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

page_text: LETTERS PATENT to William Alexander Lyttle, of the Grove,
Hammersmith, in the County of Middlesex, Engineer, for the
Invention of "IMPROVEMENTS IN THE PROCESS AND APPARATUS FOR
SMELTING IRON."
Sealed the 11th September 1874, and dated the 4th May 1874.
PROVISIONAL SPECIFICATION left by the said William Alexander
Lyttle at the Office of the Commissioners of Patents, with his
Petition, on the 4th May 1874.
I, WILLIAM ALEXANDER LYTTLE, of the Grove, Hammersmith, in the
3 County of Middlesex, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE PROCESS 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 and any other orc..

page_text: The iron ore is crushed into a coarse sandy or gravel-like consistency,
with or without a previous roasting, and is then incorporated with the
proper and usual flux of calcareous and silicious materials, these also
being in a crushed state. With these materials there is also incor-
porated 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
incorporate more carbonaceous dust with the powdered iron ore than
will be fully sufficient to deoxidize the iron as well as to render it fusible
by converting the metal into carburetted or pig iron. This amount can
only be determined by practical experience of the character of each
individual ore employed under this process.
If the lime employed is in a caustic state, it will only be necessary to
pug these materials together in a wet state in order to make a mortar or.
concrete which can be moulded into blocks and set up like bricks to
dry, or the mixture may be shaped into concrete walls which when
hard can be broken down and used for smelting. A thin "slip" of
puddled clay will also serve to impart plasticity and cohesiveness to this
conglomerate, and when the mixture is dry and hard, with or without
the aid of artificial heat, it is ready for the furnace. The clay has this
great advantage, that it harden's in the heat of the furnace and so keeps
the other materials together till the melting zone of the furnace is
reached, when the clay combines with the lime to form a flux. In this
case if the clay is rich in silica, very little, if any, sand will be needed. A
similar cohesiveness under the action of heat will be secured by pugging
the ore, the fluxing materials, and the carbonaceous matter into a
plastic state by incorporating "green" or wet peat therewith, or wet.
peat alone, and without any peat charcoal, coal, or other carbonaceous
matter intermixed, may be used to agglutinate the other materials with
or without also the admixture of a small proportion of clay. Chloride
or sulphate of alumina, used as in Barker's Patented process, will also
answer.
There are many other well-known means for the consolidation of the
dust of coal, coke, or peat charcoal, and these as well as the processes
used for the production of artificial stone, are available with more or

page_text: less advantage to the useful application of this new principle in
metallurgical practice. The conglomerate thus provided is analogous
in smelting character to the famous "black band ironstone formerly
found in Lanarkshire, and may therefore be designated artificial black
band.
"
It is evident that the mutual affinities of the several component parts
of this metallurgical concrete will act with augmented energy in con-
sequence of their minute division, especially when the iron ore is broken
small, as well as of 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 for their own fusion, the quantity of
carbonaceous matter must be 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. In that case this concrete should contain no more than
enough fuel to effect the necessary chemical reactions with the aid of
intense heat from a separate source, either as above mentioned or in the
following manner :-At one side of the body or shaft of an ordinary
iron smelting furnace, and attached in a perpendicular or nearly per-
pendicular position thereto, I provide a fuel chamber or shaft opening
at the bottom into the crucible of the furnace directly opposite the
orifices of the blast. This fuel chamber is then filled with coal dust,
common air-dried peat, common peat charcoal, peat charcoal, dust
worked up
and consolidated into lumps by intermixture with raw or wet
peat, coal dust similarly consolidated by means of raw peat, lump coal,
or any other fuel, natural or artificial. When the furnace is in blast
the contents of the fuel chamber are burned away at the crucible of the
furnace by the impact of the blast, and when bituminous coal is
employed in this chamber it is burned away at the bottom as a "hollow
fire" with intense heat. The incandescent gaseous products of com-
bustion ascend in the ordinary way through the superincumbent ore or
mass of concreted lumps of artificial black band, fusing those at the
bottom and exercising the usual reducing influence in the higher
portions of the furnace charge.
It is obvious that this fuel chamber used as described as an adjunct
to the ordinary smelting furnace, can be employed for the smelting of
ordinary ores in the ordinary well known way, and also that it furnishes

page_text: a highly advantageous means of burning the dust of coal and of peat
charcoal, as well as the several other materials herein-before mentioned
in the smelting of iron.
By using any kind of charcoal in the furnace proper in contact with
the ore and coal in the fuel chamber, the greatest economy is realized
with special purity of the iron.
In erecting new furnaces upon this principle it may in some cases be
found convenient to divide the body of the furnace into two chambers
by a vertical partition, one chamber being for the fuel alone, and the
other chamber, erected somewhat higher, being for the ore, flux, and
reducing carbon of the charge. The latter arrangement will not how-
ever answer for burning dust of coal, because the dust would fall
through the crucible and choke the hearth of the furnace. For the
combustion of such dust the fuel chamber must be constructed with an
opening at only one side of its bottom, such opening being in one side of
the crucible, and exposed to the direct impact of the blast. The
hearth and all the other arrangements of the furnace would be of the
ordinary pattern.
The fuel chamber may be of any desired height, and it should be
provided at the top with an air-tight lid or 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
fuel chamber, in order that by pressing this rod forward it may be
possible to ascertain whether the fuel has fallen too low, without
opening the top of the chamber, and also when enough fuel has been
supplied.

page_text: 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 2nd November 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ALEXANDER LÝTTLE, of the Grove, Hammersmith, in the County of
Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of May, 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,
administrators, 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 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 PROCESS 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 is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
The object of this Invention is to effect certain further improvements
in the processes for smelting iron described in the Specifications of my.
Letters Patent of this year, Numbered 749 and 1096, and entitled
respectively "Improvements in the Means and Apparatus for Smelting
Iron," and "Improvements in the Preparation and Use of Peat and
Peat Charcoal for Smelting and other purposes."

page_text: powdered state with singular facility. If very little moisture is added
to this powdered mixture of ore, lime, reducing fuel, and clay, it is ready,
when thoroughly incorporated in a "pug mill," for being moulded into
bricks by any machine which makes bricks by compression, whilst if
more water is added the mixture acquires the necessary plasticity for
being moulded into bricks without compression in any of the usual
methods of making building bricks. If the ore requires more silica for
fluxing than the clay contains, a little sand may be added to the latter.
If the ore and other ingredients thus consolidated by means of clay are
thoroughly incorporated by pugging without much water into a stiffly
plastic state, the resulting conglomerate will not need any drying before
being passed into the smelting furnace, provided it is dealt with in the
following way, so as to avoid breakage by handling the damp masses:―
This conglomerate, to which I have given the designation of "triplex
"dies" at
compound," is made to issue through circular orifices or
the bottom of the pug mill, passing out as continuous worms about
three inches in diameter, and these worms are received in suitable
trucks, into which they fall as irregular broken lengths. They may
be dusted with powdered coal or sand to prevent their sticking together.
The trucks, when thus loaded, are at once conveyed to the blast furnace
without being unloaded or disturbed, and are hoisted and discharged
into its top in the usual way. The escaping flame of the furnace
speedily dries the compound, and although it is filled with cracks by this
sudden drying, it does not crumble to powder if a sufficiently large pro-
portion of clay has been employed.
When however it is desired to reduce the quantity of clay to the
smallest amount required for fluxing with the lime it may be found
indispensable to wholly or partially dry the "triplex compound" before
it is passed into the furnace. The use of clay in this way will render
easily feasible the smelting of an incorporated and consolidated mixture
of quicklime or chalk and powdered or crushed iron ore without any
admixture of fuel, the latter being either wholly interstratified with the.
masses of consolidated lime and ore in the common blast furnace, or
being partly interstratified with the same masses as reducing fuel only
5 in the ore chamber of the duplex furnace herein-before mentioned, whilst
the remainder of the fuel is consumed in the fuel chamber of that-
furnace for the production of the requisite smelting heat. Although
under this' modification of my process the broken or powdered ore is not

page_text: brought into such intimate and economical contact with the reducing
carbon, its incorporation with the lime will enable that substance to
exercise with the greatest energy its well-known desulphurizing effect,
thus yielding a metal of superior purity.
I am well aware that lime and iron ore in a powdered state have
already been recommended for use in smelting when worked together by
pressure in a moist state, but I am also aware that the loss of all
cohesiveness by this mixture under the action of heat, before fusion of
the mass can take place, makes it wholly useless in the blast furnace.
The use of plastic clay in the way herein described obviates the entire
difficulty, because the mixture is easily consolidated, and remains firmly
coherent in the furnace till the melting zone is reached, when the clay.
and lime flux together, with much less waste of heat than when lump
silicates and lump lime are used for fluxing purposes.
Hydraulic lime or cement, never before employed for such a purpose,
may also be adopted as the means of converting the crushed or powdered
ore, without any admixture of carbonaceous matter, into a concrete in
the manner described in my aforesaid Letters Patent, Numbered 749.
Ordinary lime may, if desired, be intermixed with the hydraulic lime or
cement, but it diminishes the power which hydraulic lime and cement
possess, like clay, of resisting disintegration when exposed to a high
temperature.
If the ore to be smelted requires the addition of silicious matter to
form a flux with the hydraulic cement or lime, it will be necessary to
employ for that purpose either a clean sharp sand, or burned clay,
commonly known as "ballast," because these materials are found best
suited for the formation of a strong durable concrete.
Having now described the nature of my Invention, and the best means
known to me for carrying it into effect, what I claim is,-
Firstly. The use of a conglomerate for smelting purposes, consisting of a
iron ore, lime, and fuel, all in a crushed or powdered state, and consoli-
dated into masses by means of plastic clay as described.
Secondly. The use of a concrete for smelting purposes consisting of
crushed or powdered iron ore, and such proportion, if any, of sharp sand
or burned clay as may be necessary for fluxing the ore, all these materials 3
being thoroughly incorporated with hydraulic lime or hydraulic cement,

page_text: and thus made into a concrete with water as herein-before described, but
without the admixture of carbonaceous matter.
Thirdly. The use, in a moist undried state as described, of a con-
glomerate for the same purpose, consisting of iron ore and lime or chalk
in a crushed or powdered state, without intermixed carbonaceous matter,
the consolidation of which has been effected by means of plastic clay, as
described.
Fourthly. The use of a conglomerate for smelting iron, consisting of
iron ore and lime or chalk in a powdered or crushed state, together with
the dust of bituminous coal, all these ingredients being worked into
lumps or masses with the aid of water, but being nevertheless dependent
for their ultimate cohesion in the furnace upon the gluing together of
the mass by reason of the fusion and binding together of the bituminous
coal dust when coked in the ascending heat.
.
Fifthly. The use of "raw" wet peat as the means of supplying the
reducing carbon, wherever such carbon is required in any of the afore-
said conglomerates instead of dry powdered fuel.
In witness whereof, I, the said William Alexander Lyttle, have
set my hand and seal, this Second day of November, in the year
of our Lord 1874.