Uranium from Rare Earths Deposits

updated May 2012

• A large amount of uranium is in rare earths deposits, and may be extracted as a by-product.
• Higher uranium prices and geopolitical developments have enhanced the economic potential for recovering these.

In addition to the 5.4 million tonnes of uranium in known recoverable resources, there are substantial amounts comprising what is known as "unconventional resources". One of these is rare earths, in relation to which China has a preeminent position as supplier. This gives rise to commercial pressure for development of other deposits outside China. Some of these contain significant uranium mineralisation.

Rare earth elements (REE) are a set of seventeen chemical elements in the periodic table, specifically the fifteen contiguous lanthanoids plus the lighter scandium and yttrium. Scandium and yttrium are considered REE since they tend to occur in the same ore deposits as the lanthanoids and exhibit similar chemical properties. Most REEs are not rare. However, because of their geochemical properties, REE are typically dispersed and not often found in concentrated and economically exploitable forms. REEs are often found together, and are difficult to separate. One of the minerals involved in the progressive discovery and identification of REEs was samarskite - containing uranium. Many more contain thorium.

Economically and geologically there is a distinction between light REE, or cerium earths (scandium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium - elements 21, 57-64) and heavy REE, or yttrium earths (yttrium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium - elements 39, 65-71). Gadolinium and europium apparently can fall into either category.

Large orebodies of the cerium earths are known around the world, and are being exploited. Monazite includes cerium, and associated light REE. Corresponding orebodies for heavy REE or yttrium earths tend to be rarer, smaller, and less concentrated. Most of the current supply of yttrium originates in the "ion adsorption clay" ores of Southern China. Some of these provide concentrates containing about 65% yttrium oxide, with the heavy lanthanides. Uranium ores from Ontario have occasionally yielded yttrium as a byproduct. Xenotime incorporates yttrium and heavy REEs.

Since 1998 China has produced over 80% of the world's REE, mostly from Inner Mongolia, and the proportion is now higher. All of the world's heavy REE (such as dysprosium) come from China. Most REE is by-product from Chinese sources such as the polymetallic (iron-REE-niobium) Bayan Obo deposit in Baotou city with reserves of at least 48 million tonnes of REE grading about 6%, but predominantly light REE. There are also limited surficial clay deposits in southern China, and two in Jianxi province are exploited: Longnan, with heavy REE similar to xenotime, and Xunwu, with light REE particularly lanthanum but with little cerium. 

China has announced its intention to cut back exports of all REE from the 35,000 t level in 2010, and ban exports of terbium and dysprosium. This is leading to recommissioning of Molycorp's Mountain Pass mine in California, and enhanced interest in bringing new orebodies into production, including Mount Weld in Western Australia, Nolans Bore in Central Australia and Kvanefjeld in Greenland, the latter two with significant uranium content with the rare earth oxides (REO).

In April 2011 China's Ministry of Industry & Information Technology (MIIT) under the National Development & Reform Commission (NDRC) set a production quota for REO of 93,800 tonnes, up 5% on 2010, with a quota on REO smelting of 90,400 tonnes. No new mining licences are to be granted before mid 2012. MIIT says that no extra production beyond the quotas will be allowed.  In mid 2011 Baotou Steel Rare-Earth plans to acquire four rare-earth separation companies licensed by the Inner Mongolia government. This is part of the national government's effort to consolidate China's rare-earth sector, gain more influence over pricing in the global market and ensure sustainable growth in the industry. The Ministry of Land and Resources said that 15 southern cities with abundant heavy REE resources have signed agreements to cooperate in regulatory enforcement, and this may be under Baotou, at least in Fujian and Jiangxi provinces with heavy REE. 

In May 2011 Areva signed a memorandum of understanding (MoU) with international chemical company Rhodia to develop deposits containing a mix of uranium and rare earth elements. The companies said that they will "combine their respective expertise and competencies to put together joint offers for the development and exploitation of hitherto unworked deposits containing the two strategic resources." They could eventually cooperate in conducting joint technical audits or studies of identified deposits, create joint ventures or co-participate in mining projects carried out by Areva or third parties. 

Kvanefjeld, Ilimaussac complex, southern Greenland
Kvanefjeld is the main REE deposit with major potential for uranium production, with Zones 2 & 3 in the same Ilimaussac complex. It was investigated intensively over 1955-86, then dropped for commercial reasons. Greenland Minerals & Energy acquired the project in 2007 then with a JORC-compliant resource then of 43,000 tU at 0.022% U with 6.5 million tonnes of heavy REO at 1.07% in Lujavrite. About 9% of REOs are terbium, dysprosium and yttrium, ie heavy. The full Kvanefjeld uranium resource is now estimated at 197,000 tU, most of it as JORC indicated resources at 0.015% cut-off. The company has demonstrated over 90% co-recovery of REOs via effective beneficiation of concentrates followed by atmospheric sulfuric acid leach and solvent extraction recovery. This will lead to hydrogen reduction of uranium minerals and beneficiation followed by acid leach for REOs including yttrium. The Kvanefjeld deposit also has 1.36 Mt zinc at 0.22%.

Pre-feasibility study suggests annual production of 1000 tU with about 40,000 t REO as well as zinc concentrate, from a large open pit mine. Project cost is $1.53 billion.  A definitive feasibility study is proceeding to mid 2013, concurrently with pilot plant trials, environmental impact assessment and social impact assessment. In October 2011 the company announced a breakthrough in beneficiation, which will substantially increase the head grade for treatment. Social and environmental impact assessments are due for completion late in 2012. There is considerable further mineral potential in the immediate area - up to 600,000 tU according to IAEA estimates. As well as Kvanefjeld and adjacent Steenstrupfjeld, Zone 2 (6 km north) and Zone 3 were identified in 2011 within the project area.  In March 2012 the company announced Zone 2 inferred resources in the same geology of 62,440 tU at 0.015% cut-off (av 0.03%) and 2.67 Mt REOs, taking the project total to 197,000 tU, 1.98 Mt zinc and 9.2 Mt REO including 330,000 t heavy REO with 740,000 t Y₂O₃.  Resource figures for Zone 3 in the same geology are expected by May, and drill results so far show that its similar mineralisation outcrops extensively, with higher grade portions near surface.

A year after the Greenland government allowed the company's feasibility studies to include uranium, in December 2011 it amended the company's exploration licence to include uranium. This means that the company may apply for a mining licence including uranium, and expects to do this at the end of 2012, with a view to first production in 2015, followed by a long mine life.  The company is conducting detailed discussions under confidentiality agreements with several international consortia regarding development scenarios and their funding.

Eco Ridge, Elliot Lake, Ontario
Pele Mountain Resources Inc has received mining leases for its Eco Ridge uranium and REE orebody in Canada, 11 km east of Elliot Lake. In the decade to closure of the Stanleigh mine at Elliot Lake in 1996, the area produced REE as a commercial by-product of uranium production. The Eco Ridge deposit contains a full range of REE at 0.164% grade, including 9.5% heavy REE (including scandium, europium and gadolinium in this category, 7.4% if excluding them). Uranium grade is 0.041% U with cut-off grade 0.024%. Some 65% of the heavy REE report in the uranium leach solution without any additional milling cost. The deposit includes indicated resources of 23,500 t REO and 5860 tU, plus 43,700 t REO with 12,100 tU inferred resources (NI 43-101 compliant). An underground mine is envisaged, using underground bio-leaching and surface heap leaching, the ore being moved to the surface in haul trucks. The leachate from underground and surface will be piped to the processing facility where it will be clarified and processed in a solvent extraction circuit. Solvent extraction raffinate will be recycled to the two leach operations.  A preliminary economic assessment in 2012 suggested uranium production of 10,500 tU over 11 years.

Nolans Bore, Northern Territory, Australia
This is a deposit of light REE with 5100 tonnes uranium content at 0.02% in 850,000 t REO grading 2.8%, about 135 kilometres north of Alice Springs. Arafura Resources  intends to develop it as a REE mine and plans to process its concentrate at Whyalla, South Australia to produce 20,000 t/yr REO, 130 t/Uyr, plus phosphoric acid and gypsum co-products.

Cummins Range, Kimberley region, Western Australia
This is a deposit of light REE with uranium content of 0.01 to 0.03% depending on REO cut-off (0.0145% for inferred resource), and 10-12% P2O5. REO is 1.0 to 2.8% depending on cut-off. Subject to proving further resources, Navigator Resources Ltd spun off Kimberley Rare Earths Ltd which intends to develop it as a REE mine with uranium by-product. It is similar geologically to Mount Weld, but with ten times the uranium content. It has 120,000 t REO inferred resources at 0.5% cut-off.

Dubbo Zirconium Project, New South Wales, Australia
Alkane Resources' DZP has REE as potential by-product of zirconium production. These are 18% heavy REE (20% if including europium and gadolinium). No uranium content is reported, though this may be because until 2012 it was illegal to explore for uranium in the state.

Firawa prospect, Guinea, West Africa
Forte Energy NL has announced 4471 tU JORC-compliant inferred uranium resource at Firawa, with 1-2% rare earth elements present which are as yet unquantified.

Zandkopsdrift, South Africa
Frontier Rare Earths in 2011 reported NI 43-101 resources of 950,000 t REE (56% indicated resources) at this deposit in the Northern Cape Province. The resource includes 47 ppm U, which is more likely nuisance than by-product. Frontier has signed a definitive agreement with KORES to develop the project.



Sources:
Wikipedia, Rare Earth Element, accessed 26/4/2011
Greenland Minerals & Energy, Navigator Resources, Pele Mountain Resources