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The world's top metals

E&T describes sixteen most common metals.

Alkali metals

Lithium

Symbol:Li
Atomic number: 3
First identified: 1817
Current market price: (lithium carbonate) £3,000/Metric tonne

Primary uses: Lithium is the lightest and least dense metal. When combined with its high electrochemical potential, that makes it perfect for use in mobile and portable batteries. Lithium stearate is a widely-used all-purpose lubricant in mobile applications, and lithium salts are also used to treat depression.

Industry news: Prices of lithium-ion rechargeable batteries - the power source of choice for everything from the Tesla Roadster electric sports car to the Apple iPad - are expected to fall by up to a quarter during 2010 due to a glut in production.

Recent developments: A recent life-cycle study by the Swiss Federal Laboratories for Materials Science and Technology revealed that only 15 per cent of the total eco-footprint of lithium-ion powered electric cars is due to the batteries.

The lighter side of lithium: A little drop of lithium does you good. Researchers at Oita University in Japan found that the suicide rate was lower in communities where the tap water contained naturally higher levels of lithium.

Potassium

Symbol: K
Atomic number: 19
First identified: 1807
Current market price: £15,000/Metric tonne

Primary uses: By far the biggest commercial use of potassium is as potash (potassium salts) fertiliser, although like other alkali metals, potassium and its alloys are useful in heat transfer and control systems.

Potassium compounds are key components of gunpowder, fireworks and matches.

Industry news: Mining company BHP Billiton's $39bn (£25bn) offer for the world's largest producer of potash reflects the UN's opinion on the importance of potassium-based fertilisers.

The organisation expects global potash consumption to increase by 2.7m tonnes a year.

Recent developments: Scientists at the National Institute of Standards and Technology in New York have used potassium-bearing nanotubes in an experimental photocatalytic solar cell to triple its efficiency at producing hydrogen.

The lighter side of potassium: Three-quarters of the false alarms in detectors hunting smuggled nuclear materials are triggered by potassium-rich shipments such as bananas and cat litter, due to the presence of the mildly radioactive 40K isotope.

Alkaline Earth metals

Magnesium

Symbol:Mg
Atomic number: 12
First identified: 1808
Current market price: £2,500/Metric tonne

Primary uses: Magnesium is all about structural applications. Alloyed with aluminium, zinc, zirconium and even silver, it provides strong, lightweight components for the automotive and aerospace industries. It is also used in die-casting and in the production of iron, steel and titanium.

Industry news: Magnesium is in a state of serious over-supply, with prices up to 50 per cent below their peak. Production has become concentrated in around 300 companies in China, which together account for up to 60 per cent of world supply.

Recent developments: An Australian company recently filed a patent for the production of a green cement using calcium magnesium carbonate particles and waste gases from power plants. For every tonne of so-called Semidolime produced, seven kilograms of carbon dioxide are removed from the atmosphere.

The lighter side of magnesium: Blame a fussy cow for Epsom Salts. The therapeutic properties of hydrated magnesium sulphate were only explored by a farmer in Epsom, Surrey after he noticed his herd refusing to drink the local water.

Barium

Symbol:Ba
Atomic number: 56
First identified: 1808
Current market price: not widely available

Primary uses: Barium is used in the (waning) production of cathode ray tubes, and also in several important high temperature superconductors, with yttrium and copper oxide. Barium carbonate is used in the production of glass and ceramics.

Industry news: The Deepwater Horizon disaster may affect the industrial use of barium. Underwater oil drilling requires large quantities of dense barium sulphate to help flush out cutting debris. It was widely used in exploitation of North Sea oil and gas fields, resulting in over 1.5m tonnes of contaminated drill cuttings left on the seabed.

Recent developments: Barium titanate is at the heart of an ultracapacitor/battery being developed by US start-up EEStor. The device is claimed to deliver ten times the energy density of lead acid technologies. Despite attracting millions of dollars in funding, however, EEStor has yet to give a public demonstration of the system.

The lighter side of barium: Barium nitrate is used in Raman lasers, which have the potential to accelerate the development of optical computing - and even create extremely powerful offensive weapons.

Transition metals

Zinc

Symbol: Zn
Atomic number: 30
First identified: 2500BC
Current market price: £1,300/Metric tonne

Primary uses: Galvanising accounts for around half of the world's annual 11 megaton demand for zinc, with brass, bronze and other alloys making up another third. Over half (54 per cent) of the world's zinc is produced in Asia. The price of zinc is now rising after record lows in 2008.

Industry news: Phytoremediation is the process of using living plants to clean contaminated soil by 'hyper-accumulating' metals. One of the most efficient hyper-accumulators, Alpine pennycress, can capture 3 per cent of its weight in zinc, yielding up to 400kg of metal per hectare per year.

Recent developments: Zinc batteries are making a comeback. Not the leaky, low--power zinc carbon and zinc chloride cells of yesterday, but zinc air batteries and fuel cells. They promise high enough energy densities and reliable enough voltages to power the next generation of electric vehicles.

The lighter side of zinc: To prevent physical coins being worth more than their face value, US one-cent 'copper' coins are already 98 per cent zinc. They will eventually have to be replaced by cheaper metals, probably aluminium, as the price of zinc itself rises.

Titanium

Symbol:Ti
Atomic number: 22
First identified: 1791
Current market price: £29,000/Metric tonne

Primary uses: Titanium's low weight, immunity to environmental attack and immense strength make it invaluable in critical structural applications, such as the rotating fan blades in jet engines, alloyed into landing gear and airframes, tubing in power stations and chemical processing.

Industry news: Plans are afoot in Russia to designate an area in Sverdlovsk 'Titanium Valley', a free economic zone dedicated to producing titanium and aluminium parts for export. Boeing has already organised a joint venture in the area to machine titanium components for its much-delayed 787 aircraft.

Recent developments: Titanium's high price is largely due to the complex and expensive Kroll process needed to produce it. This may soon be replaced by a vastly simpler electrochemical process commercialised by UK-based firm Metalysis. The company expects to commission a pilot production cell for titanium (and also tantalum) later this year.

The lighter side of titanium: Paving slabs coated with titanium dioxide are being used to reduce air pollution in cities. In recent tests, Fraunhofer-Gesellschaft in Germany measured a reduction in harmful nitrogen oxide gases of up to 30 per cent at head height.

Iron

Symbol: Fe
Atomic number: 26
First identified: 3000BCE
Current market price: (scrap) £215/Metric tonne

Primary uses: Iron is by far the most widely used metal. When alloyed with carbon (as steel), nickel or chromium it can be used to build everything from bicycles to bridges. It is also in industrial magnets, and as an additive in fuels, lubricants and plastics for heat stabilisation.

Industry news: Iron-based superconductors are changing the way researchers think about superconductivity. New materials containing layers of iron and arsenic are the first high-temperature superconductors that do not contain copper. But don't get too excited: 'high temperature' in the world of superconductivity is still a chilly -220C.

Recent developments: Iron plus water equals rust. But zero valent iron (ZVI) plus wastewater equals drinking water. Scientists at Tongji University in Shanghai have found a way to use scrap iron to remove nitrogen, phosphorus, colours and dyes from the city's water supply. While iron-based nanoparticles are already used to clean contaminated soil, the new process works at a fraction of the cost.

The lighter side of iron: Iron was actually mined in the New World at around the same time the Iron Age began in the Near East. However, while Easterners smelted it on a large scale, made formidable weapons and kick-started civilisation, in the Americas metal remained as luxury goods for wealthy elites.

Nickel

Symbol:Ni
Atomic number: 28
First identified: 1500BCE
Current market price: £14,000/Metric tonne

Primary uses: Europe produces a third of the world's nickel. Nearly two-thirds of industrial nickel consumption is dedicated to stainless steel production, with other alloys accounting for 22 per cent and electroplating another 8 per cent. It's also used in older rechargeable batteries, coinage and even as a catalyst for hydrogenating vegetable oils.

Industry news: Two deposits, in Canada and Russia, are the source for around 70 per cent of the world's nickel supply. But future prospectors might raise their eyes skywards: some experts think the massive deposits are the result of ancient meteorite impacts.

Recent developments: New nickel-tungsten coatings are set to replace chrome- and gold-plating in everything from car fixtures to headphone jacks. Hexavalent chromium is carcinogenic and highly polluting, while gold is (obviously) very expensive. The new alloys developed by MIT are just as hard-wearing, corrosion-resistant and, all-importantly, shiny as the metals they replace.

The lighter side of nickel: Eurosceptics might literally be allergic to the Euro. In 2002, the University of Zurich found that a galvanic reaction between human sweat and bi-metallic Euro coins released over 200 times more nickel than permitted under European Union law: enough to give sensitive individuals a nasty rash.

Copper

Symbol: Cu
Atomic number: 29
First identified: 8500BCE
Current market price: £5,000 /Metric tonne

Primary uses: Copper is the best electrical conductor (after expensive silver), and has long been used in wiring, terminals and power transmission. It is alloyed with nickel to produce corrosion-resistant materials and is still occasionally used for waterproof roofing.

Industry news: The recent revelation by the US military of up to £650bn worth of mineral deposits in Afghanistan is already being exploited. The China Metallurgical Group is paying £260m for rights to mine for copper near Kabul: a sum that represents 40 per cent of the Afghan government's annual revenues, not including aid.

Recent developments: A team at Duke University in North Carolina has successfully produced copper nanowires (wires small enough to be transparent) for use in thin-film solar cells, flat-screen TVs and flexible displays. The wires are 100 times cheaper than current silver nanowires.

The lighter side of copper: Get ready for really chilly toilet seats. A Birmingham teaching hospital swapped conventional toilet seats, tap handles and door push-plates for items made from 70 per cent copper. In tests, the naturally anti-microbial copper surfaces carried 90 to 100 per cent fewer live bacteria than the traditional items.

Silver

Symbol: Ag
Atomic number: 47
First identified: Antiquity
Current market price: £450,000/Metric tonne

Primary uses: Although silver is associated with jewellery and coinage, up until recently about a third of US industrial consumption was in traditional photographic films and prints. While such use is now declining, silver-zinc and silver-cadmium batteries offer high-capacity storage and silver paint is used in electronic circuitry.

Industry news: Building with silver is affordable - at the nanoscale. Adding silver nanoparticles to polymer semiconductors in next-generation solar cells can increase current output by over 10 per cent. Also, researchers at Arizona University are using them alongside self-assembling DNA scaffolds to create molecular-scale sensors.

Recent developments: The commercialisation of polymetallic nodes found near hydrothermal vents has traditionally proved unprofitable. However, with precious metal prices reaching new highs and recent advances in undersea robotics and ROV technology, new ventures are gearing up to try again in the waters around Papua New Guinea.

The lighter side of silver: A study in New Zealand found that silver is the safest colour car to drive, suffering half as many serious crashes as green, brown or black vehicles. Researchers believe that the paint's high reflectivity and light colour may be responsible.

Tungsten

Symbol: W
Atomic number: 74
First identified: 1546
Current market price: £22,000 /Metric tonne

Primary uses: Tungsten remains strong at high temperatures, allowing it to be used in filaments, heating elements and arc welding. Although Russia remains one of the main producers of tungsten, around 30 per cent of world supply is recycled.

Industry news: Tungsten in light bulbs is on the way out. Not only are next-gen light emitting diode (LED) lamps far more power efficient, they can even broadcast broadband Internet by flickering at invisibly high speeds. German scientists have achieved wireless data rates at up to 230Mbps.

Recent developments: Tungsten bullets are an environmentally safe alternative to lead ammunition. The British military now uses tungsten (instead of depleted uranium) for armour-piercing munitions while US forces purchased over 90 million 'green bullets' for small arms training. But recent research has proved that tungsten can migrate to groundwater, meaning further moves to tungsten are unlikely.

The lighter side of tungsten: Tungsten has the symbol W from the mineral wolframite, which got its name from the original Italian 'lupi spuma', both meaning 'wolf's cream'. No one really knows where Renaissance scientist Georgius Agricola got that from.

Gold

Symbol: Au
Atomic number: 79
First identified: Antiquity
Current market price: £28,750,000 /Metric tonne

Primary uses: It will come as no surprise that gold, which never tarnishes, is primarily used for decoration, ornamentation and coinage. However, it is also important as a radiation-control protective coating for spacecraft, in dentistry and electronics.

Industry news: The economics of recycling electronics is driven by gold. According to E F the IEEE, gold represents two-thirds of the value of typical PC circuit board waste and end-of-life mobile phones. An average phone contains precious metals worth about 65 pence, consisting mostly of gold.

Recent developments: South Africa mines most of the world's gold. Around half the gold ever produced came from South Africa but now the USA, Australia and China mine larger quantities; over 200 tonnes each per year. Interestingly, all the gold ever refined would fit into a cube 18 metres square.

The lighter side of gold: Biomining has been used to breakdown sulphides covering minute particles of gold. Bacteria oxidise sulphur and arsenic ions, allowing soluble products to dissolve in a cyanide solution. Gold recovery from refractory minerals can increase from 15 per cent to 95 per cent after such biooxidation.

Post-transition metals

Aluminium

Symbol:Al
Atomic number: 13
First identified: 1808
Current market price: £1,600 /Metric tonne

Primary uses: Aluminium represents the largest contract traded on the London Metal Exchange. Being light, pliable and resistant to corrosion, aluminium is extensively used in transport (26 per cent of annual consumption), packaging (22 per cent) and construction (22 per cent).

Industry news: Aluminium is the latest weapon in the growing trade war between America and China. The Obama administration recently levelled any duties of up to 138 per cent on aluminium extrusions after claiming that the Chinese government had illegally subsidized them. This follows similar penalties imposed on Chinese steel products.

Recent developments: Ever wondered why Americans can't spell aluminium properly? In fact, our transatlantic cousins have it right. British chemist Humphrey Davy dubbed the element 'aluminum' in 1812. The extra 'i' was suggested by the Quarterly Review magazine, which it felt bestowed a more classical sound. Both versions are accepted by the International Union of Pure and Applied Chemistry.

The lighter side of aluminium: Many older waste disposal sites have a greater concentration of aluminium than bauxite ore, raising the possibility of landfill mining in the future. Recycling aluminium generally takes 95 per cent less energy than producing it new.

Tin

Symbol: Sn
Atomic number: 50
First identified: 3000BC
Current market price: £14,000/Metric tonne

Primary uses: Tin solder and tin plate together account for around 60 per cent of the industrial use of this shiny, malleable element. Less well known is tin's role in the production of halogenated PVC products, which take 6 per cent of the world's tin for heat and light stabilisation.

Industry news: Indium tin oxide (ITO) is used to make transparent, conductive coatings for LCDs and touchscreens. Today's layers are fragile and far from optically perfect, but the Fraunhofer Institute has just developed a nanocrystalline ITO film that can be bent aggressively, withstand temperatures up to 900C and has an optical transmission ratio of over 80 per cent.

Recent developments: 'Tin' sometimes means steel (in 'tin' cans), aluminium ('tin' foil) or even lead ('tin' soldiers). 'Tin' solder used to contain around 40 per cent lead. However, regulations in the EU and China have phased out toxic lead from electronics so that all solder is now almost pure tin - leading to the recent boom in demand and prices.

The lighter side of tin: Hundreds of tonnes of tin used internationally are 'blood minerals', extracted illegally under horrendous working conditions in the Congo. Like the better known coltan, cassiterite (tin oxide) is being mined and sold by military groups to fund further violence.

Lead

Symbol:Pb
Atomic number: 82
First identified: Antiquity
Current market price: £1,325 /Metric tonne

Primary uses: The most important use of lead today remains old-fashioned lead-acid batteries, accounting for over 70 per cent of global consumption. Lead is also used in pigments and chemicals (12 per cent), sheet and extrusions (7 per cent) - and 6 per cent of all the lead in the world is used to manufacture ammunition.

Industry news: The impacts of irresponsible lead mining are still being felt today. A Tri-State mining area spanning parts of Missouri, Kansas and Oklahoma supplied virtually all the lead bullets used in the World Wars. Now, some towns there have been abandoned due sinkholes, radon gas, airborne pollution from mine tailings and highly contaminated water supplies.

Recent developments: Estimates for the world's supply of lead range from less than 15 years to nearly 40. Half of global annual production already comes from recycled scrap metal.

The lighter side of lead: Lead exposure is certainly a bad thing - it causes developmental problems in children and possibly male infertility. However, recent research suggests lead in petrol may have slowed global warming during the 20th century by assisting the formation of ice in the upper atmosphere and reflecting sunlight back into space.

Actinoids

Uranium

Symbol: U
Atomic number: 92
First identified: 1789
Current market price: (uranium oxide) £64,000/Metric tonne

Primary uses: Uranium's main use is as fuel for nuclear power stations, and the production of isotopes for medical use. Depleted (non-radioactive) uranium is also widely used by the military as highly dense ammunition and in the construction of inertial guidance systems, compasses, shielding and missile ballast.

Industry news: Energy Secretary Chris Huhne has promised eight new nuclear power stations by 2018, ushering in a nuclear renaissance. Researchers at Imperial College and Cambridge University are predicting ship-borne fast breeder power plants by 2030, also small, sealed reactors able to generate power for 40 years without maintenance.

Recent developments: Nuclear power plants do not necessarily mean nuclear proliferation. While most current reactor designs do produce uranium 235 waste capable of being reprocessed into weapons-grade plutonium 239, highly-enriched uranium from surplus weapons stockpiles is also being used as fuel - currently about 13 per cent of world reactor requirements.

The lighter side of uranium: The going price for black market uranium 238, which can be used in a dirty bomb, is around £4m per kilo. In August, Moldovan police broke up a smuggling ring that had 1.8kg for sale. Mass spectrometers and electron microscopes make it possible to forensically identify the exact facility in which every gram of uranium was enriched.

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