part of the inclined plane or hearth F the brickwork is carried

page_text: upwards to form a shaft or chimney, which is mado squaro at its lower part.
A short distance below the opening of the shaft II a lateral aperture I is made
in each side of the furnace. These apertures I are made with an incline at
the lower part, which forms a hearth K overhanging the hearth or inclined
plane F. The apertures or rectangular openings I, through which the furnace
is charged with ore, are reached by means of a platform J, placed at a con-
venient distance below the feed openings. The brickwork L at the base of the
interior shaft II is curved, so as to cause the heat and flame of the furnace
below as it ascends towards the shaft to be reverberated or bent from its
course, and thereby to infringe on the hearth or inclined plane K. The ore or
ironstone is deposited upon the hearth K at the upper part of the furnace, for
the purpose of undergoing the process of calcination. As the heat from below
impinges upon the ore, the latter becomes highly heated, and when it has been
sufliciently roasted or calcined it is pushed off from the hearth, whence it falls
on to the inclined plane F. At this stage of the process, the flux to be mixed
with the roasted ore is conveyed into the interior of the furnace through the
opening G; the heat of the burning fuel impinges upon the the ore and fluxing
materials on the hearth F, and the metal as it reduced from the ore flows down
the hearth F collects in the chamber or recess E. The scoria or slag and
other foreign matter may be skimmed off from time to time, or tapped off by
means of an opening made in the side of the furnace for the purpose.
Another modification of the arrangement of the furnace or reducing
apparatus consists in placing the calcining or roasting furnace at right angles
to the hearth F, and arching that part over, so that the heat and flame may be
deflected downwards upon the ores. In this arrangement, the furnace is made
with an inclined hearth, similar to that shown at K, and is built so that the
roastel ore when pushed off will either fall or slide down on to the hearth E.
The mass of molten metal collected in the chamber or recess E may be run off
into pigs or moulds, or the molten metal may be subjected to the operation of
puddling. For this purpose a door M is maile in the side of the furnace, by
means of which the workman has ready access to the puddling chamber E to
stir or agitato tho molten metal and to form it into blooms in the ordinary
The balls of puddled iron or blooms thus obtained are then ready
for the operations of hammering, rolling, or being otherwise treated to give it
the peculiar character of the metal known as malleablo iron. The iron ore
used in this system or mode of manufacture is preferred as a general rule to
be highly charged with carbon, by which means the resulting product retains
all the desirable qualities of good metal. But in some kinds of ores, the
hematite, for example, the calcining or carbonizing process is unnecessary, and
manner.

page_text: the ore may be reduced without undergoing this preparatory process. During
the operation of puddling or working a charge, a second quantity may be
undergoing the process of heating upon the hearth F, and the metal resulting
therefrom may be collected in a second chamber or recess formed in the
hearth, as shown by the dotted line at N in my Sheet of Drawings. In using
this modification, however, it would be necessary to build the hearth F of
greater extent or length than is shown in the Drawing. After working off the
quantity of metal contained in the first chamber E, the molten metal in the
second chamber may be allowed to flow into the chamber E for the purpose of
undergoing the process of puddling. Instead of allowing the metal to flow
from the second or refining chamber into the puddling chamber E, it may be
drawn off from the refining chamber in a state suitable for the subsequent
operations, by Dicans of which it is converted into malleable iron.
drawing off the refined iron from the refining chamber may be effected by
means of a lateral passage or tap-hole carried through the wall of the furnace,
which may be closed by means of a block of fire stone, or a door lined with
fire clay. The communication between the refining chamber and the puddling
chamber E is effected by removing the fire-clay block at O, which forms a
bridge between the two chambers. The block O may be removed by means of
a rod passed through a door or opening made for the purpose in the side of the
furnace; the molten metal in the refining chamber then flows over the
inclined plane, indicated by the dotted line below the block O into the puddling
chamber E.
Tho
In the modification of my improvements shown in my Sheet of Drawings
the current of air passes through an open ash-pit to the fire, and thence to the
shaft or chimney. In some cases, however, the current of air thus obtained
may not be found sufficient for the purpose; this difficulty may be obviated by
the use of a blast of air driven through the furnace by a blowing engine. In
the arrangement in which a blast of air is used, the fuel should be placed in a
close chamber without grate bars.
By means of my improvements iron ores may be calcined or roasted and
reduced to a metallic state. The metal is refined and puddled in one furnace or
apparatus in a rapid, economical, and efficient manner, at the same time pre-
serving all the valuable qualities of the metal. It will be obvious to the
practical iron maker that either refined iron or malleable iron may also be
produced from pig iron in a furnace of this kind, or of a generally similar
character, with very superior results as regards quality of the metal and
economy of cost. And instead of arranging the parts in the precise manner
herein-before described, I form a duct leading from the fluxing, refining, and
:

page_text: reducing chamber, formed in the incline of the furnaco to the puddling
chamber at the foot of the incline, so that when the metal bas been fully
treated in the fluxing chamber it can be easily run off. Fresh materials may
then be brought down from above for treatment in the fluxing chamber,
and so on.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without deviating
from the principles or main features of my Invention; but what I consider
to be novel and original, and therefore claim as the Invention secured to me
by the herein-before in part recited Letters Patent, is,—
First, the general arrangement and construction of furnaces or apparatus
for the reduction of iron ores and the manufacture of malleable iron, as herein-
before described.
Second, the system or mode of reducing iron ores and manufacturing
malleable iron by the use of a compound furnace or apparatus, in which are
combined a roasting or heating shaft, a fluxing, refining, and reducing chamber,
and a puddling furnaco, the whole being heated by the same fire.
Third, the application and use of the compound furnace or apparatus
berein-before referred to for the manufacture of malleablo iron from pig or
crudo iron.
In witness whercof, I, the said Andrew Barclay, have hereunto set my
hand and seal, this Fourteenth day of May, One thousand eight
hundred and fifty-seven.