Lithium

Lithium, at about half the density of water, is the lightest of all solid elements and is the first element in the alkali metal column in the periodic table (Group I). It is silvery white, soft and reacts immediately with air to form the oxide and with water to form the hydroxide with the evolution of hydrogen. Lithium is a rare element because of its highly dispersed occurrence in the earth’s crust. Economic concentrations occur in salts from surface and subsurface brines and in the minerals petalite, spodumene, amblygonite-montebrasite and lepidolite in giant pegmatite deposits.

PROPERTIES AND APPLICATIONS OF LITHIUM

Lithium finds use as metal, compound and directly as mineral. The element’s lightness, small ionic radius, low ionization energy (high electropositivity), low melting point and other properties are exploited in a variety of applications. Lithium minerals impart zero thermal expansion, toughness and smooth finish to ceramics and glass. The fluxing action, particularly of petalite, results in lower vitrification and melting temperatures.

• Lithium batteries: Lithium’s strongly ionic character is exploited in regular and rechargeable, long-life batteries used in watches, computers, cell phones and scientific and military equipment.
• Metallurgical: Lithium carbonate is an electrolyte ingredient used in high efficiency aluminum production. Lithium metal added to aluminum creates a light strong alloy.
• Fusion Energy: The Li-6 isotope is the premium fuel (source of tritium) for fusion reactors, the first of which was the hydrogen bomb. Liquid lithium’s low neutron cross section high specific heat and low melting point make it the best heat transfer medium (coolant) for a fusion reactor.
• Lithium Chemicals: The element’s high electropositivity is an index of the number and variety of possible compounds that can be made. It is used in neoprene rubber manufacture, air conditioning systems, lubricants, sanitation, pharmaceuticals for mood disorders, etc.
• Ceramics: petalite is used to produce zero-thermal-expansion (thermal shock resistant) clay cookware and glazes for rapid, single-fire ceramics. It also improves durability of refractories subjected to rapid heating and cooling cycles.
• Glass-ceramics: petalite and/or spodumene are essential ingredients in thermal shock resistant ‘ceramic’ stovetops and Corningware®-type cookware. A new ‘glass’ armour for military use makes use of the toughness and lightness of this material.
• Glass: petalite and spodumene improve melt characteristics, save on energy and furnace refractories, increase effective plant capacity (lower temperatures > quicker melting and cooling), reduce air pollution and produce stronger glass products.