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Rare Earths |
AIMR 2008 |
Rare Earths
Rare earths are a group of 15 elements with atomic numbers ranging from 57 to 71. In order of their respective atomic numbers the elements are: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). Two other elements, scandium (Sc) and yttrium (Y), are commonly classed as rare earths because of their natural association with rare earths.
The market for rare earth elements has experienced a dramatic growth over the past decade with total rare earth oxides (REO) demand of 85,000 t in 2003 rising to 117,000 t in 2007. Consumption is predicted to increase also by 2012 to between 180,000 t and 190,000 t with a total value of US$2000 million. The biggest increases in demand are due to predicted expansion in hybrid cars with lanthanum used in rechargeable batteries and neodymium in high power magnets for 3 million vehicles by 2012 as well as disk drives and speakers. Other sectors include petroleum catalyst lanthanum and autocatalyst cerium, which has application also in glass manufacturing and polishing and multi-level electronic components, yttrium stabilised zirconia also is used in high wear resistance ceramics. The smallest sector by volume but largest by value are europium and terbium which are used in the production of phosphors for televisions and energy efficient lamps.
The main consumers of rare earths are China, the US, Japan, Korea and Thailand with China reportedly consuming about 50% of its rare earth production. The Chinese government has imposed production and export restrictions, adding upward pressure on prices for rare earths and contributing to incentives for development of rare earth resources outside China.
Resources
Geoscience Australia's latest estimate of Australia's demonstrated resources of rare earths reported as REO amounted to about 27.9 Mt (1.13 Mt EDR and 26.8 Mt sub-economic) with a further 24.4 Mt in the inferred resources category. About 45 Mt of these resources are in the Olympic Dam iron oxide copper gold deposit (dominantly 0.2% La and 0.3% Ce) and are not currently economic. Small quantities of yttrium (3,300 t Y2O3) and scandium (770 t Sc), commonly included with rare earths, were reported as inferred resources. In addition, about 4,000 t of demonstrated resources and 52,000 t of inferred resources were reported as rare earth elements (REE).
Very significant resources of rare earths are contained in the monazite component of heavy mineral sand deposits, which are mined for their ilmenite, rutile, leucoxene and zircon content. Monazite is a rare earth-thorium phosphate mineral, found within heavy mineral sand deposits in Australia. Using available information, Geoscience Australia estimates Australia's monazite resources to be of the order of 6.2 Mt. Assuming a REO content of Australian monazite to be about 60%, the heavy mineral deposits could hold an REO resource in the order of 3.72 Mt. Currently, extraction of rare earth from monazite is not viable because of the cost involved with the disposal of thorium and uranium present in the monazite.
Production
Mining operations have commenced at the Mt Weld deposit in WA and by the end of 2007 some 98,000 cubic metres of ore had been stockpiled pending the completion of a concentration plant at the mine site. There was no recorded production of REO in Australia during 2007.
Globally, the production and resources of rare earths is dominated by China which accounts for 97.8% of the production followed by India with 2.2%. The REO production figures by the Commonwealth of Independent States are not available.
World Ranking
China holds 27 Mt (32.4%) of the EDR for REO, followed by the Commonwealth of Independent States 19 Mt (22.8%) REO and the US with 13 Mt (15.6%). Australia accounts for 1.4% of world EDR with 1.13 Mt REO.
The main types of REE deposits make up the largest REO resources in the world, the Bayan Obo in China, which is predominantly REE-iron ores with bastnasite and monazite as the main REE bearing minerals, totalling at least 48 Mt REO at a grade of 6%. The only production of REOs from REE bearing carbonatite has been from the Mountain Pass deposit in California which totalled 1.8 Mt REO at an average grade of about 9% REO. Deposits associated with carbonatite laterites include Araxa Brazil with 8.1 Mt REO at 1.8% and Mt Weld in WA with 1.18 Mt REO at 9.7%. Other deposit types include Nolans Bore, NT (vein type); Toongi, NSW (alkaline trachyte); and Lovozero, Russia (peralkaline syenite).
Industry Developments
Mt Weld in WA (in laterite over alkaline carbonatite complex), owned by Lynas Corporation Ltd, started mining the deposit in 2007. In early 2008 the company announced an increase in resources to 12.2 Mt at 9.7% REO with an REO content of 1.18 Mt. The company has decided to build a concentration plant at the mine site and construction of a treatment plant has begun in Malaysia. The company anticipates beginning production in Malaysia in the third quarter of 2009 and attaining full production of 21,000 t in 2011. In another part of the carbonatite complex there are indicated (1.5 Mt) and inferred (36.2 Mt) resources totalling 37.7 Mt which include total lanthanides at 1.16% and 0.09% Y2O3.
Arafura Resources Ltd's Nolans Bore rare earth deposit is a phosphate uranium deposit located 135 km northwest of Alice Springs in the NT containing thorium (18.6 Mt at 3.1% REO). The deposit has the potential to be a large, high grade, low cost producer of rare earths. Production is expected to begin in 2010.
The Dubbo Zirconia project, owned by Alkane Resources Ltd, located 30 km south of Dubbo in NSW is undergoing a feasibility study, the results of which should be known by late 2008, with expectations of a 200,000 tpa ore throughput producing 3,000 t as zirconium sulphate, zirconium hydroxide and zirconium carbonate, 600 t of niobium pentoxide as 80% concentrate; and 1,200 t of yttrium rare earth oxide as 70% concentrate.
The Cummins Range carbonatite deposit occurs in the south east part of the Kimberley region in WA. In March 2008 Navigator Resources Ltd reported inferred resources of 3.55 Mt at 2% REO, 11.2% P2O5 216ppm U3O8 and 36ppm Th.
The Yangibana ferrocarbonatite-magnetite-rare earth-bearing dykes (ironstones) form part of the Gifford Creek Complex in WA. The dykes occur as lenses and pods, are typically the last stage of carbonatite fractionation and are enriched in REEs, fluorite and U-Th mineralisation. The Yangibana prospect has a recorded resource of 3.5 Mt at 1.7% REO. The rare earths are in coarse grained monazite containing up to 20% Nd2O5 and 1,600ppm Eu2O3.
Other deposits of possible significance include Olympic Dam iron oxide copper gold deposit and the Mt Gee uranium rare-earth deposit in SA.
