Improvements in and Apparatus for the Production of Alloys of Sodium or Potassium with Lead.
Year: 1894

page_text: Date of Application, 20th Mar., 1894
Complete Specification Left, 18th Dec., '894-Accepted, 19th J n.,
1895
PROVISIONAL SPECIFICATION.
Improvements in and Apparatus for the Production of Alloys of
Sodium or Potassium with Lead.
We ALBERT EDWARD HETHERINGTON Ph.D. and FERDINAND HURTER, Ph.D.
both of Central Laboratory Widnes in the County of Lancaster Analytical
Chemists and EDMUND KNOWLES MUSPRATT of Seaforth Hall Liverpool in the
said county a Director of The United Alkali Company Limited do hereby declare
the nature of this invention to be as follows:
It is well known that by the electrolysis of sodium or potassium hydrate the
corresponding metal is liberated at the cathode.
It is also known that if either sodium or potassium be thrown into molten lead it
will combine with the lead forming a very brittle alloy.
According to this invention we electrolyse fused sodium or potassium hydrate
using molten lead as cathode, and a metal anode capable of withstanding the action
of the caustic alkali and at the same time not forming an alloy with the lead. We
find iron to be a suitable metal.
The sodium or potassium as it is liberated alloys with the lead, and when the
alloy is sufficiently rich in alkali metal it is run into closed moulds and allowed to
solidify, when it is ready for any purpose for which it may be required.
The apparatus we prefer is a vessel in which molten lead at the bottom forms the
cathode whilst opposite or above the lead surface we place the anode. The vessel
which contains the fused alkali hydrate is best made of cast iron, and in order to
avoid electrical action at the inner surface thereof we build it up of a lower piece
of the shape of a dish or pot to contain the molten lead and of an upper part
flanged to fit a flange on the lower part the parts being insulated by a non-conductor
between the flanges. This non-conductor must withstand the action of the fused
caustic alkali and the requisite temperature.
We prefer asbestos which we may protect at the surface of contact with the
caustic alkali by a layer of caustic lime. Or we make the flanges of such width
and cool them at the periphery so that caustic alkali may solidify between them
and itself form the insulating layer.
The pot or lower part is connected to the negative pole of a dynamo and the
anode to the positive pole. The lead in contact with the pot becomes the negative
electrode. As the lead changes into an alloy the volume increases and the amount
should be so adjusted that the expansion due to the formation of the alloy does not
raise the surface of the alloy beyond the flanged joint otherwise electrical contact
will be established between the upper part of the containing vessel and it will act
as a cathode so that sodium will be formed there and be lost. In order to avoid
this we provide the cell with an overflow pipe through which any excess of alloy
may flow out and the proper level of the alloy be thus automatically main-
tained. We also provide an outlet pipe and valve through which the finished
alloy may be withdrawn and a third pipe through which fresh lead may be
introduced.

page_text: The whole cell is heated which may be done by setting it in brickwork above
gas burners or a grate so that the requisite temperature may be maintained.
We may place several such cells in series.
Dated this 20th day of March 1894
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in and Apparatus for the Production of Alloys of
Sodium or Potassium with Lead.
We, ALBERT EDWARD HETHERINGTON, Ph.D., and FERDINAND HURTER,
Ph.D., both of Central Laboratory, Widnes, in the County of Lancaster, Analytical
Chemists, and EDMUND KNOWLES MUSPRATT, of Seaforth Hall, Liverpool in, the
said county, a Director of The United Alkali Company, Limited, 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 :-
It is well known that, by the electrolysis of sodium or potassium hydrate, the
corresponding metal is liberated at the cathode. It is also known that if either
sodium, or potassium, be thrown into molten lead, it will combine with the lead
forming a very brittle alloy.
According to this invention we electrolyse fused sodium or potassium hydrate
using molten lead as the cathode and a metal anode capable of withstanding the
action of the caustic alkali, and at the same time not forming an alloy with the
lead. We find iron to be a suitable metal.
The sodium, or potassium, as it is liberated, alloys with the lead, and when the
alloy is sufficiently rich in alkali-metal, it is run into closed moulds and allowed to
solidify, when it is ready for any purpose for which it may be required.
The apparatus we prefer is a vessel in which molten lead at the bottom forms
the cathode, whilst opposite, or above, the surface of the lead, we place the anode.
The vessel which contains the fused alkali hydrate, is best made of cast iron, and
in order to avoid electrical action at the inner surface thereof, we build it up of a
lower piece of the shape of a dish or pot to contain the molten leal, and of an
apper part flanged to fit a flange on the lower part, the parts being insulated
by non-conducting material between the flanges. This non-con-lucting material
nist withstand the action of the lused caustic alkali and the required temperature.
We prefer asbestos, which we may protect, at the surface of contact with the
castle kali by a layer of caustic lime. Or we make the flanges of considerable
with a rol them at the periphery so that coustic alii may solidity between
them and itself form the insulating layer.
The pot or lower part is comected to the negative pole of the saree of electricity,
such an dynato electric machine, and the anode is competed to the positive pole
there. The end, in contact with the pot hee maes the negative eletrole. As the
lead changes into en alloy the volume increases and the amount should be so
adjusted that the expansion due to the formation of the alloy does not raise the
surface of the alloy beyond the flanged joint, otherwise electrical contact will be
established between the upper and lower parts of the containing vessel and the
upper part will act as a cathode so that sodium (or potassium) will be formed and
be lust. In order to avoid this we provide the cell or vessel with an overflow pipe
through which any excess of alloy will flow out and the proper level of the alloy
will be thus automatically maintained. We also provide an outlet pipe and
valve through which the finished alloy is withdrawn and a third pipe through
Lich fresh lead is introduced.
The whole cell or vessel is heated, which may be done by setting it in brickwork

page_text: ahove gas burners or a grate that the requisite temperature may be maintained,
and we may place several such cells or vessels in series.
In order that this invention, and the way in which it can be carried into
practical effect may be well understood, we have illustrated in the accompanying
drawing a vertical section of a pot or cell fitted for the purposes of this invention.
A, is the pot containing the molten lead. B is an outlet pipe for the finishel
alloy, the said pipe being capable of being closed by means of the valve C.
From the outlet pipe B, at a point between the pot A and the seating of the
valve C, there opens a pipe D. the upper end of which reaches outside the pot
a little above the intended highest level of the liquid alloy in the pot and serves
as an overflow for the alloy so as to maintain a proper level of alloy in the pot.
Any alloy flowing out is delivered by the funnel and pipe d into the closed mould E
into which the whole charge of alloy is also delivered when finished. Above the
pot A and insulated from it by the asbestos ring F is the containing vessel G
for the caustic alkali. The two vessels A and G are bolted together in such
manner that the bolts do not form an electrical connection between the two
vessels, which may be done by insulating the bolts themselves, as is well
understood.
A large flange g, at the top of the cylinder G, serves to support the whole
apparatus upon the brick walls of the furnace H. Above the cylinder G is the
cast iron covering plate K, insulated from the said cylinder by an asbestos
ring J. This plate K, carries the anode support L, the anode M, formed of a
wrought iron plate, being capable of being raised, or lowered, at will by the
screwed spindle m and wheel m². The electrical connections for the anode are
attached to the covering plate K, and, for the cathode, to the iron flange a, of
the pot A. Several pots may be placed over one fire-place and may be connected
in series, the positive pole of one cell being connected to the negative pole of
the next.
All the pipes, or metal parts, in connection with the pot A, must be insulated
from the walls of the furnace, and so also must the receptacle E, if the pipes be in
metallic connection therewith.
Into such a pot, we charge (through an aperture provided in the cover K)
the molten lead in such quantity as not to reach to the joint at F between the
pot A and the cylinder G. We then fill into the cylinder G, the caustic alkali
(either soda, or potash, as the case may be), adjust the anode to a proper distance,
and send an electric current of considerable density through the cell. The current
may be considerably more than 500 ampères per square foot of anode surface.
The alkali-hydrate should be kept at a comparatively low temperature, only
high enough to keep the lead alloy and the alkali-hydrate fluid. When the
lead alloy has been so far enriched as to contain 10 per cent. of the alkali metal
it will be found to have nearly doubled its volume, and when it contains 30 per cent.
of the alkali metal the volume will be trebled. If, therefore, too much lead has
been put into the pot A at first, the expansion, by reason of the formation of the
alloy, would establish an electrical connection between the cylinder G and itself,
and the cylinder G would thus act as a cathode. This is prevented by the overflow
arrangement B D d. Although the cell can be worked continuously by providing
a continuous feed of fresh molten lead, we prefer to work it intermittently and to
saturate a batch of lead with the desired amount of alkali metal. We find it
advantageous not to enrich the alloy to more than say from 10 to 15 per cent. of its
weight of alkali metal as when this limit is reached or surpassed a considerable
amount of the electric current is wasted and slight explosions occur. Also the
alloy, if too rich in alkali metal, inflames readily when in contact with atmo-
spheric air, hence a covered receptacle for its storage is needed. When it is
desired to produce an alloy of from 20 to 30 per cent. of alkali metal it is advisable
not to place a cover over the apparatus, in order that any occasional explosions
may not be confined and thus damage the apparatus. In this case the anode can
be suspended in any other convenient way instead of from the cover.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that we are
aware of Specification No. 13568, A.D., 1893, and we wish it to be understood that
we do claim anything described or claimed therein, but what we claim is :-
:―
1. In the manufacture of alloys of sodium or potassium with lead, by electrolysing
sedium or potassium hydrate, using molten lead as a cathode substantially as
hereinbefore described.
2. In apparatus for the purpose described, and claimed, a pot or vessel with a
lower part for containing the molten lead, and an upper part for containing sodium,
or potassium hydrate; the said parts being insulated from each other, and the
lower part being provided with an overflow arrangement, substantially as
herein before described.
3. An apparatus consisting of the arrangement and combination, of parts
herein before described and illustrated in the accompanying drawing, for the purpose
described.
Dated this 18th day of December 1894
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.