Improvements relating to the Electrolytic Production of Metallic Alloys, and to Apparatus therefor.
Year: 1898

page_text: Date of Application, 18th Mar., 1898-Accepted, 10th Sept., 1898
COMPLETE SPECIFICATION.
Improvements relating to the Electrolytic Production of Metallic
Alloys, and to Apparatus therefor.
I, CHARLES ERNEST ACKER, of East Orange, Essex County and State of New
Jersey, United States of America, Chemical Engineer, 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 statements: -
My invention consists of an improved electrolytic process and apparatus for
the manufacture of metallic alloys.
Briefly stated, the process consists in submitting a fused salt, eg., the chloride
of sodium, to electrolysis, while superimposed upon a molten mass of the heavy
metal, e.g., lead, constituting the cathode, and thereby forming an alloy of sodium
and lead; in mechanically circulating this alloy, so that the lighter and richer
portion formed on the surface will be removed into and accumulate in an adjoin-
ing chamber, whence it will overflow, or from which it may be periodically tapped,
or where the contained sodium may be removed by vaporization from the free
and exposed surface of the alloy and separately collected, or removed by the action
of steam, air, or any other reagent, or the alloy and the sodium may be simul-
taneously produced and separately collected.
In the process here described, continuity, regularity and uniformity of action
are secured and rich alloys produced by providing a system of circulation of the
metal of the cathode which is in effect a continuous skimming operation, whereby
the lighter surface alloy thus secured is drawn into an adjoining chamber where it
accumulates by reason of its lower specific gravity at and near the surface.
In the accompanying drawings I have shown one form of furnace which may
be used in carrying out my process.
Figure 1 is a vertical section;
Figure 2 is a section along line 2-2 of Figure 1;
Figure 3 is an enlarged detail view of the screw in elevation; and
Figure 4 is a plan view of the screw partly in section on the same scale as
Figure 3.
Similar letters of reference refer to corresponding parts in the several views
of the drawings.
K is a cast iron hearth, supporting by suitable lugs the cast iron pan or parti-
tion L, and wrought iron cylindrical chamber G. Upon the rim of the hearth
is the magnesia lining J and surrounding the chamber is a magnesia cylinder H.
A tile cover I rests on the magnesia cylinder and lining, and is provided with
openings for a suitable number of anodes as at R, and openings for feedings
salt W, as at V, side walls being provided on the salt receptacle. Through the
centre of the hearth a tube 0 projects upwardly to a point above the intended
level of alloy in th chamber, and surroundir this tube in the furnace is an
inverted cup 4, carrying at the bottom a screw M, the blades of which are designed
to force the liquid outwardly and away from the axis. The cup with the screw
Price 8d1

page_text: is mounted rigidly on the shaft N, supported, and having its bearings below the
furnace.
Suitable pipes for feeding lead, collecting the products, &c., are provided as
described later, and the whole is suitably encased in brickwork or equivalent heat
insulating material. In starting the furnace, sufficient molten lead is run in to
seal the chamber G and cover the pan or partition L. The anodes having been
previously placed in position with one of them lowered into the molten lead, the
full current is turned on, passing down through the one anode, through the lead
to the exterior of the furnace by any suitable connection, as at Z. Dry salt is
quickly fed in on top of the lead and around the anodes. The anode carrying
the full current is then raised slightly above the lead, as indicated by the volt
meter, thereby forming an are the surrounding salt quickly melts and thereafter
conducts the current, the melt soon extends to the anodes on either side, until
the entire charge is fluid, and the furnace works steadily at nearly the normal
voltage, the salt is decomposed by the current, chlorine being liberated at the
anodes and passing off through channel and pipe U to the point where it is
utilized; the sodium is liberated at the cathode surface, where it forms an alloy.
The screw M is set in motion, and by a comparatively slow but positive action,
pulls the surface alloy continuously down between the pan or partition and
chamber, when the lighter portion rises to the surface in the chamber and the
heavier alloy sinks and follows the pull of the screw and passes up under the pan
or partition to the surface, where it comes in contact with the molten electrolyte,
becomes the true cathode, and takes up the liberated sodium as it passes over the
pan toward the chamber. The screw is turned fast enough to produce a definite
movement toward and into the chamber of the shallow body of alloy in contact
with the electrolyte. The forced circulation of this surface alloy continuously
removes that part which is richest in sodium away from the molten salt. Salt is
fed at regular intervals until the desired working depth is obtained, and to replace
that decomposed. The alloy becoming richer and lighter and more bulky rises
in the chamber to a height dependent on the height of the column of salt outside
and the relative specific gravity of the alloy and the salt. An overflow pipe P
which projects upwardly in the chamber to a point previously determined, or
which runs from the exterior of the furnace thereto, may be used whenever the
alloy is to be removed bodily. Down it the alloy will overflow, into receptacle Q,
almost continuously of nearly uniform richness, provided appropriate charges
of lead and salt are fed at frequent and regular intervals. Lead is introduced
in small charges either in the molten state or in pigs of uniform weight, at definite
intervals into the pipe S which is sufficiently close to the highly heated interior
of the furnace to insure the fluidity of its contents. The charge therefore enters
the furnace from below, the oxide and seum remaining on the surface in the
feed pipe. The salt is heaped up on top of the furnace and surrounding the anodes
to a considerable depth, and thus serves to keep in the heat, to effect a packing
around the anodes by bridging over the small annular spaces, surrounding them
where they pass through the cover, and to utilize what heat would otherwise be
lost to thoroughly dry and heat the salt before it is introduced into the furnace.
I consider this utilization of the salt for purposes specified as being of great value,
dispensing as it does with packings, lutes, etc., besides conserving the heat of the
furnace.
After the furnace has been in operation several hours, and the walls have become
thoroughly heated, it will thenceforth work at maximum economy and the volt
meter needle will remain stationary as long as the proper operating conditions
are fulfilled.
I am unwilling to be confined to the details of the furnace which I have illus-
trated. Various arrangements of parts other than those illustrated may be used
without in any case departing from the essential principle of operation, described
in the specification; namely, the removal of the lighter and richer alloy from

page_text: the cathode surface into a chamber where it is no longer in contact with the
molten electrolyte.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, what I claim is:
1. The process of making an alloy of a heavy metal such as lead, tin, zinc, etc.,
with a metal of an alkali or of an alkaline earth, consisting in reducing the heavy
metal to a molten state, and employing it as a cathode, electrolytically decom-
posing a fused salt of the metal of an alkali or of an alkaline earth, while super-
imposed upon the heavy metal, removing the resulting alloy from the region of
the electrolyte, subsequently permitting its different portions to stratify, and
flowing off the lighter portion from the surface, substantially as specified.
2. The process of making an alloy of a heavy metal such as lead, tin, zinc, etc.,
with a metal of an alkali or of an alkaline earth, consisting in reducing the heavy
metal to a molten state, and employing it as a cathode, electrolytically decom-
posing a fused salt of the metal of an alkali or of an alkaline earth while super-
imposed upon a heavy metal, removing the resulting alloy from the region of the
electrolyte, subsequently permitting its different portions to stratify and returning
the heavier portion to the point where it takes up the lighter metal, substantially
as specified.
3. The process of making an alloy of a heavy metal such as lead, tin, zinc, etc.,
with a metal of an alkali or of an alkaline earth, consisting in reducing the
heavy metal to a molten state and employing it as a cathode, electrolytically
decomposing a fused salt of the metal of an alkali or of an alkaline earth while
superimposed upon the heavy metal; circulating the cathode metal in a stream
past the anode or anodes into another chamber and automatically removing a
portion of the metal when the metal rises above a certain height, substantially
as specified.
4. The process of making an alloy of a heavy metal such as lead, tin, zinc, etc.,
with a metal of an alkali or of an alkaline earth, consisting in reducing the
heavy metal to a molten state and employing it as a cathode, electrolytically
decomposing a fused salt of the metal of an alkali or of an alkaline earth while
superimposed upon the heavy metal, circulating the cathode metal in a stream
past the anode or anodes into another chamber, removing a portion of the metal
from near the bottom of said chamber and returning it to the circulation, sub-
stantially as specified.
5. In an apparatus for electrolytically decomposing fused salts, the combination
of a covering for said apparatus provided with an opening or openings for receiving
an anode and for feeding a salt, a body of salt resting on said covering partly
closing said openings, and a molten metallic cathode.
6. In an apparatus for the electrolytic manufacture of an alloy from a heavy
metal such as lead, tin, zinc, etc., with a metal of an alkali or of an alkaline earth,
the combination with an anode of a cathode composed of the heavy metal, a
chamber with which the metal of the cathode is in fluid communication sealed
against access of the electrolyte, into which the alloy rises, means for automatic-
ally removing the alloy from the chamber when it exceeds the desired level, and
a circulating device arranged to direct the surface flow of the molten metal
transversely below the electrolyte, substantially as specified.
7. In an apparatus for the electrolytic manufacture of an alloy from a heavy
metal such as lead, tin, zinc, etc., with a metal of an alkali or of an alkaline earth,
the combination with an anode of a cathode composed of the heavy metal, a
chamber with which the cathode metal is in fluid communication and which is
sealed against access of the electrolyte, a circulating device, a pan or partition
immersed in the cathode metal slightly below the true cathode surface, and
having an extension or continuation toward the circulating device, openings or
channels being provided in or partly formed by said pan or partition and its

page_text: extension, whereby the molten metal may flow underneath and over the same,
substantially as specified.
Dated this 18th day of March 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.