IMPROVEMENTS IN THE MANU- . FACTURE OF IRON AND STEEL
Year: 1873

page_text: LETTERS PATENT to Thomas James Smith, of the Firm of Robertson,
Brooman, and Company, of 166, Fleet Street, in the City of London,
Patent Agents, for the Invention of "IMPROVEMENTS IN THE MANU-
.
FACTURE OF IRON AND STEEL." -A communication from abroad by
Pierre Emile Martin, of Sireuil, France, Ironmaster.
Scaled the 14th October 1873, and dated the 17th April 1873.
PROVISIONAL SPECIFICATION left by the said Thomas James Smith
at the Office of the Commissioners of Patents, with his Petition,
on the 17th April 1873.
I, THOMAS JAMES SMITH, of the Firm of Robertson, Brooman and
Company, of 166, Fleet Street, in the City of London, Patent Agents,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF IRON AND STEEL," to be as follows:-
This Invention, which has for its object the direct manufacture of
iron and cast steel from iron ore; consists in reducing and cementing the
ore either: upon an auxiliary floor of a puddling furnace, or preferably to

page_text: a horizontal or vertical retort placed upon the said floor, mixing with the
ore, charcoal, or other combustible or reducing agent.
The ore and charcoal mixed if necessary with a flux suitable to the
gangue of the ore are previously pulverized in order to facilitate and
accelerate the reduction of the ore. The reduced and cemented ore is
then carried to or directed upon the ordinary floor of the puddling
furnace in order to be agglomerated into balls, these balls arc afterwards
submitted to the action of the stamping hammer in order to expel the
impurities, and to be beaten into masses which can be employed directly
in the production of merchantable iron, or be thrown into the bath of
the floor of a reverberatory furnace according to a former process for the
manufacture of cast steel.
The essential feature of this process for the production and cemen-
tation of ores in retorts is that the ore serves not only as in the ordinary
puddling process for the transformation of the cast-iron into iron by the
action of the oxygen in the ore, but that it augments the yield of
product; if for example the ore employed yielded on analysis 50 per
cent., it will give up about 40 per cent. to the puddling. The loss is
thus only 10 per cent., and it is besides in proportion to the richness
and purity of the ore, and contains the phosphorus, sulphur, arsenic, and
other minerals which are eliminated with the oxide of iron.
The puddling furnace constructed in order to carry out this process
can be heated by a grate or by gas. It comprises the ordinary puddling
floor, but at the front of the furnace is arranged an auxiliary floor for
the reduction and cementation of the ore. This floor is placed upon a
special grate, but it can, however, be heated by the puddling furnace
itself.
Instead of placing the ore and its reducer directly upon the floor there
is preferably arranged upon this auxiliary floor a vertical retort or even
a horizontal retort as in gas furnaces. It is in this retort that the ore,
the charcoal, or other reducer which have been previously pulverized is
placed. The ore is mixed with the charcoal in the proportion of from
about 10 to 25 per cent., and with the flux suitable to its gangue. This
reducing and cementing retort is heated like the auxiliary floor either
by a special grate, or by the heat of the puddling furnace itself. From
this auxiliary floor the reduced and cemented mineral is directed towards
the ordinary floor of the puddling furnace whence it proceeds in iron

page_text: balls, which are rolled or hammered in order to produce bars or other
picces, or which are cut up and carried into the bath of the reverberatory
furnace of the former process for the manufacture of cast steel.
The Inventor has even succeeded in obtaining iron directly from the
ore without having undergone the previous reduction in the retort by
immediately carrying the pulverized mixture (ore, charcoal, and flux),
especially wlien there is an excess of charcoal upon the floor of the
puddling furnace itself, but it required much more time for the
production, and the action of the reduction was less complete.
As a consequence from this process it is possible in order to aid and
facilitate the operation, either to carry cast iron to the ore, or to carry,
in the method called the boiling furnace method, mineral reduced in a
bath of cast iron to the puddling furnace.
The vertical or horizontal reducing and cementing retort may be fixed
or revolving, and in this retort the mineral may be exposed to a current
of reducing gas, in order to accelerate the production.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas James Smith in the Great Seal Patent
Office on the 17th October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JAMES SMITH, of the Firm of Robertson, Brooman, and Company of 166,
Fleet Street, in the City of London, Patent Agents, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of April, in the year of
our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Thomas James Smith, Her
special licence that I, the said Thomas James Smith, my executors,
administrators, and assigns, or such others as I, the said Thomas
James Smith, 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 vend, within the United Kingdom of

page_text: Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL," com-
municated to me from abroad by Pierre Emile Martin, of Sireuil,
France, Ironmaster, upon the condition (amongst others) that I, the
said Thomas James Smith, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
scals, 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 Thomas James Smith, 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
Drawings hereunto annexed, that is to say :-
The object of this Invention is the direct manufacture of iron and
steel in the puddling furnace from iron ore previously reduced and
cemented at a suitable temperature.
This previous reduction or preparatory operation of the ore takes place
either upon an auxiliary floor of the puddling furnace, or preferably in
a vertical or horizontal retort placed upon the said auxiliary floor, which
is heated by the flame or heat escaping from the puddling furnace. The
puddling furnace can itself be heated by a grate or with gas.
The iron ore to be reduced and cemented is mixed after being broken
into very small pieces, or pulverized with a carbonated or hydrogenated
reducer, and when necessary with a flux suitable to its gangue.
Pounded anthracite, pounded charcoal, pounded pit coal, lignite or
peat, hydrocarburets; and in short all other carbonated, hydrogenated,
mineral or vegetable reducers can be employed as the reducing agents.
According to circumstances, a mixture is made composed of about 10 to
25 parts of the carbonated and hydrogenated reducer, with 100 parts by
weight of the screened and pulverized iron ore, and with the suitable flux.
The mixture can be made in the form of a mortar composed, for example,
from 100 parts of iron ore, of about 10 to 15 parts of tar, and about 5 to 7
parts of charcoal or bricks can equally well be made by adding thereto as
a flux a mixture of refractory earth and lime. It is this mixture which
it is
to reduce and cement before submitting it to the puddling
necessary

page_text: operation in the puddling furnace. This reduction, as before-mentioned, is
effected in the puddling furnace itself, either upon an auxiliary floor or in
a retort placed upon the said auxiliary floor. The reduced mixture is
cemented by heating to a clear red heat, or even bringing it to a pale yellow
heat, and is then carried into the puddling furnace in order to be puddled.
The iron appears soon after the first stirring of the mixture. The work-
man collects this iron into balls, which are then carried to the hammer
in order to expel the dross, and to be beaten into lumps or blooms.
These lumps or blooms can be worked for the manufacture of the iron
of commerce or manufacture, or can be carried into the bath of the
cast steel furnace according to a previously patented process of the
present Invention, Mr. P. E. Martin.
One of the essential characteristics of this new process for the reduction
and cementation of the mixture of ore upon the floor or in the retort, is
that the ore does not serve only, as in the ordinary process, of puddling
for the transformation of foundry iron into iron by the action of the
oxygen of the ore, but the ore also augments the yield of product. If,
for example, the ore employed gives on analysis 50 per cent., it will
yield by this process about 40 per cent. to the puddling, the waste will.
therefore be only 10 per cent.; it is besides in proportion to the richness
and the purity of the ore, and it encloses the phosphorus, sulphur,
arsenic, and other matters which have become eliminated by the
oxide of iron.
The annexed Drawing shows an arrangement of puddling furnace to
carry
this process into effect.
Figure 1 is a longitudinal, and Figure 2 a horizontal section of a
puddling furnace capable of being heated by a grate or by gas. The
mixture of iron ore screened and pulverized with the carbonated or
hydrogenated reducer and the flux, either in a powdered form or in a
mortar or brick form, is introduced into the top of a retort A, resting
upon an auxiliary floor B of the puddling furnace; this retort can be
heated either by a special grate D placed beneath, or preferably by the
heat escaping from the puddling furnace itself heated by a grate D¹
when the mixture in the retort A has reached a clear red or even a pale
yellow heat, and is thus shown to be reduced and cemented; the work-
man lets it drop upon the auxiliary floor B, and carries it upon the
ordinary floor C of the puddling furnace.

page_text: In the arrangement shewn at Figure 3 the mixture of screened and
pulverized ore, together with the carbonated and hydrogenated reducer
and the flux is heated, that is to say, reduced and cemented upon an
auxiliary floor B₁, heated by a special grate D placed beneath. The
auxiliary grate B', forming a continuation of the ordinary grate C of the
puddling furnace should be placed like the latter at about 6 or 8 inches
downwards from the fire bridge and the door of the furnace, so that the
pulverized mixture either in a mortar or a bsick form can be heated at
its upper part with the flame escaping from the furnace and the flame
or gases which escape from itself in proportion to the heating and
the reduction. In both cases after reduction and cementation, the
mixture is carried upon the floor C of the puddling furnace, the stirring
causes the appearance of the iron which is then puddled, rolled into
balls, and deprived of dross or slag by the beating of the steam hammer
or by rolling.
+
The iron thus obtained can be transformed into the irons of commerce,
or can be carried intothe bath of the reverberatory furnace for the manu-
facture of steel according to the before referred to process for that purpose
of the present Invention, Mr. Martin.
The iron could be directly obtained from the mineral without the
previous reduction upon the auxiliary floor or in the retort by imme-
diately carrying the pulverized mixture (ore, carbon, or hydrocarburet
and flux) especially when there is an excess of carbon upon the floor
of the puddling furnace itself, but the operation of reduction would be
much slower and far less complete. As a consequence from what pre-
cedes the operation can be aided and facilitated either by carrying cast
iron to the orc, or by carrying in the method known as the "boiling
furnace method reduced ore into a bath of iron in a puddling furnace,
heated by a grate or by gas..
The vertical or horizontal retort for the reduction and cementation
can be fixed or revolving, and in this retort the ore can be exposed to a
current of reducing gas to promote the reduction.
And 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 substantially as herein-before described for the
direct production of iron and steel from the orcs of iron.

page_text: Secondly. The apparatus or furnaces and retort substantially as herein-
before described and shown in the accompanying Drawings for the
direct production of iron and steel from the ores of iron.
In witness whereof, I, the said Thomas James Smith, have here.
unto set my hand and scal, Fifteenth day of October One thousand
cight hundred and seventy-three.