IMPROVEMENTS IN THE MANUFACTURE OF IRON
Year: 1879

page_text: LETTERS PATENT to Albert Cahen, of Boulevard Saint Denis, No. 1, Paris,
Civil Engineer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF IRON."
of Paris
A communication by Louis Jacques Martin and Nicolas Cordier,
Sealed the 30th September 1879, and dated the 2nd April 1879.
PROVISIONAL SPECIFICATION left by the said Albert Cahen at the Office
of the Commissioners of Patents on the 2nd April 1879.
ALBERT CAHEN, of Boulevard Saint Denis, No. 1, at Paris, Civil Engineer.
"IMPROVEMENTS IN THE MANUFACTURE OF IRON." .A communication by Louis
Jacques Martin and Nicolas Cordier, of Paris.
The object of this Invention is for producing economically an iron specially
grained and homogeneous, without passing through the puddling, taking as the raw
material any kind of casting, such as those which up to the present time were con-
sidered unfit for the manufacture of Bessemer metal.
In carrying out the Invention the casting (a specimen thereof having been
analysed to ascertain the quantity and nature of the metalloids to be eliminated) is
first purified, this purification being effected by means of a second fusion in any
description of cupola, in which is previously put about 50 kilogrammes of coke
immersed in a concentrated solution of chloride of sodium. If the analysis has
revealed nothing but the existence of sulphur, we add to a hundred kilogrammes of
casting about 200 grammes of lime slacked with a solution of chloride of sodium.
When, on the contrary, the analysis indicates the presence of arsenic we cause
hydrogen to be introduced, coming from a gasometer, which passes into the cupola
and forms with the arsenic hydrogen arsenic, which is volatilized.
In the case where the analysis indicates the presence of phosphorus there is added
to the lime sodium mentioned above from about one to five hundred grammes of
litharge with about 100 kilogrammes of casting, according to the proportions of
phosphorus to be carried off. On coming out of the cupola the casting thus purified
is collected and sent directly into a Bessemer converter, which is arranged entirely
according to the present system, the necessary air for its consumption being furnished
by any description of blowing machine which sends the air into a receiving regulator

page_text: and accumulator of pressure in which the air is compressed to from 2 to 3 atmo-
spheres or thereabouts.
About 30 to 35 cubic metres of air thus injected are caused to pass through a
thousand kilometres of purified casting put into the converter. The decarburation
takes place during an interval of from 8 to 10 minutes, and we thus obtain in
turning it into the mould an iron sufficiently pure and homogeneous to be drawn
into wire without passing through the puddling, but simply reheated and flattened
or hammered according to the use one wishes to make of it.
If, on the contrary, the metal that is desired to be obtained should be ultimately
intended for the construction of steel or moulded casting, instead of working.
according to the Bessemer process, that is to say, instead of adding to the "spiegel-
eisen "
or ferromanganate in the converter, there is previously projected into the
cupola an oxide of manganese chemically pure, and the decarburation is effected in
the converter as explained above, but only sending from 20 to 25 cubic metres of
atmospheric air under pressure.
Again, to avoid a too rapid decarburation, which would not leave sufficient time
for the refining, there is introduced some carbonic acid gas at the same pressure as
the air, and the arrival of the air is intercepted.
This carbonic acid gas is decomposed into 2 equivalents of oxygen and 1 equiva-
lent of carbon, which is fixed, and permits the refining in purifying the metal.
Nevertheless at all times whilst admitting the carbonic acid gas the atmospheric
air is at the same time allowed to arrive at pleasure, so as to ensure a fixed hold of
carbon in the metal.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Albert Cahen in the Great Seal Patent Office on the 2nd October
1879.
ALBERT CAHEN, of Boulevard Saint Denis, No. 1, Paris, Civil Engineer.
"IMPROVEMENTS IN THE MANUFACTURE OF IRON." A communication by Louis
Jacques Martin and Nicolas Cordier, of Paris.
The object of our Invention is to produce economically, without passing it through
the puddling, an iron specially grained and homogeneous, and suitable also for the
manufacture of steel, by taking as the raw material any description of casting such
as those which until now have been unfit for the manufacture of Bessemer metal.
After having analysed a sample of the casting for ascertaining the quantity and
nature of the metalloids to be expelled we purify it by means of a second fusion in
any kind of cupola in which we have previously put about 50 kilogrammes of coke
or charcoal inmersed in a concentrated solution of chloride of sodium, or in a hydro-
carbon, as the case may be.
If the analysis reveals nothing but the existence of sulphur we add to 100 kilo-
grammes of casting about 200 grammes of slack lime with a solution of chloride of
sodium.
When, on the contrary, the analysis indicates the presence of arsenic we introduce
hydrogen from a gasometer. This gas passes into this cupola and forms with the
arsenic arsenious hydrogen, which is volatilized.
If the analysis indicates the presence of phosphorus we add with the sodium
lime above named from about one hundred to five hundred grammes of litharge to
one hundred kilogrammes of casting, according to the proportions of phosphorus to
be carried off.
On leaving the cupola the casting thus purified and collected is sent directly into
a Bessemer converter arranged in the ordinary manner, the necessary air for its
feeding is furnished either by any kind of blowing machine combined with a regu-
lating reservoir and accumulator of pressure in which the air is compressed to two
or three atmospheres, or by preference with the apparatus represented on the
accompanying Drawing, and which is composed of reservoirs of air compressed to 30
or 40 atmospheres, with the addition of a detainer of pressure of any description.
which distributes the air under a suitable volume and pressure with perfect
regularity.
Into a thousand kilogrammes of purified casting introduced into the converter we
cause to pass from about 30 to 35 cubic metres of air blast.
The decarburation takes place in an interval of 8 to 10 minutes, and we thus
obtain in pouring it out into the ingot mould an iron sufficiently pure and homo-
genous for being wire drawn without passing it through the puddling, but being
simply reheated, rolled, or hammered, according to the use to which it is required.
If on the contrary the metal which we wish to obtain be ultimately used for the
manufacture of steel or moulded pieces instead of working by the Bessemer process,
that is to say, instead of adding some spiegeleisen or ferromanganese into the
converter we previously project into the cupola an oxide of manganese chemically
pure, and we effect the decarburation by the converter as above described, but only.
sending 20 to 25 cubic metres of atmospheric air under pressure.
Again, in order to avoid a too rapid decarburation which would not allow a
sufficient time for the refining, we introduce some carbonic acid gas at the same
pressure as the air, and we intercept the arrival of the air.
This carbonic acid gas is decomposed into two equivalents of oxygen and one
equivalent of carbon, which is fixed and permits the refining by purifying the metal:
Nevertheless through introducing the carbonic acid gas we can at the same time
allow the atmospheric air to arrive at pleasure so as to obtain a fixed current of
carbon on the metal.

page_text: The casting thus refined is in a high degree fit for the manufacture of steel of
every quality, whether one cements the granulated iron obtained, or mixes with the
liquid casting in the same converter, some Bessemer scrap iron with old rails of same
or any other metal proceeding from furnaces. The casting can moreover be trans-
formed directly into steel by the injection in suitable proportions of carbonic acid
or carbonic oxyde or azote. This casting forms excellent malleable iron for moulding
purposes.
This mixture of the Bessemer metal and of the refined casting, and also the
reduction of the metalloids of the casting can be made without the converter in
the apparatus of transformation represented in detail on the accompanying Drawing
(Fig. 4).
The apparatuses of which we have combined the general arrangements for the
application of the principles and procedures above mentioned are represented on the
Drawing annexed to the Specification.
Figure 1 is an elevation of the whole of these apparatuses.
Figure 2 a plan, and Fig. 3 a side view thereof.
Figure 4 is a longitudinal section of the apparatus designed for the mixture of
the molten metals or for the reduction of their metalloids.
As before described the raw material is placed in the cupola A with the matters
which we have specified above, according to the analysis previously made. On leaving
the cupola A the purified casting is poured into the Bessemer converter B; this
converter has been previously put in communication with the air feeding through
the pipe T which communicates with the reservoir R¹ of compressed air.
The pipe
may open out at E into a reheater of any description, permitting if it
is necessary the raising of the compressed air to such a temperature as may be
required for the good progress of the operation.
The reservoirs R¹ formed of cylinders communicating with each other are fed
with air compressed to 30 or 40 atmospheres by a force pump connected by the
pipe P with the reservoirs.
On leaving the reservoirs R¹ the compressed air traverses a detainer D placed on
the transmission pipe T. This detainer, of any suitable kind analogous, for example,
to that employed in the locomotives on the "Francq" system, brings back the air to
the pressure of 2 or 3 atmospheres necessary for overcoming the resistance of the
molten metal in the converter.
A pipe of transmission T¹ branching from the pipe T and furnished with a sluice
cock permits of conducting the air into a gasogene G containing some coke in
combustion. The pipe T¹ branches out into the air chamber c placed at the base of
the gasogene G, the heated or cold air traversing thus from the bottom to top (at
the pressure of 2 or 3 atmospheres regulated by the detainer). The incandescent
coke is decomposed and forms carbonic oxyde and carbonic acid which escape always
at the same pressure by the pipe T branching off from the upper part of the
gasogene G. These gases are conducted into the principal pipe T, and in consequence
into the converter. The pipe T is also furnished with a sluice cock 11 which
permits with the aid of the cock 1 of completely isolating the gasogene G from the
air conductor T.
At the upper part of the gasogene is fixed a receiver H designed to receive any
kind of hydrocarbon; a cock regulates the flow of the liquid, which, injected into the
flames, furnishes the hydrogen which may be necessary for the perfect reduction of
the metalloids.
It will be understood therefore that by the arrangement of the gasogene and the
three sluice cocks 7, 1, 11, there can be sent into the converter B either pure air
heated or cold, or carbonic acid, or of carbonic oxyde combined with hydrogen or
not, or simultaneously all these gases in regular proportion at will and at a like
pressure of 2 or 3 atmospheres.
The casting thus operated in the converter could be mixed with the scrap iron or t
old Bessemer rails in the same converter for forming different qualities of steel, and

page_text: to be cast in ingot moulds; or after fusion of the scrap iron the mixture could be
effected in the mixing apparatus or reducing apparatus M (Figs. 2 and 4).
This apparatus is composed of a cast iron cylinder c¹ lined or not internally with
refractory earth. This cylinder is inclined at an angle with the ground of about 20°
for.permitting the flow of the liquid casting at a suitable speed; this is poured into
the chambered funnel g fixed at the upper part of the cylinder c¹ and falls on to the
paddles or boards of an agitator a of cast or wrought iron. This agitator revolves
with a speed determined by experience, and is driven by a belt or gearing; it mixes
thus intimately the different metals poured into the funnel g, the mixture being
poured away through the canal K.
By the aid of this apparatus M we are also able to operate directly on the liquid
casting without the intervention of the converter, whether for its transformation
into iron chemically pure or for the immediate making of steel.
For this purpose we pour into the second compartment of the funnel g (Figure 4)
some nitrate of soda of which the flow is regulated in the proportion of 4% of the
weight of the casting; this regulation being effected either as shown in Figure 4 or
by any other suitable arrangement.
The nitrate of soda in consequence of the rotation of the agitator a is intimately
mixed with the casting, and is itself decomposed.
The oxygen disengaged in great quantity reduces the metalloids, and seizing the
carbon contained in the casting, there flows away at K iron perfectly pure in grain,
which reheated, welded, and shingled by the stamper is fit for every use.
One is able also by the pipe q to inject into the cylinder c¹ a steel making gas,
azote, or other for changing the metal immediately into steel.
For avoiding the cooling of the molten metals during the operation the cylinder c¹
is surrounded with passages for heat communicating with any kind of gasogeneous
furnace, or it may be provided with a fireplace direct with any combustible of
which the flames play round the cylinder and go into a chimney.
By the choice of the ingredients placed in the vessel j of the funnel 9, and in
quantities proportioned to the composition of the casting, castings of every quality
are able to be worked in this apparatus and the same results produced.
The product, iron, chemically pure or steely, is also able, by cementation or by
second fusion, to give steels of all qualities desirable for tools, cutlery, or mechanical
construction.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect,
I would observe in conclusion that what is claimed as the Invention is,―
The application and use of our combined system of procedures and apparatus for
changing the casting into an iron specially grained and homogeneous, and for its
conversion into steel without passing it through the puddling.
This system is characterised by the following principal points :-
1. Purification of the casting by its fusion in a cupola enclosing the ingredients
specified, and of which the nature and quantity are determined by the analysis of
the casting to be operated upon, substantially as hereinbefore described, and
illustrated by the accompanying Drawing.
2. Decarburation of the casting thus purified in a Bessemer or other converter
fed with air by an accumulator reservoir furnished with any suitable kind of
detainer or regulator of pressure, substantially as bereinbefore described and
illustrated by the Drawing.
3. Facility of suppressing the arrival of the compressed air, and of replacing it
by a current of carbonic acid gas at the same pressure, for avoiding a too rapid
decarburation and recarburating in case of need, completely refining and purifying
the metal, particularly when we desire to obtain a metal fit to be changed into
genuine fine steel. Nevertheless the carbonic acid and the air can be used
simultaneously, substantially as described and illustrated by the Drawing.
4. The combination and arrangement of a special gasogene for the production of
the carbonic acid, combined with hydrogen or not, necessary for the operation,

page_text: substantially as herein before described and illustrated by the accompanying
Drawing.
5. The optional use of a mixing apparatus or reducer of the casting either isolated
or combined with the preceding apparatus as claimed, and capable of utilizing the
nitrate of soda or any other ingredient for the direct reduction of the metalloids,
substantially as herein before described and illustrated by the accompanying
Drawing.
6. The general combination of the entire apparatuses employed for the realisation
of these procedures, substantially as hereinbefore described and illustrated by the
accompanying Drawing.
In witness whereof, I, the said Albert Cahen, have hereunto set my hand and
seal, this Twenty sixth day of September, in the year of our Lord One
thousand eight hundred and seventy nine.
Witness,
ANATOLE FOSTZ,
Draughtsman, of
Rue de Crimée, 190,
at Paris.
ALBERT CAHEN. (L.S.)