Malaysia Flight 370 CARGO
Lithium Production
Lithium is a very low-density metal, prone to spontaneous
combustion. On the periodic table of the elements it lies directly
beneath hydrogen and has but three protons. It is the lightest solid
element, with a density only about half that of water. Lithium is
silvery in appearance, much like Na and K, other members of the alkali
metal series. It reacts with water, but not as vigorously as sodium.
Lithium imparts a beautiful crimson color to a flame, but when the metal
burns strongly, the flame is a dazzling white. The most common stable
isotope is Lithium-7, consisting of three protons and four neutrons;
less common, comprising 7.4 percent of normal lithium, is Lithium-6,
which has three protons and three neutrons in its nucleus.
Since World War II, the production of lithium metal and its compounds
has increased greatly. Because the metal has the highest specific heat
of any solid element, it has found use in heat transfer applications;
however, it is corrosive and requires special handling. The metal has
been used as an alloying agent, is of interest in synthesis of organic
compounds, and has nuclear applications. It ranks as a leading contender
as a battery anode material as it has a high electrochemical potential.
Lithium is used in special glasses and ceramics. The glass for the
200-inch telescope at Mt. Palomar contains lithium as a minor
ingredient. Lithium chloride is one of the most lyproscopic materials
known, and it, as well as lithium bromide, is used in air conditioning
and industrial drying systems. Lithium stearate is used as an
all-purpose and high-temperature lubricant. Other lithium compounds are
used in dry cells and storage batteries.
Lithium [Li] is a critical material for the manufacture of the
secondaries of so-called dry thermonuclear devices, which do not require
the use of liquid deuterium and tritium. The largest nuclear device
ever detonated was a multi-stage Soviet product with a yield of nearly
60 megatons. It was exploded at only half of its design maximum yield of
about 100 megatons.
Lithium enriched in the isotope Lithium-6 remains a controlled
material because of its
utility in the production of compact and highly efficient thermonuclear
secondaries.
Two-stage nuclear weapons incorporating a lithium-deuteride-fueled
component can
deliver greater nuclear yield from a smaller and lighter package than if
a pure fission device were used. The tradeoff is that the design and
construction of reliable two-stage "dry" weapons may require significant
knowledge of nuclear weapons physics and technology, knowledge which is
hard to acquire without a program involving full-yield testing of the
fission primary to be used and measurement of its production of x-rays
and their transport through a case surrounding both primary and
secondary stages. Therefore, Lithium-6 is more likely to be of interest
to a state with nuclear weapons experience than it is to a beginning
nuclear state.
Lithium-6 is most often separated from natural lithium by the
COLEX (Column
exchange) electrochemical process, which exploits the fact that
Lithium-6 has a greater affinity for mercury than does Lithium-7. A
lithium-mercury amalgam is first prepared using the natural material.
The amalgam is then agitated with a lithium hydroxide solution, also
prepared from natural lithium. The desired Lithium-6 concentrates in the
amalgam, and the more common Lithium-7 migrates to the hydroxide. A
counter flow of amalgam and hydroxide passes through a cascade of stages
until the desired enrichment in Lithium-6 is reached. The Lithium-6
product can be separated from the amalgam, and the "tails" fraction of
Lithium-7 electrolyzed from the aqueous lithium hydroxide solution. The
mercury is recovered and can be reused with fresh feedstock.
Russia, the UK, France, and China are all believed to be capable
of making Lithium-6 in the quantities needed for the manufacture of
large nuclear stockpiles. Russia exploded a device making use of
Lithium-6 before the United States did; however, the Soviet device was
not a "true" thermonuclear weapon capable of being scaled to any desired
yield. United States production of 6Li ceased in 1963.
Sources and Methods
- Adapted from - Nuclear Weapons Technology Militarily Critical Technologies List (MCTL)
Part II: Weapons of Mass Destruction Technologies
Additional Resources
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