An Improved Electrolytic Process and Apparatus for Obtaining Rich Alloys of the Metals of the Alkalies or Alkali Earths, and the Production of Halogen Elements.
Year: 1894

page_text: An Improved Electrolytic Process and Apparatus for Obtaining Rich
Alloys of the Metals of the Alkalies or Alkali Earths, and the
Production of Halogen Elements.
I, LEON PAUL HULIN, of Modane, (Savoie) France, Civil Engineer, do
hereby declare the nature of this invention to be as follows:-
This invention relates to an electrolytic process and apparatus for obtaining rich
alloys of the metals of the alkalies or alkali earths, together with the production
of halogen elements.
In order to produce by electrolysis alloys formed of a heavy metal and of a very
light metal, the method generally employed in the case of aluminium, magnesium,
etc, consists in electrolyzing a haloid compound of light metal in a state of igneous
fusion with a cathode of the heavy metal in a molten or highly heated condition.
This method does not permit of readily obtaining all the alloys of the light metals
with certain heavy metals which are difficultly fusible and which in the solid state,
and even at a red heat, are difficult to alloy with sodium, potassium, barium, etc,
nor does it afford a means of producing at will, in a direct and continuous manner,
an alloy of predetermined composition; it is also difficult to obtain by it alloys
very rich in metals of the alkalies or alkali earths.
The process which forms the subject of the present application for Letters
Patent is based on a principle which enables these different desiderata to be realized.
Succinctly presented, in the case of a binary alloy, my process consists in the
conjoint employment of two anodes acting in the same bath which is expressly
constituted by a haloid salt of the alkali metal, (fluoride, chloride, bromide,) in a
state of igneous fusion. One of the anodes is of carbon and the other is formed by
the heavy metal which is to enter into the alloy. Each of the anodes receives a
quantity of the positive current which is determined and regulated in conformity
with the composition of the alloy to be produced. During the electrolysis the
halogen element (chlorine, for instance,) goes partly to the carbon anode where it
18 immediately set free, and partly to the metallic anode which it attacks to form
with it a compound (chloride) which 18 immediately diffused through the fused
bath whilst the simultaneous electrolytic action on this mixture sets free at the
negative pole some of the alkali metal and of the heavy metal and the latter
meeting the other in the nascent state becomes completely incorporated therewith
to form an alloy of greater density than the electrolyte and which remains at the
bottom of the apparatus. Although the haloid compound of the heavy metal is
much more readily electrolyzable than the alkali compound, the latter will always
be decomposed, as it alone forms almost the whole of the bath, into which the other

page_text: enters only in proportion as its anode is attacked, which attack corresponds only to
that part of the total current which has been allotted for the purpose. The
quantity of positive current passing by the carbon anode corresponds to the quantity
of alkali metal liberated, and the quantity of positive current passing by the
metallic anode corresponds to the quantity of heavy metal to be united with the
alkali metal. It is evident that these quantities of the respective metals are
proportionate to their electro-chemical equivalents. One single cathode receives all
the negative current. The composition of the alloy is thus governed by the
distribution of the positive current through the anodes. For this purpose the
metallic anode is combined with a resistance which may be variable at will, and if
necessary with an ampère meter. No resistance is necessary for the carbon anode.
It will be seen that the halogen element produced by electrolysis by my method
is set free in part, as a conjoint product with the alloy, while the other part is
utilized for dissolving the heavy metal in the alkalı bath. The attack on the
metallic anode diminishes the counter-electromotive force in its branch circuit and
it is for this reason that a resistance is here used; there is a consequent loss of
electric energy, it is true, which may, however, be avoided if desired by employing
two independent sources of electricity having a different voltage capable of being
varied and regulated at will, in which case the two negative poles of these two
sources are connected with the cathode, while the two positive poles are connected
separately the one to the carbon anode and the other, and weaker one, to the
metallic anode without the interposition of resistance, the ampère meter being
retained. The proper quantity of electricity may be supplied to each anode by
passing the current alternately to one and the other for calculated periods or
continuously to the carbon anode and intermittently to the metallic anode, but
these variations are of little practical value.
It will be evident that in all cases the whole of the negative current is conducted
to the cathode where the alkali metal and the heavy metal unite in a nascent state.
The metallic anodes employed are generally in the form of rods or bars of any
section; in the case of certain metals, such as manganese, chromium, etc., which
are difficult to obtain in a metallic state, I employ, in place of the metal properly
so called, rods composed of an intimate mixture of an oxide of these metals with
suitable quantities of carbon, the nascent halogen element (fluorine, chlorine,
bromine,) thus combining with the metal of the oxide and setting free carbonic
oxide. If it is desired to form alloys with beavy metals fusible at the temperature
at which the electrolysis is performed, I employ for this purpose a special support
composed of a rod of carbon provided at bottom with a shallow vessel, which may
be of the same material and formed in one therewith, in which vessel is deposited
fusible metal which is immersed in the alkaline bath, the rod projecting upwards
and being suitably connected to the positive pole as before mentioned. The vessel
may also be supplied with slightly fusible metal in a granulated form or pieces of
agglomerated oxide and carbon. When it is desired to form alloys of more than
two heavy metals, the operation 18 always performed under the same conditions and
according to the same principles, but in this case I employ as many anodes
combined with a resistance of suitable value as there are metals to enter into the
final alloy, except when several of these metals may have been previously united
in the desired proportions to form a single anode. By composing the bath of a
mixture of two alkaline haloids in the desired proportions I am enabled to obtain
the two alkali metals in the alloy.
It will be evident that each kind of anode (whether of carbon or metal) may be
formed of several parts, rods, sticks, or vessels, etc., electrically connected in a
group or acting as one.
The feeding of my system thus comprises :-
1st. The replacement of the metallic anodes for the heavy metal;
2nd. The addition of the haloid salt of an alkali in the bath in fusion for the
alkali metal;
Thus constituted, my process furnishes in addition to the alloy, a halogen element,

page_text: (generally chlorine) which is collected on leaving the apparatus for utilization in
any known way. It may first be caused to pass through condensing chambers
where it will separate from any alkaline salt that may have been carried off along
with it by volatilization. It may also be washed with the same object.
The accompanying drawing represents by way of example a section of the
essential parts of the apparatus employed which is susceptible of modification as
regards dimensions, form, and accessory details, and especially in the relative
position of the anodes.
A is a wrought or cast iron or steel crucible in which the whole operation is
performed. In order to melt the alkaline salt, at least at the outset of the operation,
the vessel may be placed over a furnace. B is the alkaline bath in igneous fusion,
chloride of sodium for example. C is the outlet pipe for the free halogen element,
chlorine for example. D is a cover of insulating refractory material, down through
which pass the electrodes the joints being made as tight as possible. E is the
outlet at bottom for running off the alloy formed. F is the valve, and G the
receiver for the alloy extracted. H is an inclined lateral dip pipe, the lower end of
which is completely immersed in the molten bath which permits of continuously
supplying the alkaline salt without opening the chamber I in which the chlorine is
contained, thus preventing all loss and smell. J is the carbon electrode at which
the halogen element is set free. It may, if necessary, be suspended from a metal
rod N. K K represent a metallic anode made in two parts formed of rods of iron
for example. L is a basin-shaped anode support of carbon containing heavy metal
in a molten state such as tin, lead, &c., which may be introduced through the hollow
supporting rod which passes out at top, two holes opening laterally from the bore
near the bottom of the tray. Mj, Mk, Ml, represent the metallic supports for the
anodes They serve as conductors for the positive current after its division and
are provided with binding screw for ensuring contact and enabling the anodes to be
raised or lowered at will. O, Ok, Ol, are ampère meters whereby the intensity of
the current in each of the three anodes is controlled. Pk, Pl, are two variable
resistances each combined with an ampère meter and a metallic anode, and by
means of which the distribution of the current in the anodes is effected QR are
the two main conductors leading from the electric source (here considered as single)
the negative conductor R being in contact with the crucible A, of which the bottom
forms the cathode.
Tis the alkalı alloy produced. V is a stirrer usually made of iron mounted on
a vertical axis which is employed when it is desired to manufacture an unstable
alloy, such as those of metals having little or no mutual affinity. By means of this
stirrer which may be operated by mechanical means, the homogeneity of the alloy
is maintained throughout the entire operation.
My process entirely solves the difficulties in the electrolysis of molten alkalı salts,
particularly chlorides. I avoid, in fact, the diffusion of the alkali metal in the
electrolyte by incorporating it in a nascent state with a heavy metal also in the
nascent state. When the operation of forming the alloy has only for object to
obtain the alkali metal I select a heavy metal whose electro-chemical equivalent
and density are as high as possible in order to give the alloy a sufficient density
whilst consuming a minimum of electric current at the metallic anode.
The description of my process of making alloys of the alkalies and the essential
organization of the apparatus by means of which it is applied will enable my
invention to be clearly understood. Although the anodes L, K, K, are shewn as
placed at one time in the crucible, A, this is simply for the purpose of describing
them as it will be evident that one may be used without the other. The position
and form of the cathode may be those of any of the known arrangements.
Dated twoL

page_text: An Improved Electrolytic Process and Apparatus for Obtaining Rich
Alloys of the Metals of the Alkalies or Alkali Earths, and the
Production of Halogen Elements.
I, LEON PAUL HULIN, of Modane, (Savoie), France, Civil 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
statement:-
This invention relates to an electrolytic process and apparatus for obtaining rich
alloys of the metals of the alkalies or alkali earths, together with the production of
halogen elements.
In order to produce by electrolysis alloys formed of a heavy metal and of a
very light metal, the method generally employed in the case of aluminium,
magnesium, etc., consists in electrolyzing a haloid compound of the light metal in a
state of igneous fusion with a cathode of the heavy metal in a molten or highly
heated condition. This method does not permit of readily obtaining all the alloys
of the light metals with certain heavy metals which are difficultly fusible and which
in the solid state, and even at a red heat, are very difficult to alloy with sodium,
potassium, barium, etc., nor does it afford a means of producing at will, in a
direct and continuous manner, an alloy of predetermined composition; it is also
difficult to obtain by it alloys very rich in metals of the alkalies or alkali earths.
The process which forms the subject of the present application for Letters Patent
is based on a principle which enables these different desiderata to be realized.
Succinctly presented, in the case of a binary alloy, my process consists in the
conjoint employment of two anodes acting in the same bath which is expressly
constituted by a haloid salt of the alkali metal, (fluoride, chloride, bromide,) in a
state of igneous fusion. One the anodes is of carbon and the other is formed by
the heavy metal which is to enter into the alloy. Each of these anodes receives a
quantity of the positive current which is determined and regulated in conformity
with the composition of the alloy to be produced. During the electrolysis the
halogen element (chlorine, for instance), goes partly to the carbon anode where it
is immediately set free, and partly to the metallic anode which it attacks to form
with it a compound (chloride) which is immediately diffused through the fused
alkalı compound whilst the simultaneous electrolytic action on this mixture sets
free at same time at the negative pole some of the alkali metal and of the heavy
metal and the latter meeting the other in the nascent state becomes completely
incorporated therewith to form an alloy of greater density than the electrolyte and
which remains at the bottom of the apparatus.
Although the haloid compound of the heavy metal is much more readily
electrolyzable than the alkali compound, the latter will always be decomposed, as
it alone forms almost the whole of the bath, into which the other enters only in
proportion as its anode is attacked, which attack corresponds only to that part of
the total current which has been allotted for the purpose. The quantity of
positive current passing through the carbon anode corresponds to the quantity
of alkali metal liberated, and the quantity of positive current passing through the
metallic anode corresponds to the quantity of heavy metal to be united with the
alkali metal. It is evident that these quantities of the respective metals are
proportionate to their electro-chemical equivalents. One single cathode receives
all the negative current. The composition of the alloy is thus governed by the
distribution of the positive current through the anodes. For this purpose there
18 combined with the metallic anode a resistance which may be variable at will,
and if necessary an ampère meter. No resistance is necessary for the carbon
anode.

page_text: It will be seen that the halogen element produced by electrolysis by my method
is set free in part as a conjoint product with the alloy, while the other part is
utilized for dissolving the heavy metal in the alkalı bath. The attack on the
metallic anode diminishes the counter-electromotive force in its branch circuit and
it is for this reason that a resistance is here used; there is a consequent loss of
electric energy, it is true, which may, however, be avoided if desired by employing
two independent sources of electricity having a different voltage capable of being
varied and regulated at will, in which case the two negative poles of these two
sources are connected with the cathode, while the two positive poles are connected
separately, the one to the carbon anode and the other, and weaker one, to the
metallic anode without the interposition of resistance, the ampère meter being
retained. The proper quantity of electricity may also be supplied to each anode
by passing the current alternately to one and the other for calculated periods or
continuously to the carbon anode and intermittently to the metallic anode but these
variations are of little practical value.
It will be evident that in all cases the whole of the negative current 18
conducted to the cathode where the alkali metal and the heavy metal unite in a
nascent state.
The metallic anodes employed are generally in the form of rods or bars of any
section; in the case of certain metals, such as manganese, chromium, etc., which
are difficult to obtain in a metallic state, I employ, in place of the metal properly
so called, rods composed of an intimate mixture of an oxide of these inetals with
suitable quantities of carbon, the nascent halogen element (fluorine, chlorine,
bromine,) thus combining with the metal of the oxide and setting free carbonic
oxide.
If it is desired to form alloys with heavy metals fusible at the temperature at
which the electrolysis is performed, I employ for this purpose a special support
composed of a rod of carbon provided at bottom with a shallow vessel which may
be of the same material and formed in one therewith, in which vessel is deposited
fusible metal which is immersed in the alkaline bath, the rod projecting upwards
and being suitably connected to the positive pole as before mentioned. The vessel
may also be supplied, with the same object, with slightly fusible metal in a
granulated form or pieces of agglomerated oxide and carbon.
When it is desired to form alloys of more than two heavy metals, the operation
18 always performed under the same conditions and according to the same principles
but in this case I employ as many anodes, combined with a resistance of suitable
value, as there are metals to enter into the final alloy, except when several of
these metals may have been previously united in the desired proportions to form
a single anode. By composing the bath of a mixture of two alkaline haloids in
the desired proportions, am enabled to obtain the two alkali metals in the
alloy.
It will be evident that each kind of anode (whether of carbon or metal) may be
formed of several parts, rods, sticks, or vessels, etc., electrically connected in a
group or acting as one.
The feeding of my system thus comprises :-
1st. The renewal of the metallic anodes for the heavy metal ;
2nd. The addition of the haloid salt of an alkali to the fused bath, for the
alkali metal.
Thus constituted my process furnishes in addition to the alloy, a halogen
element (generally chlorine) which is collected on leaving the apparatus for
utilization in any known way. It may first be caused to pass through condensing
chambers where it will separate from any alkali salt that may have been carried
off along with it by volatilization. It may also be washed with the same object.
The drawing filed with my Provisional Specification represents by way of
example a section of the essential parts of the apparatus employed which is
susceptible of modification as regards dimensions, form, and accessory details, and
especially in the relative position of the anodes.

page_text: A is a wrought or cast iron or steel crucible in which the whole operation is
performed. In order to melt the alkali salt, at least at the outset of the operation,
the vessel may be placed over a furnace. B is the alkali bath in igneous fusion,
chloride of sodium for example, C is the outlet pipe for the free halogen element,
chlorine for example. D 18 a cover of insulating refractory material, down
through which pass the electrodes, the joints being made as tight as possible. E 18
the outlet at bottom for running off the alloy formed. F is the valve, and G the
receiver for the alloy extracted. H is an inclined lateral dip pipe, the lower end of
which is completely immersed in the molten bath which permits of continuously
supplying the alkali salt without opening the chamber I in which the chlorine is
contained, thus preventing all loss and smell. J 18 the carbon electrode at which
the halogen element is set free. It may, if necessary, be suspended from a metal
rod N. KK represent a metallic anode made in two parts formed of two rods (of
iron for example). L is a basın-shaped anode support of carbon containing heavy
metal in a molten state, such as tin, lead, etc., which may be introduced through the
hollow supporting rod which passes out at top, two holes opening laterally from the
bore near the bottom of the tray. M3, M k, M 1, represent the metallic supports for
the anodes. They serve as conductors for the positive current after its division
and are provided with a binding screw for ensuring contact and enabling the anodes
to be raised or lowered at will. O, Ok, Oi, are ampère meters whereby the
intensity of the current in each of the three anodes is controlled. Pk, P i, are two
variable resistances each combined with an ampère meter and a metallic anode and
by means of which the distribution of the current in the anodes is effected.
QR are the two main conductors leading from the electric source (here considered
as single) the negative conductor R being in contact with the crucible A of which
the bottom forms the cathode. T is the alkali alloy produced. V is a stirrer
usually made of iron (mounted on a vertical axis) which is employed when it is
desired to manufacture an unstable alloy such as those of metals having little or
no mutual affinity. By means of this stirrer, which may be operated by
mechanical means, the homogeneity of the alloy is maintained throughout the entire
operation.
My process entirely solves the difficulties in the electrolysis of molten alkalı salts,
particularly chlorides I avoid in fact the diffusion of the alkali metal in the
electrolyte by incorporating it in a nascent state with a heavy metal also in the
nascent state.
When the operation of forming the alloy has only for object to obtain the alkali
metal, I select a heavy metal whose electro-chemical equivalent and density are as
high as possible in order to give the alloy a sufficient density whilst consuming a
minimum of electric current at the metallic anode.
The description of my process of making alloys of the alkalies and the essential
organization of the apparatus by means of which it is applied, will enable my
invention to be clearly understood. It should be understood that although the
anodes L K K are shewn as placed at one time in the crucible, this is simply for
the purpose of describing them, as it will be evident that one may be used without.
the other. The position and form of the cathode may be those of any of the known
arrangements.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
olaim is :-
1. The process of manufacturing an alloy of an alkali metal or alkalı earth metal
with a heavy metal (and particularly a difficultly fusible metal having but little
affinity for the former) which consists in effecting the electrolysis of a suitable
haloid salt of an alkalı or alkalı earth metal when in a state of igneous fusion by
means of two anodes, one of carbon and the other formed of the heavy metal to be
alloyed.
2. The herein described method of manufacturing alloys by electrolysis, which

page_text: consists in employing as an electrolyte the fused salts of the one metallic
ingredient of the proposed alloy and an anode consisting of a carbon member and
a member composed of the other metallic ingredient of the proposed alloy, as
specified.
3. The herein described method of manufacturing alloys which consists in
employing as an electrolyte the fused salts of one metal of the alloy and an anode
consisting of a carbon member and a member composed of the other metal of the
alloy and varying the current to regulate the composition of the alloy, as
specified
•
4. In the electrolytic operation herein specified the employment as metallic
anodes of metallic oxides agglomerated with carbon.
5. In apparatus for the production of alloys by electrolysis, the combination of a
cathode consisting of a metal crucible adapted to contain an electrolyte, an anode
consisting of a carbon and one or more metal members, and a stirrer in the crucible,
substantially as described.
6. In apparatus for the production of alloys by electrolysis, the combination,
with a bath and cathode, an anode consisting of a carbon member and a dish-
shaped metal receiving member provided with a hollow stem having lateral
openings communicating with the dish, substantially as described.
7. In apparatus for the production of alloys by electrolysis, an anode metal
container consisting of a dish provided with a hollow stem having lateral openings
communicating with the dish, substantially as described.
8. In apparatus for the production of alloys by electrolysis, an anode consisting
of a carbon member and metal members consisting of one or more rods and a dish-
shaped metal container provided with a hollow stem having lateral openings
communicating with the dish, substantially as described.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.