Summary and Geology

  • Uranium is a relatively common metal, found in rocks and seawater.  Economic concentrations of it are not uncommon and quantities of mineral resources are greater than commonly perceived.
  • Its availability to supply world energy needs is great, both geologically and because of the technology for its use.

Uranium is ubiquitous on the earth.  It is a metal approximately as common as tin or zinc, and it is a constituent of most rocks and even of the sea.  Some typical concentrations are shown in the table below.

High grade ore – 2% U 20,000 ppm U
Low-grade ore – 0.1% U 1,000 ppm U
Granite 4 ppm U
Sedimentary rock 2 ppm U
Earth’s continental crust (av) 2.8 ppm U
Seawater 0.003 ppm U

Widespread use of the fast breeder reactor could increase the utilisation of uranium sixty-fold or more.  This type of reactor can be started up on plutonium derived from conventional reactors and operated in closed circuit with its reprocessing plant.  Such a reactor, supplied with natural uranium for its “fertile blanket”, can be operated so that each tonne of ore yields 60 times more energy than in a conventional reactor.

About two-thirds of the world’s production of uranium from mines is from Kazakhstan, Canada and Australia.

An increasing amount of uranium, now over 55%, is produced by in situ leaching.

In 2022 Kazakhstan produced the largest share of uranium from mines (43% of world supply), followed by Canada (15%) and Namibia (11%).

Production from mines (tonnes U)

Country 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022
Kazakhstan 22,451 23,127 23,607 24,689 23,321 21,705 22,808 19,477 21,819 21,227
Canada 9331 9124 13,325 14,039 13,116 7001 6938 3885 4693 7351
Namibia 4323 3255 2993 3654 4224 5525 5476 5413 5753 5613
Australia 6350 5001 5654 6315 5882 6517 6613 6203 4192 4553
Uzbekistan (est.) 2400 2400 2385 3325 3400 3450 3500 3500 3520 3300
Russia 3135 2990 3055 3004 2917 2904 2911 2846 2635 2508
Niger 4518 4057 4116 3479 3449 2911 2983 2991 2248 2020
China (est.) 1500 1500 1616 1616 1692 1885 1885 1885 1600 1700
India (est.) 385 285 385 385 421 423 308 400 600 600
South Africa (est.) 531 573 393 490 308 346 346 250 192 200
Ukraine 922 926 1200 808 707 790 800 744 455 100
USA 1792 1919 1256 1125 940 582 58 6 8 75
Pakistan (est.) 45 45 45 45 45 45 45 45 45 45
Brazil 192 55 40 44 0 0 0 15 29 43
Iran (est.) 0 0 38 0 40 71 71 71 21 20
Czech Republic 215 193 155 138 0 0 0 0 0 0
Romania 77 77 77 50 0 0 0 0 0 0
France 5 3 2 0 0 0 0 0 0 0
Germany 27 33 0 0 0 0 0 0 0 0
Malawi 1132 369 0 0 0 0 0 0 0 0
Total world 59,331 56,041 60,304 63,207 60,514 54,154 54,742 47,731 47,808 49,355
tonnes U3O8 69,966 66,087 71,113 74,357 71,361 63,861 64,554 56,287 56,377 58,201
% of world demand 91% 85% 98% 96% 93% 80% 81% 74% 76% 74%

* Data from World Nuclear Association. NB: the figures in this table are liable to change as new data becomes available. Totals may not sum exactly due to rounding.

Mining methods have been changing. In 1990, 55% of world production came from underground mines, but this shrunk dramatically to 1999, with 33% then. From 2000 the new Canadian mines increased it again. In 2022 in situ leach (ISL, also called in situ recovery, ISR) mining accounted for over 55% of production:

Method tonnes U %
In situ leach (ISL) 27,773 56%
Underground & open pit (except Olympic Dam) 18,569 38%
By-product 3013 6%

Conventional mines have a mill where the ore is crushed, ground and then leached with sulfuric acid to dissolve the uranium oxides. At the mill of a conventional mine, or the treatment plant of an ISL operation, the uranium then separated by ion exchange before being dried and packed, usually as U3O8. Some mills and ISL operations (especially in the USA) use carbonate leaching instead of sulfuric acid, depending on the orebody. Where uranium is recovered as a by-product, e.g. of copper or phosphate, the treatment process is likely to be more complex.

During the 1990s the uranium production industry was consolidated by takeovers, mergers and closures, but this has diversified again with Kazakhstan’s multinational ownership structure. Over half of uranium mine production is from state-owned mining companies, some of which prioritize secure supply over market considerations. In 2022, the top 10 companies by production contributed over 90% of the world’s uranium production:

Uranium production by company 2022

Company tonnes U % of world total
Kazatomprom 11,373 23
Cameco 5675 12
Orano 5519 11
CGN 4627 10
Uranium One 4454 9
Navoi Mining 3300 7
CNNC 3247 7
BHP 2813 6
ARMZ 2508 5
General Atomics/Quasar 1740 4
Other 4098 6

    The largest-producing uranium mines in 2022

    Mine Country Main owner Type Production (tonnes U) % of world
    Cigar Lake Canada Cameco/Orano underground 6928 14
    Husab Namibia Swakop Uranium (CGN) open pit 3358 7
    Inkai, sites 1-3 Kazakhstan Kazatomprom/Cameco ISL 3201 7
    Olympic Dam Australia BHP Billiton by-product/underground 2813 6
    Karatau Budenovskoye 2 Kazakhstan Uranium One/Kazatomprom ISL 2560 5
    Rössing Namibia CNNC open pit 2255 5
    SOMAIR Niger Orano open pit 2020 4
    Four Mile Australia Quasar ISL 1740 3
    Central Mynkuduk Kazakhstan Ortalyk ISL 1650 3
    South Inkai 4 Kazakhstan Uranium One/Kazatomprom ISL 1600 3
    Top 10 total 28,125 57%

    Note 1: SMCC, a joint venture between Kazatomprom and Uranium One, reported combined production of 2225 tU in 2022 at its two mines, South Inkai 4 and Akdala.

    Note 2: KATCO, a joint venture between Kazatomprom and Orano, reported combined production of 2564 tU in 2022 across its two mines, Moinkum and Tortkuduk.

    World uranium production and reactor requirements (tonnes U) world-nuclear._rg

    Source: OECD-NEA, IAEA, World Nuclear Association.

    Uranium resources by country in 2021

    Country tonnes U % of world
    Australia 1,684,100 28%
    Kazakhstan 815,200 13%
    Canada 588,500 10%
    Russia 480,900 8%
    Namibia 470,100 8%
    South Africa 320,900 5%
    Niger 311,100 5%
    Brazil 276,800 5%
    China 223,900 4%
    Mongolia 144,600 2%
    Uzbekistan 131,200 2%
    Ukraine 107,200 2%
    Botswana 87,200 1%
    USA 59,400 1%
    Tanzania 58,200 1%
    Jordan 52,500 1%
    World total 6,078,500

    Identified resources recoverable (reasonably assured resources plus inferred resources), to $130/kg U, 1/1/21, from OECD NEA & IAEA, Uranium 2022: Resources, Production and Demand (‘Red Book’). The total recoverable identified resources to $260/kg U is 7.918 million tonnes U. 

    Source Acknowledgment: The information in the preceding section is derived from world-nuclear.org.

    Uranium Exploration in Australia

    Following requests from the British and United States governments, systematic exploration for uranium began in 1944.  In 1948 the Commonwealth government offered tax-free rewards for the discovery of uranium orebodies.  As a result, several significant discoveries were made 1949-56 by prospectors in northern Australia.  These were mined primarily for weapons programs at that time.

    The development of civil nuclear power stimulated a second wave of exploration activity in the late 1960s, and most of Australia’s major orebodies were discovered as a result.  This phase was marked by the involvement of major companies with large budgets and using advanced exploration techniques and equipment.  Stimulated by buoyant prices, exploration expenditure increased again after 1975 until political policy resisted new uranium development.  Exploration expenditure generally declined to the mid 1990s largely as a result of low uranium prices.  Australia’s known uranium resources have increased little since 1982.  Over the last 20 years, uranium exploration in Canada has proceeded strongly, resulting in their known resources increasing substantially.  In 2004, exploration in Australia started to ramp up again.

    Uranium in Argentina

    • The Argentine National Atomic Energy Commission (CNEA) explored for uranium across Argentina from the mid 1950-80’s resulting in 8 mines being developed
    • In the Chubut Province radiometric and EM surveys identified two large Cretaceous paleochannels in the San Jorge Basin which extend for over 200km N-S and 30-60km E-W
    • This early exploration was very successful with numerous uranium occurrences and deposits being discovered in the sandstone outcrop
    • Three high-grade uranium deposits were delineated
      1. Cerro Condor – open pit mine – outcropping  – 6000 ppm U3O8
      2. Los Adobes – open pit mine – outcropping – 1400 ppm U3O8, and
      3. Cerro Solo – depth 50-130m – 10mlb est. – 4000 ppm U3O8

    Top mining companies in Argentina

    Government support

    • Strong central government support and broadening community agreement to develop mining in the country
    • Validated by top global miners Newmont, Barrick and Arcadium all producing in Argentina and BHP, Lundin, Ganfeng and Rio Tinto investing and/or developing new projects

    Access to skilled workforce

    • Significant regional investment with access to skilled workforce and globally competitive cost structure
    • Excellent access to infrastructure

    Mining-geared legislative benefits

    • 100% income tax deductibility for prospecting and project feasibility works
    • Accelerated 3-year depreciation on plant construction and mining related equipment
    • 0% tax on capital goods and raw materials imported for mining purposes

    Strong uranium support

    • Government supportive of uranium exploration and development projects as it seeks to lower the costs of meeting its clean energy goals
    • 3 operating nuclear reactors and 1 under construction in Argentina

    3

    Current Operating Reactors

    1

    Reactors Under Construction

    Geology of uranium deposits

    Most of Australia’s uranium resources are in two kinds of orebodies, unconformity-related and breccia complex, while sedimentary deposits are less significant then overseas.

    Unconformity-related deposits arise from geological changes occurring close to major unconformities.  Below the unconformity, the metasedimentary rocks which host the mineralisation are usually faulted and brecciated.  The overlying younger Proterozoic sandstones are usually undeformed.

    Unconformity-related deposits constitute approximately 20% of Australia’s total uranium resources and 33% of the World Outside Centrally Planned Economies Area (WOCA)’s uranium resources and they include some of the largest and richest deposits.  Minerals are uraninite and pitchblende.  The main deposits occur in Canada (the Athabasca Basin, Saskatchewan and Thelon Basin, Northwest Territories); and Australia (the Alligator Rivers region in the Pine Creek Geosyncline, NT and Rudall Rivers area, WA).  In the Alligator Rivers region, the known deposits are below the unconformity and like their Canadian counterparts, are generally much lower grade.

    Uranium exploration in the Alligator Rivers region and Arnhem Land has been restricted since the late 1970s because of the political and environmental factors.  Much of the Alligator Rivers region and Arnhem Land have only been subjected to first pass exploration designed to detect outcropping deposits and extensions of known deposits.  There has been very little exploration to locate deeply concealed deposits lying above the unconformity similar to those in Canada.  It is possible that very high grade deposits occur in the sandstones above the unconformity in the Alligator Rivers / Arnhem Land area.

    The Kintyre deposit in the Rudall River area is similar to the deposits in the Alligator Rivers region.  Metallurgical tests have shown that Kintyre ore can be radiometrically sorted and upgraded prior to milling and processing.

    Breccia complex deposits – The Olympic Dam deposit is one of the world’s largest deposits of uranium, and accounts for about 66% of Australia’s reserves plus resources.  The deposit occurs in a hematite-rich granite breccia complex in the Gawler Craton.  It is overlain by approximately 300 metres of flat-lying sedimentary rocks of the Stuart Shelf geological province.

    The central core of the complex is barren hematite-quartz breccia, with several localised diatreme structures, flanked to the east and west by zones of intermingled hematite-rich breccias and granitic breccias.  These zones are approximately one kilometre wide and extend almost 5km in a northwest-southeast direction.  Virtually all the economic copper-uranium mineralisation is hosted by these hematite-rich breccias.  This broad zone is surrounded by granitic breccias extending up to 3km beyond the outer limits of the hematite-rich breccias.

    Details of the origin of the deposit are still uncertain.  However the principal mechanisms which formed the breccia complex are considered to have been hydraulic fracturing, tectonic faulting, chemical corrosion and gravity collapse.  Much of the brecciation occurred in near surface eruptive environment of a crater complex during eruptions caused by boiling and explosive interaction of water (from lake, sea or groundwater) with magma.

    Sandstone deposits – Sandstone uranium deposits occur in medium to coarse-grained sandstones deposited in a continental fluvial or marginal marine sedimentary environment. Impermeable shale/mudstone units are interbedded in the sedimentary sequence and often occur immediately above and below the mineralised sandstone.  Uranium precipitated under reducing conditions caused by a variety of reducing agents within the sandstone including: carbonaceous material (detrital plant debris, amorphous humate, marine algae), sulphides (pyrite, H2S), hydrocarbons (petroleum), and interbedded basic volcanics with abundant ferro-magnesian minerals (eg chlorite).

    The main types of sandstone deposits include rollfront deposits – arcuate bodies of mineralisation that crosscut sandstone bedding; tabular deposits – irregular, elongate lenticular bodies parallel to the depositional trend, deposits commonly occur in  palaeochannels incised into underlying basement rocks; and tectonic/lithologic deposits – occur in sandstones adjacent to a permeable fault zone.

    Sandstone deposits constitute about 18% of world uranium resources.  Orebodies of this type are commonly low to medium grade (0.05 – 0.4% U3O8) and individual orebodies are small to medium in size (ranging up to a maximum of 50 000 t U3O8).  The main primary uranium minerals are uraninite and coffinite.  Conventional mining / milling operations of sandstone deposits have been progressively undercut by cheaper in situ leach mining methods.

    Sandstone deposits represent only about 7% of Australia’s total resources of uranium.  Within the Frome Embayment, six uranium deposits are known, the largest being Beverley, Honeymoon, East Kalkaroo and Billaroo West-Gould Dam, all amenable to ISL mining methods.  Other deposits are Manyingee, Oobagooma, and Mulga Rock in WA and Angela, NT.  At Mulga Rock uranium mineralisation is in peat layers interbedded with sand and clay within a buried palaeochannel.

    Surficial deposits – Surficial uranium deposits are broadly defined as young (Tertiary to Recent) near-surface uranium concentrations in sediments or soils.  These deposits usually have secondary cementing minerals including calcite, gypsum, dolomite, ferric oxide, and halite.  Uranium deposits in calcrete are the largest of the surficial deposits.  Uranium mineralisation is in fine-grained surficial sand and clay, cemented by calcium and magnesium carbonates.

    Surficial deposits comprise about 4% of world uranium resources.  Calcrete deposits represent 5% of Australia’s total reserves and resources of uranium.  They formed where uranium-rich granites were deeply weathered in a semi-arid to arid climate.  The Yeelirrie deposit in WA is by far the world’s largest surficial deposit.  Other significant deposits in WA include Lake Way, Centipede, Thatcher Soak, and Lake Maitland.

    In WA, the calcrete uranium deposits occur in valley-fill sediments along Tertiary drainage channels, and in playa lake sediments.  These deposits overlie Archaean granite and greenstone basement of the northern portion of the Yilgarn Craton.  The uranium mineralisation is carnotite (hydrated potassium uranium vanadium oxide).

    Volcanic deposits – uranium deposits of this type occur in acid volcanic rocks and are related to faults and shear zones within the volcanics.  Uranium is commonly associated with molybdenum and fluorine.  These deposits make up only a small proportion of the world¹s uranium resources. Significant resources of this type occur in China, Kazakhstan, Russian Federation and Mexico.  In Australia, volcanic deposits are quantitatively very minor – Ben Lomond and Maureen in Qld are the most significant deposits.

    Intrusive deposits – included in this type are those associated with intrusive rocks including alaskite, granite, pegmatite, and monzonites.  Major world deposits include Rossing (Namibia), Ilimaussaq (Greenland) and Palabora (South Africa).  In Australia, the main ones are Radium Hill (SA) which was mined from 1954-62 (mineralisation was mostly davidite) and the large bodies of low grade mineralisation at Crocker Well and Mount Victoria in the Olary Province, SA.

    Metasomatite deposits – these occur in structurally-deformed rocks that were already altered by metasomatic processes, usually associated with the introduction of sodium, potassium or calcium into these rocks.  Major examples of this type include Espinharas deposit (Brazil) and the Zheltye Vody deposit (Ukraine).  Valhalla and Skal near Mount Isa are Australian examples.

    Metamorphic deposits – In Australia the largest of this type was Mary Kathleen uranium / rare earth deposit, 60km east of Mount Isa, Qld, which was mined 1958-63 and 1976-82.  The orebody occurs in a zone of calcium-rich alteration within Proterozoic metamorphic rocks.

    Uranium Minerals – The major primary ore mineral is uraninite (basically UO2) or pitchblende (U2O5.UO3, better known as U3O8), though a range of other uranium minerals is found in particular deposits.  These include carnotite (uranium potassium vanadate), the davidite-brannerite-absite type uranium titanates, and the euxenite-fergusonite-samarskite group (niobates of uranium and rare earths).

    A large variety of secondary uranium minerals is known, many are brilliantly coloured and fluorescent.  The commonest are gummite (a general term like limonite for mixtures of various secondary hydrated uranium oxides with impurities); hydrated uranium phosphates of the phosphuranylite type, including autunite (with calcium), saleeite (magnesian) and torbernite (with copper); and hydrated uranium silicates such as coffinite, uranophane (with calcium) and sklodowskite (magnesium).