IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND CAST IRON
Year: 1884

page_text: I, HENRY EDWARD NEWTON of the Office for Patents Bream's Buildings,
Chancery Lane in the County of Middlesex, Civil Engineer do hereby declare
the nature of the invention for IMPROVEMENTS IN THE MANUFACTURE OF STEEL
AND CAST IRON to be as follows:-
The object of this invention is to produce cast steel and cast iron of the first
quality in a more expeditious and economical manner than heretofore, from metal
of any chemical composition.
In carrying out this invention the pig metal to be operated upon is placed in a
cupola or reducing furnace which has a basic or neutral lining, or is formed of fire
clay which may be cooled externally in any convenient manner.
The cupola or furnace may be of any type, the only condition being that it shall
permit of obtaining and preserving during the operation a basic slag dross or scoria
and it shall be heated sufficiently to maintain the fusion of the metal as well as the
slag scoria formed.
In order to remove the silicon and sulphur a certain quantity of lime, limestone
flux, dolomite, oxyde of iron or of manganese or of any other material suitable to
render the slag, dross or scoria fluid and basic, is introduced into the cupola. The
quantity of either of these materials employed will be such that the silica forms
with the other elements a slag or dross containing not more than 25 to 30 per cent
of silica.
If desired and to facilitate the departure of the sulphur spiegel or other suitable
material in certain proportion so as to obtain a mixture giving from 1 to 3 per cent
of manganese in the metal may be introduced into the cupola.
The metal thus deprived of its silicon and sulphur is then introduced into
a reverberatory or other blast furnace having a basic or neutral lining.
The refining operation then takes place which consists in the addition to the
metallic bath of oxydes or ores of iron or manganese or other oxydising materials
made conjointly with limestone flux, lime dolomite, magnesia or any other basic
Pin &

page_text: material in such a manner as to form a slag, dross or scoria as basic as possible, at
the same time preserving the fluidity necessary for the progress of the operation.
The proportion of silica in the scoria should never exceed 30 per cent.
The quantity of iron ore or oxydising material introduced into the furnace
should be calculated so as to furnish the oxygen necessary to eliminate the carbon
phosphorus-manganese and other impurities.
When iron ore is employed as reagent the greater part of the iron will be
reduced and will pass into the steel produced thanks to the formation of a basic
slag, dross or scoria, a result never obtained when the scoria formed is silicious.
From the fact that the silica has been removed, the oxyde of iron or other
oxydising material reacts immediately and energetically on the carbon, phosphorus
and other impurities.
When the metal is sufficiently refined the termination of the manufacture will
be effected in the usual way by the addition of spiegel or other suitable material,
in quantities sufficient to produce the quality of steel or cast iron it is desired
to make.
In some cases the recarburising of the metallic bath may be dispensed with
and the decarburised metal may be employed in any manner that may be
judged useful, as for example, it may be treated in crucibles before or after
cementation.

page_text: COMIDELE
I HENRY EDWARD NEWTON of the Office for Patents, 6 Breams Buildings,
Chancery Lane in the County of Middlesex, Civil Engineer do hereby declare
the nature of the invention for IMPROVEMENTS IN THE MANUFACTURE OF STEEL
AND CAST IRON and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
The divers methods of manufacturing steel adopted up to the present time have
all necessitated, to obtain a steel of good quality, the use of pig iron of a chemical
composition varying only in impurity within certain limits.
It is known in effect that the ordinary common pig iron produced in the
Cleveland district, in Luxemburg and in Lorraine (to cite the most notable examples)
are not employed in the production of steel but that in these countries they manu-
facture for the production of steel a phosphoric pig iron of special composition and
generally of a higher price than that of the ordinary common casting metal.
The process constituting the subject of this invention permits of the employment
of ordinary common pig iron for the economic production of cast steel of superior
quality (extra mild, mild, semi-hard and hard) and endowed with special properties.
To attain this end the inventor proceeds as follows First Operation. The pig
iron either in a solid or fluid state is charged into a cupola furnished with one or
more stages of tuyeres and lined inside with some basic or neutral refractory
material (magnesia dolmite, lime, bauxite) or refractory clay and cooled outside
by a water jacket or by a current of water or by other means.
The cupola may vary in construction so long as a basic scoria is secured and
retained during the purifying operation.
The cupola whether charged with solid or fluid metal should be sufficiently hot
to maintain in fusion the metal as well as the scoria formed in the vessel.
The air admitted into the cupola should be heated to a high temperature say by
preference from 400 to 500 degrees Centigrade.
The end in view in treating the ordinary common pig iron in the cupola is
to remove the silicon and the sulphur which it may contain.
This result is secured by the formation of a basic scoria or slag and by the
oxydation of the silicon either by the air of the tuyeres or by the action of oxide
of iron or an ore of iron introduced into the cupola together with limestone flux,
lime or dolomite.
To these substances can be added to the same end together or separately the
following bodies, manganese ore, fluor spar, chrysolite, chloride of magnesium,
chloride of calcium or alkaline chlorides or carbonates.
The proportion of lime or magnesia or other basic material charged into the
cupola should be calculated to form with the other elements of the bed of fusion,
silica, alumina etc., a basic slag or scorice containing not more than 25 to 30 per
cent of silica.
The percentage of oxide of iron will vary according to the proportion of silicon
contained in the pig iron and according to whether the cupola possesses one or more
stages of tuveres.

page_text: To obtain a good working of the cupola it is desirable that the slag or scoria
should be very calcareous by preference of a light colour and containing little or no
oxide of iron.
The percentages of sulphur and of silicon contained in the pig iron may vary
greatly but the elimination of these matters will be effected in the cupola during
this first operation and by the means and under the conditions to be described.
Thus as the result of the treatment in the cupola above indicated there will be
formed from ordinary common pig iron an intermediary product deprived of silicon
and of sulphur and containing carbon and phosphorous in quantity more or less
great, according to the amount of the crude metal employed which intermediary
product is in a state eminently favourable for economic conversion into cast steel or
iron of superior quality.
This intermediary product may be considered as suitable for the second stage or
completion of the process if after treatment in the cupola the metal (which contains
more or less phosphorous, according to the amount of phosphorous in the original
metal), does not contain (by preference) more than about two tenths (2) ths) per
cent of silicon and fifteen (15) hundredths per cent of sulphur. But it is obvious
that the means indicated for operating in the cupola permit of the facile reduction
below these limits of the percentage of silicon and of sulphur in this intermediary
product, to any proportions that will be judged necessary, to obtain the quality of
steel that it is desired to produce.
Second operation. The metal issuing from the cupola in the particular state just
defined is introduced in either a solid or fluid state into an open hearth furnace
whether constructed on the system of Martin Siemens or Pernot for example the
hearth and walls being of a basic or neutral refractory material and the furnace
being heated during the operation to the temperature necessary for the production
of cast steel or iron.
The refining of this intermediary product is effected by the addition in the basic
or neutral furnace of oxide of iron (iron ore) and of limestone flux or lime or
of dolomite or magnesia or of manganese ore or other basic material so as to form
during the duration of the operation a slag or scorice as basic as possible while
preserving to it the fluidity necessary to a proper carrying out of the operation and
permitting the oxide of iron introduced to react energetically on the impurities of
the metal. The proportion of silica in the slag ought not to be above 30 per cent.
The oxide of iron, limestone flux or dolomite may be introduced to the furnace
before or after the admission of the intermediary product from the cupola. It will
facilitate the operation to apply at first. the whole of the ore and of the basic
materials necessary to the refining, the proportions varying according to the
impurities contained in the metal introduced into the furnace.
But in some cases it may be useful to add during the course of the operation to
the basic Martin furnace either the iron ore or the limestone flux, dolomite or other
basic material
As a result of the state to which the metal is brought by the treatment in the
cupola, the refining, by reason of the absence of silicon, is effected rapidly and
economically in the basic or neutral Martin furnace by means of iron ore in
presence of a slag strongly basic. This rapidity of action will not take place if
the metal treated contains silicon in certain proportion the refining action being
retarded (all other things being equal) in proportion to the percentage of silicon
present in the metal.
The refining may be said. to be complete when whatever may be the quantity of
carbon or phosphorous or other body capable of elimination by oxydation, contained
in the metal, only traces of the impurities will be found in the refined and
decarburised metal.
}
When the iron has been decarburised, dephosphorised and refined according to
the requirement of the manufacturer any chemical composition may be given to it
that is to say it may be made to contain certain proportions of carbon.inanganeso
silicon or chrome by adding thereto spiegeleisen, ferro manganese or ferro silicon or

page_text: ferro chrome or pig iron deprived of manganese The application of my process
permits the employment of iron or steel scrap but this employment is not
necessary..
In making hard steel it has been found advantageous to add the recarburetting
metal in a fluid stato avoiding the mixture of this metal with the slag which covers
the bath.
When the slag or scorice which covers the metallic bath contains a high
proportion of phosphorous it is possible after having removed the greater part
of this slag or scorice to introduce into the open hearth furnace in a Quid state, the
basic slag resulting from the cupola, this second slag will contain but a relatively
small proportion of phosphorous.
Instead of running the molten metal when the first operation is completed direct
from the cupola into the Martin or other open hearth furnace it may by preference
and to ensure the continuity of the operations, be run into an auxiliary furnace
having a basic or neutral hearth and lining and of a capacity sufficient to receive
the quantity of metal that it is proposed to treat in the second operation in the
openhearth furnace and a certain quantity of basic slag issuing or not from the
cupola.
This auxiliary furnace will be heated so as to maintain in fusion the metal and
the slag introduced. The hearth of the furnace may be fixed or movable.
The hearth and lining of this furnace having been constructed with basic or
neutral refractory materials, limestone flux, dolomite or other material may be
introduced thereinto.
The auxiliary furnaco can then be utilised not only as a recipient of the
intermediary product but it may be used to facilitate experiments for testing
whether the intermediary product issuing from the cupola as been brought to the
desired state.
If by chance the metal issuing from the cupola has not arrived at the desired
stato the first operation on the metal might be perfected by the introduction of
iron ore or of manganese or of limestone flux into the auxiliary furnace.
It is possible even in this auxiliary furnace to commence the refining of the
metal which will have the effect further of rendering more rapid the operation in
the basic Martin or other openhearth furnace.
The slag contained in the auxiliary furnace can be at will introduced or not into
the basic Martin furnace at the same time as the metal prepared for the second
operation.
This auxiliary furnace may also serve to weigh the metal destined to be
converted into cast steel or iron. In such case the hearth of the furnace will be
inade movable and the indication of the weight will be given by the ordinary
arrangement employed in testing machines.
It will be advantageous that the hearth of the auxiliary furnace should be at a
lower level than that of the cupola and above the level of that of the Martin or
other furnace in order that the metal may be readily run from one to the other
without the necessity for using a ladle.
The new process of manufacturing cast steel or iron having been described it may
be well to refer to the characteristic point of the discovery This characteristic
point consists in taking ordinary common pig iron containing divers impurities and
notably sulphur silicon phosphorous and eliminating first by the aid of the cupola
as above described the sulphur and the silicon and to form an intermediary product
deprived of sulphur and silicon, containing carbon and phosphorous in quantity
more or less great according to the composition of the original metal and which is
eminently favourable to the economical production of steel by the reaction in
presence of a slag strongly basic of iron ore introduced into the basic or neutral
openhearth furnace and not otherwise.
The formation of this intermediary product is a characteristic of this process for
it is this produc which permits of the manufacture upon a basic hearth of steel of

page_text: various qualities and even of superior quality and to manufacture the same
economically.
This result is due to
1st The silicon, being absent in the furnace, (Martin or other) a greater rapidity
. of reaction is effected and a diminution in the quantity of slag which covers the
bath and absorbs a certain quantity of heat is obtained. Thus it is possible to
utilise in the most complete manner for the fusion of the metal the heat furnished
by the flames of the furnace and that disengaged by the oxydation of the
extraneous bodies contained in the metal and notably that of the phosphorous
which is eliminated in the second part of the operation and thereby to obtain in
the openhearth furnace easily and economically a metal which at the end of the
refining will be of a perfect fluidity although completely decarburized.
2nd The elimination of the sulphur before the treatment in the openhearth
furnace (where this latter elimination could not be produced) having taken place
there will be obtained easily after refining in the basic or neutral open hearth
furnace as has been stated, a inetal very fluid although completely decarburised and
containing if it be desired only traces of silicon, sulphur phosphorous &c.
It is possible then thus at will to give to this metal contained in the openhearth
furnace the chemical composition that is desired in carbon silicon manganese
chrome etc. by the suitable addition as stated above and to obtain a metal of
superior quality and endowed with special properties.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed as communicated to
me by my Foreign Correspondent I declare that what I claim is
1st The process as described above for economically manufacturing cast steel or
iron and consisting first in eliminating from any ordinary pig metal by an operation
in a cupola in the manner described above, the sulphur and the silicon contained in
the crude metal, whereby an intermediate product containing the greatest part of
the carbon and the phosphorous of the original metal is obtained, a product
eminently favourable for the direct and economical transformation into steel of a
superior quality, and secondly in eliminating from the intermediate product by a
second operation in a Martin, Pernot or analogous openhearth furnace having a
basic or neutral lining the extraneous bodies such as carbon and phosphorous by
the action of iron ore in presence of a strongly basic slag or scoria.
2nd The use in combination for carring out this two stage process, of a cupola
and an open hearth furnace working under the conditions described and with or
without the employment of an auxiliary furnace.