and Steel Directly from Ores.
Year: 1885

page_text: and Steel Directly from Ores.
I, OLIVER IMRAY of N° 28 Southampton Buildings, in the County of Middlesex,
Fellow of the Institute of Patent Agents do hereby declare the nature of this
invention to be as follows:-
According to this invention, the ore is mixed with suitable flux and charged into
a flame-furnace, by preference a gas-furnace, where the material is heated by
combustion of carbonic oxide or water-gas to the temperature required for reduc-
tion. As soon as this temperature is reached, all openings through which atmospheric
air can enter the furnace are carefully closed, and the ore is reduced by carbonic
oxide water-gas or other reducing gases admitted into the furnace. Finally the
reduced mass is melted down, and by suitable regulation of the flame and addition
of fluxes, chosen according to the nature of the ores under treatment, the metallic
bath is converted into the desired product.
ABEL & IMRAY,
Agents for the Applicant.

page_text: An Improvement in the Process of Extracting Wrought Iron
and Steel Directly from Ores.
I, OLIVER IMRAY of No 28 Southampton Buildings, Chancery Lane in the
County of Middlesex, Fellow of the Institute of Patent Agents do hereby declare
the nature of this invention and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement:-
All known methods of directly extracting wrought iron and steel from the ore
present the drawback of not being economical, some on account of the considerable
consumption of fuel and unavoidable waste of metal, others on account of the
costly apparatus required for carrying them into practice.
According to the present invention these drawbacks are overcome by the
employment of the following process.
The ores under treatment are first buddled and roasted if these operations be
made necessary by the special nature of the ores; they are then mixed with the
fluxes necessary for producing a slag of the required nature; and thus prepared they
are brought into the furnace which may have a fixed or rotary hearth. By the
combustion of gas in the well known manner the charge of the furnace is heated
to the temperature at which a chemical reaction between the ores and reducing
substances put in contact with them can take place. When this temperature is
reached, the access of air to the furnace is wholly cut off and reducing gases are
caused to enter the furnace. By these gases the iron is reduced in the form of
spongy iron, and it is then melted down, the furnace being heated to the required
high temperature by carrying on the combustion of gases within the same again.
To the bath of liquid iron thus obtained, the quantity of pig-iron, necessary for
carburizing the product to the required degree is added as well as the other
substances such as manganese etc by which certain qualities are to be brought
about.
When no pig-iron is to be used, or when it is desired for any other reason to
avoid the passing of the iron through the state of utmost softness, viz. its state of
nearly chemical pureness, some carbon may be added to the charge in the form of
charcoal, coke, etc. The quantity of these materials to be added depends on the
desired degree of carburization and on the unavoidable waste.
It results from the above statements that regenerative gas furnaces destined to
be used for the described process ought to be provided with suitable contrivances
which afford possibility for alternately conveying to the furnace gases mixed with
atmospheric air, that is to say gases capable of combustion, or pure gases which
exert a reducing action.
A regenerative gas-furnace adapted for the purpose in question is shewn on the
annexed drawings, in which
Fig. 1 shews at the left hand half a vertical section along the axis of the hearth
(on line I K Fig. 2), and at the right hand half a vertical section through a plane,

page_text: parallel to the back-wall of the furnace, and passing through the gas and air flues
(on line L M, Fig. 6).
Fig. 2 shews a section parallel to the hearth-bottom (on line N. O, Fig. 1).
Fig. 3 is a sectional end elevation of the furnace proper (on line P, Q. Fig. 2).
Fig. 4 is a vertical section, passing through the burners at one end of the furnace
proper, and running along the corresponding air Blue and through the reversing
valves of both the air and gas flue (on line R, S, Fig. 1).
Fig. 5 is a sectional elevation, shewing the reversing and cut-off valves of the
air flues, the flue running to the chimney and the chimney itself (on line G, H.
Fig. 6).
Fig. 6 shews at the left hand half a horizontal section through the regenerative
chambers filled up with checker work of bricks (on line A, B Fig. 4), while the
right hand half is a horizontal section, in which the top portions of both
regenerators, the space in front of the tapping hole, and the chimney are visible
(on line C D Fig. 4).
The following is a detailed description of the manufacture according to this
invention of wrought iron and steel from a special kind of ore, the ore of the
Erzberg in Styria (native ferrous carbonate) being chosen, as the composition of
this ore is generally known to metallurgists.
As stated above, the first of the operations to which the ore is to be submitted,
consists in the mixing of the same with a suitable flux, that will combine with the
earthy constituents of the ore to a slag having nearly the same melting point as
the iron. Obviously the choice of the flux will also have to depend on the nature
of the materials to be found in the vicinity of the works; in the case in question,
the nature of the ore requires for a convenient scorification the addition of an acid
flux, and the acid material to be found in the vicinity of the Erzberg is a clay-slate.
This clay-slate is of such a chemical composition as to give with the ore a mixture
of desirable quality when 3rds of the ore are roasted while rd remains raw.
The chemical composition of this mixture of calcined and raw ore is as
follows:-

page_text: the necessary quantity of flux, the groups II only of both the ore and clay-slate
analysis-table are to be taken into account, and it is determined how many units
of one group are to be combined with one unit of the other group for giving
neutral silicates that fuse with difficulty. In this manner it is found that, for the
manufacture of 100lbs of iron, there are needed 221lbs of the ore in question
and 22lbs of the flux; then 74lbs of slag are formed, 10.6lbs of water and 17.2lbs of
carbonic acid volatilized, and 41 pounds of oxygen are bound by reducing gases.
с
In order to prevent the bed or hearth of the furnace, upon which the reactions
above stated are to take place, from being corroded by the acid flux while the
scorification is going on, the said bed or hearth is provided with an acid lining of
pebble-stones; as soon as the ore mixed with the flux has been brought into the
furnace this is set to work. To this end, the reversing valves e e¹ contained in the
sheet iron casings b 61 (see Figs. 4 and 5) which connect the ends of the two air
flues c c¹ and of the two gas flues d d, are brought into the same position, and
then air is allowed to enter the casing b and gas, conveyed from a regenerator, is
made to enter the casing 61. The chimney f, which is connected to the casings or
bells b b by means of a flue g and flues h h', exerts a sucking action on those of
the gas and air flues c c¹ and dd, which are shut off from the air and gas supply
by means of the valves e and e¹, for instance on the flues c¹ and d¹; in consequence
hereof, the air and gas are sucked through the flues c and d and the regenerative
chambers ij, filled up with checker work of refractory bricks, through the burners,
which are formed by the slots o¹ d', into the furnace proper a where the mixture of
air and gas is kindled. The hot products of combustion escape through the
opposite burners d³, the regenerative chambers j¹¹, the refractory brick-checker
work of which is thus heated, and thence through the flues c¹, d³, h, h¹, g to the
chimney f. After a certain time, the direction of the current is reversed in the
well-known manner by means of the valves e and e¹, when the gas and air are
conveyed to the furnace through the flues c'd, the heated brick checker-work of
the chambers ¹ and ¹, and the burners c³ ³; as soon as the gas and air mix, they
are inflamed in consequence of the high temperature they have obtained while
passing while passing through the brick checker-work. The products of combustion
then escape through the burners c³ d', regenerative chambers ij, and flues c d h h¹g
to the chimney f.
The gas used may be oxide of carbon or water gas, according to whether the fuel
at ones disposal be lignite or pit-coal.
When the ore and flux have been heated by the described burning of gases to
the temperature required for reducing the oxides of iron, namely to a temperature
of about 1000° Celsius, the supply of air to the furnace a is wholly cut off and gas
alone is allowed to enter the same. This is effected by closing the clack-valve k
on the casing b, the disk valve v within said casing, and the valve v¹ in the
flue h, which connects the air flues c c¹ to the chimney f. The pure gas, which
now passes through the furnace a, and the velocity of the current of which can be
regulated by means of the valve * arranged in the flue h¹, deprives the oxide and
protoxide of iron, which are contained in the ore, of their oxygen, entering into
combustion therewith, while the iron remains in the furnace in the form of
spongy iron.
When the reduction is completed, as may be seen from the nature of the
escaping gases, the spongy iron requires to be melted down at a very high
temperature, and this is done by causing, as before, a mixture of gas and air to
enter the furnace; to this end the valves kvv¹ and v³ are opened again.
As soon as the iron is thus converted into the liquid state, there is yet one
operation to be carried through viz, the carburization of the metal to the desired
degree; this is done by adding to the molten mass a quantity of pig-iron which
contains the total amount of carbon to be combined with the iron.
For immersing into the metal bath this pig-iron and other materials by which,
in certain cases, special qualities are to be imparted to the wrought iron or steel to

page_text: be manufactured, the working-bole a¹ of the furnace, which has been hermetically
closed till this moment, is broken open.
Finally, the furnace is tapped at a and the finished product is allowed to flow
into chill-moulds m provided for this purpose and wherein the metal solidifies
to ingota.
It may be mentioned that, although it be recommendable to carry through the
process with the aid of a regenerative gas furnace, as such furnace enables the
obtaining of high temperatures in an economic manner, any other suitable furnace
may be used.
In regenerative gas furnaces destined to serve for the manufacture
of wrought iron and steel by the described process, the regenerators i¹ of the gas
flues are made larger than those ; ¹, of the air flues, as the former are to be used
during a longer time than the latter. As stated, the furnace may be provided
with a fixed or rotary hearth, and instead of carburizing the iron by the addition
of pig-iron to the melted mass, it may be done by adding coal to the ore.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1st The herein described process of manufacturing wrought iron and steel
directly from the ore in a single furnace, the said process consisting in heating in
a reverberatory furnace by means of the combustion of gases, and to a temperature
at which reduction can take place, the ore mixed with the fluxes necessary for the
scorification of the gangues, in then wholly cutting off the supply of air, and
causing reducing gases to flow through the furnace, then again introducing
combustible gases so as to melt down the spongy iron thus obtained, and finally
adding to the bath of liquid iron a quantity of pig-iron sufficient to carburize the
same to the desired degree with or without other materials by which special
qualities are to be produced.
2nd The herein described process of manufacturing wrought iron and steel
directly from the ore in a single furnace, the said process consisting in heating in
a reverberatory furnace by means of the combustion of gases, and to a temperature
at which reduction can take place, the ores mixed with the fluxes necessary for the
scorification of the gangues and with a quantity of charcoal or coke sufficient to
carburize the product to the desired degree, in then wholly cutting off the supply
of air, while reducing gases are caused to flow through the furnace, and in finally
melting down the spongy iron thus obtained by the renewed introduction of
combustible gases.
3rd In a regenerative gas-furnace destined to serve for the processes referred to
in the preceding claims the arrangement within the casing 6 connecting both air
flues and containing the reversing valve of a cut-off valve v; in the flue h
connecting the casing b to the chimney f of a cut-off valve v, and in the flue
connecting the gas flues to the chimney f of a regulator-valve v³ for the purpose of
cutting off at will the supply of air, and controlling the supply of gas, substantially
as herein described with reference to the accompanying drawings.
ABEL & IMRAY,
Agents for the Applicant.