Mineral Resources and Reserves Australia's Uranium Deposits and Prospective Mines
Mineral Resources and Reserves
28 October 2009
See also companion paper on Australia's Uranium Mines .
For a more detailed and up to date maps, see Geoscience Australia web site: May 2008 large-scale (2.4 MB), May 2008 A3 size (1.2 MB).
The following are internationally-recognised categories based on Australia's JORC code, which the Canadian NI 43-101 code follows.
A ‘Mineral Resource’ is a concentration minerals in the Earth’s crust with reasonable prospects for eventual economic extraction. Mineral Resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories. An ‘Inferred Mineral Resource’ is that part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with only a low level of confidence. The information on which it is based is limited, or of uncertain quality and reliability. An ‘Indicated Mineral Resource’ is that part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and testing information which is adequate to assume but not confirm geological and/or grade continuity. A ‘Measured Mineral Resource’ is that part of a Mineral Resource for which tonnage, physical characteristics, grade and mineral content can be estimated with a high level of confidence. It is based on detailed and reliable exploration, sampling and testing information with locations spaced closely enough to confirm geological and grade continuity. A ‘Mineral Reserve’ (or Ore Reserve) is the economically mineable part of a Measured and/or Indicated Mineral Resource. It allows for dilution and losses which may occur when the material is mined. Appropriate assessments and studies will have been carried out, and include consideration of realistically assumed mining, metallurgical, economic, marketing, legal, environmental, social and governmental factors. Mineral or Ore Reserves are sub-divided in order of increasing confidence into Probable Mineral/Ore Reserves and Proved Mineral/Ore Reserves. A ‘Probable Mineral Reserve’ (or Probable Ore Reserve) is the economically mineable part of an Indicated, Mineral Resource. Studies to at least Pre-Feasibility level will have been carried out, demonstrating that extraction could reasonably be justified. A ‘Proved Mineral Reserve’ (or Proved Ore Reserve) is the economically mineable part of a Measured Mineral Resource. Studies to at least Pre-Feasibility level will have been carried out, demonstrating that extraction is justified.
Australian Uranium Deposits
Jabiluka, NT
The Jabiluka 1 uranium deposit in the Northern Territory was discovered in 1971 by Pancontinental Mining Limited. In 1973 further drilling located the larger Jabiluka 2 uranium orebody about one kilometre to the east. Jabiluka lies 230 kilometres east of Darwin and 20 kilometres north of Ranger on the edge of the floodplain of Magela Creek, a tributary of the East Alligator River. It is surrounded by the Kakadu National Park, but the mine lease area is excluded from the National Park and adjoins the Ranger lease.
Jabiluka 2 has resources in excess of 160 000 tonnes of uranium oxide, and is one of the world's larger high grade uranium deposits.
An Environmental Impact Study was approved in August 1979. In August 1982 Mineral Lease MLN 1 was granted by the Northern Territory for a period of 42 years following the signing of an agreement with the Northern Land Council, representing the traditional Aboriginal owners. The agreement, approved by the Commonwealth Minister for Aboriginal Affairs, was to provide $10 million to local Aboriginal people up to the end of construction, then royalty-type payments of 4.5% of net revenue, increasing to 5% after ten years. No Aboriginal sacred sites would be disturbed.
By the end of 1982 all necessary mining and environmental approvals had been obtained from governments for the underground mining of the Jabiluka 2 orebody and the Company had been cleared by the Commonwealth to seek sales contracts. Significant marketing progress was made, firm commitments being obtained for the supply of 15 600 tonnes of uranium oxide over ten years. However, with the Australian Labor Party coming to power in the 1983 federal election, Commonwealth approval was withdrawn and development ceased.
In 1987 Pancontinental bought the 35% equity in the project then held by Texaco. In August 1991 Energy Resources of Australia (ERA), the operator of the adjacent Ranger mine, bought the Jabiluka lease from Pancontinental for A $125 million.
In 1993 ERA undertook a feasibility study with a further drilling program on the orebody. This involved more than 12,000 metres of drilling, concentrating on the eastern half of the orebody (which was temporarily renamed North Ranger 2). As a result, ERA published proved and probable reserves of 19.5 million tonnes of ore at an average grade of 0.46% U3O8 containing 90,400 tonnes of uranium oxide. The study envisaged an underground mine, with ore being milled and treated at the existing Ranger site and tailings disposed of there. A total of only 20 hectares of land would be required for the surface facilities at the mine site, or 80 hectares including the haul road (wholly on ERA leases), compared with 820 hectares required under the previously-approved 1982 proposal.
Ranger and Jabiluka leases
A new Environmental Impact Statement for mining the Jabiluka 2 orebody and milling the ore at Ranger was approved in October 1997, following public comment. A Public Environmental Report on the alternative of milling the ore at Jabiluka was approved in August 1998, conditional upon all tailings being emplaced underground. This completed the Commonwealth approvals process for the project.
The Jabiluka mine development proceeded in 1998-99 with relevant agreements in place. However, mining was deferred until Ranger output starts to decline towards the end of its life, and until agreement could be reached regarding treatment of Jabiluka ore at the Ranger mill. The mine was developed with an 1150 metre access decline and a further 700 metres of excavation around the orebody. About 50,000 tonnes of mineralised material which was removed during development was stockpiled under cover on the surface. Development then ceased and the mine was put on standby with environmental maintenance and planning.
In 2000, following intensive drilling from the underground access to the Jabiluka orebody, ERA revised the overall resource, with some reduction in actual reserves. Proved and probable ore reserves now stand at 11.8 Mt ore @ 0.50%, containing 59,000 tonnes U3O8. Additional measured and indicated resources are 21,700 tonnes U3O8in 0.43% ore, and inferred resources a further 54,700 tonnes in 0.54%. All figures are based on a cut-off grade of 0.20%.
In 2003 the Northern Territory government approved ERA's proposal for long-term care and maintenance of the Jabiluka site and this was implemented. The stockpiled mineralised material was backfilled into the decline and a similar quantity of waste rock joined it. ERA also undertook improvements to water management at the site. The new works were in line with the wishes of the Aboriginal traditional owners. They also improved the environmental management of the site and cost less than long-term management of the previous situation. ERA (whose parent company is Rio Tinto) will not proceed with the mine until there is agreement from the local Mirrar Aboriginal people.
See also ERA web site.
Koongarra, NT
Koongarra is a small but relatively high grade uranium deposit in the Alligator Rivers of the Northern Territory. It lies some 30 km south of Ranger and 3 kilometres east of Nourlangie Rock. When the Kakadu National Park was set up in 1979, the land covered by the Koongarra Special Mineral Lease was excluded. However, the Lease area is on Aboriginal land.
Koongarra was discovered by Noranda Australia Ltd in 1970. In 1980 Denison Australia Pty Ltd took over Noranda's interests in the deposit. In 1992 Total acquired a 70% interest in Koongarra, which was subsequently acquired by Cogema Australia Pty Ltd. In 1995 Cogema acquired the remaining 30% interest in the project. In 2006 Cogema mining operations became part of Areva NC.
When Denison Australia took over the deposit, a draft EIS was submitted to the Federal Government. The final EIS was approved in 1981. Denison conducted a review of the project to minimise its impacts and this resulted in the definition of a 1050 ha project site extending into the National Park. This area was excised from the National Park by the Koongarra Project Area Act 1981, but this has not yet been proclaimed. In the mid 1980s, and again in 1991, Denison negotiated Aboriginal agreements, but these did not receive the assent of the Federal Minister for Aboriginal Affairs. Development was stalled in 1983. Following the 1996 change of federal Government, all aspects of the project were reassessed by Cogema, but in April 2000 the (Aboriginal) Northern Land Council vetoed development of the project for five years. This veto was subsequently renewed, and remains in force.
The upper orebody has proved and probable ore reserves with an average grade of almost 0.8% U3O8, containing 14 500 tonnes of uranium oxide accessible by open pit mining, and with associated gold. Proposed production was 1375 tonnes U3O8 per year. A poorly-defined lower orebody is estimated to contain 2000 tonnes of uranium oxide in 0.3% ore but does not form part of the reserves.
Mount Fitch, NT
Mount Fitch was discovered in 1965 and is part of the old Rum Jungle workings near Batchelor, 64 km south of Darwin. Compass Resources NL has been active in the area for some years, primarily focused on the Browns deposit, a copper-cobalt-nickel deposit close to the old Intermediate open pit. In 2006 Compass reported resources of 4050 tonnes U3O8 at Mt Fitch, averaging 0.046%.
Angela, NT
The Angela deposit, 25 km south of Alice Springs was discovered in 1973 and extensively drilled by Uranerz Australia in 1989, under a Uranerz-MIM joint venture which reported 11,500 tonnes of U3O8 at 0.10 to 0.13% (measured, indicated, & inferred resources), spread over 5.7 kilometres strike length in sandstone to a depth of 650 metres and open at depth.
After Uranerz departed from Australia in 1991, Angela was held under a retention licence, but this was relinquished due to prevailing Labor Government policy. The NT government in February 2008 accepted a bid by 50-50 joint venturers Paladin Energy Ltd and Cameco Australia to explore the deposit with the adjacent Pamela deposit. The new Angela Project JV has committed to spend $5 million on confirming the resources once a licence is issued, with a view to then undertaking a bankable feasibility study. It is expected to have a conventional hard rock mill and an alkaline leaching circuit, with production possibly in 2011.
Bigrlyi, NT
Bigrlyi is a series of discontinuous lenses outcropping over 12.5 km in hard sandstone along the northern edge of the Ngalia Basin in NT, 390 km NW of Alice Springs. Central Pacific Minerals NL in 1982 reported resources of 2181 tonnes U3O8 averaging 0.372% in eight separate lenses, the main mineral being uraninite, along with vanadium minerals. In mid 2006 the deposit was held by a joint venture including Energy Metals Ltd (53.74%) and Valhalla Uranium (42.06%, Paladin subsidiary) who have reported indicated resources of 4050 tonnes U3O8 at 0.173% average (and 4000 t V2O5) and inferred resources of 6500 tonnes at 0.125%, with cut-off of 0.05%. Energy Metals, the operator, has announced good recoveries and relatively low acid consumption from metallurgical testwork. A proposed open cut mine is expected to produce at least 6800 tonnes U3O8 with similar amount of vanadium byproduct over ten years. An additional 550 t U3O8 would be accessible underground. In 2009 a subsidiary of China Guangdong Nuclear Power Co made a 70% takeover offer for Energy Metals, valued at $86 million.
Nolans Bore, NT
This is a deposit of rare earths, about 135 km north of Alice Springs, and has some uranium as potential by-product. Arafura Resources intends to develop it as a rare earths mine.
Napperby, NT
The Napperby project in the Northern Territory, 150 km northwest of Alice Springs, is an historic uranium prospect, comprising an extensive near-surface, consistent mineralised zone that is relatively low grade calcrete, but is close to infrastructure. An inferred resource of 670 tonnes in 0.36% ore over one kilometre of paleochannel was reported in 2006. Toro Energy took over the project from Deep Yellow, and is now defining the resource with a view to assessing the viability of mining it. The inferred resource figure was increased to 3350 tonnes at 0.036% U3O8 in March 2009, and a scoping study is under way.
Honeymoon, SA (with East Kalkaroo and Gould's Dam)
Honeymoon itself was discovered in 1972, about 75 kilometres north west of Broken Hill, 30 kilometres inside South Australia. MIM Holdings Ltd bought out CSR Ltd's 34.3% share in 1988. In 1997 Sedimentary Holdings NL reached agreement with MIM to acquire the Honeymoon leases next to its own East Kalkaroo deposit on the Yarramba palaeochannel. The 1997 agreement also included acquisition of the Gould Dam-Billaroo West leases 80 km northwest of Honeymoon.
The 1997 agreement initially brought together known uranium resources of about 4200 tonnes U3O8 averaging 0.11% and amenable to in-situ leaching. The purchase was funded by Southern Cross Resources Inc. of Toronto. Sedimentary Holdings progressively reduced its share in Southern Cross and sold the last 7% in September 2004.
The Honeymoon - East Kalkaroo deposit occurs in porous sand of the Yarramba palaeochannel at a depth of 100-120 metres and extending over about 150 hectares. Plans were developed in the late 1970s to extract the uranium oxide by in situ leaching (ISL), and some $12 million was spent in preparation. Draft and Final Environmental Impact Statements were produced, and both South Australian and Commonwealth environmental approval was subsequently obtained in 1981 for production to 450 t/yr. Field tests of the ISL process were carried out and a $3.5 million, 110 t/yr pilot plant was built, but the project was abandoned in 1983.
Aerial view of plant and infrastructure (wellfield is beyond at top left
Trial wellfield (extraction well is left of centre)
Well header building
Inside well header building
Pilot plant
Field leach trials using the refurbished process plant resumed in 1998 and led to a proposal to produce about 1000 t/yr U3O8 equivalent (as uranium peroxide) at less than US$ 6/lb U3O8. A June 2000 draft EIS covered the Honeymoon - East Kalkaroo deposits on five Mineral Claims and approval of this was granted in November 2001.
Further drilling and logging with a prompt fission neutron tool in 2004 confirmed high-grade resources which were reported in terms of grade thickness (GT) - average grade U3O8 multiplied by thickness of leachable sand holding the uranium. In the Honeymoon deposit itself 3300 t U3O8 at an average GT of 0.84 m% was confirmed, with 900 t U3O8 at an average GT of 0.38 m% in East Kalkaroo adjacent. The program failed to extend these resources, and further drilling and logging of nearby parts of the Yarramba palaeochannel immediately NW of Honeymoon in 2004 failed to confirm further resources.
Mineralisation at Billeroo West (including Gould Dam) in the Billeroo palaeochannel is similar to that at Honeymoon. Following exploration late in 2004 of one kilometre of palaeochannel using prompt neutron fission technology, the indicated resource was stated as 2000 t U3O8 at an average GT of 0.33 m% or 0.12% U3O8. Much of the palaeodrainage system there is untested.
In November 2004 the company announced revised development plans down to a 400 tpa plant at Honeymoon costing $A 44 million (US$ 31 million) and with cash operating cost of A$ 17.70/lb U3O8 (US$ 12.40/lb). Development was deferred pending higher uranium prices and the outcome of further exploration at Gould's Dam. In December 2005 Southern Cross Resources was taken over by Aflease to form SXRuraniumOne Inc. Honeymoon information is on its web site. (The 'sxr' was later dropped.)
Following a new feasibility study, in August 2006 Uranium One announced that development of Honeymoon would proceed as a 400 t/yr ISL mine. It quoted indicated resources of 2900 tonnes U3O8 at 0.24% (av grade thickness 0.42 m%) excluding some thin low-grade material included in earlier estimates. The adjacent East Kalkaroo deposit had 900 tonnes at 0.074% grade. . In January 2007 a ten-year export permit was granted.
In October 2008 the company announced a joint venture with Mitsui (49%) to complete development of the project. Similar joint ventures with Mitsui would apply to Gould Dam and Billeroo. In December 2008 Uranium One announced an engineering, procurement, and construction management contract with Ausenco Ltd to build the mine for mid 2010 start-up and commercial production in 2011 at 400 t/yr. Total capital cost is A$ 118 million. The plant, including pulsed column solvent extraction circuit, is modular and can later be relocated to Gould's Dam if required.
Early in 2009, a 20% share in Uranium One was taken by three Japanese companies, giving 59% Japanese equity in Honeymoon.
Beverley Four Mile, SA
Four Mile comprises two deposits 5-10 km NW of the Beverley mine and is being explored by Quasar Resources Pty Ltd (affiliated with Heathgate Resources). The extended Beverley mine lease is contiguous. Alliance Resources Ltd is a 25% free carried joint venture partner. An "initial resource estimate" of 15,000 tonnes U3O8 at 0.37% was announced in May 2007 for the west deposit and this subsequently became inferred resources under JORC code. Alliance in January 2008 announced preliminary indications of a similar resource in the east deposit and in June 2009 confirmed 13,000 tonnes U3O8 at 0.31%, making a total of 28,000 t at 0.35%. A cut-off of 0.5 metres at 0.05% was used for both resource estimates. Both deposits remain open, with potential for further resource upgrade.
In January 2008 Alliance announced a concept study for the project with ISL mining commencing in 2010 if resources in the eastern deposit matched those in the west deposit, which they since have. Grades are being measured with a prompt fission neutron (PFN) tool, giving much more confidence than gamma logging. There are three mineralised layers between 190 and 210 metres deep, ranging from 1.1 to 7.3 metres thick and with grades up to 1.74% U3O8.
Early in 2008 Quasar decided to proceed with mining as soon as possible. A feasibility study for the mine was brought forward, making the planned field leach trial on the west deposit redundant.
Uranium recovery will be through a satellite ion exchange plant at Four Mile then trucking the loaded resin to the main Beverley plant for stripping (elution) and precipitation.
Quasar applied for a mining lease in May 2008. An environmental assessment was published in January 2009. The mining lease is subject to registration of a Native Title Mining Agreement, following both of which on-site construction can commence. Due to delay with that Agreement, Qasar has told Alliance that "commissioning has been significantly delayed beyond April 2010". Production is to ramp up to 1400 t/yr U3O8 over three months.
Alliance has published estimated project costs of A$90 million as determined by Quasar in its feasibility study. Forecast total cash costs, including royalties, were A$38.80/lb U3O8.
Mt Gee, SA
Working with data from earlier drilling campaigns, Marathon Resources has quantified to publishable standard the uranium resources of the Paralana ore system comprising a number of uranium and polymetallic orebodies spread over 12 km in the north Flinders Ranges of South Australia. The Mt Gee deposit is part of the Paralana minerals system which is mostly low-grade but with some higher-grade portions. Other orebodies in the system are also prospective. The area has been drilled extensively since 1968 by Exoil, CRAE (Rio Tinto) and Goldstream. In 2007 Marathon initiated a pre-feasibility study and an environmental impact study for underground mining at Mt Gee. In September 2008 the company announced a revised resource estimate with indicated resources of 2800 tonnes and inferred resources of 28,500 tonnes U3O8, with 0.03% cut-off.
The Mt Gee - Mt Painter mineralisation is the source of uranium in the palaeochannels around Beverley, a few kilometres east.
Oban & Curnamona, SA
A large area including most of the Yarramba palaeochanel north of Honeymoon- East Kalkaroo was held by Havilah Resources but was floated as Curnamona Energy Ltd in 2005, with Havilah now holding 45% of the company. No resources are yet quantified.
The Oban deposit 60 km north of Honeymoon is hosted by an extensive bed of Tertiary sand. It was explored by Marathon Petroleum Australia Limited in the early 1980s with a best result of 3 metres grading 0.12% U3O8. Paladin Resources Ltd carried out additional drilling in the area in the late 1990s. The mineralisation is mostly very thin and occurs at 80-90 metres depth and is discontinuously developed over 3 km in a carbonaceous and pyritic sand unit. It has typical roll front characteristics. Most of the deposit is held under a retention lease. In March 2009 approval was given for a field leach trial which will enable resource figures to be published.
Crocker Well & Mt Victoria, SA
Uranium mineralisation in the Olary area of SA (Curnamona province) was investigated 1951-78 by the SA Mines department and private companies, and the Crocker Well deposit went through to a feasibility study then. This uranium field has six deposits over 4 sq km. Inferred resources are 12.5 million tonnes @ 0.05% U3O8with cut-off of 0.03%. The Mt Victoria deposit 7 km away has an inferred resource of 0.25 Mt grading 0.16%. Mineralisation at Crocker Well is primarily thorian brannerite in igneous rock, with some davidite, while that at Mt Victoria is davidite.
PepinNini Minerals Ltd now holds both deposits and adjacent prospective ground. Other hard rock outcrops in the area grade up to 2.1% U3O8. With a cut-off of 0.025% the total inferred resource is 8576 t U3O8 at average 0.048% grade. In March 2006 a JORC-compliant inferred resource of 6750 t was quoted with grade of 0.05% for Crocker Well. A scoping study for 500 tU/yr production encouraged the company to proceed with upgrading the resource to measured or indicated status and quantifying further mineralisation. Resource verification was due to be complete in July 2008. Metallurgical testing shows good potential for ore beneficiation prior to treatment, and also that hot leaching gives good recoveries.
In June 2007 Sinosteel Corporation of China committed $40 million for a 60% stake in PepinNini's Curnamona Project as a joint venture partner. Sinosteel committed $11 million to explore and develop the project over a two-year period. Of this, $5 million is being spent on exploratory drilling and metallurgical testing at Crocker Well, together with a process of regulatory approvals and a Bankable Feasibility Study which is now underway. Application for a mining licence was lodged in September 2008.
Prominent Hill, SA
Minotaur Resources Ltd proved up a significant mineral resource in the Gawler Craton, some 150 km NW of Olympic Dam. In 2001 copper-gold mineralisation in iron oxide similar to Olympic Dam's was discovered under 100 m of sedimentary cover by the Mount Woods joint venture, and Minotaur subsequently bought out the other parties, notably BHP-Billiton. Oxiana Ltd then farmed in towards earning 65% of the project by spending $34 million in staged exploration and evaluation. In 2005 Minotaur resources was acquired by Oxiana Ltd.
As of August 2004 an inferred resource of 97 million tonnes at 1.5% copper, 0.5 g/t gold and 103 ppm uranium in the upper chalcocite. In deeper chalcopyrite, uranium runs to 120 ppm. This gives less than 10,000 tonnes U, with unknown mineralogy and hence uncertain recovery.
Kintyre, WA
The Kintyre deposit is a significant high-grade uranium orebody with a small surface outcrop in the remote Rudall region of Western Australia. This is on the western edge of the Great Sandy Desert in the Eastern Pilbara Region of Western Australia, approximately 70 km south of Telfer and some 1200 kilometres NE of Perth. It was discovered by Rio Tinto Exploration in 1985 through surface follow-up of a number of radiometric anomalies detected during an airborne survey.
The deposit then lay less than a kilometre inside the state's largest national park, covering 1.5 million hectares. The Rudall River National Park is surrounded by vacant crown land and has boundaries defined arbitrarily by latitude and longitude rather than natural features. It was established in 1977 to preserve and demonstrate an arid desert dry river ecosystem in the Eastern Pilbara region. Mineral exploration was permitted within it. However, the Kintyre orebody is outside the catchment area which the Park had been intended to protect.
Canning Resources Pty Ltd was the Rio Tinto company which in association with Rio Tinto Exploration took over the role of assessing the feasibility of bringing a mine into production. By 1988 reserves of some 24 000 tonnes of uranium oxide (in association with other minerals) had been delineated, with a further 12 000 tonnes of inferred resources, in several contiguous parts of the orebody, with a grade of 0.2 - 0.4% U3O8 and a cut-off grade of 0.05%. This showed that development was feasible.
In 1991 Rio Tinto Exploration received the WA Minister for Mines' Award for Environmental Excellence "for the overall commitment of exploration staff to minimising the impact of exploration activities at Rudall River whilst under critical community scrutiny and for progressively rehabilitating all areas disturbed during exploration, as an integral part of the overall exploration programme."
In April 1994 the State Government excised an area of 15,100 hectares from the Rudall River National Park, including the Kintyre project area. At the same time a strip of land of 15,400 ha was added to the western boundary of the Park, part of the river system that the park was set up to protect.
Production of 1800-2000 tonnes of uranium oxide concentrate per year was envisaged, with open pit mining. There is the potential for further resources to be identified. The vein-type nature of the orebody makes it possible to use radiometric ore sorting so that the mill feed is effectively very high grade, which results in lower processing costs and a compact treatment plant. The total area disturbed by the proposed mine and treatment plant, including up to five small open cuts, will be about three square kilometres (300 ha), with the treatment plant occupying about six hectares. An additional 100 ha will be required for infrastructure. Capital cost of the project was estimated to be $120 million.
Tailings will be in two streams, both as filter cake, which will be buried in purpose-built disposal facilities or in a mined-out pit. The first stream is a conventional residue from acid leaching, containing most of the ore's radioactivity. The second is mixed gypsum and iron hydroxide from an iron precipitation stage. The other eventual waste will be some evaporite from process liquors which cannot be recycled. There will be no tailings dam.
Due to low international uranium prices and other outstanding approval requirements, the project was slowed down in 1997 and Rio Tinto Exploration put it under care and maintenance late in 1998. In 2002 it was decommissioned and rehabilitated. In 2007-08 it was put up for sale by Rio Tinto, with deadline for bids in March.
In July 2008 Cameco (70%) and Mitsubishi (30%) agreed to buy Kintyre for US$ 495 million, conditional upon state government approval for the sale and agreement with the Martu traditional owners. Cameco is operating the project and a $9 million exploration program to confirm ore reserves commences in July 2009, with feasibility study envisaged to begin about the end of 2010.
Yeelirrie, WA
The Yeelirrie deposit is between Wiluna and Leinster, WA, about 420 kilometres north of Kalgoorlie and close to the Goldfields gas pipeline. It is 130 km north of the existing infrastructure serving the BHP Billiton nickel mine at Mount Keith.
Western Mining Corporation (WMC) discovered the shallow and extensive deposit in 1972. It is reputedly the world's largest sedimentary calcrete deposit of its kind. The uranium mineralisation is carnotite (hydrated potassium uranium vanadium oxide).
In August 1978 Urangesellschaft Australia Pty Ltd bought for A$ 3 million a 10% interest in the deposit, but this was reacquired by WMC in October 1993. At the same time Esso was brought into the project and given 15% equity in return for a commitment to fund 80% of the Stage I feasibility study and pilot plant, then costed at A$ 21 million. Esso withdrew in May 1982 for commercial reasons and the share reverted to WMC. In 2005 ownership transferred to BHP Billiton Ltd.
The deposit extends over 9 kilometres, is up to 1.5 kilometres wide, up to 7 metres thick and with an average depth of about 7 metres of overburden. It comprises a mineral resource of 35 million tonnes with an average grade of 0.15%, containing 52,000 tonnes of uranium oxide, though this figure is not JORC-compliant. It could readily support a low-cost mining operation producing a proposed 2500 tonnes per year of uranium concentrate with 1000 tonnes per year of vanadium oxide by-product.
An Environmental Impact Statement was produced in 1978 and resulted in environmental approval from both state and Commonwealth governments. In the twelve years to 1983 WMC and its partners (then including Esso) spent a total of $35 million preparing to develop Yeelirrie as an open cut mine, including building and operating the pilot metallurgical plant at Kalgoorlie. A $320 million project was envisaged and sales contracts were being planned. However, the 1983 federal election and implementation of the ALP "three mines policy" meant that permission to negotiate sales contracts was withdrawn in March 1983. Plans were then abandoned, and WMC's attention focussed on developing Olympic Dam.
A new state Labor government was elected in 2002 with an ideological anti-uranium stance. Pursuant to this, the 1978 state mining agreement for Yeelirrie was revoked in March 2004. However, WMC Resources retained the mining tenements and awaited future opportunities after undertaking rehabilitation of the site by the end of 2004. In 2008 a change of state government reopened the possibility of development, and BHP Billiton listed it as an "outstanding long-term opportunity". It followed this with a new program to better define the ore resource and engage in community consultation. In May 2009 application to commence the process of environmental approval was lodged with the federal government, envisaging 2000 t/yr production from 2014 and mine construction possibly starting late 2010.
Mulga Rock, WA
The Energy & Minerals Australia (EAMA) Mulga Rock polymetallic deposits 250 km north east of Kalgoorlie were discovered by PNC Exploration in 1979. They comprise the Ambassador, Emperor and Shogun deposits, the first being some 20 km from the others and the three covering some 7 square kilometres. Mineralisation consists principally of uranium, scandium, nickel and cobalt in lignite within a sedimentary basin, with uranium apparently comprising half or less of the recoverable value of minerals. In particular the orebodies are a major scandium resource. Ore thickness is 0.5 to 5 metres at depths of 35 - 45 m. They are within the larger Narnoo project area.
PNC evaluated only the uranium content and identified an estimated resource of 46,000 t U3O8 at 0.095% U grade. In January 2009 EAMA announced an initial JORC-compliant inferred resource of 24,520 tonnes U3O8 averaging 0.055% at 200 ppm cut-off grade. Nearly one third of this is higher-grade - 0.096% - in the Ambassador deposit, which EAMA now intends to mine first. The three Mulga Rock deposits are hosted in lignite. In addition there are large (totalling over 500 million tonnes) lignite deposits - one below and adjacent to Emperor, the other 12 kilometres south of Emperor. These lignites contain kerogens (a precursor to hydrocarbons).
The deposits were acquired by Eaglefield Holdings Pty Ltd in 2000, associated with Narnoo Mining. It undertook a preliminary feasibility study on the Ambassador deposit, which indicated that an open pit producing four metals including 200 tpa Sc oxide over ten years should be viable. The other two deposits should double mine life. Metallurgical studies show high recoveries of uranium and scandium using acid leach and solvent extraction. Progress was slow due to previous state government policies relating to uranium mining. In 2005 Bullion Minerals Ltd attempted to acquire the project. In 2006 it passed to Energy & Minerals Australia Ltd when it acquired Narnoo Mining.
Double 8, WA
This deposit is about 40km southwest of Mulga Rock. It was acquired by Uranio Ltd from Paladin in 2008 and has about 5000 tonnes U3O8 as an inferred resource estimate (JORC), with 200 ppm cut-off. The deposit was found by PNC Exploration in the mid 1980s, and further analysis of original cores was undertaken over 2008-09. It is in the Ponton palaeochannel system and within a nature reserve. In May 2008 Uranio merged with Manhattan Resources and became Manhattan Corporation.
Manyingee, WA
This deposit was discovered in 1974 in the northern part of the Carnarvon Basin, 85 km south of Onslow in Western Australia.
It occurs in sandstones and siltstones at a depth of 60-110 metres, and seven mineralised rollfronts extend over 7 km but one third of the deposit occurs in 1.5 km2. Two pumping tests and one five-spot in situ leaching test have been run to evaluate whether the ore is amenable to in situ leaching and whether the leach solutions can be confined. Subsequent monitoring confirmed that there was no environmental contamination from these tests. Development was suspended due to federal Labor Government policy on uranium. The project is covered by three mining leases granted in 1989.
Following the transfer of Total's worldwide uranium assets to Cogema in 1993, the deposit became owned 92.3% by Afmeco Mining and Exploration Pty Ltd (AFMEX), a subsidiary of Cogema Australia, in joint venture with Urangesellschaft Australia Pty Ltd (7.7%). They sold the deposit to a wholly-owned subsidiary of Paladin Resources in 1998 for A$ 3.25 million plus 1% royalty, which in 1999 was renegotiated to $1 million plus $0.75 million on project approval plus increased but capped royalties. Paladin had hoped to bring the deposit into production in about 2005, but has concentrated on its African prospects while WA government policies precluded uranium development.
The previous owners spent A$16 million and defined a resource of 7,860t U3O8 at 0.12% U3O8. A revised resource model was developed by Paladin through re-interpretation of the drill data, distinguishing three geological environments. The indicated resources determined from this work stands at 8,080t U3O8 at 0.1% U3O8 and 2,810t U3O8 at 0.05% as inferred.
Oobagooma, WA
This deposit occurs in a zone averaging 2 metres thick in sandstone, 75 kilometres northeast of Derby in Western Australia. The deposit was held owned by Afmeco Mining and Exploration Pty Ltd (AFMEX), a subsidiary of Cogema Australia, but was sold to a wholly-owned subsidiary of Paladin Resources in 1998 for A$ 0.9 million plus 1% royalty. It is held under two exploration licence applications. The inferred resource calculated by AFMEX is 9950 tonnes of uranium oxide at 0.12 % U3O8, with cut off of 0.03%, though this does not conform to JORC criteria. In situ leaching appears to be the most likely method of extraction and some pump test work has been done.
Lake Way & Centipede, WA
These comprise the Wiluna Uranium Project. The Lake Way deposit, close to Wiluna, 750 kilometres north east of Perth in Western Australia, was discovered in 1972. Delhi International Oil Corporation (53.5%) and Vam Ltd (46.5%) were joint venturers initially, but Asarco Australia Ltd bought out its partner and in 1994 became Wiluna Mines Ltd, whose main focus is on gold.
Lake Way is a very shallow low-grade carnotite deposit in calcrete and clays. It averages 1.5 metres thick but ranges up to 5 metres below the surface. It was to have been mined by four or more pits over some 9 square kilometres, but plans were abandoned in 1983. The Centipede calcrete deposit is 12 km south of the Lake Way deposit. It consists of two or three lenses of 1 to 5 metre thick mineralisation containing carnotite through the carbonate matrix of a chemical delta where a 30 km drainage system enters Lake Way. Acclaim Uranium held the deposits in the 1990s but Nova Energy Ltd had them by 2006.
Toro Energy (which merged with Nova) is undertaking feasibility studies for 750 t/yr production of U3O8 with low-cost open cut mining of both deposits and using a carbonate leach plant. In June 2009 Toro reported JORC-compliant indicated and inferred resources of 11,000 tonnes U3O8 at 0.0548% average with cut-off 0.02%, fairly evenly split between the two deposits. It holds a mining lease over Centipede and in April 2009 it applied for a mining lease over Lake Way. Further drilling is expected to lead to undertaking a definitive feasibility study later in 2009 and an application for actual mining. Production is envisaged from mid 2012.
Dawson-Hinkler, WA
U3O8 Ltd has announced an inferred resource of 4700 tonnes U3O8 at its Dawson-Hinkler Well deposit near Wiluna. At 150 ppm cut-off, average grade is 0.023% U3O8. The deposit is 40 km north of Yeelirrie, 70 km northwest of Lake Maitland, and in the same palaochannel as Toro's Lake Way deposit 10 km east. The deposit occurs over 15 km strike length, and selective mining is with 1:1 waste to ore strip ratio. The company has applied for a mining licence, and is investigating the prospect of joint or toll milling with one of the three projects nearby.
Lake Maitland, WA
Several calcrete deposits occur at Lake Maitland, 100 km SE of Wiluna. Three were evaluated by Carpentaria Exploration, Esso and then Acclaim Uranium in the late 1990s. The deposit underlies the northern end of Lake Maitland itself. The mineralised zone is about 6 km long and 300-600 m wide, 1.5-2.0 m below the surface and average 1.7 m thick. In 2005 the deposit was owned by Redport Ltd, and in mid 2006 inferred resources were stated as 10,700 t U3O8 at 0.03%, 4759 tonnes of this "high-grade".
In 2006 Mega Uranium Ltd acquired Redport. In February 2009 it agreed to sell a 35% share of the project to the Itochu Corporation (10% of Japanese share) and Japan Australia Uranium Resources Development Co. Ltd. (JAURD), acting on behalf of Kansai Electric Power Company (50%), Kyushu Electric Power Company (25%) and Shikoku Electric Power Company (15%) for US$ 49 million.
In July 2009 Mega confirmed a NI 43-101 compliant indicated resource of 10,800 tonnes U3O8 grading 0.038%, plus 1000 tonnes inferred, at 100 ppm cut-off, and said it was on track to bring a mine into production. In September 2009 Mega was awarded a mining lease, and a definitive feasibility study is due in june 2010, with an environment review and managment plan in September 2010. Mega hopes to start mine construction by mid 2011, with a view to producing 750 t/yr from early 2012.
Thatcher Soak, WA
This is a shallow paleaochannel deposit in WA, north of Mulga Rock and east of the main calcrete deposits such as Lake Maitalnd. It is primarily carnotite hosted within calcrete and silcrete less than 20 metres deep and extending over 8 km. The main part of the deposit is held by Uranex NL and June 2008 figures give 17 million tonnes averaging 290 ppm, hence 4900 tonnes contained U3O8 as a JORC-compliant inferred resource.
Valhalla, Qld (Mount Isa Uranium Project)
This deposit was discovered 40 km north of Mount Isa about 1954 by a prospector. MIM took it over and sunk an exploration shaft. In the 1960s it passed to Queensland Mines Ltd which drilled it extensively and held it until 1992, when Summit Resources Ltd took over. A drilling program in 50:50 joint venture with Valhalla Uranium Ltd identified a significant deposit which remained open along strike to the north and south and at depth. The mineralisation is hosted within highly altered and mineralised tuff and shale, and includes some vanadium. A full feasibility study is planned, though the state Labor government has said it will not issue any mining lease for uranium. In September 2006 Paladin Resources took over Valhalla Uranium Ltd. Indicated resources were then quoted as 16,900 t U3O8 and inferred resources 9000 t. In 2007 Paladin launched a full takeover bid for Summit Resources and ended up with 81.8% of it. Areva bought a 10.5% stake in Summit.
Summit updated the JORC-compliant measured and indicated resource figures in January 2009 to 24,765 tonnes U3O8 at 0.023% cut-off and with average grade 0.089%. Inferred resources were 5860 t at 0.08%. It extends to 650 metres depth and along 1100 m strike but remains open at depth to the south.
Summit also holds the Andersons, Skal, Bikini and Mirrioola deposits nearby, which have some inferred resources. Total inferred resources there are 12,800 t U3O8, average grade 0.06%.
Westmoreland, Qld (& NT)
This comprises the eastern end of a series of small prospects and deposits spread over about 50 kilometres straddling the Queensland - Northern Territory border, about 400 kilometres north of Mount Isa. Westmoreland is on the Queensland side of the border and its deposits extend over about 10 kilometres.
The first uranium mineralisation was discovered here in 1956, by a prospector with a Geiger counter. Late in 1956 the Bureau of Mineral Resources flew an airborne scintillometer survey and recognised anomalies in outcrops of the Westmoreland conglomerate held by Mount Isa Mines Ltd (MIM). Further work resulted in three mining leases being pegged over the Redtree deposit in 1959.
In 1967 Queensland Mines Pty Ltd obtained an exploration permit over the area surrounding the MIM-ZC leases and commenced a major drilling program which identified further Redtree deposits and the Huarabagoo deposit. In 1975 Queensland Mines formed a Joint Venture with Urangesellschaft Australia Pty Ltd, Anglo Australian Resources NL and IOL Petroleum Ltd, with the IOL share later being taken over by a CRA subsidiary. In the period 1976 to 1983 Urangesellschaft discovered the Junnagunna deposit while they were managing the Joint Venture. In 1985 Queensland Mines resumed management.
In 1990 CRA Exploration Pty Ltd (now Rio Tinto Exploration P/L) entered the Queensland Mines - Urangesellschaft Joint Venture and took over the exploration work with a view to earning equity in the Joint Venture. In 1997 Rio Tinto took over the whole project (it already had a 100% interest in the original MIM-ZC mining leases at Redtree), but relinquished the leases in 2000.
The main deposits comprise three mineralised pods adjacent to the Redtree Dyke and flat irregular masses further from it. Grades are 0.1-0.2% and 0.04-0.15% U3O8 respectively, with associated gold. The total inferred resource for Redtree, Huarabagoo and Junnagunna was about 22,000 tonnes contained U3O8. Three other prospects contain further small known resources. The "copper/gold/uranium" leases were apparently taken up by Tackle Resources after Rio Tinto relinquished them and in August 2004 the rights were bought by Canadian company Laramide Resources Ltd for US$ 150,000 plus some Laramide shares. In 2006 Laramide announced that 7000 t of the resource had been upgraded to indicated resources in line with Canadian NI 43-101 standard. A major drilling program continues and will form the basis of a feasibility study.
Ben Lomond, Qld
This deposit, some 50 kilometres west of Townsville, was discovered in 1975 by Total Mining Australia Pty Ltd. Mining leases were granted in 1980 and 1983. In 1994, following the transfer of Total's worldwide uranium assets to Cogema, the company changed its name to Afmeco Mining and Exploration Pty Ltd (AFMEX), which is a wholly-owned subsidiary of Cogema Australia Pty Ltd. In July 1997 AFMEX agreed to sell the deposit to Anaconda Uranium Corporation of Canada for A$ 3 million plus 1% royalty, but due to state government policies Anaconda walked away from the deal after an initial payment. The deposit reverted to AFMEX.
A resource of about 6800 tonnes U3O8 with an average grade of 0.228% U3O8 and 4578 tonnes of molybdenum at an average grade of 0.149% has been delineated. A 1982 feasibility study proposed recovery of 4760 tonnes U3O8 from 0.246% ore.
Proposed mining of the deposit was to be primarily open cut, but with about one third of the orebody being underground mined, and with annual production of 500 tonnes of uranium oxide and 250 tonnes of molybdenum. The 1984 Environmental Impact Study was accepted by state and federal authorities, and a water monitoring program is continuing. Development was suspended due to both federal and state Labor Government policy on uranium. Anaconda intended to prepare a new feasibility study on the project based on "a more economic and environmentally friendly method of extracting the uranium", and to update environmental studies. The small Maureen deposit, 300 km inland, was to provide "operating synergy", and joint production facilities were envisaged. AFMEX prepared a revised Plan of Operations covering the final rehabilitation of the site. This plan was to be implemented once all regulatory approval had been obtained, but in 2005 the deposit was sold for $1 million to Uranium Mineral Ventures Inc, a subsidiary of Maple Minerals Corp of Canada. In January 2005 Mega Uranium Ltd agreed to acquire 100% of UMV and in February 2006 the Queensland government approved transfer of the leases to UMV.
In early 2008 NI 43-101 compliant indicated resources of 3600 t U3O8 at 0.27% and inferred resources of 1250t at 0.21% were quoted by Mega.
Maureen, Qld
The small Maureen uranium deposit near Georgetown in north Queensland was bought in July 1997 by Anaconda Uranium Corporation for $325,000 plus royalties, but in 1998 reverted to its previous private owners. Measured and indicated resources are almost 3000 tonnes of U3O8 grading 0.123% with 0.07% molybdenum as wll as fluorite and accessible by open pit. Some $8 million was spent on the deposit in the 1970s. In 2005 the deposit was owned by Georgetown Mining Ltd and in August 2005 Mega Uranium Ltd acquired the rights to the deposit and surrounding mineralised areas.
Recent transfers to foreign ownership
As well as foreign equity in the companies with uranium mines, in recent years there has been increased interest in exploration companies. Some companies active in Australia are foreign-based, eg Uranium One, Cameco and Areva. The following table outlines some recent investment in Australian-based or established explorers, or particular projects, which have credible resources.