Zirconium(IV) fluoride
Encyclopedia
Zirconium fluoride (Zr
F4
) is an inorganic chemical compound
. It is a component of ZBLAN
fluoride glass
. It is insoluble in water. It is the main component of fluorozirconate glasses.
Three crystalline phases of ZrF4 have been reported, α (monoclinic, β (tetragonal, Pearson symbol
tP40, space group
P42/m, No 84) and γ (unknown structure). β and γ phases are unstable and irreversibly transform into the α phase at 400 °C.
Zirconium fluoride is used as a zirconium source in oxygen-sensitive applications, e.g. metal production. Zirconium fluoride can be purified by distillation
or sublimation.
Conditions/substances to avoid are: moisture
, active metals, acid
s and oxidizing agent
s.
Zirconium fluoride in a mixture with other fluoride
s is a coolant
for molten salt reactor
s. In the mixture with sodium fluoride
it is a candidate coolant for the Advanced High-Temperature Reactor.
Together with uranium salt, zirconium fluoride can be a component of fuel-coolant in molten salt reactors. Mixture of sodium fluoride, zirconium fluoride, and uranium tetrafluoride
(53-41-6 mol.%) was used as a coolant in the Aircraft Reactor Experiment. A mixture of lithium fluoride
, beryllium fluoride
, zirconium fluoride, and uranium-233 tetrafluoride
was used in the Molten-Salt Reactor Experiment
. (Uranium-233
is used in the thorium fuel cycle
reactors.)
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
F4
Fluorine
Fluorine is the chemical element with atomic number 9, represented by the symbol F. It is the lightest element of the halogen column of the periodic table and has a single stable isotope, fluorine-19. At standard pressure and temperature, fluorine is a pale yellow gas composed of diatomic...
) is an inorganic chemical compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
. It is a component of ZBLAN
ZBLAN
Heavy metal fluoride glasses were accidentally discovered in 1975 by Poulain and Lucas at the University of Rennes in France, including a family of glasses ZBLAN with a composition ZrF4-BaF2-LaF3-AlF3-NaF....
fluoride glass
Fluoride glass
Fluoride glass is a class of non-oxide optical glasses composed of fluorides of various metals. Due to their low viscosity, it is very difficult to completely avoid the occurrence of any crystallization while processing it through the glass transition...
. It is insoluble in water. It is the main component of fluorozirconate glasses.
Three crystalline phases of ZrF4 have been reported, α (monoclinic, β (tetragonal, Pearson symbol
Pearson symbol
The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W.B. Pearson. The symbol is made up of two letters followed by a number. For example:* Diamond structure, cF8...
tP40, space group
Space group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...
P42/m, No 84) and γ (unknown structure). β and γ phases are unstable and irreversibly transform into the α phase at 400 °C.
Zirconium fluoride is used as a zirconium source in oxygen-sensitive applications, e.g. metal production. Zirconium fluoride can be purified by distillation
Distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....
or sublimation.
Conditions/substances to avoid are: moisture
Moisture
Humidity is the amount of moisture the air can hold before it rains. Moisture refers to the presence of a liquid, especially water, often in trace amounts...
, active metals, acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
s and oxidizing agent
Oxidizing agent
An oxidizing agent can be defined as a substance that removes electrons from another reactant in a redox chemical reaction...
s.
Zirconium fluoride in a mixture with other fluoride
Fluoride
Fluoride is the anion F−, the reduced form of fluorine when as an ion and when bonded to another element. Both organofluorine compounds and inorganic fluorine containing compounds are called fluorides. Fluoride, like other halides, is a monovalent ion . Its compounds often have properties that are...
s is a coolant
Coolant
A coolant is a fluid which flows through a device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, and chemically inert, neither causing nor...
for molten salt reactor
Molten salt reactor
A molten salt reactor is a type of nuclear fission reactor in which the primary coolant, or even the fuel itself is a molten salt mixture...
s. In the mixture with sodium fluoride
Sodium fluoride
Sodium fluoride is an inorganic chemical compound with the formula NaF. A colorless solid, it is a source of the fluoride ion in diverse applications. Sodium fluoride is less expensive and less hygroscopic than the related salt potassium fluoride....
it is a candidate coolant for the Advanced High-Temperature Reactor.
Together with uranium salt, zirconium fluoride can be a component of fuel-coolant in molten salt reactors. Mixture of sodium fluoride, zirconium fluoride, and uranium tetrafluoride
Uranium tetrafluoride
Uranium tetrafluoride is a green crystalline solid compound of uranium with an insignificant vapor pressure and very slight solubility in water. Uranium in its tetravalent state is very important in different technological processes...
(53-41-6 mol.%) was used as a coolant in the Aircraft Reactor Experiment. A mixture of lithium fluoride
Lithium fluoride
Lithium fluoride is an inorganic compound with the formula LiF. It is the lithium salt of hydrofluoric acid. This white solid is a simple ionic compound. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. It is mainly used as a component of molten...
, beryllium fluoride
Beryllium fluoride
Beryllium fluoride is the inorganic compound with the formula BeF2. This white solid is the principal precursor for the manufacture of beryllium metal.-Structure and bonding:...
, zirconium fluoride, and uranium-233 tetrafluoride
Uranium tetrafluoride
Uranium tetrafluoride is a green crystalline solid compound of uranium with an insignificant vapor pressure and very slight solubility in water. Uranium in its tetravalent state is very important in different technological processes...
was used in the Molten-Salt Reactor Experiment
Molten-Salt Reactor Experiment
The Molten-Salt Reactor Experiment was an experimental molten-salt reactor at the Oak Ridge National Laboratory researching this technology through the 1960s; constructed by 1964, it went critical in 1965 and was operated until 1969....
. (Uranium-233
Uranium-233
Uranium-233 is a fissile isotope of uranium, bred from Thorium as part of the thorium fuel cycle. It has been used in a few nuclear reactors and has been proposed for much wider use as a nuclear fuel. It has a half-life of 160,000 years....
is used in the thorium fuel cycle
Thorium fuel cycle
The thorium fuel cycle is a nuclear fuel cycle that uses the naturally abundant isotope of thorium, , as the fertile material. In the reactor, is transmuted into the fissile artificial uranium isotope which is the nuclear fuel. Unlike natural uranium, natural thorium contains only trace amounts...
reactors.)