IMPROVEMENTS IN THE MANUFACTURE OF SPONGY IRON AND IN APPARATUS EMPLOYED THEREFOR to be as follows:
Year: 1884

page_text: I, GUSTAV BISCHOr of Hart Street, Bloomsbury in the County of Middlesex,
Anylitical and Technical Chemist do hereby declare the nature of my invention
for "IMPROVEMENTS IN THE MANUFACTURE OF SPONGY IRON AND IN APPARATUS
EMPLOYED THEREFOR to be as follows:-
"
According to my present invention in preparing spongy metallic iron from one of
the ores or artificial products containing the iron in an oxydised state I employ as
reducing agent hydrogen obtained in the following way. Steam which is generated
in a suitable boiler or other vessel, and which preferably should be superheated, is
passed into and decomposed by strongly heated coke or other carbonaceous matter.
The products of the decomposition then taking place are essentially hydrogen,
carbonic oxide and carbonic anhydride.
Should these gases contain undecomposed steam, which may happen, according to
the manner of conducting the decomposition, the mixed gases are in the first
instance cooled, when the condensed water is separated. After this the mixed
gases are strongly heated by some such means as are commonly employed in
heating the air supplied to blast furnaces, or, if no undecomposed steam was
present, the cooling is dispensed with and the mixed gases are at once passed into
the apparatus used for raising their temperature as far as practicable.
The hot mixed gases are next passed into the lower portion of a retort or
chamber, which is erected in an inclined position and provided with internal
shelves so arranged that the ore or oxide of iron, which is fed into the upper part
of the retort or chamber, gradually passes towards its lower part, where it comes
in contact with the mixed gases and is reduced to the metallic spongy state by the
hydrogen contained in them. The spongy iron is thereupon discharged into a tube
or receptacle, in which it is cooled before being withdrawn or exposed to the air.
Such tube or receptacle is preferably surrounded by a jacket containing water.
This water, after being heated by the heat derived from the cooling of the hot
spongy iron inside the tube or receptacle, is used for raising steam and replaced by
cold water.
At a certain distance from the point at which the mixed hot gases enter the
retort or chamber, they will be found to be deprived, practically speaking, of the
hydrogen originally contained in them. The mixture however then still contains

page_text: combustible carbonic oxide, which does not reduce oxides of iron at the low
temperature I employ. In addition the mixture sometimes also contains small
quantities of hydrogen, which may have escaped being burnt by the oxygen of the
oxide of iron. Such carbonic oxide and hydrogen, being combustible, are then
burnt by admitting atmospheric air, preferably a hot blast, into the retort, the heat
thus generated being utilised for preliminary heating of the oxide of iron.
In this manner any external beating of the retort or chamber may be dispensed
with, but in certain cases, for instance, if the oxide of iron is supplied in a very wet
condition, such external heating may become necessary in addition to the heating
by the gases inside the retort or chamber.
The upper end of the retort or chamber is connected with a flue or chimney,
into the upper part of which the oxide to be reduced is introduced at a convenient
point by means of a pair of feed rollers or otherwise. The upper end of such flue
or chimney, above the point at which the oxide is introduced, should be connected
with a chamber for collecting any flue dust.
An essential and important feature of the spongy iron obtained as above, is, that
its chemical affinities are much stronger than those of ordinary spongy iron, such
as has been hitherto produced by heating a mixture of some oxide of iron with
carbonaceous matter. The latter reduction requires almost white heat, whilst
scarcely visible red heat suffices for the former. The chemical affinities are the
stronger, the lower the temperature at which the spongy iron has been prepared.
During the reduction by hydrogen a red heat, just visible in the dark, should
however be employed, as otherwise the affinities of the spongy iron may be so
strong that it catches fire even after cooling, when exposed to the air.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.

page_text: I, GUSTAV BISCHOF, of Hart Street, Bloomsbury in the County of Middlesex,
Analytical and Technical Chemist do hereby declare the nature of my invention
for IMPROVEMENTS IN THE MANUFACTURE OF SPONGY IRON AND IN APPARATUS
EMPLOYED THEREFOR" and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
According to my present invention, in preparing spongy metallic iron from one
of the ores or artificial products containing the iron in an oxidised state, I employ
as reducing agent hydrogen obtained in the following way. Steam, which is
generated in a suitable boiler or other vessel and which preferably should be
superheated, is passed into and decomposed by strongly heated coke or other
carbonaceous matter. The products of the decomposition then taking place are
essentially hydrogen, carbonic oxide and carbonic anhydride.
Should these gases contain undecomposed steam which may happen, according to
the manner of conducting the decomposition, the mixed gases are in the first
instance cooled when the condensed water is separated. After this the mixed gases
are strongly heated by some such means as are commonly employed in heating the
air supply to blast furnaces or if no undecomposed steam was present, the cooling is
dispensed with and the mixed gases are at once passed into the apparatus used for
raising their temperature as far as practicable.
The hot mixed gases are next passed into the lower portion of a retort or
chamber which is erected in an inclined position and provided with internal
shelves so arranged that the ore or oxide of iron, which is fed into the upper part
of the retort or chamber, gradually passes towards its lower part, where it comes
in contact with the mixed gases and is reduced to the metallic spongy state by the
hydrogen contained in them. The spongy iron is thereupon discharged into a tube
or receptacle, in which it is cooled before being withdrawn and exposed to the air.
Such tube or receptacle is preferably surrounded by a jacket containing water.
This water, after being heated by the heat derived from the cooling of the hot
spongy iron inside the tube or receptacle, is used for raising steam and replaced by
cold water.
At a certain distance from the point, at which the mixed hot gases enter the
retort or chamber depending upon the velocity imparted to them and the area of
oxide of iron with which they come in contact, they will be found to be deprived
practically speaking, of the hydrogen originally contained in then. The mixture
however then still contains combustible carbonic oxide, which does not reduce
oxides of iron at the low temperatures I employ. In addition the mixture
sometimes also contains small quantities of hydrogen, which may have escaped
being burnt by the oxygen of the oxide of iron. Such carbonic oxide and
hydrogen being combustible are then burnt by admitting atmospheric air, preferably
a hot blast, into the retort, the heat thus generated being utilised for preliminary
heating of the oxide of iron.
In this manner any external heating of the retort or chamber may be dispensed
with but in certain cases, for instance, if the oxide of iron has to be supplied in a

page_text: very wet condition such external heating may become necessary in addition to the
heating by the gases inside the retort or chamber.
The upper end of the retort or chamber is connected with a flue or chimney, into
the upper part of which the oxide to be reduced is introduced at a convenient
point by means of a pair of feed rollers or otherwise. The upper end of such flue
or chimney above the point at which the oxide is introduced should be connected
with a chamber for collecting any flue dust.
An essential and important feature of the spongy iron obtained as above is, that
its chemical affinities are much stronger than those of ordinary spongy iron, such as
been hitherto produced by heating a mixture of some oxide of iron with car-
bonaceous matter. The latter reduction requires almost white heat, whilst scarcely
visible red heat suffices for the former. The chemical affinities are the stronger
the lower the temperature at which the spongy iron has been prepared. During
the reduction by hydrogen a red heat just visible in the dark, should however be
employed, as otherwise the affinity of the spongy iron for oxygen may be so strong
that it catches fire, even after cooling, when exposed to the air. Another advantage
resulting from the preparation of spongy iron at such a low temperature is that
whilst for the reduction by carbon, certain very refractory iron ores are only
available any material containing oxide of iron in sutable proportion may be
employed when reducing by hydrogen.
Having now particularly described and ascertained the nature of my in-
vention and in what manner the same is to be performed I declare that what
I claim is
1, The improved manufacture of spongy iron by means of hydrogen gas wherein
the iron ore or other material containing iron in an oxidised state is subjected while
in a heated condition to the gases resulting from the decomposition of water or
steam by means of incandescent coke or other carbonaceous material, the residual
combustible constituents of such gases, after the removal of the hydrogen, being
usefully employed in heating the ore or other oxide of iron previous to its being
subjected to, the action of the hydrogen gas, substantially as herein described.
2, The use for producing spongy iron by means of hydrogen gas, of apparatus
consisting of a chamber through which the ore or other oxide of iron to be acted
upon is made to descend gradually while gases resulting from the decomposition of
steam by incandescent coke are introduced at the lower part of the chamber and
after giving off their hydrogen to the ore or other oxide of iron are brought in
contact in the upper part of the chamber with an air supply in order by their
combustion to heat the ore or other oxide in such upper part of the chamber
substantially as herein described.
3, In combination with apparatus for the production of spongy iron referred to
in the preceding claim, the use of a water jacketted receptacle at the bottom of
the converting chamber into which the spongy iron passes the heated water in the
jacket resulting from the absorption of the heat from the iron, being employed for
producing the steam required for generating the hydrogen gas, substantially as
herein described.