IM- PROVEMENTS IN THE PRODUCTION OF IRON AND STEEL
Year: 1873

page_text: LETTERS PATENT to Henry Larkin, of Theydon Gernon, in the
County of Essex, and William White, of No. 30, Thurlow Road,
Hampstead, in the County of Middlesex, for the Invention of "IM-
PROVEMENTS IN THE PRODUCTION OF IRON AND
STEEL.
PROVISIONAL SPECIFICATION left by the said Henry Larkin and
William White at the Office of the Commissioners of Patents,
with their Petition, on the 8th April 1873.
We, HENRY LARKIN, of Theydon Gernon, in the County of Essex,
and WILLIAM WHITE, of No. 30, Thurlow Road, Hampstead, in the
County of Middlesex, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE PRODUCTION OF IRON AND STEEL," to be as
follows:-
In carrying out our method for the production of iron and steel as
set forth in the Specification of our former Patent dated the Eighth day
of October 1872, No. 2964, we have found that there is a tendency in

page_text: the mixture of iron ore and carbonaceous materials to separate during
the roasting process in consequence of the great difference in the specific
gravity of the ingredients and the agitation resulting from the evolution
of gas. We prevent this separation by weighting the charge of the
retort by spreading upon it heavy iron ore or granulated iron or other
material, and afterwards when the process is complete we separate these
matters from the rest of the contents of the retort..
We obtain various modifications in the characters of iron and steel
by mixing with the powdered metallic product described in our said
former Specification previous to fusing or welding the same, any suitable 1
substances such as manganese, tungston, nickel, &c., also when possible
in a powdered condition. In this way we obtain any desirable alloy with
facility and accuracy.
In mixing the powdered materials, whether for the purposes of
reduction, testing, or fluxing as described in the before-mentioned
Patent, or for the production of alloys we use a slowly revolving
chamber, so arranged that the powdered material when placed within
may roll continually over alternately from end to end of the chamber as
well as in the lines of its revolution. We however prefer as the simplest
form of such chamber, a cylinder with the axis of revolution in a
diagonal line from one side of the circumference of one end to the
opposite side of the circumference of the other. At one end of the
revolving chamber, on the opposite side to the axis, is an aperture with
a closely fitting door or cover, which aperture, when turned upward,
may be opened for the purpose of introducing the powder to be mixed,
and when turned downward may, when the mixing is complete, be
opened to permit it to run out.
After the loose powdered material is so far prepared for the crucible
or furnace, before putting it in, we first compress it into cakes or blocks,
either by hydraulic pressure or by percussion. By this compression we
are able to operate on a much heavier quantity of material in any given
size of crucible or furnace than would otherwise be possible.
The same method of compression is similarly applicable in preparing
spongy iron for the furnace however it may be produced, and without
previous disintegration and mixing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Larkin and William White in the Great
Seal Patent Office on the 7th October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
LARKIN, of Theydon Gernon, in the County of Essex, and WILLIAM
WHITE, of No. 30, Thurlow Road, Hampstead, in the County of Mid-
dlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of April, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Henry Larkin and William
White, Her special license that we, the said Henry Larkin and William
White, our executors, administrators, and assigns, or such others as we,
the said Henry Larkin and William White, our 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 vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for “IMPROVEMENTS IN THE PRODUCTION
OF IRON AND STEEL," upon the condition (amongst others) that we, the
said Henry Larkin and William White, our executors or administrators,
by an instrument in writing under our or their hands and seals, or
under the hand and seal of one of us or them, 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 we, the said Henry Larkin and William
White, 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:
In the Specification of our former Patent dated the 8th October 1872,
No. 2964, a carefully adjusted mixture of iron ore and carbon is roasted
in a retort at a temperature sufficient to reduce the metal. The metallic

page_text: product after being submitted to a further process or processes to
accurately adjust its contents is mixed with powdered flux, and the
metal is melted or welded together. Now in conducting the roasting
or reducing process we have found that there is a tendency in the
mixture of iron ore and carbonaceous materials to separate in con-
sequence of the great difference in the specific gravity of the ingredients,
and the agitation resulting from the evolution of gas. Such a separation
of the materials is very injurious, as one object of the process is to obtain
an uniform product. We prevent this separation by weighting the
surface of the material in the retort by spreading upon it heavy iron ore
or granulated iron or other suitable heavy material. The added material
is afterwards easily separated from the contents of the retorts when the
operation is concluded. A depth of three or four inches of the weighty
material will generally be found sufficient.
We obtain various modifications in the character of the steel produced
by mixing with the powdered metallic product described in our said
former Specification, previous to fusing the same any suitable substances,
such as manganese, tungsten, nickel, &c., also when possible in a
powdered condition. In this way we obtain any desirable alloy with
facility and accuracy.
In mixing the powdered materials whether for the purposes of
reduction, testing, or fusing, as described in the before mentioned
Patent, or for the production of alloys, we use a slowly revolving
chamber so arranged that the powdered material when placed within
may roll continually over alternately from end to end of the chamber, a
as well as in the lines of its revolution. We however prefer as the
simplest form of such chamber a cylinder with the axis of revolution in
a diagonal line from one side of the circumference of one end to the
opposite side of the circumference of the other. At one end of the
revolving chamber on the opposite side to the axis is an aperture with a
closely fitting door or cover, which aperture when turned upward may
be opened for the purpose of introducing the powder to be mixed, and
when turned downward may when the mixing is complete be opened to
permit it to run out.
The size of the cylinder will vary according to the charge it is desired
to work, and this should not be too small to avoid unnecessary trouble
in sampling; one ton is a suitable charge, but the charge may be much

page_text: the cylinder may be equal to its length, but these proportions may be
varied.
After the loose powdered material is properly reduced and adjusted and
so far prepared for the crucible or furnace, before putting it in we first
compress it into cakes or blocks either by hydraulic or other heavy
pressure or by percussion, it may be with a machine similar in action to
that used for pile driving. The material is moulded in strong iron
moulds such as are commonly employed in moulding fuel blocks from
small coal. For melting in crucibles we mould the material into
circular cakes to fit the crucible, say 6" in diameter and one inch thick,
for heating, in a furnace, either for melting or welding, the blocks may
more conveniently be square. By this compression we are able to
operate on a much heavier quantity of material in any given size of
crucible or furnace than would otherwise be possible.
Having thus described the nature of our said Invention, and the
manner of performing the same, we would have it understood that we
claim as our improvements in the production of iron and steel, —
1st. The means of preventing the separation of the ore and carbon-
aceous matter by weighting it, substantially as described.
2nd. The means of obtaining an intimate mixture of the ore and
carbon, and of the metallic product and flux, substantially as described.
3rd. Moulding the metallic product of the roasting or reduction
process into cakes or blocks to prepare it to be melted or welded
together.
In witness whereof, we, the said Henry Larkin and William
White, have hereunto set our hands and seals, this Seventh day