IMPROVEMENTS IN THE TREATMENT OF ORES, MORE PARTICULARLY IRON ORE, FOR THE MANUFACTURE OF CAST IRON, WROUGHT IRON, AND STEEL THEREFROM, AND IN THE APPARATUS TO BE EMPLOYED THEREIN
Year: 1872

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN THE TREATMENT OF ORES, MORE PARTICULARLY IRON
ORE, FOR THE MANUFACTURE OF CAST IRON, WROUGHT IRON, AND STEEL
THEREFROM, AND IN THE APPARATUS TO BE EMPLOYED THEREIN."-A com-
munication from abroad by La Société Metallurgique pour l'Exploi-
tation des Procédés Ponsard, of Paris, in the Republic of France.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 8th May 1872.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
5 of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE TREATMENT OF ORES, MORE PARTICULARLY
IRON ORE, FOR THE MANUFACTURE OF CAST IRON, WROUGHT IRON, AND STEEL
THEREFROM, AND IN THE APPARATUS TO BE EMPLOYED THEREIN," a communication
to mo from abroad by La Société Metallurgique pour l'Exploitation

page_text: des Frocedes ronsard, or raris, in the Republic of France, to be as
follows:-
This Invention relates to the treatment of ores generally but more
particularly of iron ores, and to certain arrangements and combinations
of apparatus whereby cast iron, wrought iron, and steel may be manu-a
factured direct from the ore in an economical manner.
This improved mode of treatment is based upon the separation of the
reducing fuel from the heating fuel and upon the exposure on a hearth
heated both from above and below of the ore mixed with fuel to the
action of a reducing gas obtained from a gas generator, the said mode
of treatment enabling either cast iron, wrought iron, or steel to be
produced direct according to the special arrangement of the apparatus
and tho nature of the ore employed. The apparatus is heated by gas
from a generator which is supplied with hot air from a heat regenerator,
the reduction and cementation of the ore and the production of the
metal being effected in one and the same apparatus.
The apparatus for the manufacture or production of cast iron consists
of a horizontal or nearly horizontal hearth heated both above and below
by the reducing flame from the gas of a gas generator which is situate
at one end of the apparatus and which is by preference supplied with
hot air from a regenerator at the opposite end. The ore and fuel mixed
together are supplied from a hopper on to the hearth above referred
to, and being there subjected to a current of carbonic oxide gas the
reduction and cementation are accomplished. The ore is then pushed
by rakes introduced through apertures provided for the purpose on to
the melting hearth which inclines downwards to a basin at the lower
end. The usual fluxes are introduced through a second hopper pro-
vided for the purpose above the melting hearth. A little beyond this
point a current of hot air from the regenerator arrives by a special
conduit and is divided by a series of fire-bricks into a number of thin
streams, which by mingling with the inflammable gas raises the tempe-
rature rapidly, the molten metal flowing down the licarth into the basin
below, whilst the flames pass on to the regenerator for the purpose
of heating the air which supplies the gas generator and the melting
hearth.
In making wrought iron direct from the ore a similar arrangement
of apparatus is employed, the gas from the generator being first brought
into direct contact with the ore and fuel on the hearth, which is slightly

page_text: inclined and which is first heated on the under side by a current of hot
gas, which passes thence by a special aperture into the working chamber
or body of the furnace. The reduced and cemented ore is pushed off
the first hearth by rakes or rabbles into the working chamber, which is
precisely similar to that of an ordinary puddling furnace, and is pro-
vided with currents of air or water to cool the surface. Above this
chamber are the apertures for the admission downwards of thin jets
of hot air, which completes the combustion of the gas which enters
the chamber. Under the influence of the elevated temperature thus
obtained the slag melts, and the iron may be agglomerated into balls
which are taken to the shingling hammer or otherwise treated. Tho
products of combustion return by a fluc to the regenerator for the
purpose of heating the air which supplys the gas generator. This
furnace may also be advantageously employed in puddling impure cast.
iron whereby the product is greatly improved, whilst the cost may
bo
reduced by introducing rich ore into the bath of molten cast iron.
In the manufacture of steel it is proposed to employ as the decar-
burating agent in the bath of molten cast iron the ores which have
been reduced upon an inclined reducing hearth situate in front of and
descending to the body or main hearth or chamber of the furnace.
By this arrangement only the completely reduced ores are allowed to
enter the cast metal bath. The inclined and long reverberatory hearth
on which the oro is reduced is heated by the gas from the gas generator,
and the latter is supplied with hot air from the regenerator situate at
the opposite end of the furnace. The ore suitably broken up is mixed
with the purest possible fuel and charged through a hopper on to the
hearth and spread thereon by rabbles worked through openings provided
for the purpose. The reduction is effected under the influence of the
hot carbonic oxide gas, which arrives from the generator by a double
conduit, and the reduced ore is pushed along into the bath of molten
cast iron where it is melted by the intense heat generated by the
combustion of the gas by the hot air which mixes therewith and is.
supplied from the regenerator in thin streams through suitable apertures.
in the roof of the furnace. The charge of ores is removed till a suffi-
cient quantity has entered the bath to convert the cast iron therein into
steel. This ore before being introduced on to the reducing hearth is
previously charged into a chamber heated by the flames from the the body
of the furnace

page_text: In all cases it is preferred to adopt the peculiar gas generator and
beat regenerator described in the Provisional Specification filed by me
on or about the Fifth day of April One thousand eight hundred and
seventy-two, No. 1018, whereby the required elevated temperature is
readily obtained.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
"
filed by the said John Henry Johnson in the Great Scal Patent
Office on the 6th November 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Mid-
dlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of May, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Henry Johnson, Her special
license, that I, the said John Henry Johnson, my executors, adminis-
trators, and assigns, or such others as I, the said John Henry Johnson,
my executors, administrators, or assigns, should at any time agreo
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 Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE TREATMENT OF ORES, MORE PARTICULARLY IRON ORE, FOR
THE MANUFACTURE OF CAST IRON, WROUGHT IRON, AND STEEL THEREFROX, AND IN
THE APPARATUS TO BE EXPLOYED THEREIN,” a communication to me from
abroad by La Société Metallurgique pour l'Exploitation des Procedes
Ponsard, of Paris, in the Republic of France, upon the condition
(amongst others) that I, the said John Henry Johnson, my executors
or administrators, by an instrument in writing under my hand and
seal, 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.

page_text: NOW KNOW YE, that I, the said John Henry Johnson, 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, referonce being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say :-
The said Invention relates to the treatment of copper and other ores
generally, but is more particularly applicable to the treatment of iron
ores, also to certain arrangements and combinations of apparatus whereby
cast iron, wrought iron, and steel may be manufactured direct from
the ore in a more economical manner than heretofore.
This improved mode of treatment is based upon the separation of the
reducing fuel from the heating fuel, and upon the exposure on a hearth
heated both from above and below of the ore mixed with fuel to the
action of a reducing gas obtained from a gas generator, the said mode
of treatment enabling either cast iron, wrought iron, or steel to be
produced direct according to the special arrangement of the apparatus
and the nature of the ore employed. The apparatus is heated by gas
from a generator which is supplied with hot air from a heat regenerator
the reduction and cementation of the ore and the production of the
metal being effected in one and the same apparatus.
The apparatus for the manufacture or production of cast iron consists
of a horizontal or nearly horizontal hearth heated both above and below
by the reducing flame from the gas of a gas generator, which is situate
at one end of the apparatus, and which is by preference supplied with
hot air from a regenerator at the opposite end. The ore and fuel mixed
together are supplied from a hopper on to the hearth above referred
to, and being there subjected to a current of carbonic oxide gas the
reduction and cementation are accomplished. The ore is then pushed
by rakes introduced through apertures provided for the purpose on to the
melting hearth, which inclines downwards to a basin at the lower end.
The usual fluxes are introduced through a second hopper provided for the
purpose above the melting hearth. A little beyond this point a current
of hot air from the regenerator arrives by a special conduit, and is
divided by a series of fire-bricks into a number of thin streams, which
by mingling with the inflammable gas raises the temperature rapidly,
the molten metal flaming down the hearth into the basin below, whilst

page_text: the flames pass on the regenerator for the purpose of heating the air
which supplies the gas generator and the melting hearth.
In making wrought iron direct from the ore a similar arrangement
of apparatus is employed, the gas from the generator being first brought
into direct contact with the ore and fuel on the hearth, which is slightly
inclined, and which is first heated on the under side by a current of hot
gas which passes thence by a special aperture into the working chamber
or body of the furnace. The reduced and cemented ore is pushed off
the first hearth by rakes or rabbles into the working chamber, which
is precisely similar to that of an ordinary puddling furnace, and is
provided with currents of air or water to cool the surface. Above this
chamber are the apertures for the admission downwards of thin jets
of hot air which completes the combustion of the gas which enters
the chamber. Under the influence of the elevated temperature thus
obtained the slag melts, and the iron may be agglomerated into balls,
which are taken to the shingling hammer or otherwise treated. The
products of combustion return by a flue to the regenerator for the
purpose of heating the air which supplies the gas generator. This
furnace may also be advantageously employed in puddling impure cast
iron, whereby the product is greatly improved, whilst the cost may
be reduced by introducing rich ore into the bath of molten cast iron.
In the manufacture of steel it is proposed to employ as the decar-
burating agent in the bath of molten cast iron the ores which have
been reduced upon an inclined reducing hearth situate in front of and
descending to the body or main hearth or chamber of the furnace. By
this arrangement only the completely reduced ores are allowed to enter
the cast metal bath. The inclined and long reverberatory hearth on
which the orc is reduced is heated by the gas from the gas generator,
and the latter is supplied with hot air from the regenerator situate at
the opposite end of the furnace. The ore suitably broken up is mixed
with the purest possible fuel and charged through a hopper on to the
hearth and spread thereon by rabbles worked through openings provided
for the purpose. The reduction is effected under the influence of the
hot carbonic oxide gas, which arrives from the generator by a double
conduit, and the reduced ore is pushed along into the bath of molten
cast iron where it is melted by the intense heat generated by the com-
bustion of the gas by the hot air, which mixes therewith, and is supplied
from the regenerator in thin streams through suitable apertures in

page_text: the roof of the furnace. The charge of ores is renewed till a sufficient
quantity has entered the bath to convert the cast iron therein into steel.
This ore before being introduced on to the reducing hearth is previously
charged into a chamber heated by the flames from the body of the
furnace.
In all cases it is preferred to adopt the peculiar gas generator and
heat regenerator describe in the Provisional Specification filed by me
on or about the Fifth day of April One thousand eight hundred and
seventy-two, No. 1018, whereby the required elevated temperature is
readily obtained.
And in order that the said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that pur-
pose shall refer to the several Figures in the annexed Sheets of Drawings,
the same letters of reference indicating corresponding parts in all the
corresponding Figures.
Sheet 1 of the Drawings relates to a furnace for the manufacture of
cast iron.
Sheet 2 rclates to a furnace for the production of wrought iron direct,
and for the puddling of impure cast iron.
Sheet 3 relates to a furnace for the direct manufacture of steel.
Figure 1 (Sheet 1) represents a longitudinal vertical section of a
furnace taken along the line A, B, C, in Figure 2; Figure 2 is a hori-
zontal section of the same taken along the line D, E, F, G, H, and the
line D, K, in Figure 1; Figure 3 is a transverse vertical section taken
along the line L, M, in Figures 1 and 2; Figure 4 is a similar section
taken above the ground but along the line L, J, in Figures 1 and 2; and
Figure 5 is a cross section of the conduit g.
As will be seen on referring to Sheet 1 of the Drawings when it is
desired to obtain cast iron the ore mixed with the fuel necessary for the
reduction and cementation after having been previously dried by being
caused to pass through or into a chamber heated by the waste heat from
the furnace are charged by means of a hopper 2 and spread out in a thin,
layer over the hearth a, which is heated not only on the surface but also..
by the flames which circulate underneath it; in this condition the sub-..
stances to be treated are subjected to the action of reducing gases¨
arriving by the conduit c from the gas generator u, the reduction and.
cementation being effected under the influence of the current of carbonic

page_text: oxide gas which traverses the reducing chamber and of the temperature,
the elevation of which is favored by the heating of the bottom of the
hearth a.
The substances are pushed by means of rakes introduced
through the orifices fon to the inclined hearth g of the melting furnacej,
whereupon the necessary fluxes are added through the hopper 8. At
this point is effected the admission of the hot air arriving from the
regenerator m by the conduit u, and which is caused by the tiles or
slatest of refractory clay to penetrate in the form of thin sheets in to
and amongst the combustible gases. The temperature becomes rapidly
elevated and the molten ore flows into the basin p whilst the flames pass
onwards to the regenerator m by the conduit o. Openings are pro-
vided in the side walls of the furnace for the introduction of rakes
for facilitating the pushing of the ore from the hearth a to the hearth
g.
The improved high temperature gas generator ", which it is preferred to
employ, receives the fuel from the boxes e provided with weighted valves 1
or bottoms and is supplied with hot air from the regenerator m through
the conduit g, the regenerator being for this purpose divided into two
compartments by a centre wall; one of such compartments (Figure 2)
opens directly into the conduit g, whilst the other, i, communicates
with the conduit n which supplies the burners t. Pipes & moreover 2
admit small streams of water into the bottom of that compartment
of the regenerator which supplies the gas generator, which water by
generating steam increases the draught of the apparatus. Any other
arrangement producing the same effect may however be employed for
this purpose.
2
Figure 1 (Sheet 2) is a longitudinal section of another arrangement
of furnace taken along the line A, B, in Figure 2; Figure 2 is a hori-
zontal section taken along the line L, M, in Figure 1; and Figure 3 is
a transverse section taken along the line C, D, in Figure 1. In this
description of furnace, which admits of the direct production of wrought 3
iron from the iron ore, the gas which arrives from the gas generator A
by the conduit I is brought in contact with the ore mixed with fuel
or other suitable substances which is charged through the hopper J on
to the hearth K, such ore being spread by means of rakes introduced
through the side openings L of the furnace. This hearth K is like that 3
of the first described furnace heated from the under side by a current of
heated gas which circulates between the partition walls M supporting
the hearth and enter the working chamber ○ through the opening N.
The reduction is thus accomplished under the most favorable conditions.

page_text: The reduced and cemented ores are pushed forward into the second
compartment O of the furnace, which is of the same form as an ordinary
puddling furnace with its currents of air or water for cooling the hearth.
At the upper part of this chamber are provided the burners P, which
; cause the hot air arriving by the conduit Q from the regenerator to
penetrate therein and effect the combustion of the gas from the reducing
chamber. By reason of the elevated temperature thus obtained the
cinder melts and the iron may be formed into balls which are carried
to the hammer, the products of combustion finally returned by the
conduit R to the regenerator, to be there utilised for the heating of the
air before escaping through the chimney.
The mode of producing the reducing gas is effected in this apparatus
in the same manner as in the preceding case by means of the improved
high temperature gas generator, of which a modified arrangement
is represented in the Drawings. Also as in the previous case the
regenerator is divided into two parts, one of which is specially intended
for supplying the gas generator and the other the burners P of the
furnace with bot air, of which the proportion is regulated by the
dampers F. Pipes E admit water to the bottom of the regenerator,
the vapour of which increases the draught. The air thus heated enters
the gas generator A by the lateral conduit G, and the gases produced
pass out by the flue H, which opens into the conduit I, which directs
the said gas into the reducing chamber of the furnace. In this system
of gas generators the fuel introduced by the valves B is held up by the
inclined planes O disposed at the lower part of the apparatus, so that the
hot air from the regenerator shall traverse the fuel horizontally and be
there transformed into a reducing gas possessing the clevated temperature
necessary for obtaining the perfect reduction of the ores employed.
This description of furnace may also be employed for the puddling of
impure cast iron, of which the product is greatly increased, and the cost
of production reduced by causing a quantity of iron obtained from rich
and pure ores to enter the bath of cast iron.
I may here observe that the improved process for making wrought
iron may be employed concurrently with rotatory puddling furnaces
such as those of Danks and others, the interposition of an apparatus of
this kind being easily effected in the furnace which is represented on
Sheet 2 of the Drawings in substitution for the compartment or puddling.
chamber O. If desired the rotatory puddler may be used separately, the

page_text: metal being introduced thercin from the improved apparatus herein-
before described.
"
The description of furnace illustrated on Sheet 3 of the Drawings
for the manufacture of steel is based on the employment as a decar-
burating in the bath of cast iron of iron ore reduced on the hearth
which occupies the front part of the furnace; this process of manu-
facture has already been attempted, but the insufficiency of the reduction
has hitherto prevented the practical application of the process.
Figure 1 (Sheet 3) is a longitudinal vertical section of the improved
furnace taken along the line A, B, C, D, in Figure 3; Figure 2 is a
transverse vertical section of the same taken along the line E, F, in
Figure 1; Figure 3 is a horizontal section taken along the lines G, H, and
I, J, in Figure 1; and Figure 4 is a transverse vertical section taken
along the line K, L, in Figures 1 and 3.
The improved furnace admits of the introduction only into the cast 1
metal bath of ores completely reduced; it consists of a long reverberatory
furnace j followed by a regenerator f, and preceded by a high temperature
gas generator a constructed on the improved system before referred to
supplied with hot air by the conduit b. The crushed ore, mixed or not
with fuel of as pure a nature as possible, is discharged from a hopper / 2
on to the hearth d, which may or may not be heated from below, as
in the previously described arrangements, over which hearth the ore is
spread by means of rakes introduced through the openings i made for
this purpose in the side walls of the furnace.
The reduction takes place under the action of the heated carbonic 2
oxide gas, which arrives from the gas generator a by the double con-
duit c; the ore is afterwards pushed into the cast-iron bath e, where it
melts under the action of the elevated temperature which is developed
at this part by reason of the combustion of the reducing gases by the
hot air which arrives by the conduit g from the regenerator.
The charges of ore are successively renewed until the quantity of
iron introduced into the bathe is sufficient for the transformation into
steel of the cast iron contained therein.
3
The quality of the steel may be ascertained by taking several samples
which are to be forged in the ordinary manner, and the quality may be 3
modified, according to the results of the test, by adding either more orc
or more cast iron. Before the orc is introduced into the furnace it

page_text: may be dried and heated by introducing it through a hopper 2 into a
chamber m heated by the flames which issue from the body of the
furnacej through the passage k.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,―
First. The herein-before described mode of treating ores generally, and
more particularly the ores of iron, based, on the on the one part upon
the separation of the reducing fuel and the heating fuel, and, on the
other part on the exposure of the ore mixed with fuel upon a heated
hearth to the action of reducing gases supplied from a gas generator,
such mode of treatment admitting of the direct production of cast
iron, wrought iron, or steel, according to the particular arrangement
of apparatus employed, the nature of the ores operated upon, and the
treatment to which they are subjected.
Second. The herein-before described peculiar construction and com-
bination of gas heated furnace and heat regenerator, whereby the
peculiar mode of treatment herein set forth may be carried out, and the
reduction and cementation of the ore and the production of the metal
are effected in one and the same apparatus.
Third. The three special types of furnace herein-before described
whereby is accomplished the production of cast iron, wrought iron, and
steel from iron ores in the manner and by the means herein-before
specified.
Fourth. The application and use of the processes and apparatus
berein-before described to and in the treatment of copper ores.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Sixth day of November
One thousand eight hundred and seventy-two.