IMPROVEMENTS IN THE MANUFACTURE OF ALLOYS OF IRON
Year: 1874

page_text: LETTERS PATENT to Alexander Browne, of the Firm of Browne and
Company, Patent Agents, of 5, Southampton Buildings, Holborn,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF ALLOYS OF IRON."-A communication from abroad
by the Foundries and Forges Company of Terre Noire La Voulte
and Bessèges, in the French Republic.
Scaled the 31st July 1874, and dated the 2nd February 1874.
PROVISIONAL SPECIFICATION left by the said Alexander Browne at
the Office of the Commissioners of Patents, with his Petition,
on the 2nd February 1874.
I, ALEXANDER BROWNE, of the Firm of Browne and Company, Patent
Agents, of 5, Southampton Buildings, Holborn, in the County of
Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF ALLOYS OF IRON," a communication
from abroad by the Foundries and Forges Company of Terre Noire La
Voulte and Bessèges, in the French Republic, to be as follows:-

page_text: partially effecting their reduction to the metallic state prepares them for
undergoing the more severe process of subsequent complete reduction.
Second. In manufacturing alloys containing definite proportions of
iron and manganese from certain definite proportions of crude materials
used for that purpose, and in accomplishing the same not only in the
vertical furnace described in my former Patent for "A New or Improved
Process and Furnace for the Manufacture of Metallic Alloys," No. 1574,
dated 1st May 1873, but also in other furnaces whether ordinary
reverberatory or on the Siemen's or Ponsard or rotary furnaces principle,
and by such means forming alloys richer in manganese than had hereto.
fore been produced.
Third. In methods of gathering the alloy produced without waste.
The means by which I accomplish the above objects are as follows:-
The first part of my Invention consists in the preliminary treatment of
the mixed materials in the state of powder, so as to obviate the
inconveniences attending all attempts to introduce them at once into the
melting furnace which may be briefly summarized as follows:-A
quantity of such materials is carried away and lost in the draught which
settles and destroys the interior of the furnace, disturbing at the same
time the relative proportions of the mixture, and further, inasmuch as
such materials may contain either combined or hygrometric water,
carbonic acid, oxygen, capable of separation by simple heat, or in the
case of raw combustible matter carburetted hydrogen, the separation of
these and other gases more or less inert, greatly lowers the heat of the
furnace and retards the reductive action, thereby prolonging the duration
of the operation.
I introduce the mixtures whether of oxides, natural or artificial salts,
combustibles, reducing agents, and fluxes, some or all of them into
moulds made of cast or wrought iron or other suitable material, and ram
it tightly, after which the moulds are firmly closed and placed in an oven
moderately heated to the temperature of a stove or open fire, where they
are to be left until all the gases have passed off and the oxides have lost
part of their oxygen. To expedite this part of the process I propose to
make use of a furnace with a loose sole or bottom, movable on wheels
or rollers, in such way that a freshly charged sole or bottom may be
introduced into the furnace or oven simultaneously with the withdrawal
of the one that has already been subjected to its action, thus economizing
both time and heat. This may be accomplished in so many ways by any

page_text: competent engineer that a particular description of any one method is
unnecessary. The moulds should then be left to cool and not opened
until so far cooled that the oxides or metals therein contained are no
longer liable to reabsorb oxygen by simple exposure to the air. By this
means the compounds are obtained in solid masses, and may be melted
without difficulty in the manner before stated. Or the operation may
with proper care be performed by simply filling a coke oven with the
mixture and heating it either with the gases derived from the mixtures
or by special fire-places. Irregular masses are thus obtained ready for
melting, but care must be taken that before opening the oven it is so far
cooled as to avoid the risk of again bringing its contents to the state of
powder by the action of the air.

page_text: This combination however yields a slag which assumes a pasty
consistence, and does not fully melt except at very high temperature,
and this leads to the third part of this Invention which is as follows:-
This section of my Invention consists of two divisions which may be
employed together or separately, and are applicable to any and all of the
aforesaid mixtures, but are chiefly important as regards those alloys
containing the higher per centage of manganese. The first division of
these methods relates to the perfect liquefaction of the slag formed in
the operation. This is accomplished by adding to the viscid mass broken
quartz in such quantity that the slag on analysis shall yield combined
oxygen in the form of silica, bearing to the oxygen in its associated bases
the ratio Si O³ 6 RO. If due care in its apportionment and admixture
be taken the ratio may be reduced Si O³ 3 RO. As however the least
deviation from the proper time for its addition whether sooner or later
affects the result, I prefer to use in its stead fluor spar chemically known
as fluoride of calcium or fluate of lime, which is more uniform in its
action, and not so liable to fail by reason of slight error in the period of
its introduction. The necessary proportions of either of these agents
will necessarily vary by reason of slight differences in the original
minerals constituting the slag, the precise heat of the furnace, and
other minor conditions, definte quantities cannot therefore be given, but
experience will soon indicate to a skilled workman what quantity to use
in a given instance.
The second division consists of a method of collecting and gathering
together into the principal mass all scattered beads, buttons, and other
small portions of metal which would otherwise be lost in the slag. This
defect I find to be remedied by throwing into the furnace towards
the end of the operation small pieces or broken grains cither of
cast iron or of cast-iron alloyed with manganese. These should be cast
upon the prominent parts of the sole of the furnace, so as in running
down when melted to the lower parts they may absorb the scattered
portions of alloy, and thus unite them to the main body.
The study of the process and effects of consolidating metallic oxides
by pit coal and tar has guided me to the knowledge that if natural
or artificial oxides are united with coal suitable for making coke, or of
coal more or less hungry, or even of anthracite, but accompained with a
small quantity of mineral pitch or tar, it is possible by baking the mass
thus produced to obtain a coke holding as much as 40% of metallic

page_text: oxides, and suitable for introduction into high furnaces and particularly
that which I have described in my Patent of May 1st 1873, No. 1574,
and by this means manufacture metallic alloys.
All that I have now said on the alloys or combinations of iron and
manganese applies equally to alloys, and combinations of iron and carbon
with silicium, tungsten, and titanium.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Browne in the Great Scal Patent
Office on the 1st August 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
BROWNE, of the Firm of Browne and Company, Patent Agents, of 5,
Southampton Buildings, Holborn, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of February, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Alexander Browne, Her
special licence that I, the said Alexander Browne, my executors,
administrators, and assigns, or such others as I, the said Alexander
Browne, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an In-
vention for "IMPROVEMENTS IN THE MANUFACTURE OF ALLOYS OF IRON," a
communication from abroad by the Foundries and Forges Company of
Terre Noire La Voulte and Bessèges, in the French Republic, upon the
condition (amongst others) that I, the said Alexander Browne, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and

page_text: 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alexander Browne, 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, that is to say :—
On the 1st of May 1873 we made request for a Patent, No. 1574,
for a new process for manufacturing metallic alloys, and also for
consolidating the crude materials destined for that manufacture. The
description attached to that Patent shows in full detail the reasons
which led us at that time to prefer for the manufacture of metallic
alloys a vertical apparatus similar to a high furnace rather than a
reverberatory furnace, or the furnaces of Siemens and Ponsard used
until now for that purpose. Since then numerous experiments have
demonstrated that in certain definite cases there may be great advantage
in producing these alloys in gas furnaces on Siemens' system, on Pon-
sard's system, or the rotary system. We have equally established that
in the system of manufacture with a vertical furnace it is possible to
invent a system of consolidation still more advantageous than indicated
in our Patent of 1st May 1873, all with a view to introduce considerable
modifications in the method of operating which it is the obiect of this

page_text: is evident if the chief end towards which all these allows tend is borne
in mind. So far as concerns manganese, and more particularly silicium,
the end sought is to get rid of the oxidation of the metallic bath
without the addition of carbon to the steel or cast metal desired. It
is obvious that the more manganese or silicium can be condensed in a
given weight of alloy the nearer is the end sought. This necessity
becomes of supreme importance since we have shown in our Patent
of the 16th January 1874, No. 220, that it is possible to make steel
with phosphorus, provided that the carbon is eliminated from it as
much as possible, and that phosphorus could be introduced into it more
and more proportionately as the carbon is less and less.
It is evident that here is a very important end to attain, but it is
equally certain that to arrive at this result new combinations and pro-
portions are requisite.
The question now is for us to give practically and constantly 60%
of manganese in the alloy, and even to arrive without too much
difficulty as far as 82% to 22% of silicium. We have attained
theso results by the processes whereof we give a detailed description
further on.
Second. The necessity for producing economically it is unnecessary
to discuss; it is the very basis of all business; it is merely useful
to indicate that in this particular instance the obstacle to economic
production rests entirely in the introduction into the furnaces and
apparatus of reducing materials difficult to treat in the form of powder.
In practice such materials occupy an enormous space in the furnaces;
they are in bad circumstances as to combustibility from the heat, the
reduction is consequently very difficult to bring about, much time
and a very high heat must be used, and all this means great expense.
To introduce the materials into the furnace in as concentrated a form
as possible, and in a certain state of reduction, is the end we have
sought, and which has been attained by the processes which we now
proceed to describe in detail.
The processes for which we ask this Patent are then the following:-
Firstly. New proportions studied with a view to the production of
alloys more rich in manganese, silicium, titanium, tungsten, and other
similar refractory metals.

page_text: the composition of the slag may be represented in a general manner
by the formula Si O³ 9RO.
We have tried the possible influence on this result of increasing
the quantity of reducing materials, and of a prolongation of the
operation; in no case have we been able to modify the composition
of the slag. We then sought to arrive at the same result starting
with different materials.
In the first place we took an almost pure oxide of manganese con-
taining 58% of manganese, and 4.50 of silica which we mixed with.
mineral of mokta carefully selected and reduced to powder. Starting
with 100 mokta and augmenting progressively the oxide of manganese
we were only able to produce metal with 25% of manganese with the
following proportions,—
Mokta in powder
100
the composition of the slag may be represented in a general manner
by the formula Si O³ 9RO.
We have tried the possible influence on this result of increasing
the quantity of reducing materials, and of a prolongation of the
operation; in no case have we been able to modify the composition
of the slag. We then sought to arrive at the same result starting
with different materials.
In the first place we took an almost pure oxide of manganese con-
taining 58% of manganese, and 4.50 of silica which we mixed with.
mineral of mokta carefully selected and reduced to powder. Starting
with 100 mokta and augmenting progressively the oxide of manganese
we were only able to produce metal with 25% of manganese with the
following proportions,—
Mokta in powder
Oxide of manganese
100
Lime
->
Coal
->
The slag produced had the following composition,—
Silica
-
Alumina
Lime
20
150
-
14.
4.38
-
30.60

page_text: of the slag which we have discovered and established above is constant,
this slag can take no more oxide of manganese than the quantity
.strictly necessary to saturate the silica in such a way that the oxygen
of this be to the oxygen of the bases in the ratio of 1 to 3; and all the
supplementary oxide of manganese ought to be reduced (provided that
the proportion of reducing agents is sufficient) and unite with the
iron. Experiment has fully verified this hypothesis.

page_text: Baryta
Protoxide of manganese
21.00
->
56.00
Augmenting further the proportion of oxide of manganese in the
melting bed 82 and even 83% may be arrived at, but a very long time
is requisite for the reduction and research for such rich alloys is no
longer of the same interest. We had thus resolved the problem which
we had propounded to ourselves, that is to say, the production in an
oven furnace of very rich alloys, but we were struck with the great
proportion of oxide of manganese passing into the slag, and it became
necessary to investigate whether in the typical slag it was not possible to
substitute some cheaper base in lieu of it.
The alkaline bases of potash and soda have the drawback of being
very dear and becoming volatile at the very great heats of gas furnaces,
they then fiercely attack the roof and sides of the apparatus. It
remained then to try the earthy alkaline bases baryta and magnesia.
Starting from this point of view we made a series of new trials which it
would be tedious to recapitulate in this place, but which enabled us
to replace the oxide of manganese by the oxides of calcium and
magnesium at least to a large extent, and we have produced a slag of
the formation Si O³ 9RO, containing only, 18% and sometimes only
15% of oxide of manganese..

page_text: But we then found ourselves in presence of a fresh obstacle; such a
slag melts only at a very high temperature, and a brief lull in the
extreme heat of the furnace was sufficient to occasion the melted matter
to remain in a pasty or clogged state, which of itself resisted the separa-
tion of the already formed metal from the slag. It became impossible
from a practical point of view to persevere in this routine unless we
could find means to render this slag perfectly liquid.
Now if silica has what may be called a devouring affinity for the oxide
of manganese it has none such for the manganese as metal, and starting
from this fact we have been led in practice to add to the viscid reduced
mixture such a quantity of quartz that the slag assumed the form
Si O 6RO, and even Si O³ 3RO. In both cases the separation is
cleanly made, and the slag becomes perfectly liquid.
In the end we have been led to replace this addition of quartz, which
required to be very precise, by an addition of fluor spar. It may be
understood in fact that if the quartz is introduced a little too carly into
the furnace if it still meets with some unreduced portion of oxide it
seizes on it greedily, and the proposed end is not attained. The fluoride
of calcium has not the same objection, and it is now part of our daily
practice.
In fine all the trials which we here relate, and which have occupied
a lengthened period, have brought us to the following conclusions:
First. The bulk of the charge placed in the furnace being limited, and
the time employed in reducing and melting it being the same whatever
be its composition, it is proper in an economic point of view to seck to
produce the richest alloy, whether that containing 70% or 80% of
manganese.
Second. It is both possible and desirable largely to replace the oxide
of manganese in the slag by either lime or magnesia, and thus produce
an almost infusible dross.
Third. This drossy slag may be restored to a perfectly liquid state by
the addition of quartz or fluor spar.
If from the stand point of using the furnace in the most economical
way we found it advantageous to produce the alloy richest in manganese

page_text: happens, whatever care may be taken, an important draught of powdered
materials, which encumber and attack the regenerators or recuperators
according as Siemens' or Ponsard's furnace is made use of, or the flues
leading to the chimney if an ordinary furnace is used. Besides which
these materials in a state of minute division always contain water, either
combined or hygrometric, carbonic acid, oxygen, capable of being dis-
engaged by the application of heat, and finally hydrocarbons when raw
fuels are employed as reducing agents.
The remedy the inconveniences alluded to above we divide the opera-
tion, which has for its end the manufacture of the alloys before
mentioned, into two parts entirely distinct. In the first we obtain by
means of an apparatus independent of the melting furnace the separation
of the inert gas of a part of the oxygen and of the volatile portion of
the reducing combustibles. In the second we proceed to the fusion of
the material thus prepared.
In order to carry out the first operation we introduce the mixture of
salts, natural or artificial oxides, reducing combustibles and fluxes, such
a mixture as we have mentioned in the first part of this Specification,
into cast-iron moulds.
The reducing material may be clean pit coal more or less bituminous,
pure anthracite or wood charcoal in powder mixed with mineral pitch,
tar, or cheap fatty or oily substances, or a mixture of these materials.
The mixture as perfect as possible is tightly rammed into moulds of
cast or wrought iron composed of several parts put together. The
mould when filled is firmly shut and placed in an oven of a moderate
heat similar to a stove or a smouldering oven, wherein it is to remain
until all the inert gas is liberated and the metallic oxides have lost part
of their oxygen. The moulds must then be left to cool after being
withdrawn from the oven or stove, but they should not be opened
until the temperature is such that the partially reduced metals or inferior
oxides produced are no longer capable of absorbing oxygen from the air.

page_text: Thus are obtained solid masses which contain all the elements of the
alloy or combination to be produced.
The second part of the operation simply consists in melting these
solid masses in one of the furnaces and by the processes set forth in the
first part of this Specification.
We find it of advantage to bake these solid masses in an oven whose
solc consists of a movable carriage, which permits the rapid entry and
exit of the moulds without leaving the furnace time uselessly to lose
its accumulated heat. Thus with a second carriage constantly ready
loaded can be realized a continuous manufacture of solidified masses.
It is equally possible to fill a space similar to a coke oven highly heated,
that is to say, heated both from the bottom and sides or gas retorts with
the above-mentioned mixtures in powder, and bring about the baking as
for cokes, whether by means of the disengaged gases or partially by
means of special fire-places. Thus is obtained a mass divided into
irregular fragments, which may be transferred to the melting furnace,
but it is indispensable that this mass should be left to cool in the baking
oven or retort to avoid subsequent oxidation, and return to the state of
The substances prepared as above described must be melted in an
ordinary reverberatory furnace or in a gas furnace of a suitable construc-
tion, but it is evident that if the oxide of iron or manganese not
completely reduced are exposed to a high temperature on a sole made of
silica, sand, or clay, these oxides will soon form an unlimited quantity of

page_text: scoria. Soles made of metallic oxides cannot either be used, as the
oxides would be reduced, part of which would pass in the metallic alloy,
and thereby alter the proportion of the alloyed metals. Therefore
natural or highly basic substances only can be used, such as carbon,
lime, and magnesia, which may be used either separately or mixed
together; but owing to its neutrality carbon is the one preferable.
We generally proceed in the following manner:-Pure natural or
artificial graphite, pure anthracite, or coke containing little ashes are
finely pulverized. These or mixtures of these are mixed with residue of
coal tar or tar so as to form a thick paste. This paste is then pressed in
cast-iron moulds, which may be easily taken to pieces. The moulds are
closed and taken in a drying place or oven at a low temperature, where
they are left until all the gases have escaped through the joints of the
moulds. They are then taken out and allowed to cool. Bricks of all
sizes are thus obtained, which are very hard and compact, and with
which the sole of the furnace as well as those parts exposed to the
metallic oxides are constructed. The joints of these bricks are made
with the same mixture of carbonaceous substances and tar. The sole
may also be made by ramming the above mixture, but then in order to
prevent the deformation during the cooking it must be covered over with a
metallic shape heavily loaded, which keeps the material in shape during
the expulsion of the gases. This mode therefore is only applicable to
small soles. When lime or magnesia are used for making the sole care
must be taken to prevent these substances coming in contact with the
silicious parts of the furnace by means of carbon bricks.
AS TO WHAT CONCERNS THE PROPORTIONS.
First. Accurate proportions of materials to be mixed with a view to
obtain a definite and extremely basic slag.
Second. By means of these proportions to produce in reverbatory or
grated furnaces, Siemens' or Ponsard's gas furnaces or rotary furnaces,
alloys or combinations of iron, carbon, and manganese containing 30 to
82% of manganese, which had not before been realised.
R

page_text: the operation of quartz or of fluor spar.
Fourth. Introduction into the furnace towards the end of the operation
of silicic or manganesic cast iron or rich alloys of iron and manganese
to complete the reduction, thin the bath to the consistency required, and 5
gather up the metallic globules.
Fifth. Production by the same processes of alloys of carbon and iron
with silicium, tungsten, titanium, and other similar refractory metals.
AS TO WHAT CONCERNS CONSOLIDATION.
First. Manufacture of slabs or bricks or solid masses containing the 1
clements of metallic alloys of iron with carbon, manganese, silicium,
tungsten, titanium, and other similar refractory metals.
Second. Preparatory reduction in a separate furnace of the masses thus
made.
Third. Manufacture of a metallurgic coke containing in sufficient 1
quantity the clements of these same alloys.
Fourth. Manufacture of the aforesaid metallic alloys by the reduction
and melting of these masses in reverberatory furnaces or gas furnaces
on Siemens' or Ponsard's plans, or in rotary furnaces, or lastly in a
vertical furnace similar to that whereof the description is given in our 2
Patent of May 1st 1873.
In witness whercof, I, the said Alexander Browne, have herc-
unto set my hand and scal, this First day of August, in the
year of our Lord One thousand cight hundred and seventy-
four.
2