IMPROVEMENTS IN for the Invention of OBTAINING IRON
Year: 1871

page_text: LETTERS PATENT to James Anderson, of Newbuildings, in the County
"IMPROVEMENTS IN
of Londonderry, Ireland, for the Invention of
OBTAINING IRON."
Sealed the 16th May 1871 and dated the 17th March 1871.
PROVISIONAL SPECIFICATION left by the said James Anderson at the
Office of the Commissioners of Patents, with his Petition, on the
17th March 1871.
I, JAMES ANDERSON, of Newbuildings, in the County of Londonderry,
Ireland, do hereby declare the nature of the said Invention for " IMPROVE-
MENTS IN OBTAINING IRON," to be as follows, that is to say:
"
:-
This Invention has for its object to obtain an improved quality of iron
more highly carbureted and freer from phosphorus than that obtained by
smelting processes hitherto in use; and it consists in taking silicates
obtained in the manner described in the Specification of certain Letters
Patent granted to the present applicant, and dated 5 October 1867
(No. 2801), and in introducing them into the common smelting furnace,

page_text: or other suitable furnace, along with the iron ore and the additional lime
or flux that may be requisite.
The processes described in the said earlier Specification for decomposing
the silicates are carried out in the present application, and whilst the
potassium or sodium or their compounds pass off in a volatile state and
are collected in receivers or condensers, the iron is obtained as cast iron
at the bottom of the furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Anderson in the Great Seal Patent Office
on the 14th September 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
ANDERSON, of Newbuildings, in the County of Londonderry, Ireland,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of March, in the
year of our Lord One thousand cight hundred and seventy-one, in
the thirty-fourth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said James Anderson, Her
special licence that I, the said James Anderson, my executors, adminis-
trators, and assigns, or such others as I, the said James Anderson, 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
OBTAINING IRON," upon the condition (amongst others) that I, the said
James Anderson, 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 James Anderson, do hereby declare
the nature of my said Invention, and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and by the
following statement in writing, that is to say :-
My said Invention has for its objects to obtain an improved quality of
iron more highly carbureted and freer from phosphorus than that
obtained by smelting processes hitherto in use, and to reduce the cost of
the iron; and it consists mainly in so modifying existing iron smelting
processes as to apply or adapt thereto or utilise therein principles,
developments, or extensions of certain chemical actions described in the
Specification of Letters Patent granted to me, and dated 5th October
1867 (No. 2801).
In
my
said earlier Specification I described a mode of forming silicates
and aluminates of alkalies, and a mode of separating the alkalies from
such silicates or aluminates with the aid of the reducing action of carbon
and a high temperature, alkaline earths being added to combine with the
silica, phosphorus also being separated from its compounds by a similar
action.
The latter part of these processes I, by my present Invention and
under one modification thereof, cause to be carried on conjointly with
the ordinary process of smelting iron ores, making provision for with-
drawing from the furnace at a suitable point or points the vaporised
alkalies and phosphorus, with the reasonable expectation that if the
phosphorus is allowed to pass off from the furnace in the manner
indicated the cast iron obtained at the hearth will be practically free
from phosphorus, and also from sulphur, any of the latter that may be
present in the lower part of the furnace passing off with the phosphorus
and alkalies. The conjoining of the processes will also, I expect, lead
to great economy in obtaining the various products, or in other words
the cost of the iron will be greatly reduced in consequence of the
simultaneous production, utilisation, or collection of other substances
of considerably greater value than the materials from which they are
derived.
In the ordinary operation of smelting iron small quantities of potassium,
sodium, phosphorus, and sulphur generally exist in the materials put into
the furnace, and I believe these substances do in the ordinary blast
furnace really undergo the reducing action described in my earlier
Specification, but hitherto advantage has not been taken of their
vaporised condition to obtain their withdrawal and separation.

page_text: '
In carrying out my present Invention silicates or aluminates obtained
as described in my earlier Specification, or natural silicates or aluminates,
are put into the furnace along with the usual materials, that is, the ore,
the lime or flux, and the coke or coal. Then as the materials gradually
descend and become.heated the potash and soda, not already in com-
bination with silica or alumina, combine with these earths, from which
they are afterwards separated at a higher temperature by the action of
the more fixed lime. The phosphoric acid in combination with the
alkalies or alkaline earths is also separated therefrom by silica or
alumina. The oxygen of the potash, soda, and phosphoric acid combines
with the carbon of the coal, and the vapors of potassium, sodium,
and phosphorus or compounds thereof are led out of the furnace by a
passage or passages at the side along with a portion of the hot gases.
The sulphur compounds are also reduced, and the sulphur is volatilised
by being subjected to the same treatment, and passes out of the furnace
along with the other gases and vapors. The vapors are separated from
the gases by cooling and condensing or by washing them out. The
cyanides, phosphides, sulphides, carbides, or carbonates so obtained are
collected and utilised. The carbonic oxide and nitrogen gases from
which the vapors have been separated are returned to the furnace again
by a passage or passages entering the side of it at a level higher than
that by which they escaped. They may be reheated before entering.
The carbonic oxide will then perform its part in reducing the ore as if it
had not been taken out. A portion of the carbonic oxide may be
burned for reheating the portion returning into the furnace, or a portion
may be employed for heating the air for the blast. I however prefer to
heat the re-entering gases in an economical manner by transferring heat
to them from the hot freshly issuing gases and vapors which require to
be cooled. This is effected by causing the hot and cold currents of gases
and vapors to flow in opposite directions on the opposite sides of thin
partitions of iron or other suitable material, a series of channels being
formed with the hot and cold currents in each alternate channels
respectively, and provision being made by doors for the periodical
removal of saline matters deposited from the hot gases or vapors
through the influence of the cold currents in the adjacent channels.
It is desirable for the satisfactory carrying out of my improvements to
have the blast as highly heated as is conveniently possible, for the hotter
that the lower part of the furnace is so much more complete will be the

page_text: dissociation of the vapors from the slag and iron; also so much higher
will be the point at which fusion commences; also so much greater will
be the height of incandescent coke through which the iron and slag will
have to percolate; also so much more opportunity will there be for the
ascending heated gases to separate and carry with them the dissociated
vapors of potassium, sodium, phosphorus, and sulphur. The temperature
of the blast will also determine the proper height for the outlet for
leading these vapors from the furnace; but in practice the proper
position for the said outlet will be easily ascertained by trials in each
case. The zone in which the vapors are most abundant is the part
immediately below that where the gradually diminishing temperature
would cause them to begin to condense and become redeposited on the
descending solid or liquid materials in the furnace, and the aperture or
apertures for their escape should be placed at this zone. It is further
most desirable that the furnace should be of such a total height as to
extend up above the zone just referred to sufficiently to contain a depth
or column of ore and lime that will absorb and utilise a large portion of
the heat of the gases before they escape to the atmosphere, and so cool
them low enough to cause the deposition on the ore and lime of any
valuable substances they may have carried up in a vaporised state. This
deposition or condensation will take place more rapidly when the tem-
perature falls below 212 degrees Fahrenheit, as the steam present then
condenses, and the water wets the surface of the minerals and induces
the adherence of the vaporised substances thereto. When the depth or
column of minerals is not sufficient to keep the temperature low enough
water or a saline solution, such as sea water, may be showered on the
minerals to cool them. Then as the minerals descend and get hotter
the water will be evaporated, and the saline crust formed on the surface
will be carried down into the furnace, and will undergo the reducing
process already described, and its vaporised constituents will be ulti-
mately carried out of the furnace with the hot gases as cyanides and
the like.
By carrying out the herein-before described improvements not only
do I save and utilise the valuable vaporised substances that are lost in
the ordinary smelting of iron, and at the same time remove along

page_text: withdrawal of phosphorus and sulphur, as the latter are diffused or
suspended in the former, and in proportion to the quantities of the
former that are present.
Having thus particularly described my said Invention, and the manner
in which the same is to be performed, I have to state that what I believe
to be novel and original and claim as secured to me by the hercin-before
in part recited Letters Patent is,-
1. The obtaining of iron comparatively free from phosphorus or
sulphur by withdrawing hot gases from a part of the smelting furnace
where those substances are in a vaporised condition and mixed with or
suspended in the gases, as herein-before described.
2. The increasing of the quantity of vaporised potassium or sodium or
their compounds in the hot gases by introducing silicates, aluminates,
or other suitable salts of potassium and sodium for the purposes of
inducing the more complete withdrawal of phosphorus or sulphur, and
of obtaining the vaporised substances and the iron economically, as
hercin-before described.
3. The returning of the gases after separating therefrom the vaporised
substances, and the transferring of heat to such returning gases from
the freshly issuing gases and vapors, as herein-before described.
4. The keeping of the minerals at the top of the furnace sufficiently
cool to insure the deposition and retention of valuable vaporised substances
as herein-before described.
In witness whereof, I, the said James Anderson, have hereunto set
my hand and seal, this Fifteenth day of August, in the year of
our Lord One thousand eight hundred and seventy-one.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JAMES ANDERSON. (L.s.)