AN IMPROVED MODE OF AND MEANS FOR REDUCING IRON ORES
Year: 1869

page_text: LETTERS PATENT to George James Snelus, of Dowlais, in the County
of Glamorgan, Metallurgical Chemist, for the Invention of "AN
IMPROVED MODE OF AND MEANS FOR REDUCING IRON ORES."
Sealed the 20th August 1869, and dated the 27th February 1869.
PROVISIONAL SPECIFICATION left by the said George James Snelus
at the Office of the Commissioners of Patents, with his Petition,
on the 27th February 1869.
I, GEORGE JAMES SNELUS, of Dowlais, in the County of Glamorgan,
Metallurgical Chemist, do hereby declare the nature of the said Inven
tion for "AN IMPROVED MODE OF AND MEANS FOR REDUCING IRON ORES," to
be as follows:-
The nature of my Invention consists in reducing iron ores while
in a fine state of division by feeding the ore into a vertical chamber
containing a number of bearers so arranged that while the powdered
ore falls from bearer to bearer it becomes heated to a temperature
sufficient to allow the oxygen of the ore to combine with the reducing
clements. These reducing elements or bodies may be derived from a

page_text: stream of carburetted and carbonous gases forced into the chamber, and
also from carbonaceous matter, such as finely ground coal, introduced
with the powdered ore, or from both sources together. Some of the
said bearers are hollow and communicate with flues at the sides of the
reducing chamber in such a manner that a current of heated gas passes
through the hollow bearers. The flues are so arranged that sufficient
air can enter them to burn the gases while passing and repassing
through the bearers. The waste gases from the reducing chamber are
also brought into these side flues, and there burnt with the other gas
supplied to the flues. By these means the temperature of the reducing
chamber is kept at such a height as to allow of the reduction of the
ore without fusing the gangue it may contain. The lower bearers of
the reduction chamber are made of metal, and a current of cold water
flowing through them keeps this part of the chamber cool, and thus by
lowering the temperature of the finely divided iron I prevent its taking
fire in the air. With the same end in view the receptacle into which
the ore falls is kept cool, and is fitted with double doors to prevent, as
far as possible, the contact of air with the metallic iron. In certain cases
also I prefer to pass a current of carbonic acid gas into and among the
reduced ore to displace any retained hydrogen. The entrance of air into
the reduction chamber is prevented by keeping the pressure of gas in
it slightly above that of the external atmosphere. The bearers are
cleared from time to time by means of "clearers," which when out of
use are kept in recesses in the front part of the chamber. I prefer that
the gas supplied to the reduction chamber should be generated by
blowing air through a column of incandescent fuel in a separate appa-
ratus, as I can then regulate the pressure. Part of the gas from this
generator can be taken to the flues to afford the necessary heat by its
combustion in air, but the production of these combustible reducing
gases forms no part of my present Invention. The spent gases pass through
a hollow chamber on the top of the furnace, the roof of which serves as
a floor on which to dry the ore before it enters the reduction chamber.
I prefer to grind the ore and pass it through a sieve with about thirty
holes to the linear inch. In some cases I calcine the ore, and it should
always be freed from hygroscopic moisture before allowing it to enter
the reduction chamber. The metallic iron thus produced may be run at
once into a furnace containing a bath of molten pig iron, whereby it is
dissolved and rendered fluid, or it may be worked up by any other
process; but this subsequent treatment forms no part of my present

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George James Snelus in the Great Seal Patent
Office on the 27th August 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
JAMES SNELUS, of Dowlais, in the County of Glamorgan, Metallurgical
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of February, in
the year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George James Snelus, Her special
licence that I, the said George James Snelus, my executors, adminis-
trators, and assigns, or such others as I, the said George James Snelus,
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 "AN
IMPROVED MODE OF AND MEANS FOR REDUCING IRON ORES," upon the condition
(amongst others) that I, the said George James Snelus, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and scals, 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 inonths next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said George James Snelus, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification:-
The nature of my said Invention consists in reducing iron ores by
first crushing or otherwise bringing them into a state of powder, and

page_text: then feeding them continuously into a vertical chamber containing a
series of horizontal bearers, as in the calcining furnace known as
"Gherstenofer's," such chamber being kept at a red heat by any
convenient means and filled with reducing gases at a pressure slightly
above that of the atmosphere.
In the ordinary process of making iron the ore is reduced under such
conditions that it immediately takes up carbon and is converted into
cast iron. Several attempts have been made to produce wrought iron
direct from the ore, but either owing to the process not being continuous,
its requiring too much time and fuel, or its inapplicability to the
treatment of fine orc, and its incomplete reduction of the ore, none of
these attempts have yet been successful in such a degree as to afford
the means of making iron or steel so economically as can be done by
first forming pig iron in the blast furnace.
I have ascertained that if the orcs are powdered and properly exposed
to a reducing atmosphere at a dull red heat a few minutes will be
sufficient to remove the oxygen from the ores and leave metallic iron
in the form of a fine grey powder. Other conditions being the same,
the greater the amount of surface exposed the quicker the orc will be
reduced. To get the greatest amount of surface I powder the ore and
pass it through a sieve with from ten to sixty holes to the linear inch
according to the nature of the ore, and to continually renew and expose
fresh surfaces and also to obtain a continuous process I allow the ore
to trickle through a vertical chamber filled with a series of horizontal
bearers arranged as in the "Gherstenofer " furnace. herein-before
mentioned. This chamber must be kept at about a dull red heat by
any convenient means. I prefer for this purpose to make the bearers
hollow, causing flame to pass through them. To obtain a reducing
atmosphere in the chamber I mix a small quantity of coal, coke, or
charcoal powder with the ore, and also pass into it a current of gas
formed by blowing air through a column of incandescent fuel, If the
iron powder thus produced should be run at once into a bath of molten
pig iron without exposing it to the air there is no need of cooling it,
but if it is to be in anywise exposed it must first be carefully cooled in
a non-oxidizable atmosphere.
In order that my said Invention may be more clearly understood, I
will now proceed more fully to describe the same by the aid of the
accompanying Drawing.

page_text: .
Figure 1 is a plan of a furnace as I prefer to construct it for the
purposes of my Invention; Figure 2 is a front elevation of the same;
Figure 3 is a vertical section on the line x, x, Figure 1; Figure 4 is a
vertical section on the line y, y, Figure 1; Figure 5 is a horizontal
section on the line z, z, Figure 3; Figure 6 is a horizontal section on
the line 2, 21, Figure 4. Like letters indicate the same parts throughout
the Drawing.
a is the receptacle for the powdered ore; b is the chamber or passago
leading to the bearers c; d and are the receptacles at the bottom of
the furnace; e and e¹ are pipes for conveying the reducing gases into
the chamber fand side flues g; h is a flue for conducting away the
waste gases; and i is a chamber through which the products of com-
bustion pass away from the furnace. The powdered ore is fed from the
receptacle a into the reducing chamber f by a pair of fluted rollers a¹,
which are made to revolve slowly by appropriate machinery; passing
down the channel 6 the ore falls upon the top bearer c and gradually
descends from bearer to bearer until it reaches the bottom. The
bearers c, c, c, may be made of any sufficiently fire-resisting material.
The lower sets of bearers c³ and the receptacle d are kept cool by a
current of water running through them for the purpose of lowering
the temperature of the iron powder to prevent its being re-oxidized in
case it has to be exposed to the air. To the same end the second
receptacle d is added, and if necessary a current of carbonic acid gas.
is forced into it. From this chamber the material can be dropped into
trams for removal. It should be kept dry and worked up quickly. The
reducing gases generated in a separate apparatus are forced into the
chamber through the pipe e. The pressure must be above that of the
atmosphere to effectually keep air from entering the reduction chamber.
Some of the same gas is forced through the pipes into the side flues
and takes with it an induced current of air, by which means it is burnt
in passing and repassing through bearers and the flues g, and thus heats
the reduction chamber f. Care must be taken not to allow the
temperature to get so high as to fuse the gangue which the ore contains.
The waste gases from the chamber pass off by the flue h and are brought
by the pipe i into the flue g and there burnt. The products of com-
bustion after heating the top set of bearers pass through the chamber j

page_text: and away to the stack. The top of this chamber serves as a drying floor
for the ore. The bearers gradually get full of ore and require to be
cleared from time to time, and this is done by means of "clearers" k
recessed in the front part of the furnace, which are lengthened by a
bayonet joint when in use.
The cooling part of the chamber may be dispensed with and the
upper portion built over a steel melting furnace, so that the iron
powder may be dropped at once into a bath of molten pig iron, but
the mode of working up the iron powder forms no part of my
present Invention, which extends only to its production and.
preservation.
Having now ascertained and described the nature of my said
Invention, and the manner in which the same may be conveniently
and advantageously carried into practice, I claim, the reduction of
iron ores by supplying them in a finely powdered state to a vertical
chamber containing a series of horizontal bearers, in which they are
at the same time subjected to the action of reducing agents, and are
kept at a sufficiently high temperature to ensure reduction, substantially
as set forth.
In witness whereof, I, the said George James Snelus, have hereunto
set my hand and seal, this Twenty-sixth day of August, in the
year of our Lord One thousand eight hundred and sixty-nine.
GEORGE JAMES SNELUS. (L.S.)