RE SPECIAL: Minerals for the digital age

By Simon Moores
Published: Tuesday, 25 May 2010

How heavy and light rare earth elements (REE) are fundamental to today’s most advance technology markets

Magnets

Primary REE:
Neodymium (Nd), Samarium (Sm)

Secondary REE:
Dysprosium (Dy)

Magnets are the driving market for rare earth demand. Not only is it the dominant consumer by volume (32%) and value (38%, $500-550m.), but the applications of magnets are in critical environmental and defence technologies.

Neodymium-iron-boron (Nd-Fe-B) has the highest strength of all magnets (see, p.44) and are used a wide variety of applications including: computer hard disc drives, wind turbine motors, missiles, and guidance systems commonly used by the USA.

The crux of the issue is that the USA does not like the idea of being dependant on China for the rare earth elements (REE) or magnets that make their missiles and guidance systems function.

The discovery of Nd-Fe-B magnets was a result of attempts to reduce dependency on copper in the late 1970s to early 1980s. In a situation which may serve as a warning for rare earths today, the price of copper rocketed in the 1970s on the back of a civil war in the Democratic Republic of Congo (then Zaire) a major supplier of copper.

With Fe the industry had a readily available magnetic mineral, and an alloy together with Nd and B was created that actually resulted in a higher strength magnet than expected.

Each magnet contains: 30-33% Nd*, 66-69% Fe, and 1% B (*note that small amounts of dysprosium, Dy, can be used with Nd at a ratio of 9:1).

In terms of volume, 1 kg of Nd metal uses a feedstock of 1.16kg of neodymium oxide (Nd2O3).

In 2008, 51,000 tonnes of Nd-Fe-B magnets was produced globally this is expected to increase to 60,000 tpa within five years.

The other rare earth magnet, samarium-cobalt (Sm-Co), is not as widely used as its Nd counterpart but is perhaps critical. Sm-Co can operate at higher temperatures (>250¡C) than Nd-Fe-B without losing its magnetic field. This is a very desirable trait for technology used in the armed forces such as ballistic missiles and stealth helicopters.

Sm-Co magnets, for example, are used to create white noise to hide a stealth helicopters from radar detection.



Erbium is central to fibre optic cables, but a host
of rare earth elements give functionality to many
digital and hi-tech products such as mobile phones,
plasma TVs and electric vehicles


Phosphors

Primary REE:
Yttrium (Y), Europium (Eu)

Secondary REE: incl. Lanthanum (La), Dysprosium (Dy), Gadolinium (Gd)

Phosphorescent proprieties of rare earths Ð the ability to glow after exposure to energy Ð lights up energy saving bulbs, gives mobile phones their colour, and are central to plasma televisions and computer monitors.

Eu is a phosphor that gives the red colour to a digital picture, La phosphors are used in x-rays to reduce radiation exposure, while Gd is used in colour televisions.

In terms of volume to value ratio, phosphors are by far the most valuable market for rare earths representing only 7% of industry tonnages (9,000 tpa) but 32% of its total value (400-450m.).

This is unsurprising when comparing the average cost of 1kg of rare earth oxides (REO) into this sector: $45/kg versus $3/kg for catalysts and $8/kg for metal alloys.


Catalysts

Primary REE:
Lanthanum (La)

Secondary REE: Cerium (Ce), Praseodymium (Pr), Neodymium (Nd)

Representing the third largest market by volume with a 19% market share, but only 5% of the industry’s value, La is used as a fluid cracking catalyst to refine oil.

It provides the means to separate a number of petroleum products Ð such as gasoline, kerosene and naphtha jet fuel and diesel from heavy crude oil.

The REO structurally and chemically stabilises the zeolite filter through which the crude oil passes, allowing it to operate at higher temperatures. The more crude or lower quality the oil is, the increased volume of REO is needed.

At present the market volume is 20-25,000 tpa the bulk of the product shared between consumption in China and the USA (~9,000 tpa each) and Japan (~3,000 tpa).

La is the primary REO used but should availability become an issue, oil companies can use Ce, Pr and Nd in similar quantities.

The market drivers behind this will be the types of oil being extracted. As the world runs dry of higher quality sweet crude oil, extraction from more unconventional deposits such as tar sands in Alberta, Canada, will see and increased use of REOs to covert the increasingly crude oil into usable every day chemicals. REOs will be central to this.

Ce is also used as key component in catalytic converters on cars.


Metal alloys

Primary REE:
Many including Praseodymium (Pr), Scandium (Sc)

Metal alloys is a category which covers a wide variety of uses for metal products that contain a combination rare earths rather than specific elements. The uses range from nickel-metal hydride (NiMH) rechargeable batteries for portable electronics, hybrid and electric cars.

Pr is consumed to the high strength metals produced for aircraft, while Sc is used in aluminium alloys in aerospace and leisure goods (ie. tennis rackets, golf clubs).

Over the last ten years significant growth in the magnet industry has seen it separate out from this category into one of its own. However even without the substantial share of the industry that magnets bring, metal alloys still account for 19% of its volume (22,000 tpa) and 13% of the value ($175-183m.).

Another application with growing interest is fuel cells. Like a rechargeable battery, rare earths are used in a number of components of a fuel cell. For example in a solid oxide design, the anode is made from yttria-stabilised-zircon (YSZ), and the cathode from strontium doped lanthanum magnetite. The electrode can use up 2kgs per 2kWH of YSZ as well as samarium doped ceria (IM May 2010, p.81: End user focus: fuel cells).


Polishing

Primary REE:
Cerium (Ce)

Representing 12% (15,000 tpa) of the volume market, rare earth polishing powders are used predominately on high value glass such as flat glass, and glass for CRT, LCD, TFT televisions.

The higher content of total rare earth oxide (TREO) in the powder, the more specialist the end use and the higher the value the polishing product. For example, 88% TREO is used to polish products from flat glass to television screens; TREO of 90% is used to hi-tech optical lenses; and a TREO of 93% is used on precision lenses like those used in medical equipment.

Polishing grades of REO sell for an average of $4/kg but the polishing product can considerably more: cerium oxide polishing powder from Inner Mongolia, China for example is selling for $688/kg.

The sector holds a value of $45-56m.


Ceramics/Glass

Primary REE:
Neodymium (Nd), Praseodymium (Pr), Erbium (Er), Yttrium (Y)

The application of rare earths in ceramic component is predominately such as crucibles and pigments. The market accounts for 3% of the industry’s value and 6% of the volume and is a more recent development. The market value of glass is $25m.(2%); in tonnes this equates to 12,000 tpa with the lowest average REO selling prices a kilo of the whole industry at $2.

Yttrium based ceramics are used for holding molten metal and as a refractory nozzle for jet casting molten alloys.

As a ceramic pigment, the introduction of REO to the ceramic melt gives the body the unique colour: Nd (blue/lavender), Pr (green/yellow), Er (sharp pink). The offer additives that are stable within ceramics (and glass).


Other uses

Lasers:
Yttrium crystals are core to lasers for communication systems, lanthanum’s phosphors are used in lasers that detect radiation in the medical sector, while neodymium lasers are used in heavy industry like welding and also in MRI scanners.

Submarine communication systems can utilise the lesser know promethium (Pm), and scandium and andium are also suited to laser technology.

Fibre optics: This has emerged in the last decade as a suitable communications technology through which to send high quality, rapid data in light pulses. In recent years, telephone communications and television channels have begun to be received by this technology which has more familiar uses in the medical industry. Erbium doped optical fibres have allowed for major progress in the communications industry.


By value

Total value $1.2-1.4bn


By volume



Total tonnages: 124,000

Source: IMCOA, Roskill Information Services