IMPROVEMENTS IN for the TREATING IRON ORES OR IRONSTONES
Year: 1868

page_text: LETTERS PATENT
to Henry Aitken, of Falkirk, in the County of
Britain, for the Invention of "IMPROVEMENTS IN
Stirling, North Britain, for the
TREATING IRON ORES OR IRONSTONES."
Sealed the 7th May 1869, and dated the 14th November 1868.
PROVISIONAL SPECIFICATION left by the said Henry Aitken at the
Office of the Commissioners of Patents, with his Petition, on the
14th November 1868.
I, HENRY AITKEN, of Falkirk, in the County of Stirling, North
Britain, do hereby declare the nature of the said Invention of "IMPROVE-
'MENTS IN TREATING IRON ORES O IRONSTONES," to be as follows, that is to
say:-
This Invention relates to an improved mode of treating iron ores or
ironstones in order to effect their better purification and more economical
reduction into metal, also for utilizing the volatile matters. To carry
these objects into effect the iron ores or ironstones are placed in any
[Price 8d.]

page_text: convenient kind of retort, kiln, oven, or chamber made as air-tight as
possible, which may be placed vertically, horizontally, or at any angle,
and a fire is placed so as to act in the retort, kiln, oven, or chamber,
which is so constructed that no air is admitted without having first
passed through the fire so as to consume the oxygen that is in the air.
The fire-place may be built separate from the retort, kiln, oven, or
chamber and be connected therewith by a flue or flues, or it may be
made moveable, or the retorts, kilns, ovens, or chambers may be con-
nected by means of flues with one another so that the heat of one
kiln may be drawn or forced through the others, and so economised, or
the gases of any blast furnace or other furnace or fire may be used, care
being taken to exclude all or as much as possible of the oxygen in the
air. The iron ores or ironstones having been heated to such a degree
as to deprive them of the carbonic acid and other volatile matters the
fire is withdrawn or shut off, and the retort, kiln; oven, or chamber is
allowed to cool down, or the same may be discharged, watered out and
cooled, or watered out and cooled in place, care being taken that the
carbonised iron ores or ironstones come in contact with the air as little
as possible, or in place of treating the iron ores or ironstones in the
manner last specified, they may be removed at once and reduced by a
blast furnace or other means. Before the iron ores or ironstones in the
retort, kiln, oven, or chamber is cooled down steam, or salt, or water, or
salt water is charged into the kiln in order as much as possible to
neutralize and volatilize any sulphur and phosphorus that may be in the
iron ores or ironstones. In some cases it may be necessary in order
thoroughly to expel the sulphur and phosphorus to heat the iron ores or
ironstones more than once and charge with steam, water, salt, or salt
water. This operation may be repeated as often as thought proper.
In order to cause the fire to burn quickly a flue or flues may be
connected with a stalk, or with a steam jet, or fans, or other means for
creating a draught. The volatile matters so drawn off may be condensed
and collected and utilized, or the same may be used either partly or
wholly by being burnt in place of the fire before mentioned, or they may
be burnt for any other purpose for which heat is required. With almost
all kinds of iron ores or ironstones it is advantageous to charge the
retort, kiln, oven, or chamber with a small quantity of coal or car-
bonaceous matter along with the iron ores or ironstones. In cases
where the volatile matter consists partly or wholly of sulphur cither
the same is made in sulphuric acid in the usual way or it is deposited

page_text: in a close chamber as sulphur in the ordinary manner. When the
volatile matters contain oil or tar they are condensed in the usual kind
of oil condenser and the oil or tar is passed into holders, and in cases
where phosphorus is present with the volatile matters and where salt is
used it is collected by passing them through or over lime, water, or
lime and water.
SPECIFICATION in pursuance of the conditions of the Letters Parent,
filed by the said Henry Aitken in the Great Seal Patent Office on
the 14th May 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME I, HENRY
AITKEN, of Falkirk, in the County of Stirling, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of November, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Henry Aitken, Her special
license that I, the said Henry Aitken, my executors, administrators,
and assigns, or such others as I, the said Henry Aitken, my executors,
administrators, or 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 TREATING
IRON ORES OR IRONSTONES,' upon the condition (amongst others) that I, the
said Henry Aitken, by an instrument in writing under my hand and
seal, 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 Henry Aitken, 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

page_text: My said Invention relates to an improved mode of treating iron ores
or ironstones in order to eflect their better purification and more
economical reduction into metal, also for utilizing the volatile matters.
To carry these objects into effect the iron ores or ironstones are placed
in any convenient kind of retort, kiln, oven, or chamber made as air-
tight as possible, which may be placed vertically, horizontally, or at any
angle, and a fire is placed so as to act in the retort, kiln, oven, or
chamber which is so constructed that no air is admitted without having
first passed through the fire so as to consume the oxygen that is in the
air. The fire-place may be built separate from the retort, kiln, oven, or
chamber, and be connected therewith by a flue or flues, or it may be
made moveable, or the retorts, kilns, ovens, or chambers may be con-
nected by means of flues with one another so that the heat of one kiln
may be drawn or forced through the others and so economised, or the
gases of any blast furnace or other furnace or fire may be used care
being taken to exclude all or as much as possible of the oxygen in the
air. The iron ores or ironstones having been heated to such a degree
as to deprive them of the carbonic acid and other volatile matters, the
fire is withdrawn or shut off, and the retort, kiln, oven, or chamber is
allowed to cool down, or the same may be discharged, watered out and
cooled or watered out and cooled in place care being taken that the
carbonised iron ores or ironstones come in contact with the air as little
as possible; or in place of treating the iron ores or ironstones in the
manner last specified they may be removed at once and reduced by a
blast furnace or other means. In order to cause the fire to burn quickly
a flue or flues may be connected with a stalk or with a steam jet or fans
or other means for creating a draught. The volatile matters so drawn
off may be condensed and collected and utilized, or the same may be
used either partly or wholly by being burnt in place of the fire before
mentioned or they may be burnt for any other purpose for which heat
is required. With almost all kinds of iron ores or ironstones it is
advantageous to charge the retort, kiln, oven, or chamber with a small
quantity of coal or carbonaceous matter along with the iron ores or iron-
stones. In cases where the volatile matter consists partly or wholly of
sulphur either the same is made into sulphuric acid in the usual way, or
it is deposited in a close chamber, as sulphur in the ordinary manner.

page_text: When the volatile matters contain oil or tar they are condensed in the
usual kind of oil condenser and the oil or tar is passed into holders.
And in order that my said Invention may be properly understood I
now proceed to set forth one system of apparatus in or under which the
same is or may be used or practically carried into effect, reference being
had for the sake of more complete elucidation to the several Figures upon
the explanatory Sheet of Drawings which I have hereunto appended,
that is to say, the right hand part from line a to line 6 of Figure 1 is a
front elevation of part of a row of kilns or ovens in which the iron ores
or ironstones are coked or carbonised. A section of one of the kilns or
retorts is shown at the left-hand part of Figure 1 from line 6 to line c,
and a plan of the kilns is shown at Figure 2. Figure 3 is a transverse
section on the line g, h, Figure 1. The fire-place C is built separate
from the kilns D and is connected therewith by a flue E, Figure 3,
which extends along the back of the row of kilns, each one of which
communicates with the main flue E by inlet flues F entering through
the floor, as shown at Figures 2 and 3; the flues F being provided with
dampers for shutting them off when required, being held in position by
counterweights y, as shown at Figure 3. After the products of com-
bustion from the furnace C have passed up through the iron ores or
ironstones which are being treated they escape through the outlet
flue G, Figures 1 and 3, into the iluc H which communicates with the
stalk or chimney I, whence they escape into the atmosphere. The
flues H are provided with dampers for closing them when they require
to be shut off. The volatile matters, when these are to be collected, are
drawn off by means of a stalk or steam jet through the pipe J, Figures 2
and 3, and are condensed in the pipe K from which the oil and tar are
drawn off into tanks or other holders. The iron ores or ironstones are
filled into the kiln through a hopper L placed in the roof and are
conveyed thither in hutches or waggons on a railway M. When the
kiln is charged all communication with the atmosphere is cut off so
that no air is admitted without having first passed through the fire C
connected to the kiln by flues in the manner herein-before described.
When the iron ores or ironstones have been sufficiently coked or
carbonised the fire is withdrawn or communication between it and the
kiln in which the coked or carbonised iron ores or ironstones are
contained is cut off by means of a damper placed in the flue and the
kiln is allowed to cool down or water may be put in amongst the

page_text: carbonised iron ores or ironstones to expedite the process of cooling, or
the contents may be discharged by the openings N on to the inclined
plane O and watered out, or they may be removed from the kiln at once
and reduced by a blast furnace or by other means. Before the iron ores
or ironstones in the retort, kiln, oven, or chamber are cooled down steam
or salt, or water, or salt water is charged into the kiln in order às much
as possible to purify the iron ores or ironstones. In some cases it may
be necessary in order more thoroughly to purify the iron ores or iron-
stones to heat them more than once and charge with steam water, salt,
or salt water; this operation may be repeated as often as thought proper.
When salt is to be used the salt instead of being put direct amongst
the carbonised iron ores or ironstones may be placed on or in the fire or
furnace and so volatilized and diffused among the carbonized iron ores
or ironstones. The hot gases and products of combustion from the fire C
may be made to pass through all the kilns in succession by connecting
them together by partition flues, as shown at P, Figure 2, any number
of which may be put
into communication with each other, or communica-
tion cut off by means of dampers placed in the partition flues P, and in
this way one or more of the chambers or kilns may have the coking or
carbonising operation going on within them at the same; time or each
kiln may be heated by passing the products of combustion of the fire C
through a separate flue for each kiln branching off from the main flue E,
as shown in dotted lines. Instead of heating the kilns from a fixed
furnace as herein-before described a moveable or portable furnace may
be employed. The furnace Q, Figure 3, is carried on wheels and travels
on a railway as shown at R, Figure 3, and dotted at Q, Figure 2, in
this manner the furnace may be stationed immediately behind any kiln
or set of kilns which are to be heated, communication with any one or
more of the others being cut off by dampers placed in the flues. In this
case projecting flues S, shown dotted at Figure 2, are attached to the
main flue E so that they may correspond to the flue of the portable
furnace Q, and each one of which is provided with a damper for closing
up when not in communication with the furnace. In place of employ
ing kilns or ovens arranged in the manner herein last set forth, they may
be arranged in a circle, as shown in plan at Figure 5, and also in trans-
verse section at Figure 4. In this arrangement the kilns D are heated
by the hot air and products of combustion passing from the fixed
furnace C which communicates with the kilns D on either side, as
shown in Figure 5, communication with the kilns on one side of the
it

page_text: furnace C being cut off by a damper d whilst any one or more of the
kilns on the other side are being heated. The hot gases and products
of combustion may be permitted to pass through all the kilns in succes-
sion by means of the flues P, Figure 5, or any number of the kilns may
be cut off by means of dampers placed in the flues P, Figure 5, as shown,
and the products of combustion pass from the last heated kiln into the
flue H by cross flues H', shown in dotted lines, the flues H. communi-
cating with the chimney I by a flue S, shown dotted at Figure 5. When
the volatile matters are to be collected they are drawn off by the pipes J,
Figure 4, also shown dotted at Figure 5, and arc condensed in the pipe
K, from which the oil and tar is drawn off into tanks or other holders.
The method of heating by a moveable furnace may be applied to these
kilns as shown. The furnace Q is placed on a circular line of rails R
laid on the ground space within the range of kilns, and on which the
furnace may be run to the back of any kiln or kilns which are to be
heated. The products of combustion pass from the furnace Q into the
flue E by a projecting flue or lined pipe shown dotted at U, Figures 4
and 5, and from the flue E they pass by the flues F into the kiln D, as
shown on Figure 4. The iron ores or ironstones are filled into the
kilns D through the hoppers L and are conveyed thither on a railway M,
Figure 4. When the iron ores or ironstones have been sufficiently coked
or carbonised the fire is withdrawn or shut off and the kiln or oven is
allowed to cool down, or water may be put in amongst the carbonised
iron ores or ironstones to expedite the process of cooling, or they may
be discharged on to the inclined plane O, Figure 4, and watered out,
care being taken that the carbonised iron ores or ironstones come in
contact with the air as little as possible. Before however that the coked
or carbonised iron ores or ironstones are cooled down they are treated
with salt, water, or salt and water in the manner herein-before described.
In cases where the volatile matter consists partly or wholly of sulpher
the same is either made into sulphuric acid in the usual way, or it is
deposited in a close chamber or sulphur in the ordinary manner.
It
may be here further mentioned that in almost all cases it is advisable to
charge a little coal or carbonaceous matter with the iron ores or iron-
stones, and in order to neutralize any oxygen that may get amongst the
gases a small quantity of coal or carbonaceous matter is placed by
preference in the flue or on the bottom of the oven or chamber; the
requisite neutral flame or heat may be obtained by any of Wilson's or
Siemen's Patent furnaces, or the flame issuing from a blast furnace may

page_text: be employed. In some cases it may be advisable to fire the gases on
their passage from one kiln to another, and this is done by allowing air
to mix therewith as they pass between one kiin and another. In place
of arranging the flues E and H in the manner herein-before described
they may be built or placed entirely separate from the retorts, kilns, or
chambers D and be connected thereto by means of moveable connecting
pipes which may be placed so as to operate upon whichever retorts,
kilns, or chambers may be desired, plugs or stoppers being provided to
exclude the air and prevent the escape of the gases when the said con-
necting pipes are removed.
Having now described the nature of my said Invention, and manner
together with apparatus under and with which the same may be carried
out into practice, I wish in conclusion to remark that I do not confine
or restrict myself thereto as any other chambers, vessels, or kilns may
be used into which a neutral flame is admitted or oxygen which has
before hand passed through a fire is allowed to enter; but what. I do
consider as novel, and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,--
1st. The coking or carbonising of iron ores or ironstones in vessels,
chambers, retorts, or kilns by means of flame or heat in which the free
oxygen has been as much as possible neutralized before the flame or
heat reaches the iron ores or ironstones to be acted on applied sub-
stantially in the manner herein-before described.
2nd. The purification of coked or carbonised iron ores or ironstones by
means of common salt, that is, chloride of sodium applied in the manner
and according to the methods herein-before described.
In witness whereof, I, the said Henry Aitken, have hereunto set
my hand and seal, this Twelfth day of May, One thousand eight
hundred and sixty-nine.
HENRY AITKEN. (L.S.)