Year: 1886

page_text: Date of Application, 14th July, 1886.
Complete Left, 14th Apr., 1887.
Complete Accepted, 12th July, 1887.
I, PAGET HIGGS, L.L.D. of 70 The Outer Temple, in the County of Middlesex,
Electrical Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to the electro-metallurgy of zinc by a process wherein I obtain
from zinte ores not only zinc or spelter but also various other valuable products.
By zinc ore I mean preferably "calamine" or any ore of zinc not requiring
roasting,'
""calcination or equivalent treatment, but I do not confine myself to this
quality of ore as I can employ "blende," native zinc oxide, and other zinc ores
without essential modification of the process herein described.
I am aware that several processes have been described for the reduction of zine
from its ores by electrolysis, notably those of Luckow and Letrange.
In these processes, it appears that the sole object has been the reduction of the
metal and that no useful result has been sought from the unavoidable secondary
action accompanying such reduction.
Moreover, the use of materials evolving chlorine is considered unadvisable in these
processes, partly because of the fumes of chlorine. I am aware also of the processes
proposed for the electrolysis of chloride solutions and for the collection of the gas or
other products, as represented typically by the process of Alexander Watt described
in the Specification of Letters Patent No. 13755 of 1851 granted to him. In this
process and in others, the chlorine chamber is closed and the gas is conducted away
through pipes instead of being drawn or aspired away as hereinafter described.
According to my invention, I utilize the accompanying actions of the electrolysis
in obtaining other products, the sale of which will greatly reduce the cost of the
production of the zinc.
For this purpose, I electrolyse a solution more or less concentrated of an alkaline
or soluble basic chloride, the electrolytic bath being heated to a temperature of about
120 degrees Fahrenheit, the zinc ore, when rendered properly conducting by admixture
with graphitic coke, as hereinafter described, forms the anode, and a conducting plate
upon which the metal zinc is deposited forms the cathode. I sometimes use, for

page_text: instance, chloride of magnesium in solution, obtained by treating magnesite with
hydrochloric acid, in which case my products are spelter or zinc, chlorine and hydrate
of magnesia, but I prefer to use a solution of chloride of sodium or even sea-water of
the proper concentration. In this case, my products are spelter, sodic hydrate, and
chlorine, which chlorine I prefer to utilize to produce oxy-chloride of lime.
This oxy-chloride I can afterwards subject to heat to obtain chloride of calcium of
considerable purity. From the sodic hydrate I produce caustic soda either by
simple concentration or by concentration of the containing solution with lime added
in small proportions.
To carry out my process and obtain all the products in a continuous manner, I
construct a series of electrolytic baths, each bath consisting of a vessel made of a
material unacted upon by chlorine or by caustic alkali when subjected to a heat of
about 120 degrees Fahrenheit. This vessel is divided vertically into two compart-
ments, preferably of unequal capacity, by a wall or diaphragın of porous material
such as asbestos cloth or other suitable material. I line the larger compartment with
slabs or plates of graphitic carbon. In the smaller compartment, I hang a series of
The edges
metallic or metallised plates connected as cathodes to the electric source.
of these plates next the diaphragm I protect from deposit by strips of wood or earthen-
ware to prevent "treeing" of the deposited metal. This compartiment is provided
with a hood made steam-tight except where it is provided with a hole through which
a hydrometer or thermometer may be inserted. It is also provided with an inlet and
an outlet tap, by the inlet tap water is introduced; by the outlet tap sodic hydrate
solution is drawn off. The large compartment lined with the carbon plates is
preferably provided with a false-bottom of carbon blocks triangular in transverse
section, and supported at the base on bars of paraffined teak or other wood, or upon
blocks of concrete. These blocks are sufficiently near together to prevent too ready
passage between them of the contents of the compartment, that is to say, broken ore
mixed with common salt and broken retort-coke in pieces of such size as will pass,
but not very freely between the blocks of the false-bottom. The said false bottom
may be made liquor-tight if necessary. It is so arranged as to permit access to the
space underneath the blocks to facilitate the clearance of the said space.
In starting the work, the interstices of the false-bottom are filled with rammed sand
and then the charge of ore is filled in. When it is desired to remove the partially or
wholly exhausted charge of ore, the rammed sand is raked out from below the false-
bottom, it will be found that the earthy matters of the ore have settled to the bottom
of the tank taking the place of the sand in preventing too rapid flow of liquid between
the blocks.
During the process, the ore becomes disintegrated and sinking with the broken
retort-coke comes finally with this coke into electrical connection with the carbon-
blocks of the false-bottom, where, in passing, it experiences a final energetic action of
the electric current. If the tanks or baths are of the proper depth, the percolation of
liquid through the disintegrated and exhausted ore residuum resting on the false-
bottom and between the blocks thereof is very small and the liquid may be returned
to the anode compartment of the bath. This compartment of the bath is provided
with a hood and the gas is drawn away to the chlorinating chamber by aspiration
resulting from the heat generated in that chamber by the chemical reaction. The hood
is provided with a hopper for feeding in the ore-charge.
The chlorinating chamber is of novel construction. It has been usual in chlorina-
ting lime, to pass the gas over shelves strewn with lime, which is from time to time
raked over to present a new surface or fresh succession of atoms for chlorination.
This method has obvious disadvantages. According to my invention, I cause the
chlorine to enter at a slight distance above the bottom of a tall chamber or tower
constructed of sheet lead. At the top of the said chamber is a hopper into which
powdered lime is introduced. From the hopper, the lime falls on to a fine sieve, to
which an oscillatory motion is imparted to sift the lime. The lime falls in a finely
divided state, through the current of gas, and great heat is generated in its com
bination. Chlorine being heavier than the atmosphere, the gas has no other tendency

page_text: to rise than that due to the heat, and, although this is excessive, the rising current
can be controlled by regulating the shower of falling lime. When the lime arrives at
the base of the chamber, it is thoroughly chloridised and appears as bleaching powder
of high purity rich in chlorine. It falls on to the sloping floor of the chamber, whence
it is drawn off through a chute into suitable receptacles
I sometimes use a modified form of my chlorination chamber in which a metal tray
is connected electrically to one pole of a high tension machine, and a metal plate is
connected to the other pole of the said machine. The tray contains powder to be
chlorinated by gas passing between the tray and plate. The powder is kept in
Constant agitation being attracted from the tray by the plate and after touching the
hatter being repelled therefrom and attracted by the tray. This tray and plate and
their connections are sometimes so arranged that particles of the lime will be carried
by the gas passing between the said tray and plate and will fall to the ground or into
any suitable receptacle. I do not intend to claim the improved chlorinating chamber
except when used in carrying on the continuous process herein described of
manufacturing zine or spelter, caustic soda, and chloride of lime.
To obtain pure chloride of calcium, the oxy-chloride of lime obtained as above
described is heated to a sufficiently high temperature to drive off the oxygen for which
the calcium has less affinity than for the chlorine.
By my invention, the merchantable products, that is to say, the spelter, caustic
soda, chloride of lime, and chloride of calcium, are, or can be, all produced by a
continuous series of reactions comprised in one process and chemically sequent.
Dand thi 19th day of I.... 1996
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.

page_text: An Improved Process and Apparatus for Obtaining Spelter and
Caustic Soda, Chloride of Lime, Chloride of Calcium, or other
Products.
I, PAGET HIGGS, L.L.D. of 70 The Outer Temple, in the County of Middlesex,
Electrical 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:-
68
"6
"
My invention relates to the electro-metallurgy of zinc by a process wherein I
obtain from zinc ores not only zine or spelter hut also various other valuable products.
By zine ores I mean preferably "calamine" or any other ore of zinc not requiring
preliminary roasting," calcination or equivalent treatment, to adapt it for
subsequent treatment by my process, but I do not confine myself to this preferable
kind of ore, as I can employ "blende" native zinc-oxide, and other zinc ores without
essential modification of the process herein described.
I am aware that several processes have been described for the reduction of spelter
from zinc ores by electrolysis, notably those of Luckow and Letrange. In these
processes, it appears that the sole object has been the reduction of the metal, and that
no useful result has been sought from the unavoidable secondary action accompanying
such reduction. Moreover, the use of materials evolving chlorine is considered
inexpedient in these processes, partly because of the fumes of chlorine. I am aware
also of the processes proposed for the electrolysis of chloride solutions and for the
collection of the gas or other products, as represented typically by the process of
Charles Watt described in the Specification of Letters Patent No. 13755 of 1851
granted to him. In this process and in others, the chlorine chamber is closed and the
gas is conducted away through pipes and lost, instead of being drawn or aspired away
to be afterwards utilized as hereinafter described.
According to my invention, I utilize the accompanying actions of the electrolysis in
obtaining other products, the sale of which will greatly reduce the cost of production
of the spelter.
I
For this purpose I electrolyse a solution, more or less concentrated, of an alkaline
or soluble basic chloride, the electrolytic bath being heated to a temperature of about
120 degrees Fahrenheit; the zinc ore, when rendered properly conducting by admixture
with graphitic coke as hereinafter described, forms the anode, and one or more
conducting plates, upon which the metal zinc is deposited, form the cathode.
sometimes use, for instance, chloride of magnesium in solution, obtained by treating
magnesite with hydrochloric acid, in which case my products are spelter or zinc,
chlorine and hydrate of magnesia, but I prefer to use a solution of chloride of sodium
or even sea-water of the proper concentration. In this case, my products are spelter,
sodic hydrate, and chlorine. I utilize the chlorine as evolved in the electrolysis to
produce oxy-chloride of lime.
This oxy-chloride I afterwards subject to heat to obtain chloride of calcium of
considerable purity. From the sodic hydrate, I afterwards produce caustic soda either
by simple concentration or by concentration of the containing solution with lime
added in small proportions.

page_text: To carry on my process and obtain all the products in a continuous manner,
construct a series of electrolytic baths, each bath consisting of a vessel made of a
material (such for example, as concrete) which will not be effected by the chlorine or
by the caustic alkali when heated to a temperature of about 120 degrees Fahrenheit.
This vessel is divided into two compartments, preferably of unequal capacity, by a
vertical wall or diaphragm of suitable porous material such as asbestos cloth. This
diaphragmn may be conveniently and advantageously applied by stretching the material
upon a suitable frame and inserting the said frame in vertical grooves or channels in
the sides of the vessel. In the smaller compartment, I hang a series of metallic or
metallized plates connected as cathodes to the electric source. These plates are
preferably arranged at right angles to the diaphragm, in which case their edges next
the diaphragm are protected from deposit by strips of wood or earthenware to prevent
"treeing" of the deposited metal, these strips may be secured upon the edges of the
said plates in any convenient manner. This compartment is provided with a hood
made steam-tight except where it is provided with a hole through which a hydrometer
or thermometer may be inserted, and a screw-cap or plug is provided for closing this
hole. This smaller compartment is also provided with an inlet and an outlet tap; by
the inlet tap water is introduced; by the outlet-tap sodic hydrate or other resulting
solution is drawn off. I line the anode or larger compartment with slabs or plates of
graphitic carbon, and I provide the said compartment with a false-bottom or grate
composed of carbon blocks triangular in transverse section, the said blocks being
supported at their bases on bars of paraffined teak or other wood, or upon blocks of
concrete. These carbon blocks are placed sufficiently near to each other to prevent
too ready passage between them of the contents of the compartment, as hereinafter
described. I place in this compartment broken ore mixed with common salt and
pieces of broken retort coke of such size as will pass, but not very freely, between the
carbon blocks of the false-bottom. The proportions of these substances are not
necessarily limited, but there should be an excess of common salt above the quantity
necessary to evolve sufficient chlorine to combine with the zinc of the ore. By
mixing the ore with the coke, I ensure the proper conductivity of the said ore for
the purpose of electrolysis. The said false-bottom is so arranged as to permit access
to the space underneath the blocks to facilitate the clearance of the said space as
hereinafter explained.
In starting the work, the interstices of the false-bottom are filled with ramuied sand;
and then the charge of ore, mixed with the salt and retort-coke as above described,
is filled in together with water or a solution of salt. When it is desired to remove the
partially or wholly exhausted charge, the rammed sand is first raked out from below
the false-bottom, in a similar manner to that in which ashes are raked out of the grate
of a furnace; the earthy matters of the ore settle and rest upon the false-bottom of
the compartment, taking the place of the sand in preventing too rapid flow of liquid
between the blocks.
During the process, the ore becomes disintegrated and, sinking with the broken
retort-coke, comes finally with this coke into electrical connection with the carbon-
blocks of the false-bottom, in passing which, it experiences a final energetic action of
the electric current. If the tanks or baths are of the proper depth, the percolation of
liquid through the disintegrated and exhausted ore residuuin resting upon the
false-bottom and between the blocks thereof is very small and the liquid may be
returned to the anode compartment of the bath. This compartment is also provided
with a hood which is connected by pipes with the chlorinating chamber; the chlorine
gas evolved by the electrolysis is drawn away to the chlorinating chamber by the
aspiration resulting from the heat generated in that chamber by the chemical reaction
as hereinafter described. The said hood is provided with a hopper for feeding in the
subsequent ore-charges.
The chlorinating chamber is of novel construction. It has been usual, in chlorinating
lime, to pass the gas over shelves strewn with lime, which is from time to time raked
over to present a new surface or fresh succession of atoms for chlorination. This
method has obvious disadvantages. According to my invention, I cause the chlorine

page_text: to enter at a slight distance above the bottom of a tall chamber or tower constructed
of, or lined with, sheet-lead. At the top of the said chamber is a hopper into which
powdered lime is introduced. From the hopper, the lime falls on to a fine sieve, to
which oscillating or vibratory motion is imparted to sift the lime. The sifted lime
falls, in a finely divided state, through the ascending current of gas, and great heat is
generated in its combination therewith. Chlorine being heavier than the atmosphere,
the gas has no other tendency to rise than that due to the heat, and, although this is
excessive, the rising current and also the heat generated in the chamber can be
controlled by regulating the shower of falling lime. When the lime arrives at the
base of the chamber, it is thoroughly chloridised and appears as bleaching powder of
high purity rich in chlorine. It falls on to the sloping floor of the chamber, whence
it is drawn off through a chute into suitable receptacles, in which it is, if desired,
heated to produce pure chloride of calcium, as hereinafter described.
I sometimes use a modified form of my chlorinating chamber in which a metal
tray is connected electrically to one pole of a high tension machine, and a metal plate
is connected to the other pole of the said machine and is arranged parallel to and a
short distance above the said tray. The tray contains powder (such as powdered lime)
to be chlorinated by gas passing between the tray and the plate. This powder is kept
in constant agitation, being attracted from the tray by the plate and, after touching
the latter, being repelled therefrom and attracted by the tray. This tray and plate are
sometimes so inclined and arranged that the particles of the lime will be carried by
the current of gas passing between the said tray and plate, and will fall to
the ground or into any suitable receptacle. In some instances, I use two or
more of these trays and plates arranged one above another in the chlorinating
chamber.
To afterwards obtain pure chloride of calcium, the oxy-chloride of lime obtained
as above described is heated to a sufficiently high temperature to drive off the
oxygen, for which the calcium has less affinity than for the chlorine.
By my invention, the merchantable products, that is to say, for example, the
spelter, caustic soda, chloride of lime (and chloride of calcium) are, or may be all
produced simultaneously by a continuous series of reactions comprised in one
process.
I might, with less advantage, obtain the desired result by electrolysing a solution of
hydrochloric acid, using the ore as one electrode properly supported and rendered
conducting as hereinbefore described; in this case, I could use the chlorine evolved
to produce a merchantable chloride, oxychloride, hypochlorite or chlorate.
It may be advantageous to utilize the chlorine evolved to partially excite the
negative plates of a battery to produce the current required for electrolysis, in cases
where the reduction of cost of procuring electric energy would be a source of greater
profit than the production of a combination of chlorine.
In the accompanying drawing, I have shown how my improved apparatus may
conveniently and advantageously constructed and arranged.
Figure 1 is a vertical longitudinal section of one form of my improved apparatus.
Figure 2 is a perspective view showing details of construction, and
be
Figure 3 is a vertical longitudinal section illustrating a modification of my
invention.
Like letters indicate corresponding parts throughout the drawing.
A is one of the electrolytic baths which I employ; a is the porous diaphragm or
partition; b, b are the metallic or metallized plates which are suspended by means of
clips from rods e suitably supported in the vessel A. d, d are strips of wood or
other suitable material secured upon the edges of the plates b to prevent "treeing" of
the deposited metal. e is the steam-tight hood for the small or cathode compartment.
fis the inlet pipe and the outlet pipe of the said compartment. 9, 9 are slabs or
plates of graphitic carbon wherewith the larger or anode compartment is lined. h, h
are the carbon blocks which form the false-bottom of the said compartment, and
which are supported upon bars i of wood or other suitable material. is the hood of
the larger compartment, which is provided with a hopper ; whereby the charges may

page_text: be introduced into the said compartment. k is a pipe connecting the hood j with a
chamber 1, which is connected by another pipe m with the chlorinating chamber B.
This chlorinating chamber is made in the form of a tall chamber or tower and is
provided with a hopper n through which the powdered lime or other material is
introduced, and with a vibrating sieve o which may be operated by any well known
or suitable means. P, Pare outlets for the escape of the gas. is the sloping floor
of the chamber, upon which the chloridized or chlorinated material falls and whence
the said material passes through an aperture or chute into any suitable receptacle.
In the modification of my chlorinating chamber illustrated in Figure 3, s is the
metal tray upon which is to be placed the material to be chlorinated, and which is
connected by a wire s¹ with one pole of an electrical machine. is a metal plate
which is secured in any convenient manner a short distance above the said tray, and
which is connected by a wire t¹ with the other pole of the said machine. u is a chute
for the discharge of the chloridized or chlorinated material, and v is a pipe for the
escape of the gas.
It is obvious that my improved process may, if desired, be carried on by means of
other apparatus than that hereinbefore described.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I wish it understood that I claim:-
First. The simultaneous production of spelter, chlorine and an alkaline hydrate
by electrolysis, substantially as hereinbefore described.
Second. The combined production of spelter, caustic soda, and bleaching powder,
substantially as hereinbefore described.
Third. The improved process substantially as hereinbefore described, whereby I
provide for the production of spelter, chlorine and a combination or compound thereof
and sodic or other alkaline hydrate in a continuous manner.
Fourth. The improved electrolytic apparatus consisting of a tank or vessel divided
into compartments by a porous diaphragm, and having in one of the said compartments
one or more metallic or metallised plates which form the cathode, and in the other
compartiment a false-bottom composed of carbon blocks for supporting the ore and
other substances which form the anode, substantially as set forth.
Fifth. The combination of an apparatus for the electrolysis of zinc-chloride
solutions with an apparatus for the chlorination of lime or other bases, so that the
chlorine gas evolved by the electrolysis may be utilized in the production of bleaching
powder or other valuable products.
Sixth. The improved chlorinating chamber wherein the lime or other substance to
be chlorinated is caused to descend in a finely divided condition so that it will meet
and combine with the ascending chlorine, and which is so constructed and connected
with the anode compartment of the electrolytic apparatus that the heat generated in
the said chamber by the chemical reactions as hereinbefore described will maintain a
continuous aspiration or draught of the gas from the said compartment, substantially
as set forth.
Seventh. The modification of my chlorinating chamber wherein the lime or other
substance to be chlorinated is alternately electrically attracted to, and repelled from,
metal plates or trays between which the chlorine is passed, substantially as, and for
the purpose, set forth.
D
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.