Improvements in, and in Means or Apparatus for use in, the Manufacture of Iron and Steel.
Year: 1898

page_text: Date of Application, 23rd Apr., 1898
Complete Specification Left, 23rd Jan., 1899-Accepted, 18th Mar.,
1899
Improvements in, and in Means or Apparatus for use in, the
Manufacture of Iron and Steel.
I, WILLIAM JAMES FOSTER, of New Buildings, Railway Street, Darlaston, in
the County of Stafford, Blast Furnace Manager, do hereby declare the nature
of this invention to be as follows:
-
This invention has for its object an improved method of, and improved means
or apparatus for use in, the manufacture of iron and steel.
In the improved method of manufacture, according to this invention, molten
cast iron, such as from a cupola or blast furnace, is treated within a suitable
vessel, which I term a purifier, with oxide of iron in any convenient form, such
as in the form of scale or ore, or with other oxidizing material, such as manganese
dioxide, and the molten metal is kept in a state of agitation, preferably by
agitating the vessel within which it is contained such as by rocking it to-and-fro
on trunnions, until the phosphorus, silicon and sulphur, have been entirely, or
almost entirely, removed from the metal by oxidation with the oxidizing material
used. Oxidizing material may be added from time to time, as may be required.
The elimination of the impurities above mentioned may be effected entirely by
the use of the oxidizing material without the use of air or of an oxidizing gas.
For some purposes, the conversion of the metal may be completed in the purifier,
the removal of the carbon being effected by an excess of the oxide. For superior
qualities of steel, however, the metal may be removed from the purifier to a
secondary furnace where the conversion may be completed according to any
ordinary or convenient method.
The oxidizing material, aforesaid, which is placed within the purifier previously
to the molten metal being introduced thereinto, is fused before its mixture with
the molten metal, and this may be conveniently accomplished by the combustion
in the lower portion of the purifier of air and gas brought down thereinto, The
air may be brought through an inclined passage-way formed through one of the
trunnions of the vessel and the gas through a corresponding passage-way formed
through the other trunnion, or the air and gas may be brought through separate
passage ways formed through one of the trunnions, or through each trunnion. The
Hame should, of course, not be a reducing one, but should, preferably be somewhat
oxidizing.
The apparatus employed, according to this invention, for carrying out the
above process, consists of a basic-lined vessel which is provided with trunnions
which are mounted in suitable bearings, and is suitably geared or connected
with a source of power in a manner which enables it to be continuously oscillated
or rocked to-and-fro. A convenient method of causing the desired movement, is
to fix upon one or each of the trunnions a spur wheel, and to gear with such
wheel on opposite sides thereof toothed racks, which are reciprocated by means of
pistons within hydraulic cylinders. These racks may be kept in gear with the

page_text: wheel by means of rollers mounted in fixed bearings. The oscillating or rocking
movements of the purifier of course keep the molten metal therein in a constant
state of agitation, and to facilitate the flow of the metal, the purifier is, preferably,
or conveniently, made of a circular shape in transverse section, except for the
portion thereof which forms the neck and mouth. The purifier has very much
the appearance, in transverse section, of a Florence flask with the main portion of
the neck cut off. For the purpose of breaking up and causing the mixture of
slag with the molten metal, as the purifier is oscillated, in order that any portion
of the slag not neutralized may take up further impurity, beating bars, formed
of refractory material of a basic character, pass across the interior of the purifier
on opposite sides of the trunnion axis thereof and near to the lining of the vessel.
These beating bars are passed through openings in the casing of the vessel at
one end, and into the lining of the vessel at the opposite end, and are thus securely
held in place. In lieu of the beating bars, shoulders may be formed to project
from the sides of the lining. Inlets, which slant downwards, are formed through
the trunnions, or through one of the trunnions, for the passage of the air and
gas which is used for fusing the oxidizing material which is placed within the
purifier before the molten metal is run thereinto. Before the molten metal is
run into the purifier, these openings are, of course, stopped; and this is effected
by suitable stoppers, of which the inner ends, or portions which are exposed to
the molten metal as it is agitated, are composed of suitable refractory basic
material.
The trunnion bearings are kept cool by water, which is allowed to stream
continuously thereupon.
Dated this 22nd day of Annil 1900
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.
Improvements in, and in Means or Apparatus for use in, the
Manufacture of Iron and Steel.
WILLIAM JAMES FOSTER, Blast Furnace Manager, of Wells Street. Kings Hill,
Wednesbury, in the County of Stafford, late of New Buildings, Railway Street,
Darlaston, in the County of Stafford, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention has for its object an improved method of and improved means
or apparatus for use in the manufacture of iron and steel. In the improved
method of manufacture according to this invention molten cast iron from a
cupola or blast furnace is treated for the elimination of its impurities with oxides
of iron, or an oxide of iron and oxides of manganese, within a vessel from which
air or an oxidising gas such as blast is excluded, the said molten iron being kept
in a state of agitation during its treatment by the rocking to and fro of the vessel
containing it. This vessel will be hereinafter termed a converter and its construc-
tion is preferably that of the one hereinafter described as according to this inven-
tion, although it is not necessarily so so long as it is capable of excluding atmo-
spheric air or other oxidising gases, as the impurities of the metal treated are
eliminated entirely by the aid of the oxides of iron or oxides of iron and oxides
of manganese. The objects of the said invention are firstly, to materially increase
the bulk of the product at less cost than is possible under the existing method of

page_text: treatment, and prevent the loss of metallic iron which is the case under the old
system of eliminating the impurities; secondly, to cause the silicon, phosphorus
and manganese to be useful instead of detrimental during the manufacture, and
also easy of elimination; thirdly, to retain in the resultant metal, which has the
properties of an ingot iron or crude steel, a considerable amount of carbon which
by the method of treatment now adopted is almost the first to be burnt out in
getting rid of the impurities; and, fourthly, to construct a simple apparatus or
converter in which the molten cast iron can be easily and effectively treated.
In carrying that part of the invention into effect which deals with the manu-
facture, a suitable amount of pure oxide of iron (Fe304), or other oxide of iron
free from silica, is fused within a suitable vessel having a basic lining such as
dolomite or bauxite and being capable of oscillation, blast being used for the
purpose. To this oxide of iron when fused is added the necessary quantity of
molten cast iron from a cupola or blast furnace, and all atmospheric oxygen is
then excluded from the vessel or converter which at this time is only open to
a small extent at its top for the exodus of the combustion products. The molten
metal and the fused oxide in the converter are thoroughly mixed by oscillating
the vessel, until such time as the phosphorus, silicon and sulphur contained in the
molten mass have been changed and eliminated by oxidation with the oxygen in
the fused oxide of iron, after which the properties of the metal are that of an
ingot iron or crude steel containing a small percentage of impurities and a fair
percentage of carbon. During this treatment the phosphorus, silicon and sulphur
act upon the fused oxide (which is rich in oxygen) as reducing agents.
The large percentage of carbon contained in the resultant metal is due, in the
first place, to the presence of the oxide of iron and, in the second place, to the
exclusion of atmospheric oxygen during the metals treatment, as the great affinity
of the silicon and phosphorus for the oxygen in the oxide, causes the said silicon
and phosphorus to become oxidised and neutralized to form salts of iron before the
carbon has been, for all practical purposes, attacked.
It is estimated that the impurities in the molten cast iron when placed in the
purifier is 7% viz:-
дап.
so that the amount of carbon, silicon, phosphorus, sulphur and manganese
removed during the process would be 5.815%. A small amount of lime may be
used to help to neutralize the silicious matter and also to eliminate a portion of
the sulphur.
It is estimated that the total amount of pure oxide of iron (Fe304) required
for the treatment of 10 tons of cast iron would be 3'486 tons, and that the amount
of metallic iron from the oxide alone that would go into the crude steel would be
25238 tons; therefore in treating ten tons of molten cast iron by the method
herein before set forth, the crude steel would be represented by 10-5815 (available
impurities) +25238 tons iron (from oxide) - 119 tons (crude steel). It will
thus be seen that as well as the crude steel containing 1% of carbon, its bulk is
largely increased by the metallic iron from the Fe304, and this at a cost con-
siderably less than if the whole of the crude steel had been produced from molten
cast iron.
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page_text: It will be thus understood that according to this invention the conversion of
the pig iron into ingot iron or crude steel is entirely accomplished by utilizing
the oxygen from the fused oxides of iron, or oxides of iron and oxides of man-
ganese, and that the amount of silica present during the said conversion is reduced
to a minimum by the use of a basic lining, such as dolomite, in the converter.
During the conversion or treatment, as aforesaid, the chemical changes which take
place in the molten metal in the converter are based upon the thermal chemical
capacity or combining powers of the elements present in the iron treated, as the
physical conditions momentarily produce chemical changes which would evolve
the most heat and at the same time decompose the fused oxides.
The following is approximately the calorific values of the changes expressed
by their formula, weight in grams: --
(a) 2 C₂ + Fе0), = 4 CO + Fes
265.8 = 29.4 x 4 = 116
Calorific value
The foregoing equations therefore tend to prove it is possible under the method
of treatment according to this invention to obtain a very good steel or ingot iron
by using a pig iron considerably low in carbon and silicon, but high in phosphorus
and manganese.
It is to be understood that the amount of oxide of iron used in the treatment
is gauged according to the requisite amount of carbon desired in the metal after
treatment, and that for all practical purposes the whole of the carbon can be
removed by an excess of the oxide, in which last named case the resultant metal
would be an ingot or soft iron.
The improved means or apparatus according to this invention will be best
understood by reference to the annexed sheet of drawings, in which Fig. 1 is a
vertical section taken through the apparatus in one direction, Fig. 2 a vertical
section through the vessel of the apparatus only, taken transversely to Fig. 1,
Fig. 3 a horizontal section of Fig. 1 on a reduced scale, and Fig. 4 a separate view
of one of the parts of the apparatus.
In the said drawings the vessel or container of the apparatus takes the form of

page_text: a basic-lined enclosure a somewhat resembling the shape of a cheese, i.e. circular
in one direction and rectangular in another, and it is provided with opposite
trunnions c, c, on its two flat sides, so that it may oscillate or rock from its centre.
This vessel is for the most part an enclosed one, as it is only open at its mouth a³,
but it has formed through its walls and through its trunnions, c, c, all-through
holes c, which are adapted to be closed when necessary by plugs or stoppers c³,
such as are shown in Fig. 4. These all-through holes in the trunnions are for the
purpose of admitting hot air and gases, or blast" to the inside of the vessel so
as to play down onto the metal, and they are adapted to be connected to a hot
air or gas supply, but to be capable of being closed and shut off from the blast by
the stoppers before mentioned. The said stoppers and holes care, preferably,
tapered as shown.
"
The trunnions c, c, are fixed to the flat sides of the metal casing a³ of the
vessel by the ordinary rivetted-on band c, and they are mounted within plummer
blocks, such as d, Fig. 1, carried upon a suitable framework .
The mechanism for rocking the vessel a embraces a toothed pinion e fixed on one
of the trunnions, and a pair of racks e,e2, which gear in with the said pinion and
which are reciprocated back and forth by some motive power. Rollers ³, e³,
bear against the backs of each of these racks to ensure the meshing of their teeth
with the pinion.
Within the interior of the vessel a are provided projecting parts, bars or
beaters 9 of refractory material, which are adapted to beat the molten metal
and displace it when the vessel is rocked in its bearings; so that the metal is
not only agitated by the rocking but its surface is constantly broken up and
changed.
The trunnions may have one or more holes such as 2 through them.
The construction of the body walls of the vessel forms no part of this invention,
but the basic lining should, when the apparatus is used for the process of manu-
facture hereinbefore described, be either dolomite or bauxite.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:
First. In the manufacture and production of soft iron and crude steel, treating
molten cast iron during its purification with fused oxides of iron, or with fused
oxides of iron and oxide of manganese, in a basic-lined (preferably dolomite)
vessel for the most part enclosed and from which atmospheric oxygen or blast
is entirely excluded, and utilizing the oxygen from the fused oxides only as the
oxidising agent during the conversion, and the impurities which are to be elimin-
ated as useful reducing agents to the said oxides, for the purposes substantially
as described .-
Second. Treating molten cast iron during its purification with fused Fe304 in
a basic-lined (preferably dolomite) vessel from which atmospheric oxygen or
blast is at the time excluded and to which is given an oscillating movement
so as to agitate the molten mass, so that the oxygen, from the oxides may be
used for oxidation and the impurities as reducing agents by the chemical changes
enumerated, substantially as described.
Third. An apparatus for treating molten metals, characterised by an enclosed
basic-lined rocking vessel to contain the material to be treated, and which has hollow
trunnions fixed to its sides communicating from the outside of the vessel to the
interior for the supply to the said interior of hot air or gases of any suitable form,
and which said hollow trunnions are capable of being closed by plugs or stoppers,
for the purpose substantially as described.
Fourth. The particular design and arrangement of the basic-lined vessel and
the means for oscillating or rocking it, substantially as described and set forth.
Fifth. The method described for treating molten cast iron for the elimination of its
impurities and its formation into soft iron or crude steel when used in conjunction

page_text: with the apparatus constructed and arranged substantially in the manner set
forth.
Dated this 19th day of January 1899.
W. P. THOMPSON & Co.,
11, Burlington, Chambers, New Street, Birmingham,
Also of Liverpool, London, and Manchester,
Patent Agents for the Applicant.