IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1879

page_text: LETTERS PATENT to George Edward Dering, of Lockleys, near Welwyn, in the
County of Herts, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF IRON AND STEEL."
Sealed the 27th December 1879, in pursuance of an Order of the Lord Chancellor,
Sealed the 27th December 1879, in pursuance of an Order of the Lord Chancellor,
and dated the 29th April 1879.
PROVISIONAL SPECIFICATION left by the said George Edward Dering at the
Office of the Commissioners of Patents on the 29th April 1879.
GEORGE EDWARD DERING, of Lockleys, near Welwyn, in the County of Herts.
"IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL."
The improvements consist in modified modes of conducting certain well known
processes of converting cast iron and obtaining malleable homogeneous metal, and
have mainly for their object to practically enable a superior product to be derived
from more or less impure raw materials.
In the manufacture of cast steel or ingot iron by the Bessemer process it has
been necessary to use only those kinds of cast-iron which contain but a small per-
centage of phosphorus, as when the Bessemer converter is lined with a silicious
lining the phosphorus is not eliminated, and its presence causes the product to be
brittle and worthless. To remedy this, and to enable cast steel or ingot iron to be
manufactured from cast-irons containing phosphorus, it has been proposed to line
the converter with a basic lining, and to add basic-slag-producing materials to the
metal during the converting operation.
By this means it is said that the phosphorus is removed and good steel produced.
The lining of the converter with a basic lining is however difficult and costly, and
such lining when worn cannot readily be repaired, as fresh material applied to the
old will not cohere.
Similar difficulties have been met with in the manufacture of cast steel or ingot
iron by the Siemens-Martin and other "open hearth" processes.
According to my Invention I first treat the cast-iron in a converter, or vessel, or
(stationary or revolving) furnace, lined in the ordinary manner with a siliceous
lining, which can readily be renewed and repaired, or in some cases lined with a
carbonaceous lining, this primary operation consisting either in removing the silicon
and a great part of the carbon from the iron by blowing into it streams of air, or
otherwise supplying oxygen to it, or in lessening the proportions of those elements

page_text: by the infusion of malleable or partially reduced metal, or in a combination of such
methods, and I then transfer the molten metal, from which the slag or cinder
present at the end of the first operation should be removed previously to the subse-
quent treatment, into another converter or vessel, such vessel being in some caseз
the ordinary discharging ladle, having their interior preferably brought to a high
temperature beforehand, or (stationary or revolving) furnace, or it may be into n
different part or compartiment of the same one (precautions being then generally
requisite to separate the two descriptions of lining by a zone of some neutral
material), lined with a basic lining of sufficiently refractory character, and therein
complete the purification of the metal by the removal of phosphorus from it, cither
by exposing it to the reaction of suitable metallic oxides or other de-phosphorizing
reagents, or mixtures of such materials, placed preferably in the secondary con-
verter, or vessel, or furnace before the molten metal is poured into it, and in some
cases mechanically held in position so as to prevent flotation, or it may be to the
mere reaction of the lining itself, or by the same means combined with the blowing
into the metal streams of air or other gases (cold or heated), mixing or agitating
during the operation by any available mechanical method being in either case had
recourse to if desirable.
The removal of the phosphorus from the iron may thus be effected with but little
destruction of the basic lining of the secondary converter, or vessel, or furnace, and
the expense and difficulties attending the use of such a description of lining when
exposed to the intense heat of the interior of a converter or steel-furnace, and to
the chemical action of their contents, throughout the whole period occupied in
converting cast iron by the pneumatic or open-hearth processes will be obviated.
Moreover the system of first oxidising the silicon and carbon contained in the crude
cast-iron, and then proceeding to treat the inetal by a secondary operation for the
removal of the phosphorus and other residual impurities, will enable comparatively
expensive materials, such as nitrate of soda, fluoride of calcium, and other energetic
reagents to be used for effecting their elimination, as but a small quantity (which
according to the law of chemical equivalents may be roughly estimated at less than
oue-fourth the amount that would be necessary if the burthen were also thrown
upon it of removing the silicon and carbon) will then be required to be used of
such material, and so a metal of superior purity, bearing consequently, as is well
understood, the subsequent addition of a proportionately large percentage of carbon,
and thus corresponding to high class crucible-steel, may be obtained as a converter
or open-hearth furnace product.
After the phosphorus has thus been removed from the metal, spiegel-eisen, ferro-
manganese, or their equivalent may be added as usual, the slag present being pre-
ferably first separated, which mixture may in soine cases be best effected by
returning the metal to the former converter, vessel, or furnace for the purpose, and
the fluid finished product is then finally run into ingot or other moulds according
to the ordinary practice.
Another modification of the Invention consists in substituting a carbonaceous
lining for the basic lining, as described, of the separate converter, or vessel, or
furnace, or the separate part or compartment of one, in which the secondary, that is
to say, the purifying operation by means of de-phosphorizing reagents, with or
without the combined use of injected streams of air or gases, and with or without
in either case the employment of mechanical methods of mixing or agitating, no
silica or siliceous slag, or but very little, being allowed to be present, is carried out.
The reagents used must generally, however, in this case, in order to avoid the lining
being acted on by them, be introduced into the midst of the molten metal, instead
of being placed in the carbonaceous-lined secondary vessel or furnace previously to
the metal being poured into it. A carbonaceous instead of a siliceous lining may
under these circumstances still be, as before stated, adopted in the converter, or
vessel, or furnace employed for conducting the primary, that is, the operation for
removing the silicon and most of the carbon from the metal under treatment, or
lessening their proportions by the infusion of malleable or partially reduced metal

page_text: and in fact one single carbonaceous-lined converter, or vessel, or furnace may be
used for both the primary (silicon and carbon oxidising) and secondary (de-phos-
phorizing) operations. I am aware that there is nothing new in the proposition to
employ carbonaceous-lined converters, or vessels, or furnaces for certain portions,
and perbaps for the whole, of processes for converting cast-iron and obtaining
malleable cast metal products, but the novelty consists in the combination and suc-
cessive order of operations as indicated. When carbonaceous-lined vessels are
employed in accordance with this Invention for the secondary (de-phosphorizing)
operation, as described, it may be necessary or advisable in some cases to supplement
the same by an oxidising operation conducted in a siliceous-lined converter, vessel,
or furnace, which might be a different part or compartment of the carbonaceous-
lined one, for the purpose of removing residual carbon previously to the addition
(if such addition is made) of the spiegel-eisen, ferro-manganese, or their equivalent.
My Invention also has reference to the Bessemer, open-hearth, or other cast-steel
or ingot-iron manufacturing processes when wholly conducted in basic-lined con-
verters, or vessels, or furnaces. Although by the use of such linings the presence
of acid slag is in a great measure prevented, yet a certain amount of silica will
necessarily be produced by the oxidation of the silicon contained in the cast-iron
under treatment, and the presence of even the comparatively small quantity of
silicic acid or siliceous slag thus generated will be unfavourable to the elimination
of phosphorus from the metal. In order to obviate this I run off or otherwise
separate the existing slag at the period of the process when it is judged (by well
known indications) that all the silicon has become oxidised, and previously to that
later stage at which the removal of the phosphorus may be expected to take place
under the influence of the oxidizing agencies at work and the basic or other chemical
reagents, if such are employed.
It is well known that some descriptions of cast iron, and amongst them some
Swedish and other varieties of exceptional purity as regards phosphorus and other
hurtful foreign substances, are deficient of silicon, and therefore unsuitable for
treatment by the Bessemer process, as the requisite temperature cannot be obtained.
In order to be enabled to deal satisfactorily with such irons, and obtain high-class
steel from them by the pneumatic process of conversion, I line the converter with
a basic or a carbonaceous lining, and work under excess of pressure by checking
the egress of the issuing gases from the converter by any suitable means, or
inject powdered fuel with the blast, or 1 make use of both these methods conjoined,
with or without the combined use of purifying reagents. And I similarly employ
excess of pressure in the converter, which may in that case have a siliceous, or
basic, or carbonaceous lining, or injection of powdered fuel with the blast, or both
methods conjoined, in order to obtain a sufficient elevation of temperature for the
successful " blowing " of metal that has been previously de-phosphorized by
any treatment which has likewise had the effect of depriving the iron of its
silicon.
In order to bind and hold together the basic materials used as a lining to a con-
verter, or vessel, or furnace in which cast steel or ingot iron is to be produced, I
mix with them iron turnings or borings or small scrap, which may be previously
more or less rusted upon the surface. These will serve to some extent to retain the
lining together, even if it contract or split when heated.
To produce a serviceable lining of calcareous, aluminous, or other materials
subject to great shrinkage, in the interior of a converter, or vessel, or furnace,
instead of plastering or ramming in the usual way I compress the material in a
pulverulent or plastic condition into place against the metallic casing of the same
by means of the hydraulic press or other sufficiently powerful mechanical appli-
ances for considerably reducing the bulk and increasing the density of the substance
used, thus to prevent contraction taking place to any serious extent afterwards,
the lining being then preferably fired to a high temperature before use.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Edward Dering the Great Seal Patent Office on the 29th
December 1879.
GEORGE EDWARD DERING, of Lockleys, near Welwyn, in the County of Herts.
"IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL."
The improvements consist chiefly in modified modes of conducting certain well
known processes of converting cast iron and obtaining malleable homogeneous metal
therefrom, and have for their main object to practically enable a superior product
to be derived from more or less impuro raw materials.
In the manufacture of cast steel or ingot iron by the ordinary Bessemer process,
it has been necessary to use only those kinds of cast iron which contain but a very
small percentage of phosphorus, for the reason that when the Bessemer convertor is
lined with a siliceous lining the phosphorus is not eliminated, and its presence (in
more than a very minute per-centage) causes the product to be brittle and worthless.
To remedy this and to enable cast steel or ingot iron to be manufactured from cast
irons containing phosphorus, it has been proposed to line the convertor with a basic
lining, and to add basic-slag-producing materials to the metal during the converting
operation. By this means it is said that the phosphorus is removed and good steel
produced. To line the convertor with a satisfactory basic lining is however a com-
paratively costly operation; and such lining, when worn, cannot be repaired in the
simple and expeditious manner that the siliceous linings are, as fresh material
applied to the old will not cohere.
Similar difficulties have been met with when attempting to manufacture cast steel
or ingot iron from phosphoretic cast irons or ores by the Siemens-Martin, Siemens,
and other " open hearth"
processes.
According to my Invention I first treat the cast-iron in a convertor or vessel, or
in a (stationary or revolving) furnace, lined in the ordinary manner with a siliceous
lining which can readily be renewed and repaired, this primary operation consisting
either (a) in removing the greater part of or practically all the silicon, and also the
greater part of or practically all the carbon from the iron by blowing into it streams
of air or other suitable gases, cold or heated (in accordance with the Bessemer
process or other pneumatic methods of conversion), or otherwise supplying oxygen
to it (for example, the well known "pig-and-ore" system of open-hearth steel
manufacture); or (b), in lessening the proportions of those elements down to as
low a percentage as may be deemed advisable by the infusion of malleable or
partially reduced metal (in accordance with the methods originally proposed and
experimentally realized by Reaumur and by Heath, and more recently brought to
practical success by Martin and Siemens), or, if thought advisable, in a combination
of such methods; and I then (the proper period for doing so being readily ascer-
tainable by well known indications) transfer the molten metal, from which the slag
or cinder present at the end of the first operation should be separated previously to
the subsequent treatment, into another convertor or vessel, such vessel being in
some cases the ordinary discharging ladle, having their interior preferably brought
to a high temperature beforehand, or "open-hearth or other (stationary or
revolving) furnace, or it may be into a different part or compartment of the same
one (precautions being then generally requisite to separate the two descriptions of
lining by a zone of some neutral material, such as carbon, preferably in the hard
condition of graphite or plumbago), lined with a basic lining of sufficiently refrac-
tory character, and therein complete the purification of the molten metal by the
removal of phosphorus from it, either by exposing it to the reaction of suitable
metallic oxides or other de-phosphorizing reagents or mixtures of such materials
placed preferably in the secondary convertor, or vessel, or furnace before the metal
is poured into it, and in some cases mechanically held in position so as to prevent
"

page_text: flotation, or it may be, to the mere reaction of the lining itself, or (what is perhaps
cheapest and best) by the same means, combined with the blowing into the metal
streams of air or other suitable gases (cold or heated), the basic oxides or other
reagents being, if thought advantageous, wholly or in part introduced by and with
the blast, mixing or agitating during the operation by any available mechanical
method being in either case had recourse to if desirable. The removal of the
phosphorus from the iron may thus be effected with but little wasting or wear-and-
tear of the basic lining of the secondary convertor, or vessel, or furnace, and the
difficulties and expense attending the use of such a description of lining when
exposed, as has hitherto been the case, to the intense heat of the interior of the
convertor or steel-furnace, and the destructive chemical action of their contents
throughout the whole period occupied in converting cast iron by the pneumatic or
open-hearth processes will be obviated. Moreover the system of first oxidizing tho
silicon and the carbon contained in the crude cast iron, and then proceeding to treat
the metal by a secondary operation for the removal of the phosphorus and other
residual impurities, will enable comparatively expensive materials, such as nitrate
of soda, fluoride of calcium, and other energetic reagents, to be commercially
employed for effecting their total or almost total elimination if desirable, as so much
a smaller quantity (which, according to the law of chemical equivalents, may be
roughly estimated at less than one-fourth the amount that would be necessary if
the burthen were also thrown upon it of removing the silicon and the carbon) will
under this mode of working be required to be used of such material, and so a metal
of superior purity, bearing consequently, as is well understood, the subsequent
addition of a proportionately larger per-centage of carbon, and thus corresponding
to high class crucible-steel, may under this Invention be obtained as a convertor or
open-hearth furnace product.
After the phosphorus has thus been removed from the metal, spiegel-eisen, ferro-
manganese, or their equivalent may be added as usual, the slag present being pre-
fembly first separated, which mixture may in some cases be best effected by
returning the metal from the latter to the former convertor, vessel, or furnace for
the purpose, and the fluid finished product is then finally run into ingot or other
moulds according to the ordinary practice.
If the phosphorus present in the metal under treatment does not suffice to keep
it fluid enough to admit of being satisfactorily transferred to and dealt with in
the second convertor, or vessel, or furnace, carbon may be added by any suitable
means, ns, for example, by blowing it in in a state of powder by and with the
Bessemer air-blast, or by adding some spiegel-eisen either before or after the
transfer.
Instead of a siliceous lining a carbonaceous lining may be employed in the
convertor, or vessel, or furnace in which the primary operation is conducted. Tho
comparatively small quantity of siliceous slag formed when a carbonaceous lining
is thus used instead of requiring to be separated from the metal previously to the
secondary operation may be neutralized by an equivalent small quantity of basic
material; and this mode of working has also the further advantage of the metal
being better able in consequence of more or less carbon remaining in it to undergo
the transfer without risk of losing its fluidity.
From the foregoing description it will be sufficiently understood by the practical
metallurgist that the duplex system of cast-steel or ingot-iron manufacture, con-
sisting in a primary and secondary refining or purifying operation, performed
respectively in differently lined convertors, or vessels, or furnaces, as indicated,
admits of being conducted, amongst others, in the four following simple ways,
namely:-
(A.) Primary operation performed in silicious-lined Bessemer convertor, followed
by secondary operation performed in basic-lined Bessemer convertor.
(B.) Primary operation performed in silicious-lined open-hearth furnace, followed
by secondary operation performed in basic-lined open-hearth furnace.

page_text: (C.) Primary operation performed in siliceous-lined Bessemer convertor, followed
by secondary operation performed in basic-lined open-hearth furnace.
(D.) Primary operation performed in siliceous-lined open-hearth furnace, followed
by secondary operation perforined in basic-lined Bessemer convertor.
I would add that (C) and (D), and especially (D), are the varieties of the process
which I consider the most advantageous, and recommend for adoption.
Another modification of the Invention consists in substituting a carbonaceous
(and therefore chemically neutral) lining for the basic lining, as described, of the
separate convertor, or vessel, or furnace, or the separate part or compartment of one,
in which the secondary, that is to say the purifying operation, by means of
de-phosphorizing reagents, with or without the combined use of injected streams of
air or other suitable gases, and with or without in either case the employment
of mechanical methods of mixing or agitating, no silica or siliceous slag, or but very
little, being allowed to be present, is carried out; the reagents used should however
in this case, if they are of such a nature that the lining would be chemically acted
on by them, be introduced into the midst of the molten metal instead of being
placed in the carbonaceous-lined secondary vessel or furnace previously to the metal
being poured into it. A carbonaceous instead of a siliceous lining may under these
circumstances still be, as before stated, adopted in the convertor, or vessel, or
furnace employed for conducting the primary, that is, the operation consisting in
oxidizing the bulk of the silicon and carbon in the metal under treatment, or
lessening their proportions by infusion of malleable or partially reduced metal, or
both such processes in conjunction; and in fact one single carbonaceous-lined
convertor, or vessel, or furnace may be used for both the primary (silicon or carbon
removing or lessening), and secondary (de-phosphorizing) operations. I am aware
that there is nothing new in the proposition to employ carbonaceous-lined con-
vertors, or vessels, or furnaces for certain portions, and perhaps for the whole, of
processes for converting cast iron and obtaining malleable homogeneous metal
products, but the novelty consists in the combination and successive order of
operations as indicated; that is to say, either (a) the separation by pouring off or
otherwise from the metal under treatment of the siliceous slag generated, followed
by the addition to the charge (preferably after its transfer if it is transferred to a
second convertor, or vessel, or furnace) of basic oxides or other reagents, by which
to effect the removal of the phosphorus; or (b), the neutralization by addition of
basic material of the siliceous slag generated, followed by or in combination with
the addition to the charge (preferably after its transfer if it is transferred to a
second convertor, or vessel, or furnace) of basic oxides or other reagents (which
may be an excess of the same material used to neutralize the siliceous slag) to effect
the removal of the phosphorus.
"
"
When carbonaceous-lined convertors or vessels or furnaces are employed in
accordance with this Invention for the secondary (de-phosphorizing) operation, or
for both the primary (silicon and carbon removing or lessening) and also the
secondary (de-phosphorizing) operation, as described, it may be necessary or
advisable to supplement the same by a "blowing" or other oxidizing operation
performed upon the metal, from which the phosphorus containing slag should first
be separated in a siliceous-lined convertor, vessel, or open-hearth or other
(stationary or revolving) furnace, which might be a different part or compartment
of the carbonaceous-lined one, for the purpose of removing residual carbon
previously to the addition (if such addition be made) of the spiegel-eisen, ferro-
imanganese, or their equivalent. The carbonaceous linings to be employed in the
various ways described should be of hard and dense character, sawn blocks of gas-
retort carbon, cemented together by a mortar made by admixing ground coke and
tar, being a suitable mode of formation.
To produce a serviceable lining of calcareous, aluminous, or other basic or neutral
materials, especially such as are subject to great shrinkage when heated in the
interior of a convertor, or vessel, or furnace, instead of plastering or ramming in

page_text: the usual way I compress the material, in a pulverulent or plastic condition, into
place against the metallic casing of the same by suitable compressing tools or
surfaces actuated by means of the hydraulic press or other sufficiently powerful
mechanical appliance for considerably reducing the bulk and increasing the density
of the substance used, the lining being then preferably fired to a high temperature
before use.
The method which I find it advantageous to adopt when carrying out this part
of the Invention as applied to a Bessemer convertor consists in having its head and
bottom readily removable; and when the convertor is to be lined, the head and
bottom having first been detached, a slightly tapering circular mandrel previously
lubricated or dusted with plumbago introduced within the cylindrical convertor-
casing (which should be very much stouter and stronger than usual), and the lining
material as tightly rammed as possible by hand between the exterior of the mandrel
and the interior of the casing, then temporarily attaching strong annular ends to
the casing in order to prevent the lining material from being squeezed out, and
finally causing the mandrel to be forced, the small end of course foremost, by the
action of a hydraulic or other press, or drawn by means of a steam windlass com-
pletely through the shell or casing, thus compressing the lining with great force
against the interior and leaving it in the compressed state in position there. The
head and bottom of the convertor may have their lining mechanically compressed
by direct vertical force exerted upon it by a compressing surface actuated by a
hydraulic or screw press. For mechanically compressing the linings of all
descriptions of reverberatory and open-hearth furnaces I propose to employ the same
direct method, whilst for the cylindrical casings of revolving furnaces the taper-
mandrel system, as described in relation to cylindrical Besseiner-convertor bodies,
will probably be best adapted.
Having thus described the nature of my Invention, and the best manner I am
acquainted with of putting the same into operation, I would have it understood
with reference to the first part of the Invention, when the mode selected for
performing the primary operation is by "blowing "the metal in a Bessemer con-
vertor, that I am aware it has been proposed by others (although so far as I know
no practical method of carrying this into effect has hitherto been disclosed) to
divide the Bessemer process, as it is now commonly termed, when dealing with
phosphoretic irons, into two successive operations conducted in separate convertors.
According to the propositions hitherto made the first convertor is lined with a
siliceous or with a carbonaceous lining and the second with a basic lining. During
the former operation the silicon or much of the silicon is to be removed, and during
the latter the phosphorus and also the carbon. In the case of such propositions as
I have above referred to the period at which the first operation is to stop and the
transfer of the inetal into the second convertor is to take place is left undefined,
but it is indicated that it takes place before what is technically called the "blow"
is completed in the first convertor, or, in other words, before there is a practical
removal of the carbon from the metal in the first operation. According to my
Invention however I do not stop the first operation at any such early stage, but I
continue it until the "blow" is complete; that is to say, I continue it when using
a siliceous-lined convertor until practically all the silicon and all the carbon are
removed, and when using a carbonaceous-lined convertor until practically all the
silicon and also a large proportion of carbon, as much carbou in fact as will go with
the silicon (the metal being in contact with a carbonaceous lining), are removed.
What I claim is,―
First. Treating molten cast iron by two successive operations substantially as
herein described, the first being carried on in a convertor lined in the ordinary manner
with a siliceous lining, so as to remove by blowing" practically all the silicon and
carbon, or carried on in a convertor lined with a carbonaceous lining, so as to remove
by "blowing" practically all the silicon and as much carbon as will go with it; the
second operation consisting in subsequently transferring such partially purified iron
(the siliceous slag previously formed being separated, or when a carbonaceous

page_text: lining is employed being either separated or neutralized by addition of basic
material before the secondary operation) into a second convertor or vessel, or into
another compartment of the same one lined with a basic lining, and therein com-
pleting the purification of the metal by the removal of phosphorus from it, either
by exposing it to the reaction of suitable metallic oxides or other dephosphorizing
reagents or by blowing streams of air or other suitable gases through the molten
metal, or by both means combined; the metal remaining in a Quid state during
the whole process, and when the process is completed being poured in this state
from the convertor or vessel.
"
Second. Treating molten cast iron by two successive operations, substantially as
herein described, the first being carried on in an "open-hearth" or other (stationary
or revolving) furnace lined in the ordinary manner with a siliceous lining so as to
remove by oxidation practically all the silicon and carbon, or so as to lessen by
infusion of malleable or partially reduced metal the proportion in which these
elements were combined with the iron; or carried on in an "open-lcarth
or other
(stationary or revolving) furnace lined with a carbonaceous lining so as to remove
by oxidation practically all the silicon and as much carbon as will go with it, or so
as to lessen tlie proportion in which the silicon and carbon were combined with the
iron by infusion of malleable or partially reduced metal; the second operation con-
sisting in subsequently transferring such partially purified iron (the siliceous slag
previously formed being separated, or, when a carbonaceous lining is employed, being
either separated or neutralized by addition of basic material before the secondary
operation) into a second "open-hearth" or other (stationary or revolving) furnace,
or into another compartment of the same one, lined with a basic lining, and therein
completing the purification of the metal by the removal of phosphorus from it either
by exposing it to the reaction of suitable metallic oxides or other dephosphorizing
reagents, or by blowing streams of air or other suitable gases through the molten
metal or by both means combined, the metal remaining in a fluid state during the
whole process, and when the process is completed being run in this state from the
furnace.
Third. Treating molten cast iron by two successive operations, substantially as
herein described, the first being carried on in a convertor or vessel lined in the
ordinary manner with a siliceous lining so as to remove by oxidation practically all
the silicon and carbon, or so as to lessen by infusion of malleable or partially
reduced metal the proportion in which these elements were combined with the iron;
or carried on in a convertor or vessel lined with a carbonaceous lining so as to
remove by oxidation practically all the silicon and as much carbon as will go with
it, or so as to lessen the proportion in which the silicon and carbon were combined
with the iron by infusion of malleable or partially reduced metal; the second
operation consisting in subsequently transferring such partially purified iron (the
siliceous slag previously formed being separated, or when a carbonaceous lining is
employed being either separated or neutralized by addition of basic material, before
the secondary operation) into an "open-hearth" or other (stationary or revolving)
furnace lined with a basic lining, and therein completing the purification of the
metal by the removal of phosphorus from it either by exposing it to the reaction
of suitable metallic oxides or other dephosphorizing reagents, or by blowing streams
of air or other suitable gases through the molten metal or by both means combined,
the metal remaining in a fluid state during the whole process, and when the process
is completed being run in this state from the furnace.
Fourth. Treating molten cast iron by two successive operations, substantially as
berein described, the first being carried on in an "open-hearth" or other (stationary
or revolving) furnace lined in the ordinary manner with a siliceous lining, so as to
remove by oxidation practically all the silicon and carbon, or so as to lessen by
infusion of malleable or partially reduced metal the proportion in which these
elements were combined with the iron; or carried in an "open-hearth" or other
(stationary or revolving) furnace lined with a carbonaceous lining so as to remove
by oxidation practically all the silicon and as much carbon as will go with it, or so

page_text: as to lessen the proportion in which the silicon and carbon were combined with the
iron by infusion of malleable or partially reduced metal; the second operation con-
sisting in subsequently transferring such partially purified iron (the siliceous slag
previously formed being separated, or, when a carbonaceous lining is employed,
being either separated or neutralized by addition of basic material before the
secondary operation) into a convertor or vessel lined with a basic lining, and therein
completing the purification of the metal by the removal of phosphorus from it,
either by exposing it to the reaction of suitable metallic oxides or other dephos-
phorizing reagents, or by blowing streams of air or other suitable gases through the
molten metal, or by both means combined, the metal remaining in a fluid state
during the whole process, and when the process is completed being poured in this
state from the convertor or vessel.
open-
Fifth. Treating molten cast iron by two successive operations, substantially as
herein described, the first being carried on in a convertor or vessel or in an
hearth or other (stationary or revolving) furnace, lined in the ordinary manner
with a siliceous lining so as to remove by oxidation practically all the silicon and
carbon from the iron, or so as to lessen by infusion of malleable or partially reduced
metal the proportion in which these elements were combined with the iron; or carried
ou in a convertor or vessel, or in an "open-hearth" or other (stationary or revolving)
furnace, lined with a carbonaceous lining so as to remove by oxidation practically
all the silicon and as much carbon as will go with it, or so as to lessen the propor-
tion in which the silicon and carbon were combined with the iron by infusion of
malleable or partially reduced metal; the second operation consisting in subse-
quently transferring such partially purified iron (the siliceous slag previously formed
being separated or neutralized by addition of basic material) into a second convertor
or vessel or open-hearth" or other (stationary or revolving) furnace, or into
another compartment of the same one, lined with a carbonaceous lining, and therein
completing the purification of the metal by the removal of phosphorus from it,
either by exposing it to the reaction of suitable metallic oxides or other de-phos-
phorizing reagents, or by the same means combined with blowing streams of air or
other suitable gases through the molten metal, the metal remaining in a fluid state
during the whole process, and when the process is completed being poured in this
state from the convertor or vessel or furnace.
"
Sixth. The combined operation carried on substantially as herein described by
treating molten cast iron in a convertor or vessel, or in an "open-hearth" or other
(stationary or revolving) furnace lined with a carbonaceous lining so as to remove
by oxidation the silicon and carbon, or so as to lessen by infusion of malleable or
partially reduced metal the proportion in which these elements were combined
with the iron, the siliceous slag formed being poured off or otherwise separated from
the iron, or being neutralized by addition of basic material, and afterwards com-
pleting the purification of the inetal by the removal of phosphorus from it, either
by exposing it to the reaction of suitable metallic oxides or other de-phosphorizing
reagents (which may be an excess of the same material used to neutralize the
siliceous slag), or by the same means combined with blowing streams of air or other
suitable gases through the molten metal, the metal remaining in a fluid state during
the whole process, and when the process is completed being poured in this state
from the convertor or vessel or furnace.
"
Seventh. Combining, substantially as herein described, the treating cast iron in
the ways forming the subject of the foregoing claims, No. 5 and No. 6 respectively,
with the operation wherein the resulting purified or partially purified metal
(separated from the phosphorus-containing alag) is subjected to subsequent treat-
ment in another convertor, or vessel, or 'open-hearth," or other (stationary or
revolving) furnace, or a different compartment of the one previously employed, lined
with a siliceous lining, so as to remove residual carbon from it by oxidation or lessen
the proportion of residual carbon by infusion of malleable or partially reduced
metal, the metal remaining in a fluid state during the whole process, and when the

page_text: process is completed, being poured in this state from the convertor or vessel or
furnace.
Eighth. Forming a basic or neutral lining around the interior of convertors or
vessels or furnaces, substantially as herein described, by compressing the lining
materials against the interior of the convertor, or vessel, or furnace, by means of
compressing tools or surfaces actuated by a hydraulic or other press, or other powerful
mechanical appliances.
In witness whereof, I, the said George Edward Dering, have hereunto set my
hand and seal, this Twenty-ninth day of December, in the year of our Lord
One thousand eight hundred and seventy nine.