Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy
The analysis of the conditions for industrial production of zirconium by the electrolysis of a melt of potassium fluorozirconate and potassium chloride in a sealed electrolyzer with a current load of 10 kA was carried out. It is shown that the developed method of preparing the raw material without t...
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irk-123456789-1949502023-12-01T20:36:35Z Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy Mukhachev, A.P. Nefedov, V.G. Kharytonova, O.A. Thermal and fast reactor materials The analysis of the conditions for industrial production of zirconium by the electrolysis of a melt of potassium fluorozirconate and potassium chloride in a sealed electrolyzer with a current load of 10 kA was carried out. It is shown that the developed method of preparing the raw material without the use of chlorine, with electrolytic reduction of zirconium provides the production of a metal of nuclear purity, with a hafnium content of less than 0.005 wt.% polyvalent ion electrodes. The current output of zirconium is 55...60%, which may be due to reversible oxidation-reduction on the electrodes of polyvalent ions. The low resistance of the graphite anode is due to both chemical interaction with the released fluorine and chlorine, and its mechanical destruction. Проведено аналіз умов промислового отримання цирконію електролізом розплаву фторцірконата калію і хлориду калію в герметичному електролізері зі струмовим навантаженням 10 кА. Показано, що розроблений метод підготовки сировини без застосування хлору з електролітичним відновленням цирконію забезпечує отримання металу ядерної чистоти з вмістом гафнію, менш 0,005 мас.%. Вихід по струму цирконію становить 55…60%, що може бути пов'язано з оборотним окисленням-відновленням на електродах полівалентних іонів. Невисока стійкість графітового анода обумовлена як хімічною взаємодією з фтором і хлором які виділяються, так і механічним його руйнуванням. Проведен анализ условий промышленного получения циркония электролизом расплава фторцирконата калия и хлорида калия в герметичном электролизере с токовой нагрузкой 10 кА. Показано, что разработанный метод подготовки сырья без применения хлора с электролитическим восстановлением циркония обеспечивает получение металла ядерной чистоты с содержанием гафния менее 0,005 мас.%. Выход по току циркония составляет 55…60%, что может быть связано с обратимым окислениемвосстановлением на электродах поливалентных ионов. Невысокая стойкость графитового анода обусловлена как химическим взаимодействием с выделяющимися фтором и хлором, так и механическим его разрушением. 2019 Article Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy / A.P. Mukhachev, V.G. Nefedov, O.A. Kharytonova // Problems of atomic science and technology. — 2019. — № 2. — С. 111-115. — Бібліогр.: 6 назв. — англ. 1562-6016 http://dspace.nbuv.gov.ua/handle/123456789/194950 621.357.1: 661.883.1 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Thermal and fast reactor materials Thermal and fast reactor materials |
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Thermal and fast reactor materials Thermal and fast reactor materials Mukhachev, A.P. Nefedov, V.G. Kharytonova, O.A. Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy Вопросы атомной науки и техники |
| description |
The analysis of the conditions for industrial production of zirconium by the electrolysis of a melt of potassium fluorozirconate and potassium chloride in a sealed electrolyzer with a current load of 10 kA was carried out. It is shown that the developed method of preparing the raw material without the use of chlorine, with electrolytic reduction of zirconium provides the production of a metal of nuclear purity, with a hafnium content of less than 0.005 wt.% polyvalent ion electrodes. The current output of zirconium is 55...60%, which may be due to reversible oxidation-reduction on the electrodes of polyvalent ions. The low resistance of the graphite anode is due to both chemical interaction with the released fluorine and chlorine, and its mechanical destruction. |
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Article |
| author |
Mukhachev, A.P. Nefedov, V.G. Kharytonova, O.A. |
| author_facet |
Mukhachev, A.P. Nefedov, V.G. Kharytonova, O.A. |
| author_sort |
Mukhachev, A.P. |
| title |
Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy |
| title_short |
Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy |
| title_full |
Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy |
| title_fullStr |
Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy |
| title_full_unstemmed |
Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy |
| title_sort |
electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2019 |
| topic_facet |
Thermal and fast reactor materials |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/194950 |
| citation_txt |
Electrode processes in electrolysis of zirconium at production of plastic zirconium for nuclear energy / A.P. Mukhachev, V.G. Nefedov, O.A. Kharytonova // Problems of atomic science and technology. — 2019. — № 2. — С. 111-115. — Бібліогр.: 6 назв. — англ. |
| series |
Вопросы атомной науки и техники |
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AT mukhachevap electrodeprocessesinelectrolysisofzirconiumatproductionofplasticzirconiumfornuclearenergy AT nefedovvg electrodeprocessesinelectrolysisofzirconiumatproductionofplasticzirconiumfornuclearenergy AT kharytonovaoa electrodeprocessesinelectrolysisofzirconiumatproductionofplasticzirconiumfornuclearenergy |
| first_indexed |
2025-07-16T22:38:23Z |
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2025-07-16T22:38:23Z |
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1837844926831788032 |
| fulltext |
ISSN 1562-6016. PASТ. 2019. №2(120), p. 111-115.
UDC 621.357.1: 661.883.1
ELECTRODE PROCESSES IN ELECTROLYSIS OF ZIRCONIUM AT
PRODUCTION OF PLASTIC ZIRCONIUM FOR NUCLEAR ENERGY
A.P. Mukhachev, V.G. Nefedov*, O.A. Kharytonova**
Center of Chemical Technologies AINU, Kamenskoe, Ukraine;
*Dnieper State University of Chemical Technology, Dnipro, Ukraine;
**Dniprovskyi State Technical University, Kamenskoe, Ukraine
E-mail: eah@ukr.net
The analysis of the conditions for industrial production of zirconium by the electrolysis of a melt of potassium
fluorozirconate and potassium chloride in a sealed electrolyzer with a current load of 10 kA was carried out. It is
shown that the developed method of preparing the raw material without the use of chlorine, with electrolytic
reduction of zirconium provides the production of a metal of nuclear purity, with a hafnium content of less than
0.005 wt.% polyvalent ion electrodes. The current output of zirconium is 55...60%, which may be due to reversible
oxidation-reduction on the electrodes of polyvalent ions. The low resistance of the graphite anode is due to both
chemical interaction with the released fluorine and chlorine, and its mechanical destruction.
INTRODUCTION
An industrial method of producing plastic zirconium
of nuclear purity for the manufacture of products of a
wide range of pipes, rods, sheets, wires used as part of
nuclear fuel (JF) was developed in the USSR on the
basis of the electrolysis of molten salts from the K2ZrF6-
KCl-KF electrolyte. A mixture of fluorocirconate and
potassium fluoride salt was first obtained in the process
of sintering zircon with potassium fluorosilicate
(K2SiF6) at a temperature of 800 °C. To separate
zirconium and hafnium, the process of fractional
crystallization of their fluorides was mastered, based on
the different solubilities of Zr and Hf salts in water at a
temperature of 90 °C [1]. Its disadvantages were the low
yield of zirconium in an attempt to reduce the content of
hafnium in salt from 2 to 0.01%, the production of
enriched hafnium concentrate (6…10%) requiring
processing, the presence of solid and liquid wastes
requiring disposal.
To extract zirconium when processing zircon more
than 70%, it was decided to limit the content of Hf in
the Zr salt to 0.005% by weight, which did not meet the
requirements of the ASTM standard for zirconium. This
limited the sale of zirconium products for export.
Plans for the development of zirconium production
in the 70 s of the twentieth century to a level of 2.0…4.0
thousand tons per year required new, more efficient
technological processes for the processing of zircon,
which would ensure comprehensive processing of raw
materials, with maximum extraction of zirconium and
hafnium and obtaining high-purity metals on new
technologies for the development of nuclear energy,
environmental requirements for environmental
protection.
Zircon chloride processing technology operating in
the USA [2] under the conditions of Ukraine could not
be implemented due to the formation of chloride
effluents that cannot be recycled, which was harmful to
the environment.
Ukraine had a successful experience in opening
zircon by sintering with chalk, which did not have the
disadvantages inherent in the processes of chlorination
and sintering of zircon with K2SiF6. Its use at PChZ
allowed us to obtain zirconium and hafnium salts, which
are soluble in nitric acid, to extract them on a TBP-
kerosene extractant to obtain pure Zr and Hf salts,
without a fractional crystallization process. In this case,
Zr, K2ZrF6 salt was obtained with a hafnium content of
less than 0.005% and a hafnium salt suitable for
producing nuclear-grade hafnium, which reduced the
cost of zirconium by 20…30%.
Despite the positive experience in the development
and implementation of chlorine-free processing
technology for zircon, with the production of nuclear-
grade zirconium alloys on the scale of pilot production
of 130 t zirconium per year, Ukraine continues to import
zirconium rolled products. Therefore, the choice of the
method of obtaining zirconium of nuclear purity from
domestic raw materials to replace imports remains
relevant.
In this article, the results of the first studies of the
electrolysis of potassium fluorocirconate of Ukrainian
production were published, the reasons for the low
current output of zirconium and the rapid destruction of
the anode from graphite were analyzed, the quality of
electrolytic zirconium powder was evaluated.
1. TECHNIQUE OF INDUSTRIAL
THEORY OF ELECTROLYSIS
OF ZIRCONIUM
During electrolysis at the cathode, reactions of
reduction of zirconium and potassium proceed [3]:
)(6)(Zr4)(2
6 fusionFfeеfusionZrF , (1)
KeK 444
. (2)
The released potassium partially interacts with
potassium fluorozirconate and restores zirconium by the
reaction:
2 6 4 6 .K ZrF K Zr KF (3)
The confirmation of this reaction is the appearance
of finely dispersed zirconium powder in the cathode
product, as well as the accumulation of potassium
fluoride in the melt.
The presence of potassium metal in the cathode
product was detected during the evolution of hydrogen,
as a result of the decomposition of water:
mailto:eah@ukr.net
22 2232 HKOHOHK . (4)
The release of zirconium at the cathode is preceded
by its recovery to the divalent state. Therefore, near the
cathode in the melt there is an equilibrium between the
metal and its ions of higher and lower valency:
)(2)()( 24 fusionZrfeZrfusionZr . (5)
The equilibrium constant of this reaction is
determined from the expression:
][
1][Zr
][Zr
K
2
4
22
Zr
x
x
, (6)
where x is the proportion of divalent zirconium [Zr] =
[Zr
2 +
] + [Zr
4 +
].
The cathode current density during electrolysis is
3.16 A/cm
2
.
At the anode, as a result of strong depolarization, the
discharge potential of fluorine ions decreases from 2.93
to 0.9 V, which is lower than the discharge potential of
chlorine ions, equal to 1.2 V. When this occurs two
electrochemical reactions:
222 CleCl
, (7)
CFeCF 2222
. (8)
When CF interacts with chlorine, a thermodynamic
ally unstable compound CFCl is formed, which
decomposes into a series of more stable freons of
composition (where m = 0, 1, 2, 3):
2 31.5CF Cl CFCl , (9)
CFClClCF 22 2 , (10)
CClCFCFCl 222 , (11)
CClClCFCFCl 23 23 , (12)
4 24 2 3CFCl CF Cl C . (13)
As a result of these reactions, carbon appears in the
electrolyte and is captured by СР.
In turn, the appearance of compound CF at the
anode reduces the potential of chlorine discharge from
1.2 to 0.78 V, which provides preferential release of
chlorine, the content of which in the anode gas can
reach 60%. Anode current density is 0.26 A/cm
2
.
Freons F11, F12, F13, F14 containing carbon,
chlorine and fluorine are released in proportions
determined by the potential for the discharge of ions.
Freons are complex reagents and can be used to produce
chlorides and metal fluorides in molten salts.
The total reaction of obtaining zirconium powder,
accompanied by the destruction of the graphite anode,
can be described by the following equation:
2 6
3 2 2
3 4 2
10 19 8 42
10 37 2 2
2 3 5 .
K ZrF KCl C e
Zr KF K CCl F CCl F
CClF CF Cl
(14)
Analyzes of the composition of the anode gas
showed the presence of the amount of freon F-11, F-12,
F-13, F-14, chlorine, CO, CO2, O2 and N2. Cleaning gas
from chlorine was carried out with lime milk. Chloride
drains were pumped into the subterranean horizon.
Freons, after purification of anode gas from chlorine,
were dumped into the atmosphere.
Zirconium powder, which is formed in the process
of electrolysis and released in the composition of CP,
has a dendrite-like and volume-centered structure. The
intergrowths of zirconium crystals have impregnations
of the salts that make up the electrolyte containing KCl,
KF, K2ZrF6. To open large intergrowths, ensuring
minimal powder loss, the technological scheme of CP
processing includes the following stages: crushing to a
fraction 2…5 mm, first carbonate treatment with 10%
p-rum ammonium carbonate, grinding to a fraction
1.0 mm. The second carbonate treatment is conducted
with a 5% ammonium carbonate solution. This is
followed by water treatment of the powder, its flotation,
acid and water washings. Chloride drains are pumped
into the underground horizon.
2. DESCRIPTION OF THE ELECTROLYZER
FOR THE ELECTROLYSIS OF ZIRCONIUM
For electrolytic production of zirconium, an
electrolyzer with a current load of 10 kA, shown in
Figure, is used.
The scheme of the electrolyzer to obtain zirconium.
Cross section: 1 – anode; 2 – cathode; 3 – caisson; 4 – garnissage; 5 – bunker: 6 – shaft, 7 – cutter
The cell has a rectangular shape. In order to prevent
the interaction of the materials of the walls of the
electrolyzer with the electrolyte, during the starting
period a layer of garnissage with a resistance of
50…60 is built up on the walls cooled by water. A
shaft with two cathodes is installed along the major axis
of the electrolyzer. Three pairs of prefabricated graphite
anodes are located near the cathodes. The cathodes in
the form of segments are made of steel Х18Н9Т and
fixed on a hollow shaft cooled from the inside with a
water-air mixture.
After increasing the sediment, once per shift, the
cathodes are rotated, and when rotated by 270º, the CP
is cut with knives and dumped into a bunker cooled with
argon. The electrolyte is corrected after cutting a CP
once a shift is a mixture of salts consisting of 20%
K2ZrF6, humidity not more than 0.05 and 80% KCl with
humidity up to 1%. The loading of fluorocirconate and
potassium chloride is made by screw feeders from two
bunkers.
To maintain a constant electrolyte composition, it is
drained daily.
KP contains zirconium powder, K2ZrF6,
hygroscopic salts of KCl and CF, which requires careful
handling. CP humidification during storage in air can
lead to powder burning in closed systems, since
zirconium can ignite spontaneously in air at a humidity
of less than 10%. Merged electrolyte is cooled, crushed
and recycled.
When the electrolyte is drained, the electrolyzer
operates in the open mode, so the powder is obtained
with a high content of oxygen and nitrogen and
undergoes iodide refining.
3. RESULT AND DISCUSSION
3.1. THE MATERIAL BALANCE
OF THE ELECTROLYSIS PROCESS
It should be noted that in industrial production
conditions, mass electrolysis indices inevitably differ
from stoichiometric ones. In the process of working in
the electrolyte decreases the content of zirconium,
chlorine and increases the content of potassium fluoride.
The electrolyte in the electrolysis process has a content
of, K2ZrF616%, KCl20%, KF63%, C1%. The
consumption of K2ZrF6 in the process of electrolysis
was 360 kg/day. Drain molten electrolyte is 200 kg/day.
Electrolyte entrainment with a cathode product is
200 kg/day. The developed mathematical models [3]
made it possible to calculate the consumption of salt
components, the yield of the cathode product, the
weight of excess electrolyte. The method of automatic
control of the flow of salts allowed to stabilize the
composition of the electrolyte [4-6]. This allows you to
calculate the material balance of the process of
electrolysis of zirconium.
2 6
( )
(360 32 32)92
105 ,
283
A S C Zr
Zr
K ZrF
G G G M
G
M
kg
day
where GZr is mass of zirconium, accumulating in the
electrolyte; GA – is the mass of K2ZrF6 in the incoming
salt; GS – is the mass of K2ZrF6 in the outgoing salt, GC
– is the mass of K2ZrF6 in the СP cathode sediment mass
of cathode sediment; M are molecular masses of
substances. The amount of zirconium that is released on
the cathode in the form of metal is 105 kg/day. The
content of gaseous impurities in zirconium is: O2 less
than 0.1%; N2 less than 0.005%, which ensures its
high plasticity.
3.2. EVALUATION OF THE CURRENT OUTPUT
OF ZIRCONIUM
3.2.1. Calculation of the cost of electricity
The estimated operating time of the electrolyzer is
taken 20 h a day. The amount of electricity passed can
be estimated as
10000 20 200000 А h.Q I (15)
The electrochemical equivalent of zirconium,
determined from (1), is approximately 0.86 g/(А·h). For
the specified amount of electricity, according to
Faraday's law, 172 kg of zirconium should stand out.
Zirconium current output will be equal to
105
0.61.
172
В (16)
3.2.2. Calculation of the amount of electricity, which
went to the selection of anode products
The amount of transmitted electricity can be
determined by the anode process, since it is known the
amount of chlorine and freon produced.
Upon receipt of 1 t of zirconium, 0.6 t of chlorine
and 1.0 t of freon are released.
Analyzes of the composition of the anode gas
showed the following concentrations of freon: F-11
(5 ± 1)%; F-12 (4 ± 1)%; F-3 (9 ± 2)%; F-14
(18 ± 2)%, and chlorine (57 ± 3)% with a sum of Co,
CO2, O2, and N2 equal to 5%. Thus, the share of freons
in the anode gas is approximately 36%, and the share of
each freon in the freon mixture is F-11 14%, F-12
11%, F-13 25%, F-14 50%
Electrochemical equivalents of chlorine and freon
F11, F12, F13, and F14 are determined from the total
equation using the formula:
zF
M
k
(17)
and make, respectively, kCl2 = 0.33 g/(А·h), kF11 = 0.128 g/(А·h);
kF12 = 0.225g /(А·h); kF13 = 0.195 g/(А·h); kF14 = 0.246 g/(А·h).
On the allocation of chlorine is spent, respectively:
3
6
2
2
600 10
1.81 10 А h
0.33
Cl
Cl
M
Q
k
(18)
and on the allocation of the amount of freon:
F
F
F11 F12 F13 F14
6
6
М
Q
10
0,205 10 А h.
4.88
k k k k
(19)
The total amount of electricity in (18) and (19) is
2.09∙10
6
А·h.
To get one ton of zirconium should go (19)
electricity:
3
61000 10
1.176 10 А h
0.86
Zr
Zr
Zr
M
Q
k
(20)
The current output in this case will be:
6
6
1.176 10
В 0.56,
2.09 10
(21)
which is close enough to (16).
The material balance of the electrolysis process
indicates that the low current efficiency of zirconium
cannot be associated with metal losses during the
electrolysis and processing stages. We believe that in
addition to the electrode reactions described in Section
2, redox processes may occur on the electrodes. For
example, the reduction of tetravalent zirconium at the
cathode to a bivalent state by reaction (5), its transfer by
convective currents to the anode, followed by oxidation
to tetravalent. In addition, a certain change in the
magnitude of the zirconium current output may be due
to a change in the stoichiometric ratio of Freon F11,
F12, F13, and F14. So, in the conditions of allocation
only F11, the amount of electricity for its allocation will
be about 0.78∙10
6
A∙h, and the total amount of
electricity is only 2.59∙10
6
A∙h. The current output of
zirconium, calculated according to 3.2.2. in this case
will reach 55…60%.
A change in the composition of freons formed in
different electrolysis modes is confirmed
experimentally. So, with the anodic effect, the content
of F14 significantly increases, which indicates a high
concentration of CF in the electrolyte and the need for
its partial removal. The output of zirconium in KP is
significantly reduced.
The current output is significantly reduced.In
general, it can be noted that the electrolysis of K2ZrF6,
with a Hf content of less than 0.005%, provided the
production of zirconium powder of the same degree of
purity as for hafnium, while the purity of zirconium was
99.9%.
3.2.3. Evaluation of the quality of zirconium powder
Processing KP according to the above scheme
allows you to extract in the finished product 80% of the
powder corresponding to THE 95.259-88. 20% of fine
zirconium powder contaminated with impurities is sent
for recycling. The content of metal impurities in the
powder corresponds to ASTM B349-80, and the content
of hafnium is less than 0.005%, while the silicon
content was two times less. The granulometric
composition of the powder corresponded to the powder
of the standard product. In general, it can be noted that
the purity of zirconium was 99.9%. The quality of the
powder depends on the quality of the original zirconium
salt. In the process of electrolysis, additional metallic
impurities are not introduced.
3.3. ANALYSIS OF THE CONDITION
OF COMBUSTION OF A GRAPHITE ANODE
The destruction of anodes from graphite EG-0 is the
inevitable result of the process of electrolysis in
chloride-fluoride melts and determines its duration. The
formation of freons F11, F12, F13, and F14 according to
reactions (8)–(13) occurs on the anode surface and is
accompanied by the release of carbon into the melt in
quantities of 1, 2, and 3 moles per mole of freons F12,
F13, and F14, respectively. Taking into account the
stoichiometric coefficients in equation (14), this means
that an additional 15 moles of carbon are involved in the
reaction. They can remain on the surface or stand out in
a fine state and accumulate in the electrolyte. If we
assume that these 15 moles of carbon are emitted in a
finely dispersed form, then the calculation of carbon
consumption should be made not by 8, but by 23 moles.
Then the value of the electrochemical carbon equivalent
will be:
23 12
0.257 g/(А h).
40 26.8
Ck
(22)
The consumption of carbon (graphite) in the reaction
of release of freon according to (14) is
6
C F CM Q k 1.26 10 0.257 324 kg.
Let's analyze the obtained values.
Industrial measurements have shown that the
specific consumption of graphite is approximately
600 kg per 1 t of powder. If all the carbon involved in
the formation of freon goes into an electrolyte in a fine
form, the destruction of the anodes is not exhausted by
this process. The assumption that the loss of anode
material due to the combustion of graphite when
interacting with oxygen (as in the production of
aluminum or magnesium) is unlikely due to the low
humidity of the raw materials used. Most likely, when
freons are released on an inhomogeneous electrode
surface, mechanical destruction of graphite occurs with
the accumulation of scree in the electrolyte. The carbon
content in the powder is limited by a limit of 0.02% of
the mass, therefore, in the washing processes, the
zirconium is necessarily cleaned from carbon by the
flotation method. The flotation product containing fine
fractions of powder and carbon is recycled.
The participation of carbon in the anode process
requires the replacement of anodes after 50 days of
continuous electrolysis.
CONCLUSIONS
1. It is shown that the process of electrolysis of
zirconium from salt K2ZrF6 obtained after estractional
separation of zirconium and hafnium, retains the content
of hafnium in zircon less than 0.005%, which meets the
requirements of ASTM B349-80. Zirconium powder has
a purity of 99.9%.
2. During electrolysis of fluoride-chloride
electrolytes, the current efficiency of zirconium is
55…60%. The relatively low current efficiency may be
associated with redox processes at the electrodes of
polyvalent zirconium ions.
3. Consumption of anode material is determined by
its chemical interaction with fluorine and chlorine, and
mechanical destruction.
4. Accumulation of KF and release of chlorine at the
anode are side effects of electrode processes.
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Article received 14.01.2019
ЭЛЕКТРОДНЫЕ ПРОЦЕССЫ В ЭЛЕКТРОЛИЗЕ ЦИРКОНИЯ ПРИ ПРОИЗВОДСТВЕ
ПЛАСТИЧЕСКОГО ЦИРКОНИЯ ДЛЯ ЯДЕРНОЙ ЭНЕРГИИ
А.П. Мухачев, В.Г. Нефедов, Е.А. Харитонова
Проведен анализ условий промышленного получения циркония электролизом расплава фторцирконата
калия и хлорида калия в герметичном электролизере с токовой нагрузкой 10 кА. Показано, что
разработанный метод подготовки сырья без применения хлора с электролитическим восстановлением
циркония обеспечивает получение металла ядерной чистоты с содержанием гафния менее 0,005 мас.%.
Выход по току циркония составляет 55…60%, что может быть связано с обратимым
окислениемвосстановлением на электродах поливалентных ионов. Невысокая стойкость графитового анода
обусловлена как химическим взаимодействием с выделяющимися фтором и хлором, так и механическим его
разрушением.
ЕЛЕКТРОДНІ ПРОЦЕСИ У ЕЛЕКТРОЛІЗІ ЦИРКОНІЮ
ПРИ ВИРОБНИЦТВІ ПЛАСТИЧНОГО ЦИРКОНІЮ ДЛЯ ЯДЕРНОЇ ЕНЕРГЕТИКИ
A.П. Мухачов, В.Г. Нефьодов, О.А. Харитонова
Проведено аналіз умов промислового отримання цирконію електролізом розплаву фторцірконата калію і
хлориду калію в герметичному електролізері зі струмовим навантаженням 10 кА. Показано, що розроблений
метод підготовки сировини без застосування хлору з електролітичним відновленням цирконію забезпечує
отримання металу ядерної чистоти з вмістом гафнію, менш 0,005 мас.%. Вихід по струму цирконію
становить 55…60%, що може бути пов'язано з оборотним окисленням-відновленням на електродах
полівалентних іонів. Невисока стійкість графітового анода обумовлена як хімічною взаємодією з фтором і
хлором які виділяються, так і механічним його руйнуванням.
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