IMPROVEMENTS IN THE MANUFACTURE OF STEEL
Year: 1877

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of " IMPROVEMENTS IN
THE MANUFACTURE OF STEEL." A communication from abroad by Léon
Krafft and Hippolyte Julion Sauve, both of Paris, France.
Scaled the 16th November 1877, and dated the 22nd June 1877.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 22nd June 1877.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN THE MANUFACTURE OF STEEL." [A communi-
cation from abroad by Léon Krafft and Hippolyte Julien Sauve, both of Paris,
France.]
This Invention relates to the conversion without fusion into fine steel of pig or
cast iron, wrought iron, Bessemer, Martin, and other so-called steels, resulting from
the refining or decarburization of pig iron.
The processes hitherto employed for converting pig iron into steel, such as the
Bessemer process or the Réaumur reaction process, improved by Siemens, Martin,
and others, produce only compositions intermediate between pig iron, wrought iron,
and steel. These products, notwithstanding their undoubted utility and very low
cost, are not suited for the purposes for which fine steel or cementation steel are
used.
The object of this Invention is to remedy this defect by imparting to these metals
all the qualities necessary, and this is effected by maintaining them at a cherry-red
heat for some hours in a medium of carbon, over which is passed slowly a current
of nitrogen, carbonic oxide, and various hydrocarbons.
In carrying the Invention into effect wood, wood charcoal, peat, coke, or other
vegetable matter, well dried and heated to about 50° Cent. is immersed in a hydro-
carbon, such as dead schist oil, which is heated to the same temperature, and of
which 12 to 15 per cent. is absorbed.
Bars of Besseiner, Martin, or other metal produced by the decarburization of cast
iron, as above mentioned, are placed in alternate layers with the vegetable matters,
prepared as above described, in a species of gas retort, and gradually raised to a
D.

page_text: cherry-red heat, whereby the excess of oxygen contained by the vegetable matters
in presence of the hydrocarbon vapors is converted into carbonic oxide, and their
nitrogen into ammonia, the metals being thus immersed in the gaseous atmosphere
most suitable for converting them into fine or cementation steel. As, however, it
may happen that before this complete conversion is effected the matters producing the
cementing gases may become exhausted by distillation, care is taken to avoid this
defect by passing through the apparatus a current of carbonic acid, or of carbonic
oxide mixed or not with nitrogen. When this gaseous mixture is supplied by the
products of combustion of the furnace used to heat the apparatus, it is deprived of
free oxygen and converted into carbonic oxide by passing it over red-hot coals
before use.
A Siemens, Ponsard, Müller, or other analogous furnace will furnish a mixture of
gases which may be employed both for heating the apparatus and for converting
the metal into true steel. The gases discharged from blast furnaces may also be
utilized for like purposes. When, on the other hand, the gaseous mixture is
obtained by calcining limestone, or a mixture thereof with coal, the carbonic acid
and carbonic oxide produced are conducted directly into the apparatus containing
the alternate layers of carbon and metal.
The lime produced may serve to convert into pyrolignite of lime the small
amount of pyroligneous acid that disengages during the heating from the wood
and peat impregnated with hydrocarbons, and which is, collected as is usually done
in the distillation of wood.
The cementing gases, of whatever origin or composition, after passing through
the apparatus, may be collected in a gas holder for use again, or be passed into the
furnace of the apparatus to be utilised as fuel, The products thus treated yield on
fusion cast steel of first quality.
It will be seen that by this Invention steel of the first quality, suitable for files
and other tools, is obtained without fusion from Bessemer, Martin, or other metal
produced by refining cast iron.
Besides steel I also obtain lime, ammonia, pyroligneous acid, tars (hydrocarbons),
which may again be used, and wood or peat charcoal of great density, which are
applicable not only for domestic uses, but also for metallurgical purposes.
If cast iron be exposed at a red heat in a retort to a current of carbonic acid,
.either alone or mixed with air, it will be converted into steel, and the gas trans-
formed into carbonic oxide. By passing the latter gas into another retort, charged
with Bessemer metal at a red heat, the conversion of the latter into true steel will
be effected, the carbonic oxide again becoming carbonic acid.
The carbonic acid (CO²) takes from the cast iron its excess of carbon (C), and
becomes carbonic oxide (2 CO), which, in passing over the iron, Bessemer, or other
metal, parts with the carbon (C), and again becomes carbonic acid (CO²).
Hence it will be seen that a volume of carbonic acid gas, contained in a gas
holder, may by being passed through a series of retorts at a red heat, and charged
"the first with cast iron, the fourth with Bessemer metal, and so on, provided that
'the series of retorts, commencing with cast iron, terminates with one or two retorts
charged with Bessemer metal, be made to convert the whole of the metal contained
into steel; and by collecting the gas in another holder it may again serve for use
indefinitely in the same process.
If the gas be passed through a converter charged with cast iron in fusion, the
conversion will be effected in a more regular and quiet manner, and with much less
loss in iron.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the 22nd
December 1877.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN THE MANUFACTURE OF STEEL." A communi-
cation from abroad by Léon Krafft and Hippolyte Julien Sauve, both of Paris,
France:
The existing processes for transforming cast iron into steel (refining by the
oxygen of the air or Bessemer method, refining by reaction or Reaumur method,
improved by Siemens, Pierre Emile Martin, &c.,) have not given, and will never
give, more than imperfect results, compositions intermediate between true cast iron,
iron and steel. Although of great utility, and of low price; these products are not
adapted for the uses of fine steel or of cemented steel.
In order to remove. these faults, and to give the products all the desired qualities,
I keep them for some hours at cherry-red in a medium filled with coal or
fuel, over which passes slowly a current of nitrogen, oxide of carbon, and different
carbonated hydrogens; I place wood charcoal, peat coke, or other kind of vegetable
matters, well dried, and heated to about 120° Fahrenheit, in a hydrocarburet (such
as heavy oil of schist) heated to the same temperature. The latter is absorbed in
the proportion of 12 to 15 per cent. I form alternate layers with bars of Bessemer,
Martin, or other metal arising from the refining of cast iron by the methods above
mentioned; the whole enclosed in a vessel (a sort of gas retort) is gradually heated
to cherry-red. The excess of oxygen which the vegetable matters enclose in the
presence of the hydrocarburets in vapor is transformed into oxide of carbon,
and their nitrogen into ammonia, so that the metals in question are immersed
in the gaseous medium which is the most adapted for converting them into fine
steel or cemented steel. However, as before this absolute conversion is completed,
the productive source of the cementing gases may be exhausted by distillation.
I prevent this difficulty by causing the apparatus to be traversed by a current of
carbonic acid or oxide of carbon mixed or not with azote. When I take this gaseous
mixture from the products of combustion of the fire-place which heats the apparatus
I deprive it of free oxygen, and change it into oxide of carbon by causing it to
pass over charcoal heated to redness before sending it over the metal.
The Siemens, Ponsard, Muller, and other furnaces, the principle of which is based
on the gasefication of the fuel, give a mixture of gases which I employ both for
the heating of the apparatus and for the transformation of the metal into true steel.
The gases which escape from blast furnaces may also be employed for this double
purpose. When, on the contrary, I obtain this gaseous mixture by the direct
calcination of limestone, or by that of the mixture of this with coal, the gases pro-
duced (carbonic acid and oxide of carbon) are sent directly into the apparatus con-
taining the layers of fuel and metal. I obtain at the same time lime, which may
serve to convert into pyrolignite of lime the little pyroligneous acid which is dis-
engaged during the heating to cherry-red both of the hydrocarburetted wood and
peat, and which I take care to collect, as is usually done in the distillation of
wood.
It need hardly be said that the cementing gases, whatever be their origin and
composition, which have passed through the apparatus, can at their exit be collected
in a gas holder to be used again as before, or to be sent into the fire-place of the
apparatus, where they are utilized as fuel. If the products thus prepared be
melted there is obtained after my treatment cast steel of the first quality. Thus I
obtain without fusion first quality steel suitable for making files or other tools from
Bessemer, Martin, or other metal produced by refining with the oxygen of the air,
or by refining by reaction.
Besides the steel I obtain simultaneously lime, ammonia, pyroligneous acid, tars

page_text: (hydrocarburets), which I use again, and wood or peat charcoal much denser than
usual, and which is not only suitable for domestic use, but also for metallurgy.
I can also effect this transformation in the Bessemer converter itself, and in a
short time, as follows:-When cast iron is transformed into Bessemer metal with a
current of air, which is composed of 79 of azote and 21 of oxygen, before burning
the carbon of the iron, it seems that the oxygen of the air passing into the iron in
fusion, which has for formula Fe C, and which is a carburet of iron, there is
formed oxide of carbon CO and carbonic acid CO2; these two gases partly decar-
burize the iron.
In this reaction with the air, the oxygen being free, there is formed oxide of iron
before the formation of oxide of carbon, which prevents the obtaining of a homo-
geneous metal, but it would not be so if the operation was as follows:-The operation
which constitutes the Bessemer process having been finished, instead of running
into ingots, there is introduced in lieu of a current of air a current of oxide of
carbon gas mixed or not with proto or bicarbonated hydrogen gas; the Bessemer
metal is then immediately transformed into true steel.
I obtain this transformation by causing to pass during a determined time these
same gases over Bessemer ingots at a temperature of 1100° to 1475°. In the same
way in the converter I can produce the decarburation of the cast iron by causing a
current of carbonic acid to pass into the cast iron, as the atmospheric air has already
been passed into it. The carbonic acid CO2 would be transformed into 2 equiva-
lents of oxide of carbon CO CO. If cast iron is particularly in question, and if I
expose this iron heated to redness in a retort to a current of carbonic acid alone, or
mixed with air, it will be transformed into steel, and the gases will become oxide
of carbon, which, in passing into another retort charged with Bessemer metal at
redness, will complete the conversion of this metal into true steel, itself returning
to the state of carbonic acid. Thus the carbonic acid CO2 removes from the cast
iron its excess of carbon C, becoming transformed into oxide of carbon (2 CO); this
passing over the iron, Bessemer metal, &c., will deposit carbon C, and will return
to the state of carbonic acid CO2.
Whence, being given a volume of carbonic acid gas enclosed in a gas holder, I can
by causing this gas to pass into retorts heated to redness, and charged the first with
cast iron, the second with Bessemer metal, the third with cast iron, the fourth with
Bessemer metal, and so on (provided that the series commencing with cast iron
terminates with one or two retorts charged with Bessemer metal), transform all the
metal into steel, and by collecting the gas in a second gas holder utilize it to recom-
mence indefinitely the same operations.
If the passage of the gases takes place in a converter charged with cast iron in
fusion the transformation of the cast iron into metal is made more regularly, in a
calmer manner, and with less loss of iron.
When I employ a Ponsard furnace, and when continuity of the operation is
necessary in consequence of the dimensions of the bars and ingots, I proceed in the
following manner-For the production of the gases, both for heating and for the
transformation of the metals into true steel, I replace the fuels on the grate of the
gas furnace with incandescent coke, on which I allow to fall gradually a hydro-
carburet, which, thrown upon the coke, produces hydrocarburetted gases. Although
a like result may be obtained by injecting steam under the grate, I prefer the
hydrocarburets.
If I wish to decarburize cast iron, either in moulded pieces or in ingots, I clean
it, and put it in the compartments in which cementing boxes are ordinarily placed;
then putting carbonate of lime into one of the retorts heated by the gases of the
furnace I produce carbonic acid, which, passing over the melted and suitably
heated pieces, removes an equivalent of carbon from the iron, and is transformed into
CO, which is oxide of carbon gas. These same gases, passing afterwards over
ingots of Bessemer metal placed in another compartment. of the furnace, transform
them into true steel without the aid of fusion.

page_text: The results above explained, which I obtain with a Ponsard furnace, are likewise
obtained with a Siemens, Muller, or other gas furnace; a blast furnace is also a gas
furnace.
I have already mentioned that I employ the gas on issuing from the furnace
mouth both for heating and for the transformation into steel of Bessemer or other
metal. These gases, however, effect this transformation more efficaciously and
more quickly when, on issuing from the mouth, they are charged by any suitable
means with a slight quantity of hydrocarburet and ammonia in whatever place
they are made to traverse a layer of fuel heated to redness, whether it be over
grate bars or in a retort.
In the case where the gases both from blast furnaces and Siemens, Ponsard, or
other furnaces, and also those arising from the distillation of peat, are not suffi-
ciently azoted, I distil bones either mixed with peat or separately by directing
thereon the aminoniacal gases produced in the cementing boxes.
Figure 1 of the annexed Drawings is a vertical section of a blast furnace with an
auxiliary furnace M adapted for my mode of transformation.
Figure 2 is a vertical section through the line A, B, C, D, E, F. The supply of
the oxide of carbon and carbonic acid is obtained from the blast furnace by seven
equidistant openings I, I, I, formed in the inner circumference of the cone or body
4 or 5 yards below the mouth. These gases are conducted into an annular channel
III. by seven flues II., and escape by a pipe IV., which conducts them into a cast-
iron box V. A damper or regulator b, which can be opened or closed by means of
the rod b, c, and hand wheel d, serves to intercept at will the communication of the
gases from the blast furnace with the furnace M, and a valve a situated in the
pipe IV. near the gas box V. serves to regulate the introduction of these gases into
the furnace M. The gas box V. has seven flues P, P, P, by which the gases are
distributed in the upper part Q of the furnace M, which contains lumps or pieces
of iron produced by the Bessemer process or bars of the same iron, or even boxes
for cementing. The furnace M is arched in cast iron, as indicated in Figures 1 and
2, and carries a plate a likewise of cast iron, which forms the division between the
upper chamber Q and the lower chamber R, the gases from the blast furnace being
introduced into the upper chamber Q. I introduce gradually by the pipe T, by
raising the plug Z, the necessary amount of liquid hydrocarburet which is con-
tained in the vessel Y, and which, becoming vaporized in the chamber Q, combines
with the oxide of carbon and carbonic acid gas coming from the blast furnace.
The gases contained in the upper chamber Q are naturally in contact with the
Bessemer iron which has been placed therein, and which, being raised to a tempera-
ture of about 1380° Fahrenheit, become transformed into true steel by this contact.
The gases, which can be preserved at will in the chamber Q by means of the
regulator q, escape afterwards by seven flues N, and spread in the lower chamber R,
where, combining with the oxygen of the air which enters by 7 flues U, are ignited
therein to heat the plate x and upper chamber. The gases of this combustion
afterwards escape by four flues B, and issue by the chimney. It will be under-
stood that I can have a continous series of two or more furnaces thus arranged.
Having now described the nature of the said Invention, and in what manner the
same is to be performed, I declare that I claim,—
First. The process herein-before described of transforming into fine steel, and
without fusion, Bessemer, Martin, and other metals, as before referred to, iron,
and generally all metallic products obtained by refining cast iron by air or by
reaction.
Second. The fusion of the said products as herein-before described, so as to
make steel of the first quality.
Third. The decarburation of cast iron by carbonic acid alone or mixed with air
in a converter or in retorts, as lierein-before described.
Fourth. The utilization as herein-before described of the gases produced in Ponsard,
Siemens, Muller, and other gas furnaces by fuels such as peat, lignite, coal, coke,
and in short fuels charged or not with hydrocarburets, whether these hydro-

page_text: carburets be supplied before combustion or be thrown in during combustion, in
order to transform with or without fusion Bessemer metal into truc steel, puddled
steel into fine steel, to produce the cementation of iron or the decarburation of
cast-iron ingots or pieces of moulded cast iron.
Fifth. The employment for the same purposes of the gases from blast furnaces
which have or have not been charged on issuing from the furnace mouth with
ammonia and hydrocarburets with or without the addition of the products of a dis-
tillation of bones, as herein-before described.
Sixth. The particular arrangement of furnace as herein-before described and
represented in the annexed Drawings for carrying out the improved process or mode
of treatment.
=
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Twenty-first day of December, One thousand eight
hundred and seventy-seven.
A. M. CLARK. (L.S.)