IM- PROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1857

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New
Cannon Street, in the City of London, for the Invention of "IM-
PROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL,"
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the
20th November 1857.
I, HENRY BESSEMER, of Queen Street Place, New Cannon Street, in
the City of London, do hereby declare the nature of the Invention for "Iм-
PROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL," to be as follows:-
The first part of my said improvements relates chiefly to the treatment of
hematite or other rich oxides or carburets of the oxides of iron, and consists in
subjecting such ores, in close or partially closed chambers, vessels, or retorts,
to the action of carburetted hydrogen or other gases containing carbon or
hydrogen, until the oxides therein contained are reduced and the metallic iron
is converted. into a carburet of iron, the said chambers, vessels, or retorts,
being heated by the external application of fire thereto, or heated solely by the
introduction therein of the gas or gases in a highly heated state, or the
necessary heat may be obtained by the joint action of the heated gases and by

page_text: the external heat which is applied to the chamber, vessel, or retort, the
charging and discharging of which may be performed at intervals, through
suitable doors or valves, or it may be carried on continuously by the descent
of the oro or iron through upright chambers or retorts, arranged in a similar
manner to those described in a patent granted to me for "Improvements in tho
Manufacture of Cast Steel and Mixtures of Steel and Cast Iron," and bearing
date the 18th of June 1855, No. 1384, such retorts being provided with a
proper door or valve to close or open as desired, and being provided also with
suitable pipes for the admission therein, and exit therefrom, of the gas or gases
employed in tho deoxydizing process, or the process may be carried on in
horizontal or inclined retorts or chambers, as may be found most convenient.
In some cases I mix with the ores some charcoal or other solid or fluid
carbonaceous matters, in addition to the use of carburetted or hydrogenated
gases or hydrocarbons; under some circumstances as much solid or fluid
carbonaceous matters may be used as will be sufficient of themselves to
convert tho said oxides or ores of iron into carburets of iron without con-
veying any gas into the said chambers, vessels, or retorts, but in either case,
I carry on the process until the lumps or pieces of iron, produced from the ore
by either or overy of the deoxydizing agents before named, have taken up so
much carbon as to become a carburet of iron, capable of forming crude or pig
iron, by being fused or melted in a reverberatory or cupola furnace, or in a
covered crucible, as may be desired, and whereby the lumps or pieces of
carburet of iron so obtained may be employed by founders in iron, in lieu
of the ordinary pig metal now employed for founding various articles of
cast iron.
"
The metallized oro may thus become an article of commerce, and be used
alono or as a mixture with other kinds of iron by founders and others, and
which material by way of distinction I call carburetted iron ore.
And here I would remark, that when the ore to be treated as above
described has been found by analysis to contain sulphur or other matters
capable of being removed by roasting, that that process may be performed on
the broken ore previous to the commencement to the deoxydizing thereof
either in the same chambers, vessels, or retorts, or in any other suitable
apparatus. In preparing carburetted bydrogen gas for the purposes of this
Invention, I employ coal that has been separated from the pyrites it contained
by washing or otherwise, and I also prefer to purify such gas by lime or by
other known means; so also when using coal or coke in the solid form in the
chambers, vessels, or retorts, I use that which has had the pyrites separated
therefrom, the gaseous matters escaping from the chambers, vessels, or retorts,

page_text: used in carrying out this part of my said Invention, may be conducted into the
furnace used to heat the retorts, or they may be employed for generating
steam, or for other useful purposes.
Secondly, my improvements consist in treating the lumps or pieces of
carburet of iron obtained in the manner herein-before described, in such
manner as to prevent their rapid oxidation by exposure to the air, or to the
oxygen present in the melting furnace; for this purpose I avail myself of the
porous nature and condition of the pieces of carburet of iron by causing them
to absorb and become coated with pitch, tar, or rosin, or any other fluid
carbonaceous matter, or I use a wash or "slip" composed of lime, clay, or
silica, or either of them, alone or mixed with any suitable saline flux, depending
on the peculiar earthy constituents of the ore.
Thirdly, my Invention consists in employing carburet of iron, produced
direct from the ore, as above described, in the production of charcoal iron in
the Catalan forge or charcoal refinery.
Fourthly, my Invention consists in puddling ores that have been converted
into carburets in the manner herein-before described, such carburetted ores
containing as much carbon as will cause them to fuse or run down and form
pig or crude metal in the puddling furnace, and be afterwards granulated,
worked and balled in a manner similar to that generally employed in the
puddling of crude, pig, or finery iron.
Fifthly, my Invention consists in the employment of carburet of iron, pro-
duced as aforesaid, in lieu of granulated pig or refined iron, in the manufacture
of steel or malleable iron by the process of decarbonization in covered
crucibles or chambers, externally heated by any of the peculiar modes
heretofore known or used for that purpose.
Sixthly, my Invention consists in the employment of molten crude iron,
obtained by melting carburet of iron, produced as aforesaid, in the manu-
facture of malleable iron or steel, by the forcing of jets of air, or of steam, or
air and steam mixed, or other gaseous or solid matters upon or into the said
molten iron, until it is converted into malleable iron or steel while still
retaining the fluid state.
Seventhly, my Invention consists in smelting rich lumps or pieces of
carburet of iron, produced by the deoxydation and carburation of hematite
or other oxide ores of iron, by introducing such carburet of iron in a heated
state into a suitable chamber or vessel, also previously heated, and containing
some molten crude iron, into and below the surface of which I force cold or
heated air, alone or mixed with steam or with gaseous or solid carbonaceous
matters, and thereby generate sufficient beat to smelt the lumps or pieces of

page_text: carburet of iron; the molten metal as it accumulates being run off into
another vessel to be further treated in a similar manner, or the metal so
obtained may be used for other purposes. The smelting process may thus
continue as long as the supply of carburet of iron is kept up, or in lieu of this
continuous process of smelting, after melting down the required quantity
of carburet of iron, the whole of the metal accumulated in the vessel may bo
further blown and acted upon by the blast until the same is converted into
malleable iron or steel while still retaining the fluid state.