IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1856

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New Cannon
Street, in the City of London, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF IRON AND STEEL."
Sealed the 18th November 1856, and dated the 25th August 1856.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the 25th
August 1856.
I, HENRY BESSEMER, of Queen Street Place, New Cannon Street, in the
City of London, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF IRON AND STEEL," to be as follows:--
My Invention consists in obtaining crude or grey pig iron, hard white iron,
and steel, or malleable iron direct from carbonaceous iron ores, or from
any mixtures of carbonaceous ores, with oxides or other ores of iron, by the
application thereto of a blast of hot or cold air or steam, or of any other
gaseous matter containing or capable of evolving oxygen or hydrogen gas, and
without the requiring any fuel except such as is contained in or is evolved from
the said ores of iron, and from the gaseous matters forced into and among the
pieces of ore, and into and among the particles of fluid metal which have been
separated from the ore. This my Invention may be carried into practical
operation in several forms or modifications of furnaces or apparatus, with more.
or less advantage; it will, however, be found that a vessel or furnace similar in
form to the generality of blast furnaces is well suited for this purpose. The
iron ore, either raw or previously roasted, and in a cold or in a heated state
from such roasting process, is to be put from time to time into the upper part

page_text: of the furnace or vessel. The blast of air or other gaseous matter being forced
through suitable tuyeres situated below the surface of the fluid metal; or the
blast may be in part directed into and among the pieces of ore at a level above
the surface of the molten metal, so that the heat generated by the combustion
of the carbon contained in the fluid metal below, and also in part by the com-
bustion of a portion of the iron itself, may pass upward and act upon the upper
part of the charge of ore, and gradually melt it down, the slags being allowed to
pass out of the vessel or furnace above the fluid metal, the discharge hole for
the metal being situated below that through which the slag or scoria escapes.
Or, in lieu of using the description of furnace herein described, my Invention
may be carried into practical operation by using a reverberatory furnace, so
constructed as to be heated by the heat-evolved from fluid iron, and so that
the fluid metal shall occupy a sunk chamber at one part thereof; in which
case, the ores are to be so placed as to receive heat from the reverberated heat
and flame arising from the combustion of the carbon contained in the fluid iron
which occupies the sunk chamber, and into which the very highly heated ore,
or the molten metal therefrom, will pass. The fluid iron thus obtained may
be cast into pigs, ingots, or other articles in moulds; or it may be run into a
separate vessel, and be there converted into steel or malleable iron, in the
manner described in the Specification of a Patent granted to me on the
Twelfth day of February, One thousand eight hundred and fifty-six.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Bessemer in the Great Seal Patent Office on the
25th February 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of Queen Street Place, New Cannon Street, in the City of London,
send greeting.
WHEREAS Her most; Excellent Majesty Queen Victoria, by Her. Letters
Patent, bearing date the Twenty-fifth day of August, 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
Henry Bessemer, Her special licence that I, the said Henry Bessemer, my
executors, administrators, and assigns, or such others as I, the said Henry
Bessemer, my executors, administrators, 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

page_text: 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," upon thé condition (amongst others) that I; the said:
Henry Bessemer, my executors or administrators, by an instrument in writing
under my, or their, or one of their bands 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.
NOW KNOW YE, that I, the said Henry Bessemer, 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 Invention consists in obtaining crude or grey pig iron, bard white iron;
and steel, or malleable iron, direct from carbonaceous iron ores, or from
any
mixtures of carbonaceous ores, with oxides or other ores of iron, by
the application thereto of a blast of hot or cold air or steain, or of any other
gaseous matter containing or capable of evolving oxygen or hydrogen gas, and
without the requiring any fuel except such as is contained in or is evolved from
the said ores of iron, and from the gaseous matters forced into and among the.
pieces of ore, and into and among the particles of fluid metal which have been
separated from the ore.
This my Invention may be carried into practical operation in several forms.
or modifications of furnaces or apparatus with more or less advantage; it will,
however, be found that a vessel or furnace similar in form to the generality of
blast furnaces is well suited for this purpose. I, however, prefer that the
furnace should be of smaller dimensions than the generality of blast furnaces
now used for smelting iron, but the shape and proportions of the interior may
remain the same, and which are so well known and understood as not to render
ore, either raw or
any further description thereof necessary. The iron
previously roasted, (I, however, prefer to use the ore raw,) and in a cold or
in a heated state from such roasting process, is to be put from time to time
into the upper part of the furnace or vessel. The blast of air or other gaseous
matter being forced through suitable tuyeres situated below the surface of the
5 fluid metal; or the blast may be in part directed into and among the pieces of
ore at a level above the surface of the molten metal, so that the heat generated
by the combustion of the carbon contained in the fluid metal below, and also
in part by the combustion of a portion of the iron itself, may pass upward and
act upon the upper part of the charge of ore, and gradually melt it down, the

page_text: slags being allowed to pass out of the vessel or furnace above the fluid metal,
the discharge hole for the metal being situated below that through, which the
slags or scoria escapes. In practically carrying out this system of fusing
the carbonaceous ores of iron, I insert one or more fire-clay tuyere pipes on
three sides of the hearth of the furnace, the fourth side being provided with
a tapping hole at the lowest level of the hearth, the tuycres, before referred to,
being placed by preference near to the bottom or sole of the hearth, so that
the air or other gaseous matters may enter beneath and. bubble up through
the fluid matters occupying the hearth of the furnace; I also fix other tuyeres
above the level of such fluid matters, so that the air or other gaseous matters
-propelled through them will enter among the masses-of-solid matter under
operation, consisting of pieces of carbonaceous iron ores and lime, or other.
fluxes used to assist in their fusion and in giving fluidity to the molten
materials. In thus forcing air into a furnace or vessel containing ores of iron
rich in carbon, it will be found that a very high degree of temperature will be
produced in part by a further combination of such carbon with the oxygen of
the air, and in part by other combinations of oxygen with combustible materials
contained in the iron ore, and that the solid masses of ore will, by means of the
heat so generated, pass from the solid to the fluid state, and settle down to the
lower part or hearth of the furnace; the temperature of the furnace may also
be assisted by the introduction of hydrogen, which, by uniting with the oxygen
present in the materials, will also assist in raising the temperature and in the
reduction of the metal; hydrogen for this purpose may be most advantageously
obtained in the form of carburetted hydrogen gas distilled from coal. When
using air alone, large quantities of fluid cinder rich in oxide of iron are pro-
duced, and may be run into another chamber; and solid carbonaceous substances
or carburetted gases may be forced into and below the surface of such liquid
cinder, whereby the oxide of iron will become reduced and metallic iron
formed, as described in a Patent granted to me for improvements in the manu-
facture of iron and steel, and bearing date the 19th day of August 1856; or,
in lieu of using the description of furnace herein described, my Invention may
be carried into practical operation by using a reverberatory furnace, so con-
structed as to be heated by the heat evolved from fluid iron, and so that tho
fluid metal shall occupy a sunk chamber at one part thereof, in which case the
ores are to be so placed as to receive heat from the reverberated heat and
flame arising from the combustion of the carbon contained in the fluid iron
which occupies the sunk chansber, and into which the very highly heated ore,
or the molten metal therefrom, will pass.
The fluid iron thus obtained may
be cast into pigs, ingots, or other articles in moulds; or it may be run into

page_text: a separate vessel, and be there converted into steel or malleable iron, in the
manner described in the Specification of a Patent granted to me on the 12th
day of February 1856.
Although I have described how my Invention may be carried into operation
in a reverberatory furnace, I nevertheless desire it to be understood that
I prefer to use a furnace or vessel constructed on the plan of the blast furnace,
as before described, because the ore and its fluxes are gradually beated by the
ascent of heated matters among them in the upper part of the furnace, and the
heat thereby economized. In commencing to work with such a furnace, I put
some coke into the crucible or hearth of the furnace, and by a blast of
air through the tuyers I thoroughly ignite the same; I then put on to the
coke some pig iron, which will be rapidly melted and sink down on to the sole
of the hearth. The furnace is then charged with carbonaceous iron ores and
lime or other fluxes, not mixed, as in the ordinary process, with coke, coal, or
other fuel; the lower tuyeres may then be opened and a blast of air allowed
to enter the molten iron; the intense heat produced acting on the iron ore will
cause its fusion, accompanied by a further evolution of heat, and thus the
process may be kept up, the charging on of materials going on as the charge
diminishes from below, so that a continuous fusion of the ore may be kept up
without the use of any fuel other than is contained in the ore and in the air or
other gaseous matter forced therein.
Having described the nature of my Invention, and in what manner the
same may be carried into effect, I desire it to be understood that I do not
confine myself to the precise details, provided that the peculiar character of my
Invention herein described be retained.
In witness whereof, I, the said Henry Bessemer, have hereunto set my
hand and seal, this Twenty-fourth day of February, in the year of
our Lord Oue thousand eight hundred and fifty-seven.
Witness,
B. GOBBY,
24, Southampton Buildings,
Chancery Lane.
HENRY BESSEMER. (L.s.)