IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN FURNACES AND APPLIANCES THEREFOR
Year: 1878

page_text: LETTERS PATENT to Alfred Longsdon, of Queen Victoria Street, in the City
of London, Civil Engineer, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF IRON AND STEEL, AND IN FURNACES AND APPLIANCES
THEREFOR." A communication from abroad by Alfred Krupp, of Essen, in the
Empire of Germany, Cast Steel Manufacturer.
Sealed the 17th December 1878, and dated the 3rd August 1878.
PROVISIONAL SPECIFICATION left by the said Alfred Longsdon at the Office
of the Commissioners of Patents on the 3rd August 1878.
ALFRED LONGSDON, of Queen Victoria Street, in the City of London, Civil
Engineer. "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND in
FURNACES AND APPLIANCES THEREFOR." (A communication from abroad by Alfred
Krupp, of Essen, in the Empire of Germany, Cast Steel Manufacturer.)
The object of this Invention is to free iron or iron ores from manganese, silicon,
and sulphur, and the greater part of the phosphorus, and to increase the yield of
the ore.
The Invention refers,-
1. To the cleansing of iron from phosphorus, manganese, silicon, and sulphur by
bringing it down with basal oxides of iron, with or without addition of oxides of
manganese and limestone in a shaft furnace of any desirable construction, which is
lined with iron ore, bauxite, magnesia, coal, slate, or other base, or with a material,
principally carbon, or in shaft furnaces where the lining is replaced by water
cooling, and the hearth or fore hearth of which is provided with a basal or carbon
coal lining.
2. To the cleansing of a fluid iron (tapped fluid from a blast furnace) from its
phosphorus, manganese, silicon, and sulphur, running this iron through a shaft fur-
nace which is filled with coke and basal oxides of iron, with or without the addition
of oxides of manganese and limestone.

page_text: 3. To the application and use of ore briquettes with the process described here-
after, instead of the application of separated coke and ore.
4. To the multiple use of the cleansing ores with the process described here-
after.
5. To the moving of the proper smelting space into a higher part of the shaft
furnace by means of high situated main tuyeres, so that the fluid materials travel a
greater way together, and the application of one or several rows of tuyeres for re-
heating the already fluid iron, and to keep it fluid.
6. To the construction of a transportable fore hearth (on wheels) for the foregoing
and other applications.
7. To the construction of a furnace in stories or tiers, for the purposes described.
8. To the application of an overflow for the slags, of known construction, between
the upper and lower shaft of a furnace in stories, and between the shaft of the
furnace and the hearth.
For this purpose the tuyeres are applied high in the furnace. Such furnace may
be of any suitable construction, such as a shaft furnace lined with iron ores, bauxite,
manganese, coal, slate, or other base, or with a material, chiefly carbon, or such
furnace where the smelting is effected, not lined, but provided with double walls
and water jacket, and the hearth lined with basal or neutral material.
The metal is melted in the upper part of the furnace, while there are several other
rows of tuyeres below which serve to reheat the already molten metal, and in this
way a gradual and comparatively slow melting takes place, and the reverse of that
which ordinarily takes place in cupola furnaces is effected.
Instead of charging the ore as ore it can be coked to briquettes with a coking
coal. With sufficient coke the product will always get into the hearth at a tempe-
rature which is higher than the melting point of the final product; this result of
the iron in a cupola is of value for this reason, the iron which is to be cleansed in
the furnace need not contain manganese in order to preserve the carbon.
The iron would only be less fluid if an essential decarbonization takes place after
the iron has arrived in the hearth. To prevent this the hearth or fore hearth can
be provided with a carbon lining; also if the smelting space should be lined with
ore or other suitable substance, and moreover the iron can be separated from the
slag by an overflowing arrangement of known construction when it runs into
the fore hearth, so that in the fore hearth the slag can no more operate upon the
iron.
Besides the fore hearth can be heated still by a connection with the shaft of the
furnace on one side, and with the open air on the other side, and by this means
losses of carbon are made innoxious. For this purpose the furnace with the cooled
shaft without lining of the smelting part of the furnace is most suitable. The walls
of this furnace become covered with a layer of ore, and all repairs in the smelting
space are obviated.
With reference to the cooling a cooled vessel may be applied at bottom of the
shaft, and a rammed-up fore hearth. The fore hearth, which is often subject to
repairs, in this case can be thus arranged that it is easy to be replaced, and the fluid
iron can be transported in it (when, for instance, it is put on wheels) to the place
where it is to be further worked (as if the hearth were a ladle at the same time).
This transportable fore hearth can be constructed, as is the case with that known as
Krigar's" cupola, so that the aperture through which the iron runs from the shaft
of the furnace into the fore hearth is applied on the middle of the cooled bottom of
the shaft, and the fore hearth, which is open then at the top, exactly has the shape
of a ladle; it is run then under the shaft, and made tight against the bottom by
fire-clay.
"
"
As already mentioned it is desirable to have for the process a high furnace with
high smelting space, but being confined in the height of the furnace so one can
apply with advantage a furnace in stories" in such manner that the lower shaft
is the fore hearth of the upper shaft. Leaving the upper shaft one can run the iron
with the ore into the lower shaft, in which case only the travel of the fluid masses

page_text: is elongated; or one can also separate the iron from the slag at this moment by an
overflow. The metal then gets into the second shaft, which receives in this case
fresh ore, together with the coke, a fluid pig iron which is freed of the greatest part
of its phosphorus and impurities, and which is cleansed again by going down with
fresh ore.
In this case one can give much fresh ore to the lower shaft, and use the
slag of the lower shaft, in which the finer (higher) cleansing takes place as ore or
like ore for the upper shaft.
The lower shaft of the furnace in stories will consume very little fuel, as it
receives the iron in fluid state. For this reason it can be considerably more narrow
than the upper shaft; or the lower shaft can serve at the same time for the several
upper shafts,
With this, as last-described double cleansing process also, a very phosphorus iron
can be brought to a minimum of phosphorus.
The addition of limestone with this process will render possible the consumption
of considerably less ore, as the silicic acid of the coke will then combine with lime
and not with ore. It is then perhaps desirable to work with pretty much ore,
and to use again a part of the slag instead of ore.
"
The described cleansing process can also be carried out at the blast furnace by
tapping the iron from the blast furnace, and running it directly through a "high
with ore and coke, or with ore briquettes, filled cupola, or "cupola in stories," or
that the iron is tapped from the blast furnace into a ladle, that this ladle is
transported over a cupola, and the iron is run through a small opening into the
cupola; the cupola will thereby consume very little ore.
The above-described process is not only for farther working the fluid material
in the Martin furnace, or in the combined reverberatory and Bessemer furnace, and.
so forth, it is also especially suitable for the puddling process, with which then again
phosphorus is extracted; then the cleansed iron can be taken from the cupola.
according to want, and be brought in fluid state to the puddling furnace, the
hearth of which will not be attacked in the same manner as is usually the case
with a fluid iron run into it, as the iron is almost free of manganese and silicon.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred Longsdon in the Great Seal Patent Office on the 3rd
February 1879.
ALFRED LONGSDON, of Queen Victoria Street, in the City of London, Civil
Engineer. "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN
FURNACES AND APPLIANCES THEREFOR." (A communication from abroad by Alfred
Krupp, of Essen, in the Empire of Germany, Cast Steel Manufacturer.)
The object of this Invention is to free iron or iron ores from manganese, silicon,
and sulphur, and the greater part of the phosphorus, and to increase the yield of
the.ore.
L
The Invention refers,―
1. To the cleansing of iron from phosphorus, manganese, silicon, and sulphur by
· bringing it down or reducing with basal oxides of iron, with or without addition of
oxides of manganese and limestone in a shaft furnace of any desirable construction,
which is lined with iron ore, bauxite, magnesia, coal, slate, or other base, or with a
material, principally carbon, or in shaft furnaces where the lining is replaced by
water cooling, and the hearth or fore hearth of which is provided with a basal or
carbon coal lining.
2. To the cleansing of a fluid iron (tapped fluid from a blast furnace) from its
phosphorus, manganese,, silicon, and sulphur, running this iron through a shaft
furnace, which is filled with coke and basal oxides of iron, with or without the
addition of oxides of manganese and limestone.
3. To the application and use of ore briquettes with the process described here-
after, instead of the application of coke and ore separately.
4. To the multiple use of the cleansing ores in and with the process described
hereafter.
5. To the moving of the proper smelting space into a higher part of the shaft
furnace by means of main tuyeres situated high up, so that the fluid materials travel
a greater way together, and the application of one or several rows of tuyeres for
re-heating the already fluid iron, and to keep it fluid.
6. To the construction of a portable fore hearth (on wheels) for the foregoing and
other applications.
7. To the construction of a furnace in stories or tiers for the purposes described.
8. To the application of an overflow of known construction for the slags between
the upper and lower shaft of a chamber or furnace in stories, and between the shaft
of the furnace and the hearth.
In order to make the cleansing as perfect as possible the tuyeres are applied high
in the furnace. Such furnace may be of any suitable construction, such as a shaft
furnace lined with iron ores, bauxite, manganese, coal, slate, or other base, or with
a material, chiefly carbon, or such furnace where the smelting is effected, not lined
but provided with double walls and water jacket, and the hearth lined with basal
or neutral material.
Examples of this latter construction arc illustrated by Figures 1, 2, and 3.
Figure 1 shows water spaces at a, b, and c; and Figures 2 and 3 similarly at a and b.
A is the shaft or chamber for the charge, and B the hearth.
When the metal is melted in such a furnace, together with basal oxides of iron,
with or without the addition of oxides of manganese and lime, the iron loses the
greatest part of its manganese, silicon, and sulphur, and the greatest part of its
phosphorus. A part of the ore is also thereby reduced, and the yield is thus
increased.
The metal is melted in the upper part of the furnace, even above the aforesaid
upper tuyeres, while there are several other lower rows of tuyeres below, which
serve to reheat the already molten metal, and in this way a gradual and compara-

page_text: tively slow melting takes place, the melted masses passing through as long a distance
together as possible, and thus acting on each other as much as possible. By this
arrangement of tuyeres the reverse of that which ordinarily takes place in cupola
furnaces is effected. From the same reason the furnace shaft should be as high as
convenient or possible.
Instead of charging the ore as ore it may be coked to briquettes with a coking
coal with sufficient coke. It is of no importance in this process if the carbon per-
centage in the iron is effected, as the product will always, with a sufficient coke
supply, get into the hearth at a temperature which is higher than the melting point
of the final product, and that whether the latter be cast iron or steel. This feature
of the iron in a cupola is of value, because for this reason the iron which is to be
cleansed in the furnace need not contain manganese in order to preserve the
carbon.
The iron would only be less fluid if an essential decarbonization took place after
the iron had arrived in the hearth. To prevent this the hearth or fore hearth may
be provided with a carbon lining, also if the smelting space is lined with ore or
other suitable substance. Moreover, the iron may be separated from the slag by an
overflow arrangement of known construction where it runs into the fore hearth, so
that in the fore hearth the slag can no more operate upon the iron. An arrange-
ment of this sort is illustrated by Figure 4, where an overflow is shewn at d.
The fore hearth may besides be heated by a connection with the shaft of the
furnace on one side, and with the open air on the other side, and by this means
losses of carbon are made innoxious. For the purpose of this Invention the furnace
with the cooled shaft without lining of the smelting part of the furnace is most.
suitable. The walls of this furnace become covered with a layer of ore as required,
and all repairs in the smelting space are obviated.
With reference to the cooling a cooled vessel may be applied at bottom of the
shaft, and a rammed-up fore hearth, as shewn at Figures 1 and 3. The fore hearth B,
which is often subject to repairs, may in this case be so arranged portable so as to
be easily removed and replaced, and the fluid iron thus can be transported in it
(when for instance it is put on wheels, as here shown) to the place where it is to be
further worked (as if the hearth were a ladle at the same time). This portable fore
hearth can be constructed, as is the case with that known as "Krigar's" cupola, as
shown at Figure 2; or so that the aperture through which the iron runs from the
shaft of the furnace into the fore hearth is applied on the middle of the cooled bottom
of the shaft, as shown at Figure 3, and the fore hearth B, which is open then at the
top, has exactly the shape of a ladle; it is run under the shaft A, and made tight
against the bottom by fire-clay.
N
"
As already mentioned, it is desirable for the process to have a high furnace, with
the smelting space high up; but being confined in the height of the furnace a
furnace in tiers or stories may with advantage be applied in such manner that the
lower shaft A' forms the fore hearth of the upper shaft, as shown at Figure 4. The
iron on leaving the upper shaft A may then run with the ore into the lower shaft A¹²,
in which case the travel of the fluid masses is elongated; or one can also separate
the iron from the slag at this moment by an overflow, as shown at e, Figure 4.
The metal then gets into the second or lower shaft A¹ (which in this case receives
fresh ore together with the coke) in the form of a fluid pig iron, which is freed of
the greatest part of its phosphorus and impurities, and which is cleansed again by
going down with fresh ore. In this case one may give much fresh ore to the lower
shaft A', and use the slag of the lower shaft, in which the finer or (higher) cleansing
takes place, as ore or like ore for the upper shaft A. f, f, are the tuyere openings.
The lower shaft A' of the furnace in stories will consume very little fuel, as it
receives the iron in a fluid state. For this same reason it may be considerably
narrower than the upper shaft, or the lower shaft may be made to serve at the same
time for several upper shafts.
By this last-described double cleansing process a very phosphorus iron can be
.

page_text: The additions of limestone with this process reduce the consumption of ore con-
siderably, as the silicic acid of the coke will then combine with lime and not with
It is then in some cases desirable to work with pretty much ore, and to use
again a part of the slag instead of ore.
ore.
The described cleansing process can also be carried out at the blast furnace by
tapping the iron from the blast furnace, and running it directly through a "high,"
with ore and coke, or with ore briquettes, filled cupola, or "cupola in stories," or
tapping the iron from the blast furnace into a ladle, transporting this ladle over a
cupola, and running the iron through a small opening into the cupola; the cupola
will hereby consume very little ore.
"
The above-described process is not only suitable for further working the fluid
material in the " Martin" furnace, or in the combined " reverberatory and Bessemer
furnace, and so forth, but it is also especially suitable for the puddling process with
which then again phosphorus is extracted. The cleansed iron can be taken from the
cupola as required, and be brought in fluid state to the puddling furnace, the hearth
of which will not be attacked in the same manner as is usually the case with a fluid
iron run into it, as the iron is almost free from manganese and silicon.
Having thus described and ascertained the nature of the said Invention, and in
what manner the same is to be performed, I declare that I claim as the improve-
ments in the manufacture of iron and steel, and in furnaces and appliances
therefor,―
First. Purifying iron from phosphorus, manganese, silicon, and sulphur by
reducing it with basal oxides of iron, with or without the addition of oxides of
manganese and limestone, all substantially in the manner described.
Second. Purifying iron from phosphorus, manganese, silicon, and sulphur by.
passing it as tapped from the blast furnace through a furnace charged with coke
and basal oxide of iron, or coke briquettes, with or without oxides of manganese
and limestone, all substantially in the manner set forth.
Third. The application of furnaces constructed or adapted substantially as described
to the purification of iron.
Fourth. The construction of portable fire-hearths, substantially as and for the
purpose set forth.
Fifth. The application of ore briquettes in the process herein-before described,
instead of cokes and ore.
Sixth. The repeated application of the purifying ores in the process described.
In witness whereof, I, the said Alfred Longsdon, have hereunto set my hand
and seal, this Twenty-ninth day of January, in the year of our Lord One
thousand eight hundred and seventy-nine.
ALFRED LONGSTON