Improvements in the Process of and Apparatus for Extracting Iron from its Ores and in Obtaining Bye-products.
Year: 1888

page_text: Improvements in the Process of and Apparatus for Extracting Iron
from its Ores and in Obtaining Bye-products.
I HENRY HUGH EAMES of 301 North Charles Street, Baltimore City, in the County
and State of Maryland United States of America, Geologist and Chemist, 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 and accompanying drawings :-
My Invention relates to improvements in the method and devices for extracting iron
from its ores and in obtaining bye-products and consists of such construction and
operation of the device whereby a current of electricity is caused to pass through the
mass of heated ore and produce therein by the electrolyzing action, such molecular
change in the ore that the substances thereof which usually combine with the metal
will be liberated and escape therefrom, and leave a pure metal. Special arrangements
being provided for collecting the pure sulphur from sulphide ores, which will be
liberated from these ores in the purifying process; all of which I accomplish by the
devices hereinafter fully described and claimed, reference being had to the accom-
panying drawings in which,
Fig. 1. shows a side elevation of the device, a portion of the casing removed; the
furnace and one retort shown in section.
Fig. 2. is an enlarged detailed view of one retort shown partly in section.
Fig. 3. is a view looking down on the device, a part of the cover removed.
Fig. 4. is a view looking down on the retort, as shown in Fig. 2, the cover of
the hopper removed.
Fig. 5. is a cross sectional view of the retort, the section being indicated by the
line A---A in fig. 2.
The same figures refer to the same or similar parts throughout the several
views.
The figure 8 denotes the casing of the device which may be constructed of brick
as shown in Fig. 1, or it may be constructed of iron, in which case the interior
thereof is lined with some suitable insulating material which will retain the heat
therein. Placed inside the casing, in such manner that the heated gases from the
furnace 31 will impinge against the exterior surfaces thereof are the retorts 9 of the
cylindrical form shown, the lower ends extending through the bottom of the casing
and having thereon the chamber 10 in which is provided the perforated, sliding
bottom 11. The upper ends of these retorts 9, which extend through the top of the
casing are provided with a hopper 12 thereon for convenience of charging the retort ;

page_text: a cover 13 serving to render this top air tight and prevent the
of
escape gases there
through a vent for the retort being formed by the pipe 14 through which the gases
from the roasting ore escape to the atmosphere through the trap 15, whereby the
accumulating gases in the retort should there be such, will be relieved automatically
and an inflow of air prevented. The furnace 31 may be of any of the known forms
wherefrom the heated gases of combustion will pass through the flue 32 into the
interior of the casing 8 and impinge on the exterior surfaces of the retorts which
are so distributed in the said casing as to receive the greatest action from these
heated gases in their passage to the smoke pipe 33.
Under each retort 9 is placed an independent and air tight receiving vessel 16 in
which may be deposited the refined ore or wherein will fall, through a suitable opening
in the bottom 11, the liquid sulphur which has been liberated from the ore in the
retort by the heating and electrolyzing action therein; the bottom of the chamber 10
terminating in the open flanged end 17 by which an air-tight joint is made with the
corresponding flanged opening 18 of the receiving vessel 16, which is made of such
height that these two flanged ends 17 and 18 will meet and may be rendered air-tight
by clay or any of the devices in common use. The receiving vessels 16 which catch
the sulphur are lined with porcelain or some suitable non-metallic material to prevent
the action of the sulphur on the material of which the vessel is formed, and in order
to exclude the air from the interior thereof, preparatory to its removal from the retort,
there is provided in the open end thereof the sliding cover 19 which on being closed
keeps the heated sulphur in the vessel out of contact with air until it becomes
sufficiently cooled when this cover 19 is slid from over the mouth of the vessel and
the sulphur may be removed there through, or if deemed more convenient, suitable
doors may be provided in the side of the vessel from which to remove the hardened
sulphur.
now come to the construction of the retorts 9 whereby a current of electricity is
caused to pass through the mass of the ore with which the retorts are charged and by
which such molecular change is produced in the ore that all the sulphur and other
combined matter, in the ore which is foreign to the metal, will, by the action of heat,
and electricity, be eliminated therefrom and the metal left in such condition that it
may be easily obtained by the usual methods of magnetization.
As shown in the drawings the retorts 9 are of cylindrical form and may be
built of brick, or, as shown, the casing 20 thereof may be of iron, in which case, to
preserve proper insulation for the electrolyzing process, the interior of the retort is
lined with fire clay 21 or some suitable insulating material that will stand the
temperature to which the retort is subjected; on the inner surface of this lining 21
are placed the metallic plates 22-23 which may be of carbon or any suitable
conductor of electricity, they being of a segmental form, set opposite and insulated
one from the other and extended nearly or wholly the length of the retort. Attached
to the plates 22-23 are the conducting rods 24 that extend outside the retort and may
be extended through the casing 8, the conducting wires 25 connecting the respective
plates with the negative and positive poles of a dynamo or galvanic battery; suitas e
insulating boushes 26 being. provided in the metallic casings 8 and 20 to preserve
proper insulation at these points whereby the said plates 22-23 will form the
terminals of the dynamo or galvanic battery.
The following is the manner of operating when it is desired to refine either the
oxide or the sulphide ores of iron, wherefrom is to be eliminated the oxygen, sulphur
and phosphorus.
The sliding bottom 11 of the retort being closed the retorts are charged, with the
iron ore 27 which has been broken into lumps of convenient size and has mixed
therewith a suitable quantity of carbon in any of the common forms and lime stone;
the quantities of the carbon and lime stone depending upon the character of the ore to
be treated which may contain more or less of oxygen, sulphur and phosphorus that
are to be acted upon by the carbon and lime stone. Thus prepared the ore is placed.
in the retorts 9, through the hopper 12, after which the cover 13 is closed and
rendered air tight by the locking device 28; whereby the ore may be heated in the

page_text: retort out of contact with the air and other extraneous gases; the vent pipe 14 and
the trap 15 thereof serving to relieve any excess of pressure from accumulating gases
in the retort without permitting the air to enter; the electrodes 22-23, which form
the terminals of a dynamo or galvanic battery, being so placed in the retort that the
entire mass of the ore to be treated will be primarily placed between the said
electrodes, and at the proper stage of the operation the electric circuit between the
said electrodes will be completed, by the conductivity of the ore; the entire mass of
the ore being in and forming part of the electric circuit.
To impart the necessary heat to the ore in the retorts 9 the gases from the furnace 31
is caused to impinge upon the exterior surfaces of these retorts, whereby the heat will
be transmitted to the ore through the material forming the vessel, and the ore therein
will be heated out of contact with the gases of combustion.
The ore placed in the retorts, as described, possesses in the natural, cold state
insufficient conductivity to complete the electric circuit between the plates 22-23°
which condition of the ore continues until a temperature of about 1000 degrees Far.
has been imparted thereto from the furnace, at which temperature a liberation of the
oxygen of the ore will begin; this oxygen uniting with the carbon in the retort to
form carbonic acid and carbonic oxyd gases; a part of the oxygen of the ore uniting
with the sulphur of the ore, which is likewise freed at this temperature, and forming
sulphurous acid which in turn, in consequence of the affinity therefor, immediately
unites with the lime of the lime stone, and forms a sulphate of lime, that may easily
be separated from the refined ore; the phosphorus of the ore will likewise be
liberated at this temperature and will unite with other parts of the lime of the lime stone
in contact therewith and form a phosphate of lime which, like the sulphate of lime,
may be easily separated from the refined ore; the gases which have been evolved in
the retort escaping to the atmosphere through the trap 15 in the manner described.
When this temperature of about 1000 degrees Far. has been imparted to the ore in
the retort which temperature it is found best to maintain throughout the operation-
and the liberation of the oxygen, sulphur. and phosphorus of the ore has commenced,
the mass of the ore will at this stage of the operation possess sufficient conductivity
to permit the passage there through of the electric current and thus complete the
circuit between the plates 22-23, the conductivity of the ore increasing as the refining
process approaches completion and the tension of the electric current inay be lessened
proportionally as the conductivity of the ore increases; as in the opertion the quantity
of electricity passed through the mass of the ore is of more importance than a high
tension of electricity, which condition of the current can at any time be ascertained by
a suitable instrument therefor placed in the circuit. As soon as the electric current is
established through the mass of the ore a molecular change is produced therein which
causes a more rapid liberation of the oxygen, sulphur and phosphorus thereof, this
molecular action extending to the centre of each lump of ore and causing all the
matter which is combined with the metal in the ore to be driven therefrom which
liberation continues until all the said combined matter is carried off when the refined
ore may be discharged into the vessel 16 wherein it may be cooled out of contact with
the air this vessel 16 fitting air-tight to the bottom of the retort 9 and having an
air-tight sliding cover 19 by which the air is excluded from the vessel and any
oxidation of the refined ore prevented while in the heated state.
3
In view of the variable quantities of the oxygen, sulphur and phosphorus which
each different character of ore may contain, it is found necessary in practice to mix
there with a greater quantity of the carbon and limestone than is absolutely required
to produce the chemical changes and new combinations herein set forth; the excess of
the carbon and limestone which has been mixed with the ore passing through the
process unchanged and which in the end may be easily separated from the refined ore.
It will thus be seen that the quantity of carbon and limestone will depend upon the
character of the ore to be treated; the quantity absolutely required to support the
desired chemical change being about five (5) per cent. of carbon and two (2) per cent.
of limestone and to meet this absolute requirement an excess of the carbon and lime-
stone is mixed with the ore.

page_text: The process just described is the manner of operating when the ore to be treated is
an oxyd of iron in which case sufficient carbon has been mixed therewith to unite with
the oxygen of the ore and form carbonic acid or carbonic oxide gas the lime of the
limestone serving to convert the sulphur of the ore into the sulphate of lime and the
phosphorus thereof into the phosphate of lime; the carbonic oxide gas which has been
liberated from the limestone with that formed by the oxygen of the ore with the
carbon, serving, with the aid of the electric current, to more rapidly eliminate the
remaining matter combined with the ore. This method of refining the ore by heat
and electricity may be employed with equally good results in refining the sulphide
ores of iron in which case the carbon and limestone are omitted, the ore being broken
and placed in the retort 9 as heretofore described, and therein heated to about 1000
degrees Far.. at which temperature the conductivity of the ore will become sufficient
to establish the electric current between the plates 22-23 and at the same time the
liberation of pure sulphur will begin which at this temperature is in the liquid state
and will, per descendum, fall to the bottom of the retort from whence it falls into the
receptical 16 as described, the conductivity of the ore becoming greater as the process
advances and producing such molecular change in every particle of the ore as to expel
therefrom, by this action of heat and eloctricity, all the sulphur therein and leave the
metal in a pure state.
A striking advantage of my invention is that by performing the operation as herein
set forth (by the action of the electricity in an air-tight vessel, whereby a continuous
supply of heat is supplied the ore out of contact with the gases of combustion) I
absolutely control the changes of condition required to produce the pure metal; as in
dealing with the oxide ores of iron sufficient carbon and lime stone is mixed therewith
to produce by the action of heat and electricity, the desired result and in treating the
the sulphide ores of iron all extraneous influences are avoided whereby the puro
sulphur is eliminated by the said action of heat and electricity and the pure metal
remains.
Having described my invention and the manner of operating what I claim and
desire to secure by Letters Patent is :
1st. The process of desulphurizing the ores of iron consisting in first mixing with
the ore a suitable quantity of carbon and line stone and in this condition placing the
ore in a closed vessel wherein it will be heated out of contact with the air and with the
gases of combustion and in this air-tight and heated state causing a current
of electricity to pass through the entire mass of the ore for the purpose set forth.
2nd. A device for the desulphurization of the ores of iron.consisting of an air-
tight vessel in which is placed the ore to be treated and which is provided in the
interior thereof with the electrodes of a dynamo or galvanic battery; the said
electrodes occupying such position in the closed vessel that the entire mass of the ore
to be treated is primarily placed there between and held thereat during the entire
process of desulphurization, the exterior walls of the said closed vessel being wholly
surrounded and impinged upon by the heated gases from a furnace, whereby the ore
therein will be heated out of contact with the gases of combustion and when the
required temperature is reached such conductivity will be imparted to the ore that the
electric current between the said electrodes will be completed by the ore, the entire
mass of which will be in and form part of the electric circuit; and whereby additional
heat will be imparted to the ore, through the walls of the said closed vessel, during
the passage of the electric current through the ore, for the purpose set forth.
1
1000
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.