IMPROVEMENTS IN THE MANUFACTURE OF MALLEABLE IRON, CAST IRON, AND STEEL, AND IN THE CONSTRUCTION OF FURNACES TO BE EMPLOYED FOR SUCH PURPOSES
Year: 1867

page_text: LETTERS PATENT to Charles Gelstharp, of Wincomble, Low Walker,
Dear Newcastle-on-Tyne, in the County of Northumberland, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF MALLEABLE IRON,
CAST IRON, AND STEEL, AND IN THE CONSTRUCTION OF FURNACES TO BE
EMPLOYED FOR SUCH PURPOSES."
Sealed the 25th February 1868, and dated the 2nd September 1867..
PROVISIONAL SPECIFICATION left by the said Charles Gelstharp at
the Office of the Commissioners of Patents, with his Petition, on the
2nd September 1867.
I, CHARLES GELSTHARP, of Wincomble, Low Walker, near Newcastle-on-
Tyne, in the County of Northumberland, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF MALLEABLE
IRON, CAST IRON, AND STEEL, AND IN THE CONSTRUCTION OF FURNACES TO BE
EMPLOYED FOR SUCH PURPOSES," to be as follows:-
This Invention, so far as the same relates to the manufacture of malleable
iron, cast iron, and steel, consists of certain improvements whereby the
melting and reduction of iron ores, and also the melting of reduced iron
ores, is effected by the application of heat produced by the combustion of gas,
and whereby also the gases employed are purified; and, further, in certain
methods of carburization, when required, of the reduced iron in order to

page_text: produce steel or cast iron. The improvements in the construction of furnaces
to be used for the before-mentioned purposes will be most conveniently
explained in connection with the description of the other portions of the
. Invention.
The gases employed for the purposes of this Invention may be produced
from any solid or liquid fuel, and will consist of carbonic oxide, hydrogen,
and hydrocarbons, either separate or in mixture, and may contain small
portions of sulphur and its compounds. A preferable mode however of
obtaining the gas is by blowing air through a column of ignited fuel con-
tained in a vertical chamber. The chamber in which the fusion of the
reduced iron ore is effected is similar to the hearth and boshes of an ordinary
blast furnace, but not of necessity circular. The gas and the air required
for combustion are blown into this chamber, and should be mixed as inti-
mately as possible before reaching the interior thereof. For this purpose it is
preferable that the air pipe should pass through the interior of the gas pipe,
both terminating at some distance from the interior of the chamber. Each
pipe must be fitted with a valve for regulating the proportions of air and gas.
The melting chamber is surmounted by a reducing chamber similar to the
upper part of an ordinary blast furnace. The gases from the melting chamber
are not allowed to pass directly into the reducing chamber, but are passed
first through a column of fuel contained in a chamber adjoining the main
shaft. The top of the melting chamber is closed by an arch with a central
opening passing upwards into the bottom of the reducing chamber, and a side
opening passing into the fuel chamber. The central opening is furnished with
a damper, by which communication between the melting and reducing
chambers is prevented, unless when it is required to admit reduced ore to the
melting chamber. The fuel chamber communicates at its upper part with
the bottom of the reducing chamber, so that the gases from the melting
chamber only come in contact with the ore after passing through the fuel
chamber which is kept supplied with fuel. More than one fuel chamber
may be used if desired. The ore may be reduced by heating it in mixture
with carbonaceous matter in close chambers. The arrangements for this
purpose consist of a number of narrow parallel chambers with flue spaces
between them; these chambers may be heated by a fire placed at one end, or
fires may be placed at both ends of the set, the flames from which pass
upwards and downwards through the alternate flue spaces, or the chambers
may be heated by gas introduced at each end of the set alternately; the
chambers may also be heated by the waste heat of the melting chamber
employed for melting the reduced ore. The ore having been thus reduced is

page_text: compressed if not sufficiently coherent, and introduced into a melting
chamber similar to the melting chamber in the furnace first described, and
melted by gas heat; the melting chamber in this case is not connected with
fuel and reducing chambers, but the heated gases escaping from it may be used
for heating the close chambers in which the ore is reduced, or for heating the:
blast. The gases are purified by passing them through reduced or unreduced;
iron ore or lime after leaving the generator, and again if necessary after
leaving the fuel chamber, or the reduced or unreduced iron or lime may be
mixed with the fuel in the generator and the fuel chamber. The ore is
mixed with fluxes if required (as well understood), and if no carbonaceous
matter is mixed with it in the reducing chamber of the first form of furnace,
or no excess used in the second, the produce will be malleable iron. To
produce steel or cast iron either of the following methods may be employed:-
Carbonaceous matter may be introduced with the ore into the reducing
chamber or into the melting chamber in the first form of furnace. In the
close chambers' an excess of carbonaceous matter may be used in reducing the
ore, or carbonaceous matter may be introduced with the reduced ore from the
close chambers into the melting chamber. Carbonaceous matter may be
added. to the molten metal obtained in either way after the removal of the
slag; the iron may also be carbonised by mixing it with highly carbonised'
iron or with spielgeleisen.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Gelstharp in the Great Seal Patent Office on the
2nd March 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
GELSTHARP, of Wincomble, Low Walker, near Newcastle-on-Tyne, in the
County of Northumberland, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of August, in the year of our Lord One.
thousand eight hundred and sixty-seven, in the thirty-first year of Her reign,.
did, for Herself, Her heirs and successors, give and grant unto me, the said..
Charles Gelstharp, Her special licence that I, the said Charles Gelstharp,.
my executors, administrators, and assigns, or such others as I, the said:
Charles Gelstharp, 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

page_text: make, use, and 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 MANUFACTURE OF MALLEABLE IRON, CAST IRON, AND
STEEL, AND IN THE CONSTRUCTION OF FURNACES TO BE EMPLOYED FOR SUCH PUR-
POSES," upon the condition (amongst others) that I, the said Charles Gelstharp,
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 Charles Gelstharp, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, and to
the figures and letters marked thereon, that is to say:-
My said Invention, so far as the same relates to the manufacture of mal-
leable iron, cast iron, and steel, consists of certain improvements whereby the
melting and reduction of iron ores, and also the melting of reduced iron ores,
is effected by the application of heat produced by the combustion of gas; and,
further, in certain methods of carburization, when required, of the reduced
iron in order to produce steel or cast iron.
My said Invention further consists in certain improvements in the con-
struction of furnaces to be used for the before-mentioned purposes, and which
improvements will be most conveniently explained in connection with the
description of the other portions of the Invention.
The blast furnace employed in carrying out the objects of my said Invention
is separated into two chambers, that is to say, a melting chamber and a
reducing chamber. The melting chamber in which the fusion of the reduced
iron ore is effected is similar to the hearth and boshes of an ordinary blast
furnace, but is not necessarily of a circular form. The melting chamber is
surmounted by a reducing chamber, which latter is similar to the upper part
of a blast furnace. In addition to the two chambers before mentioned a fuel
chamber is provided in a shaft adjoining the main shaft of the furnace, and
through which fuel chamber the gases from the melting chamber pass, as
herein-after mentioned. The top of the melting chamber is closed by an
arch with a central opening passing upwards into the bottom of the reducing
chamber and a side opening passing into the fuel chamber. The central
opening is furnished with a damper, by which communication between the

page_text: melting and reducing chambers is prevented, unless when it is required to
admit reduced ore to the melting chamber. The use of solid fuel in the
melting and reducing chambers is avoided, combustible gases, which may
be produced from any suitable solid or liquid fuel, and consisting of car;
bonic oxide, hydrogen, and hydrocarbon vapours or gases, either separate or
in mixture, being employed for the purposes of my said Invention.. The
mode which I prefer of obtaining such gases is by, blowing air through.
a column of ignited, fuel contained in a vertical fuel chamber. The
gases are blown into the melting chamber with nearly the proportion of
air required for their perfect combustion, and either the gas or air may be
slightly in excess, as a reducing or oxidising flame may be required. The gas
aud air should be mixed as intimately as possible before reaching the interior
of the furnace, and for this purpose I prefer that the air pipe should pass
through the gas pipe, both terminating at some distance from the interior of
the furnace; each pipe should be fitted with a valve for, regulating the pro-
portions of air and gas. The gases from the melting chamber should not be
conveyed directly into the reducing chamber, but are first passed through a
column of fuel provided for that purpose in the before-mentioned shaft
adjoining the main shaft of the furnace. The fuel chamber communicates at
its upper part with the bottom of the reducing chamber, so that the gases
from the melting chamber only come into contact with the ore after passing
through the column of ignited, fuel, as before, mentioned, which latter should
be so deep as to reduce all the carbonic acid to carbonic oxide. The several
fuel chambers are kept supplied with fuel by means of hoppers with double
slides, or by cups and cones, to allow of their being charged with fuel quickly
without admitting air in any considerable quantity. More than one, fuel
chamber for each purpose may be used if desired. The reducing chamber of
the furnace is charged in the usual way with ore and fluxes, but without fuel
mixed with the charges, and the charge as the ore becomes reduced by the
gases from the fuel chamber is from time to time passed from the reducing
chamber into the, melting chamber, from which the metal is tapped when it
has accumulated, and the slag is allowed to flow over a dam, as in ordinary
blast furnaces. Should no solid carbonaceous matter have been used malleable
iron will be obtained by means of the before-mentioned treatment, and this
malleable iron may be carburized to any required degree, and converted into
steel or cast iron by any of the well-known methods. Coal, coke, or charcoal
may be introduced into the melting chamber, or to produce steel I prefer
to mix cast iron or spiegeleisen with the iron either in the hearth or after
tapping.

page_text: Ores of iron may be reduced in accordance with my said Invention by
heating them in mixture with solid carbonaceous matter, and without being
in contact with the air or with any current of oxidising gas. Many forms
of apparatus have been used for this purpose, but the furnace which I employ
will be more clearly understood by reference to the annexed Drawings;
Figure 1 being a longitudinal section, Figure 2 a cross section, and
Figure 3 a plan view.
The ore is mixed with the solid reducing agent and spread on the beds
of the furnace a, a, a, and kept heated to bright redness, or if a gaseous
current is employed as the reducing agent the heat need not be so high, but
in that case the ore must be turned over occasionally to expose it completely
to the reducing gas. The flame by which the furnace is heated must not
be of an oxidising character, and to this end I feed the fire with a hopper g
(Figure 1) fitted with a slide, so as to allow no air to pass into the furnace
unless between the bars of the grate d (Figure 1). The flame, after passing
over the charge on the beds a, a, a, passes under the tiles forming the beds
in the flue b, b, (Figures 1 and 2). The charge except when the reducing
agent is gas is not stirred, and when on sampling and testing the ore is
found to be almost entirely reduced to metallic iron, it is drawn through the
holes c into the iron vessel e (Figure 1), in which it is covered until nearly
cold. The iron, now in the so-called "spongy" state, may be compressed
while hot in the receiver e (which must be made of proportionate strength)
by hydraulic pressure or by percussion. When a bed is being drawn or
charged the damper ƒ (Figure 3) should be kept closed, so as to prevent a
current of air passing through the working doors h (Figures 2 and 3) over
the charge. This furnace, although represented in the Drawings as being
heated by an ordinary fire, may be so modified as to be heated by gas or
by waste heat.
When the ore has been reduced in a separate furnace, of
whatever kind, I melt it in a blast furnace similar to the melting chamber in
the furnace first described or to the ordinary blast furnace, but as the ore is
already reduced this furnace need not be of great height. The gases by
which it is heated should, as described before, be perfectly mixed before
reaching the interior of the furnace, and after they have performed their
functions therein are allowed to escape, or may be utilised, as may be
desired. The reduced ore obtained as last described, if not sufficiently
coherent, is compressed while hot by any of the known methods; the degree
of carburization of the iron may be regulated by the proportion of carbonaceous
matter mixed with the ore before reduction. If necessary the iron may be
carburized by means of cast iron or solid fuel being added in the furnace

page_text: or hearth, as before described. The heated gases which escape from this
furnace may be made available for heating the furnace in which the ore is
reduced. The combustible gases obtained by blowing air through ignited
fuel, as herein-before mentioned, will in some cases contain small proportions
of sulphur and its compounds, and which I remove by passing the gases
while at a high heat over reduced iron, iron ore, or lime, or by mixing
such substances with the fuel.
In extracting copper and other metals from certain ores a residue is
obtained which contains a large proportion of oxide of iron. This residue
generally contains sulphates only slightly soluble in water and dilute acids,
such as sulphates of lead and lime. I digest such residue before reducing it
in a solution of one or other of the alkalies or their carbonates, so as to
decompose the sulphates and remove their acid, thus ensuring a purer
product in the subsequent treatment of the ore. I should here mention
that it has been before proposed to smelt iron ores by the heat of gas in a
blast furnace, and that therefore I do not claim the application of gas for this
purpose.
In reducing iron ore without fusion to metallic iron, forming the so-called
spongy iron, close or retort-formed furnaces have been used, and also furnaces
with the heating flame passing directly over and in contact with the ore. In
the former the work is slow and expensive; in the latter it is necessary to
turn over the ore several times to expose it to the heat, thus entailing much
labour, and injuring the product by admission of air.
When the flame is
passed under the bed, as herein-before mentioned, no stirring is required, so
that the furnace is only open to the air in drawing and charging.
The purification of gases for metallurgical purposes by passing them over
spongy iron has before been proposed, and therefore I do not claim this as
constituting any part of my said Invention.
Having thus declared and fully ascertained the nature of my said Invention,
and the manner in which it is to be performed, I would observe in conclusion
that what I consider novel and original, and therefore claim as constituting
the Invention secured to me by the said herein-before in part recited Letters
Patent are,
First. The construction of the blast gas furnace with separate melting and
reducing chambers, and the arrangement of a separate fuel chamber in
connection therewith, as and for the purposes substantially herein-before
described and set forth, or any mere modifications thereof.
Secondly. The construction of furnaces for reducing iron ore with solid or
gaseous fuel by direct heating with a non-oxidising flame passing under the

page_text: ore bed before or after passing over the ore, or any mere modifications
thereof.
Thirdly. The application of the gas blast furnace to the melting of spongy
iron as herein-before described.
And, fourthly. The methods of treatment in the manufacture of malleable
iron, cast iron, and steel substantially herein-before set forth and described,
or any mere modifications thereof.
In witness whereof, I, the said Charles Gelstharp, have hereunto set
my hand and seal, this Twenty-eighth day of February, in the year
of our Lord One thousand eight hundred and sixty-eight.
Witness,
E. P. H. VAUGHAN,
Patent Agent,
54, Chancery Lane,
CHARLES GELSTHARP. (L.S.)