AN IMPROVED PROCESS AND APPARATUS FOR CONVERTING CAST IRON INTO STEEL
Year: 1859

page_text: LETTERS PATENT to Pierre Amable de Saint Simon Sicard, of Paris, in
the French Empire, Chemist, for the Invention of "AN IMPROVED PROCESS
AND APPARATUS FOR CONVERTING CAST IRON INTO STEEL."
Sealed the 24th June 1859, and dated the 17th January 1859.
PROVISIONAL SPECIFICATION left by the said Pierre Amable de Saint
Simond Sicard at the Office of the Commissioners of Patents, with his
Petition, on the 17th January 1859.
I, PIERRE AMABLE DE SAINT SIMON SICARD, of Paris, in the French Empire,
Chemist, do hereby declare the nature of the said Invention for "AN IMPROVED
PROCESS AND APPARATUS FOR CONVERTING CAST IRON INTO STEEL," to be as
follows:-
Various modes of converting cast iron into steel by exposing it to air or
oxygen have been proposed, but they have mostly been defective in not suffi-
ciently subdividing the metal so as to expose every particle as much as possible
to the oxidizing action.
By the present Invention the iron is thoroughly exposed to the oxidizing
action, and the conversion is afterwards effected or completed, as herein-after
described. The melted cast iron, (which may be white cast iron,) is reduced to
a very fine state of division by being repeatedly projected or thrown against a
surface or surfaces by a revolving or moving apparatus or agitator. One form
of the apparatus is a horizontal, or inclined, or vertical cylinder, with an

page_text: agitator rapidly revolving within it; the agitator may have straight or spiral
blades, and the metal may be scattered upon it by a revolving cup or other-
wise. The cylinder is heated either on the exterior or on the interior, and
may be of iron lined or cased with clay or other suitable material; or the
metal may be allowed to fall in a sort of cascade on a series of bars or surfaces.
At the same time I introduce with the metal nitrate of potash or soda, or other
nitrate or substance capable of yielding oxygen, to the iron; the quantity of
nitrate may be about two or three per cent. of the weight of the iron, but may
vary considerably. It may be introduced in a regular stream of powder while
the iron flows in in a small stream. The iron is thus oxydized, and is partly
heated by its own oxydation, and by the repeated blows of the agitator it is
reduced almost to powder and converted wholly or partially into oxide of iron.
Some of the impurities of the iron, such as sulphur, phosphorus, and silica,
combine with the potash or soda, and are thus rendered soluble in water.
.
Any large lumps of metal may be crushed, or if imperfectly acted on may
be again beated in a similar manner. The whole is washed in water so as to
dissolve out and remove the soluble matter, and may be again washed with
water and a little hydrochloric acid to remove earthy matters; the acid should
not, however, be employed until after the sulphurets are washed out.
The iron or oxide of iron thus prepared is carburetted in crucibles or in a
reverberatory or puddling furnace, with a bed more or less hollow, on which
is first placed a layer of soot, or the purest charcoal mixed with carbonate of
ammonia. The oxide of iron and this mixture, either alone or with other fluxes
are placed in alternate layers, or all mixed together, and then covered with a
layer of the most refractory clay and fragments of charcoal; about nine parts
of charcoal may be used with about one of carbonate of ammonia, and from
three to nine parts of this mixture may be used for one hundred parts of iron,
but the proportions may be varied; when well melted the whole is agitated
with a rake or bar, at the end of which is a perforated wrought-iron box, or a
case made of iron wire containing carbonate of ammonia. This operation
facilitates the formation ofslag, if any earths remain in the metal and also purifies
it if such impurities as sulphur, phosphorus, or arsenic remain in it, and if it
is over carburetted, it may be partially decarburetted by this means, and the
quality of the steel improved. Small portions or samples are taken out and
examined from time to time. Nitrate of potash or other nitrate may be
applied in a similar manner. If more carbon should be required, it may be
given by charcoal, soot, prussiate of potash, sugar, resins or other carbonaceous
substance, or by agitating the mass by a piece of wood inserted in it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Pierre Amable de Saint Simon Sicard in the Great Seal
Patent Office on the 1st July 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
AMABLE DE SAINT SIMON SICARD, of Paris, in the French Empire, Chemist,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of January, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Pierre Amable de Saint Simon Sicard, Her special licence that I,
the said Pierre Amable de Saint Simon Sicard, my executors, administrators,
and assigns, or such others as I, the said Pierre Amable de Saint. Simon
Şicard, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and yend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED PROCESS AND
APPARATUS FOR CONVERTING CAST IRON INTO STEEL," upon the condition (amongst
others) that I, the said Pierre Amable de Saint Simon Sicard, my executors
or administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Pierre Amable de Saint Simon Sicard,
do hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accompanying
Drawing, and to the figures and letters marked thereon, that is to say:-
Various means have been employed or proposed for converting cast iron directly
into steel, that is to say, to purify or free it from the foreign substances which
it contains while leaving in it or restoring to it the requisite proportion of
carbon. Some of these means or processes have appeared to be rational and
would perhaps have succeeded, were it not for the great difficulty of bringing
every particle of the metal in contact with the reactives or chemical agents.
Cast iron is from its nature and specific gravity very difficult to penetrate or

page_text: to reduce to a fine state of division. Being in masses, it presents but little
surface to the reactives, so that when, for example, it is melted with oxides,
a portion of the oxygen is driven off before the fusion of the cast iron, and
with scarcely any action upon it. When it is melted, most of the remaining
oxygen escapes through a few issues, which act like vent pipes, so that a very
small quantity is brought to act on the foreign matters in the iron. The mechan-
ical processes for agitating the cast iron in a large mass, such as those proposed
by Mr. Bessemer and others, are very defective, and even in some respects
inferior to the refinery process in which the rake or bar is covered successively
with thin layers of the metal, and presented and retained by the workman for
a considerable time before the tuyere, so that not only is there sufficient time
to get rid of the volatile matters, but also to coagulate the metal while the
earthy matters or scoria being fusible at a lower temperature, sweat out or
run on the surface, and are easily driven out by the process of hammering.
With the aforesaid processes for agitating the iron in a large quantity or mass,
this is not the case, for the metal (being rapidly presented or brought to the
surface) loses indeed a portion of the volatile matters, but becomes coagulated
before losing the whole of them, while it retains all the earthy matter, and
produces a very impure article. One of the principal objects therefore to be
attained, is to reduce the cast iron to the most complete state of division,
either mechanically or chemically, which I have effected in the manner
hereit-after described. My process is at once mechanical and chemical, and
consists of two distinct operations, having the object of, firstly, granulating the
melted cast iron by projecting it violently several times in rapid succesion,
and in small quantities together with chemical agents or reactives, against a
wall or casing of any sort, so as to reduce it almost to the state of powder,
and to convert it entirely or in great part into oxide of iron, and thus to
purify or separate it from the foreign matters which it contains; and, secondly,
to deoxydize and carburize the granulated matter after having previously
submitted it to one or more washings to remove the soluble bodies and earths
liberated in the first operation. For the first operation any apparatus may bé
employed which is capable of reducing the cast iron to a fine state of division
by beating or striking it against a surface, although I prefer to employ the
apparatus shown in vertical longitudinal section in Figure 1, and in transverse
section in Figure 2 of the accompanying Drawing, and which apparatus I
call a "percussive oxidizing granulator." A is a case of cylindrical or other
suitable form, which is heated to a brown red heat, or more or less, by a
furnace B; C is an inlet for the metal, and D is an inlet for the chemical
agents; K is an outlet for gases or volatile matters; E is an agitator or

page_text: beater, which is capable of being turned on its axis by a winch F, or a
pulley F, or otherwise. The beater E is put in rapid motion, and the melted
cast iron is allowed to flow in at the opening C from a ladle or from a
reverberatory furnace placed at a higher level. At the same time powdered
nitrate of potash or nitrate of soda is allowed to run in through the
opening D, in the proportion of two or three parts to one hundred parts of
cast iron. A portion of the salt may be advantageously introduced before the
imetal begins to enter, so that the metal may immediately enter into com-
bustion, and thus become highly heated. The metal is thus kept in the liquid
state, and is beaten into globules by the beater, and burned or oxydized by the
oxygen of the nitrate, and thus reduced almost to powder and almost entirely
converted into oxide. The foreign matters are separated and the volatile
imatters driven off, while others, such as sulphur and silica, combine with the
alkali. The stream of cast iron ought to be small in proportion to the size of
the apparatus, so that it may be thoroughly beaten up and divided, and the
apparatus ought to be kept hot, but not so hot as to endanger the adhering of
the cast iron to it; moreover, such an accident may be prevented to a certain
extent by lining or washing the inside with clay or carbon. It is necessary to
take care that the metal does not coagulate too quickly before it has been
beaten about several times and reduced to small globules. However, not-'
withstanding all precautions, there will generally remain some globules or
granules which are larger than others, but quite spongy and easily crushed,
and containing in their numerous cells, oxide of iron, and sulphurets and
phosphurets of potassium and other bodies almost entirely soluble produced.
during the combustion, and completely isolated from the metal. These
granules are placed aside to be reinelted and granulated in the next operation,
or they are crushed by a hammer or by rollers, and then washed with the rest
of the granules. The first washing is made with water, the granules being
stirred up with paddles or otherwise, and the soluble matters are thus removed.
A subsequent washing may be effected with water containing a little muriatic
acid so as to dissolve the earths which may remain; but the sulphurets should
be well washed out before the acid is used, otherwise sulphur will be preci-
pitated, and will again combine with the metal during the carburizing process.
The melted cast iron might also be granulated, although less perfectly, by
allowing it to fall upon blades or gratings or plates inclined or horizontal.
My "percussive oxidizing granulator" may either be horizontal, as shown
in Figure 1, or more or less inclined or vertical and continuously acting like
that shown in vertical section in Figure 3. The case A may be cylindrical or
wider, or of a different form in the upper part, as shown in Figure 2, and it

page_text: may be made in one piece or preferably in two pieces capable of being opened
to facilitate the removal of the beater either for cleaning it and removing the
granules, or detaching any granules which may stick between the beater and
the case.
The beater may have straight blades as in Figure 2, or curved or
spiral blades as shown at I, in Figure 3. In the horizontal or slightly inclined
apparatus the beater ought to graze or almost graze the bottom of the case so
as to bring up and fling about the metal at every turn. In the very oblique
or in the perpendicular apparatus shown in Figure 3, the beater I ought to be
made with helicoidal blades so as to arrest the iron longer in its fall, and
ought to graze or almost graze all the interior surface of the cylinder; this
helicoidal beater is furnished with a cup J at its upper part, into which the
reagents fall through the aperture D before or while the melted cast iron runs
in through the aperture C. The gases may escape at the bottom of the case
or through an opening K, with or without a valve. The lower part B of the
apparatus forms a receptacle for the granules, and may also be used as the
furnace for heating the apparatus by means of a fire on a moveable grate L,
which is withdrawn at the opening M when the apparatus is sufficiently
heated. The case A is surrounded by a sheet iron case or envelope N, and
the intermediate space is filled with powdered carbon or sand or other bad
conductor of heat. O is an opening for feeding, the fire and for the escape of
the oxygen or other gases, which may be collected and introduced into the
apparatus in conducting another operation, if desired. R is a cross, which
supports the cylinder A and the spindle of the beater I. The melted cast
iron and the nitrate fall into the revolving cup J, and are flung against the
sides of the case A, and falling on the spires of the helicoidal beater I, are
repeatedly flung against the sides of the case, and at last fall into the
receptacle B.
I will now proceed to describe the second or deoxydizing and carburizing
process. The product obtained as herein-before described, after being washed
and dried, consists of oxide of iron and metallic iron, with perhaps a little
earthy matter, and is therefore adapted for producing excellent steel when
treated with carbon. To carburize it, I employ crucibles of refractory
materials, or to operate more economically and on a larger scale I use a
puddling or arched reverberatory furnace with a floor or bottom more or
less hollow, on which is placed a bed or layer of a mixture of soot and
the purest powdered charcoal with some small fragments of carbonate of
ammonia. Successive and alternate layers of this mixture and of the gra-
nulated oxidized iron are added, or in place of separate layers the whole
may be mixed together; the whole is then covered with fire clay and

page_text: coarsely powdered charcoal. The fire is urged until the mixture is melted,
and the mixture is kept covered with the clay and charcoal to prevent
oxidation or decarburization. The aforesaid mixture of powdered charcoal
and carbonate of ammonia consists of nine parts of charcoal and one part of
carbonate of ammonia. From three to nine parts of this mixture are
employed with one hundred parts of the granulated oxidyżed iron, according as
it is more or less oxidized, and it is wished to obtain steel more or less hard.
When the mixture is well melted, it is agitated in every direction with
a rake
or bar, at the end of which is a box of perforated sheet iron or of strong wire
gauze or net containing carbonate of ammonia. Not only does this agitation
facilitate the formation of slag or cinder if any earths or oxides should remain
in the granules, but the decomposition of the carbonate of ammonia com-
pletes the purification of the metal if by accident there should remain any
such impurities as sulphur, phosphorus, or arsenic. This is also a means of
decarburizing the steel if it should be slightly over-carburized, which may be
ascertained by taking out a sample or proof from time to time by dipping a
cold iron bar into it, and withdrawing it, and immediately forging the coating
of steel which adheres to it. I can thus not only obtain very nearly or exactly
the desired quality of steel by using the proper proportions of the granules and
the aforesaid mixture, but I can also restore the metal to the required quality,
if over carburized, by stirring or working it with the carbonate of ammonia,
and I can thus reduce it to the state of very tough senii-steel, or even to the
state of soft iron or wrought iron. Nitrate of potash or other nitrate may be
stirred in in a similar manner and with the same object; if, on the contrary,
there is a deficiency of carbon, it may be supplied by known means, by adding
charcoal, soot, ferrocyanide of potassium, sugar, resin, or other carbonaceous
substances, or even by stirring or inserting in the melted mass a piece of
green wood as in the refining or "poling" of copper.
I prefer to employ white cast iron for the purpose of my Invention. The
proportions of the materials admit of variation, and other fluxes or materials
may be added to those herein-before mentioned.
Having now described the nature of my said Invention, and in what
manner the same is to be performed, I wish it to be understood that what
I claim is,
First, the oxidation and consequent purification of cast iron, by causing the
melted cast iron in conjunction with nitrate of potash or soda, or other nitrates
or oxidizing reagents, to be rapidly granulated or reduced to powder by my per-
cussive oxidizing granulator, or any other suitable means of striking or projecting
it against a surface or surfaces, or bars or gratings, as herein-before described.

page_text: Second, the application of carbonate of ammonia in the carburizing process
and for decarburizing the melted metal, as herein-before described.
Third, the application of nitrate of potash or soda, or other nitrate by means
of a perforated box or case plunged into the melted metal for decarburizing
and purifying it in manner herein-before described.
Fourth, the combined process for converting cast iron into steel by oxidizing,
purifying, and granulating it by percussion while melted and in contact with
nitrate of potash or other oxidizing reagents, and then deoxidizing and car-
burizing it, as herein-before described.
Fifth, the apparatus herein-before described under the name of the
"percussive oxidizing granulator," and shown in Figures 1, 2, and 3 of the
accompanying Drawing..
In witness whereof, I, the said Pierre Amable de Saint Simon Sicard,
have hereunto set my hand and seal, this Twenty-eighth day of June,
in the year of our Lord One thousand eight hundred and fifty-nine.
Witness,
CH. ARMENGAUD,
Ingr. Civil,
P. A. DE SAINT SIMON SICARD. (L.S.).
23, Boulevard de Strasbourg, à Paris.