IMPROVEMENTS IN THE MEANS AND APPARATUS FOR SMELTING IRON
Year: 1874

page_text: LETTERS PATENT to William Alexander Lyttle, of The Grove, Ham-
mersmith, in the County of Middlesex, Engineer, for the Invention
PROVISIONAL SPECIFICATION left by the said William Alexander
Lyttle at the Office of the Commissioners of Patents, with his
Petition, on the 28th February 1874.
I, WILLIAM ALEXANDER LYTTLE, of The Grove, Hammersmith, in
5 the County of Middlesex, Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE MEANS AND APPARATUS FOR
SMELTING IRON," to be as follows:-
· These improvements consist, firstly, in the preparation of the ore in
combination with other materials for the furnace; and secondly, in the
method of providing heat for the smelting of this prepared ore.
The iron ore is crushed into a sandy powder, with or without a previous
roasting, and is then incorporated with the proper and usual flux of

page_text: calcareous and silicious materials, these also being in a powdered state.
With these materials there is also incorporated a quantity of the dust or
small fragments of coal or other carbonaceous matter, the amount of
which will depend upon the function which such combustible powder is
intended to perform.
If the heat necessary for the reduction and fusion of the ore is to be
obtained from a separate charge of fuel, it will not be necessary to in-
corporate more carbonaceous dust with the powdered iron ore than will
be fully sufficient to deoxidise the iron as well as to render it fusible by
converting the metal into highly carburetted or pig iron, also to reduce
into carbonic oxide the carbonic anhydride produced by the blast in the
throat of the furnace. This amount can only be determined by practical
experience of the character of each individual ore employed under this
process.
When these powdered materials are compounded in the required
smelting proportions, they are thoroughly incorporated with ground
Portland or other hydraulic cement or hydraulic lime, with the addition
of water, for the purpose of effecting their consolidation into masses as
described in the Specification of my Letters Patent numbered 4131, of
last year, entitled "An Improved Process for Effecting the Consolidation
of Dust or Small Fragments of Coal, Coke, or Peat Charcoal into Masses
suitable for Fuel." In using hydraulic cement for this purpose the
proportion of fluxing lime herein-before mentioned must be reduced,
because the lime contained in the cement will assist in fluxing the ore as
soon as the consolidated mass of which it forms a part has reached the
proper heat. So far as the consolidation of the mass is concerned,
sufficient solidity is ensured by the use of from fourteen to seventeen
per cent. of Portland cement, or of a mixture of Portland cement and
ground hydraulic lime, such as that designated blue lias.
It is evident that the mutual affinities of the several component parts a
of this metallurgical concrete will act with augmented energy in con-
scquence of their minute division, as well as their close incorporation
and contact, and also that economy of fuel must result therefrom.
If these concreted masses of ore, flux, and fuel are intended on
passing down into the throat of the furnace to supply the heat needed 3
for their own fusion, the quantity of carbonaceous matter must be

page_text: regulated in larger proportion accordingly. On the other hand these
concreted masses may be interstratified with coal or other fuel, and so
smelted in the usual manner in ordinary furnaces.
I prefer however to prepare this metallurgical concrete so as to contain
no more than enough fuel to effect the necessary chemical reactions with
the aid of intense heat from a separate source in the following manner :-
At one side of the body or shaft of the furnace, and in a perpendicular
or nearly perpendicular position I provide a fuel chamber or shaft
opening at the bottom into the throat of the furnace directly opposite
the orifice of the blast. This fuel chamber is then filled with coal dust
or any other fuel, and when the furnace is in blast its contents are
burned away at the throat of the furnace by the impact of the blast.
The incandescent gaseous products of combustion ascend in the ordinary
way through the superincumbent mass of concreted lumps, fusing those
at the bottom and exercising the usual reducing influence in the higher
portions of the furnace charge.
:
The hearth and all the other arrangements of the smelting furnace
would be of the ordinary pattern.
Thc fuel chamber may be of any desired height, and it may be pro-
vided at the top with a hopper, the cover of which should fit so tightly
as to prevent the escape of gases or blast in that direction. This hopper
may also have a sliding or a drop-valve bottom, in order that when the
Hopper is filled and its lid closed the fuel may be allowed to fall to the
bottom of the chamber, the valve or bottom being adjusted to work upon
bearings accessible outside the fuel chamber. This fuel chamber should
also be provided with a trying or probing rod passing through a closely
fitting hole in the side or top of the fucl chamber, in order that by
pressing this rod forward it may be possible to ascertain whether the fucl
has fallen too low without opening the top of the chamber. In order to
provide a self-acting warning when the fuel has fallen too low it may be
desirable to attach this trying rod to a guiding standard, which will
serve to direct its upward or downward movement. From the top
of the rod a chain should be carried to a pulley on the top of the
standard, and thence downward to the ground. By pulling this chain
the trying rod may be raised before fuel is added, and when the chain
is set free, the rod, properly weighted for the purpose, will fall till

page_text: it reaches the top of the charge of fuel. This falling of the rod will
continue as the fuel falls in consequence of its combustion underneath,
and by connecting any of the usual alarum bell escapements with the
rod or its chain at the required point the fall of the rod may be made to
give timely warning to the stokers.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Alexander Lyttle in the Great Seal Patent
Office on the 28th August 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM.
ALEXANDER LYTTLE, of The Grove, Hammersmith, in the County of 1
Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of February, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Alexander Lyttle, Her special
licence that I, the said William Alexander Lyttle, my executors, admi-
nistrators, and assigns, or such others as I, the said William Alexander
Lyttle, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 MEANS AND APPARATUS FOR SMELTING IRON,"
upon the condition (amongst others) that I, the said William Alexander
Lyttle, 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.
NOW KNOW YE, that I, the said William Alexander Lyttle, do hereby
declare the nature of my said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement :-
These improvements consist firstly in the preparation of the ore in
combination with other materials for the furnace; and, secondly, in
the method of providing heat for the smelting of this prepared
ore.
As regards the first of these points the object. which I have in view is
to produce in solid masses a compound possessing many of the charac-
teristics of the mineral known as "black band" iron ore, by having the
crushed ore and fuel intimately incorporated, with the addition of the
usual fluxing materials in a powdered state, so as to effect the required
smelting reactions with considerable saving in fuel.
The iron ore is crushed into a sandy or gravel like consistency, with
or without a previous roasting, and it is then incorporated with the
proper and usual flux of calcareous and silicious materials, these also
being in a powdered or plastic state. With these materials there is also
incorporated a quantity of the dust or small fragments of coal or other
carbonaceous matter, the amount of which will depend upon the function
which such combustible powder is intended to perform.
If the heat necessary for the reduction and fusion of the ore is to be
obtained from a separate charge of fuel it will not be necessary to incor-
porate more carbonaceous dust with the powdered iron ore than will bę
fully sufficient to deoxidize the iron, as well as to render it fusible
by converting it into highly carburetted or pig iron. This amount of
fuel dust can only be determined by practical experience of the character
of each individual ore employed under this process.
When these powdered materials are compounded in the required
smelting proportions, they are thoroughly incorporated with Portland
or other hydraulic cement or hydraulic lime, with the addition of water,
for the purpose of effecting their consolidation into masses by brick-
making machines, and are dried in any convenient way as a metallurgical
concrete, to which, with the various modifications of the same, I havo,
given the designation of "artificial black band iron ore." In using
hydraulic cement for this purpose the proportion of fluxing lime,
separately used must be reduced, because the lime contained in tho.

page_text: cement will assist in fluxing the ore as soon as the consolidated mass of
which it forms a part has reached the proper heat. So far as tho
consolidation of the mass is concerned, sufficient solidity is ensured by
the use of from fourteen to seventeen per cent. of Portland cement, all
the other ingredients together amounting accordingly to from eighty-six
"to eighty-three per cent.; or the pure Portland cement may be replaced
by a mixture of that cement with ground hydraulic lime, such as that
designated "blue lins." This concrete may also be built in walls,
which when hardened can be broken down into lumps for smelting.
It is evident that the mutual affinities of the several component parts
of this metallurgical concrete will act with augmented energy, and
therefore cconomy, in consequence of their minute division with close
incorporation and contact.
If these concreted masses are intended on passing down into the
throat or "crucible" of the furnace to supply the heat necessary for
their own fusion, the quantity of carbonaceous matter must be regulated
in larger proportion accordingly. On the other hand, and preferably,
these concreted masses may be interstratified with lump coal or other
lump fuel, and so smelted in the usual manner in ordinary furnaces. In
that case this metallurgical concrete should contain no more than enough
fuel to effect the necessary chemical reactions.
Intense smelting heat may be obtained from a separate supply of fuel
either as above mentioned or in the following manner:-Figure 1 repre-
sents a furnace, which I designate a "duplex furnace" consisting of two
adjacent chambers A, B, and E, D; A, B, being intended to hold either:
the artificial black band iron ore alone, or common lump iron ore inter-
stratified with the fluxing materials and only as much fuel as may
suffice for the deoxidation of the iron, whilst E, D, shall contain the
whole of the fuel required in order to produce the requisite smelting
heat. I therefore designate A, B, as the ore chamber, and E, D, as the
fuel chamber.
The blast pipes C, Figuro 1, and T, T', Figure 2, are arranged in such
a position that the blast shall not strike through the falling molten iron,
but shall impinge directly against the bottom of the fuel in the fuel
chamber, an opening being provided for that purpose between the two a
chambers at one side of the crucible C, as shewn in Figures 1 and 2.

page_text: When the furnace is in blast the contents of the fuel chamber are
burned away by the impact of the blast, and the top of the fuel
chamber being closed air tight by means of any convenient trap door,
the incandescent gaseous products of combustion ascend in the ordinary
way through the superincumbent mass of materials contained in the
ore chamber, fusing the metal and fluxes at the bottom of that chamber
and exercising the usual reducing effect in the higher portion of its
contents.
1
The duplex furnace provides a highly valuable means of utilizing the
dust of coal or of peat charcoal, because the fuel chamber may be
charged with such dust, and in that case it is not necessary to use the
trap door F, because the dust of fuel is impervious to the blast. Great
purity of the iron smelted by this furnace, as well as economy of
fuel can be best ensured by using a pure powdered fuel in making the
artificial black band ore in such quantity only as will suffice for the
reduction of the oxide of iron, and by smelting this artificial ore with
the heat derived from inferior fuel burned in the fuel chamber as already
described..
If the black band ore is made with charcoal the product will be charcoal
pig, although the smelting heat is derived from coal. In a somewhat
similar way a pure iron can be had by making the "black band" ore
with pure reducing fuel, even when it is to be interstratified with inferior
lump coal for smelting in the common furnace.
66
Where lump fuel. is burned in the fuel chamber it may be desirable to
prevent the escape of the blast whilst charging in fresh fuel, and "this
can be done by providing the top of the chamber with a hopper. This
hopper should be fitted with a close cover or lid and a close fitting
drop" bottom, like the drop bottom of railway coal trucks, the bearings
of which are made accessible outside the hopper in order to facilitate tho
raising or dropping of such bottom. When the hopper is filled and its
top lid closed, the drop bottom is released, and the coal falls into the
chamber without escape of blast.
There is an obvious modification of this furnace which can be adopted
when lump fuel only is employed, and that is to reverse the functions of
the two chambers shewn in Figure 1, making A, B, the fuel chamber with
the trap F removed to its top, and making E, D, the ore chamber sur-

page_text: mounted by the open chimney top L. In that case the blast pipes should
not be directed against the bottom of the chamber E, D, but would either
retain the position which they now occupy in the common furnace, or
they should be directed upward against the bottom of the lump fuel in
chamber A, B..
The structural details or fabric of this duplex furnace, with its hearth,
and all the other arrangements not mentioned above, may be of the same
description as in the common smelting furnace.
In order to provide a self-acting warning or fuel gauge to indicate the
height of the fuel in the fuel chamber it may be desirable to provide a
small wire rope or fine chain passing vertically through a close fitting
hole or gland at one side of the top of that chamber, with a metal ball
inside the chamber attached to that end of the rope or chain, whilst the
other end, after passing over a suitably placed pulley, is carried down to
the ground outside the furnace. When fuel is about to be added this
rope should be pulled and the metal ball thereby raised to the top of the
chamber, and as the fuel is consumed it sinks in the chamber followed
by the metal ball, which also draws with it the rope or chain... An
alarm bell of the ordinary kind may be attached to this rope or chain
at such a point as to call the stokers when the fuel is falling too
low.
Having now described the nature of my Invention, and the best
means known to me for carrying the same into effect, what I claim
is,—
Firstly. The use of the "artificial black band iron ore," containing
all the several necessary component parts of a smelting furnace charge,
`incorporated and consolidated as herein-before described.
Secondly. The smelting of this artificial ore in a common blast furnace,
either with heat derived from the combustion of lump fuel interstratified
therewith in the furnace, or by means of powdered fuel incorporated in
sufficient quantity for that purpose with the said black band oro.
Thirdly. The use of the "duplex furnace" in the manner and for the
purpose herein-before described.
Fourthly. The manufacture of either charcoal pig, or very pure
common pig iron, with smelting heat derived from common coal burned
in the fuel chamber of the duplex furnace, as herein-before specified.

page_text: Fifthly. The smelting of natural iron sands and other pulverulent
iron ores by using such ores in making the aforesaid artificial black
band iron ore.
In witness whereof, I, the said William Alexander Lyttle, have
hereunto set my hand and seal, this Twenty-seventh day of
August, in the year of our Lord 1874.
W. A. LYTTLE. (L.8.)