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73-613: The mine produced the most economical uranium ore in the world and was used for the Manhattan Project and subsequent nuclear weapons produced by the United States in the 1940s and 50s. Before World War II, uranium extracted here was originally taken to Belgium to be processed; this supply was captured by the Wehrmacht in 1940 and subsequently used for the unsuccessful German nuclear program . The Shinkolobwe mine

146-541: A fold - fault . Uranium minerals, and associated cobalt , silver , nickel , bismuth and arsenic , occur as massive sulfide ore in veinlets along fractures , joints , and minor faults within the Katanga synclinorium . Uraninite mineralization occurred 630 Ma ago, when uraniferous solutions percolated into the dolomitic shales of the Precambrian Mine Series (Serie des Mines), under

219-451: A freak occurrence in nature. It contained a tremendously rich lode of uranium pitchblende . Nothing like it has ever again been found. The ore already in the United States contained 65 percent U 3 O 8 , while the pitchblende aboveground in the Congo amounted to a thousand tons of 65 percent ore, and the waste piles of ore contained two thousand tons of 20 percent U 3 O 8 . To illustrate

292-558: A garrison was also established, with a supporting NATO military base in Kamina . Jadotville became a security checkpoint for foreigners. However, by the time of Congo independence, Union Minière had sealed the mine with concrete. Despite the American presence in the 1940s and 1950s, the increased opening of uranium mines in the US and Congolese independence made the United States in 1960 leave

365-782: A large hematite -rich granite breccia complex in the Gawler Craton overlain by approximately 300 metres of flat-lying sedimentary rocks of the Stuart Shelf geological province. Another example for the breccia type is the Mount Gee area in the Mount Painter Inlier, South Australia. Uranium mineralised quartz-hematite breccia is related to Palaeoproterozoic granites with uranium contents of up to 100 ppm. Hydrothermal processes at about 300 million years ago remobilised uranium from these granites and enriched them in

438-694: A maximum of 50,000 t U 3 O 8 ). Sandstone hosted uranium deposits are widespread globally and span a broad range of host rock ages. Some of the major provinces and production centers include: Significant potential remains in most of these centers as well as in Australia, Mongolia, South America, and Africa. This model type can be further subdivided into the following sub-types: Many deposits represent combinations of these types. Tabular deposits consist of irregular tabular or elongate lenticular zones of uranium mineralisation within selectively reduced sediments. The mineralised zones are oriented parallel to

511-688: A request for information by the Group of Experts the Government of the United Republic of Tanzania has provided limited data on four shipments that were seized over the past 10 years. Unfortunately the Government chose not to provide information about the quantities of the seized consignments nor the specific method of smuggling. At least in reference to the last shipment from October 2005, the Tanzanian Government left no doubt that

584-706: A significant tonnage. Very large phosphorite deposits occur in Florida , Idaho , Morocco , and some middle eastern countries. Collapse breccia pipe deposits occur within vertical, circular solution collapse structures, formed by the dissolution of limestone by groundwater. Pipes are typically filled with down-dropped coarse fragments of limestone and overlying sediments and can be from 30 to 200 metres (100 to 660 ft) wide and up to 1,000 metres (3,300 ft) deep. Primary ore minerals are uraninite and pitchblende , which occur as cavity fills and coatings on quartz grains within permeable sandstone breccias within

657-473: Is fissile (will support a neutron-mediated chain reaction ). Uranium, thorium , and one radioactive isotope of potassium ( K ) as well as their decay products are the main elements contributing to natural terrestrial radioactivity. Cosmogenic radionuclides are of less importance, but unlike the aforementioned primordial radionuclides , which date back to the formation of the planet and have since slowly decayed away, they are replenished at roughly

730-550: Is another significant surficial deposit. Olen, Belgium Olen ( Dutch pronunciation: [ˈoːlə(n)] ) is a municipality located in the Belgian province of Antwerp . The municipality comprises three towns, situated on a south–north axis: In 2021, Olen had a total population of 12,600. The total area is 23.10 km . In the 1920s and 1930s the Union Minière du Haut Katanga company, operating in

803-495: Is dissolution of uranium from the formation or nearby strata and the transport of this soluble uranium into the host unit. When the fluids change redox state, generally in contact with carbon -rich organic matter, uranium precipitates to form a 'front'. The roll front subtype deposits typically represent the largest of the sandstone-hosted uranium deposits and one of the largest uranium deposit types with an average of 21 million lb (9,500 t) U 3 O 8 . Included in this class are

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876-566: Is especially concentrated along thin carbonaceous seams or carbon leaders. Strong regional scale alteration consists of pyrophyllite , chloritoid , muscovite , chlorite , quartz, rutile , and pyrite . The main elements associated with the uranium are gold and silver. Gold contents are much higher than in the Elliot Lake type with U:Au ranging between 5:1 and 500:1, which indicates that these gold-rich ores are essentially very low grade uranium deposits with gold. Sedimentological controls on

949-482: Is far from ideal, as it does not consider that similar processes may form many deposit types, yet in a different geological setting. The following table groups the above deposit types based on their environment of deposition. Unconformity -type uranium deposits host high grades relative to other uranium deposits and include some of the largest and richest deposits known. They occur in close proximity to unconformities between relatively quartz -rich sandstones comprising

1022-503: Is in fuel for nuclear reactors . Globally, the distribution of uranium ore deposits is widespread on all continents, with the largest deposits found in Australia, Kazakhstan , and Canada. To date, high-grade deposits are only found in the Athabasca Basin region of Canada. Uranium deposits are generally classified based on host rocks, structural setting, and mineralogy of the deposit. The most widely used classification scheme

1095-438: Is in the development stage at Patterson Lake (Triple R deposit) with an estimated mineral resource identified as; "Indicated Mineral Resources" estimated to total 2,291,000 tons at an average grade of 1.58% U 3 O 8 containing 79,610,000 pounds of U 3 O 8 . "Inferred Mineral Resources" are estimated to total 901,000 tons at an average grade of 1.30% U 3 O 8 containing 25,884,000 pounds of U 3 O 8 . The deposits of

1168-449: Is nonexistent to very weak at best, and the weak chlorite and sericite are believed to be mainly post-ore effects. Other post-depositional alteration includes pyritization , silicification , and alteration of titanium minerals. The most prominent geochemical associations with the uranium are thorium and titanium. This schematic model represents the original depositional setting. The Huronian underwent mild post-depositional folding during

1241-455: Is one of the most common elements in Earth's crust, being 40 times more common than silver and 500 times more common than gold . It can be found almost everywhere in rock, soil, rivers, and oceans. The challenge for commercial uranium extraction is to find those areas where the concentrations are adequate to form an economically viable deposit. The primary use for uranium obtained from mining

1314-927: Is only naturally formed in supernova explosions. The primary uranium ore mineral is uraninite (UO 2 ) (previously known as pitchblende). A range of other uranium minerals can be found in various deposits. These include carnotite , tyuyamunite , torbernite and autunite . The davidite - brannerite - absite type uranium titanates, and the euxenite - fergusonite - samarskite group are other uranium minerals. A large variety of secondary uranium minerals are known, many of which are brilliantly coloured and fluorescent. The most common are gummite (a mixture of minerals), autunite (with calcium ), saleeite ( magnesium ) and torbernite (with copper ); and hydrated uranium silicates such as coffinite , uranophane (with calcium) and sklodowskite (magnesium). There are several themes of uranium ore deposit formation, which are caused by geological and chemical features of rocks and

1387-423: Is similar to that for roll front deposits except that the source of uranium may be in the watershed leading into a stream or in the bed load of the palaeochannel. This uranium is transported through groundwater and is deposited either at a reduced boundary or in ephemeral drainage systems such as those in deserts of Namibia and Australia; it is deposited in calcretised evaporation sites or even in saline lakes as

1460-606: Is the largest deposit of this class). These deposits are hosted in palaeochannels filled with Cenozoic sediments and sourced their uranium from uranium-rich Paleoproterozoic to Mesoproterozoic rocks of the Mount Painter Inlier and the Olary Domain of the Curnamona Province. Tectonic-lithologic controlled uranium deposits occur in sandstones adjacent to a permeable fault zone which cuts

1533-457: The Athabasca Basin in Canada, including the two largest high grade uranium deposits in the world, Cigar Lake with 217 million pounds (99,000 t) U 3 O 8 at an average grade of 18% and McArthur River with 324 million pounds (147,000 t) U 3 O 8 at an average grade of 17%. These deposits occur below, across and immediately above the unconformity. Additionally, another high grade discovery

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1606-646: The Inkai deposit in Kazakhstan and the Smith Ranch deposit in Wyoming. Probably more significant than their larger size, roll front deposits have the advantage of being amenable to low cost in situ leach recovery. Typical characteristics: Basal channel deposits are often grouped with tabular or roll front deposits, depending on their unique characteristics. The model for formation of palaeochannel deposits

1679-613: The McArthur River basin in the East Alligator Rivers region of the Northern Territory of Australia (including Jabiluka , Ranger , and Nabarlek ) are below the unconformity and are at the low-grade end of the unconformity deposit range but are still high grade compared to most uranium deposit types. There has been very little exploration in Australia to locate deeply concealed deposits lying above

1752-755: The Penokean orogeny around 1.9 billion years. The main regional structure is the Quirke syncline along the margins of which the majority of the known deposits are situated. Ore bodies range from subhorizontal to steeply dipping . Only one iron oxide copper gold ore deposit is known to contain economically significant quantities of uranium. Olympic Dam in South Australia is the world's largest resource of low-grade uranium and accounts for about 66% of Australia's reserves plus resources. Uranium occurs with copper, gold, silver, and rare-earth elements in

1825-542: The Variscan orogeny , extension took place and hydrothermal fluids overprinted fine grained materials in shear zones with a sulfide-chlorite alteration. Fluids from the overlying sediments entered the basement mobilising uranium and while uprising on the shear zone, the chlorite-pyrite material caused precipitation of uranium minerals in form of coffinite, pitchblende and U-Zr-silicates. This initial mineralisation event took place at about 277 million to 264 million years. During

1898-520: The atomic bomb in World War II. Edgar Sengier , then director of Union Minière du Haut Katanga , had stockpiled 1,200 tonnes of uranium ore in a warehouse on Staten Island , New York. This ore and an additional 3,000 tonnes of ore stored above-ground at the mine was purchased by Colonel Ken Nichols for use in the project. Nichols wrote: Our best source, the Shinkolobwe mine, represented

1971-610: The Belgian mining company Union Minière . The company collaborated with Mossad in shipping out the ore from Antwerp to Genoa for a European front company which then surreptitiously transferred the ore to another vessel at night on the Mediterranean Sea. The mine was officially closed on January 28, 2004, by presidential decree. However, eight people died and a further thirteen people were injured in July 2004, when part of

2044-601: The Czech Republic. Also they are closely related to the granites, the mineralization is much younger with a time gap between granite formation and mineralisation of 20 million years. The initial uranium mineralisation consists of quartz, carbonate , fluorite and pitchblende. Remobilisation of uranium occurred at later stages producing polymetal veins containing silver, cobalt , nickel , arsenic and other elements. Large deposits of this type can contain more than 1,000 individual mineralized veins. However, only 5 to 12% of

2117-640: The Huronian deposits appear to be much stronger than in the Witwatersrand deposits. Ores grade from uranium through thorium to titanium -rich with decreasing pebble size and increasing distance from their source. While evidence of post- diagenetic remobilization has been identified, these effects appear far subordinate to the sedimentological controls. Ore consists of uraninite with lesser brannerite and thucholite. These occur in thin beds exhibiting graded bedding reminiscent of placer sorting. Alteration

2190-485: The Huronian deposits are situated at the base of the sequence, whereas the mineralized horizons at Witwatersand are arguably along tectonized intraformational unconformities. Uranium minerals were derived from uraniferous pegmatites in the sediment source areas. These deposits are restricted to the Archean and early Paleoproterozoic and do not occur in sediments younger than about 2,200 million years when oxygen levels in

2263-1227: The Katanga stratigraphic column consists, top to bottom, of the Precambrian Kundelungu System (Upper, Middle and Lower), the Grand Conglomerate and Mwashya Systems, the Schist-Dolomite System (Roan System-Mine Series of R.G.S., C.M.N., S.D., R.S.C., R.S.F., D. Strat., R.A.T. Gr., and R.A.T.) and the Kibara Group. Uraninite crystals from 1 to 4 centimeter cubes were common. New minerals identified here include ianthinite , becquerelite , schoepite , curite , fourmarierite , masuyite , vandendriesscheite , richetite , billietite , vandenbrandeite , kasolite , soddyite , sklodowskite , cuprosklodowskite , dewindtite , dumontite , renardite , parsonsite , saleite , sharpite , studtite , and diderichite . Similar uraninite deposits occur 36 km (22.4 mi) west at Swampo, and 120 km (74.6 mi) west at Kalongwe. Surface ores consist of oxidized minerals from supergene alteration above

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2336-609: The Precambrian to the Cenozoic, but because of the shallow levels at which they form, preservation favors younger age deposits. Some of the more important deposits or districts are Streltsovskoye, Russia ; Dornod, Mongolia ; and McDermitt, Nevada . The average deposit size is rather small with grades of 0.02% to 0.2% U 3 O 8 . These deposits make up only a small proportion of the world's uranium resources. The only volcanic hosted deposits currently being exploited are those of

2409-908: The Roche Argilotalqueuse (R.A.T.) nappe . The Mine Series is a Schist - Dolomite System postulated to be in the Roan System. This schistose-dolomite appears structurally between two contacts of the Kundelungu System, the Middle Kundelungu and the Lower Kundelungu, of the Katanga Group. The Lower and Upper Kundelungu form a double syncline, the northern limb of which overlies the Shinkolobwe Fault. These structural complexities aside,

2482-613: The Shinkolobwe mine: 149. During an investigation into alleged smuggling of radioactive materials, the Group of Experts has learned that such incidents are far more frequent than assumed. According to Congolese experts on radioactive materials, organs of State security have, during the past six years, confiscated over 50 cases containing uranium or cesium in and around Kinshasa . The last significant incident occurred in March 2004 when two containers with over 100 kilograms of stable uranium-238 and uranium-235 were secured. 150. In response to

2555-594: The Streltsovkoye district of eastern Siberia . This is in fact not a single stand-alone deposit, but 18 individual deposits occurring within the Streltsovsk caldera complex. Nevertheless, the average size of these deposits is far greater than the average volcanic type. Surficial deposits are broadly defined as Tertiary to Holocene near-surface uranium concentrations in sediments or soils. Mineralization in calcrete ( calcium and magnesium carbonates ) are

2628-871: The Triassic a further mineralisation event took place relocating uranium into quartz-carbonate-uranium veins. Another example of this mineralisation style is the Shinkolobwe deposit in Congo containing about 30,000 t of uranium. Intrusive deposits make up a large proportion of the world's uranium resources. Included in this type are those associated with intrusive rocks including alaskite , granite , pegmatite and monzonites . Major world deposits include Rossing ( Namibia ), Ilimaussaq intrusive complex ( Greenland ) and Palabora ( South Africa ). Marine sedimentary phosphorite deposits can contain low grade concentrations of uranium, up to 0.01–0.015% U 3 O 8 , within fluorite or apatite . These deposits can have

2701-640: The UN report of July 18, 2006. It gives "Tanzanian customs officials" as its sole source for the claim that the uranium was destined for processing in the former Soviet republic of Kazakhstan via the Iranian port of Bandar Abbas . American journalist Douglas Farah has compared this to North Korean attempts to get uranium from the same mine. Uranium ore Uranium ore deposits are economically recoverable concentrations of uranium within Earth's crust . Uranium

2774-558: The US by Sengier's African Metals Corp., a commercial arm of Union Minière. After the September 1942 agreement with Nichols, an average of 400 tons of uranium oxide was then shipped to the US each month. Initially, the port of Lobito was used to ship the ore, but later Matadi was used to improve security. Only two shipments were lost at sea. The aerodromes in Elizabethville and Leopoldville were also expanded. Additionally,

2847-622: The Witwatersrand deposits, ores are found along unconformities, shale and siltstone beds, and carbonaceous seams. The West Rand Group of sediments tend to host the most uranium within the Witwatersrand Supergroup. The uranium rich Dominion Reef is located at the base of the West Rand Supergroup. The Vaal Reef is the most uranium rich reef of the Central Rand Group of sediments. Structural controls on

2920-612: The atmosphere reached a critical level, making simple uranium oxides no longer stable in near-surface environments. Quartz pebble conglomerate uranium deposits are typically low grade but characterized by high tonnages. The Huronian deposits generally contain higher grades (0.15% U 3 O 8 ) and greater resources (as shown by the Denison and Quirke mines), however some of the Witwatersand gold deposits also contain sizeable low grade (0.01% U 3 O 8 ) uranium resources. In

2993-621: The basal portion of relatively undeformed sedimentary basins and deformed metamorphic basement rocks . These sedimentary basins are typically of Proterozoic age, however some Phanerozoic examples exist. Phanerozoic unconformity-related deposits occur in Proterozoic metasediments below an unconformity at the base of overlying Phanerozoic sandstone. These deposits are small and low-grade (e.g., Bertholene and Aveyron deposits in France). The highest grade uranium deposits are found in

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3066-477: The context of poverty alleviation is essential to address this problem and avoid further human and environmental catastrophes. On July 18, 2006, the DRC Sanctions Committee ( United Nations Security Council Committee Established Pursuant to Resolution 1533 (2004), to give it its full name) released a report dated June 15, 2006, which stated that artisanal mining for various minerals continues at

3139-521: The direction of groundwater flow, but on a small scale the ore zones may cut across sedimentary features of the host sandstone. Deposits of this nature commonly occur within palaeochannels cut in the underlying basement rocks. Tabular sandstone uranium deposits contain many of the highest grades of the sandstone class, however the average deposit size is very small. Roll-front uranium deposits are generally hosted within permeable and porous sandstones or conglomerates . The mechanism for deposit formation

3212-405: The element uranium. The basic themes of uranium ore genesis are host mineralogy, reduction-oxidation potential , and porosity . Uranium is a highly soluble and radioactive heavy metal . It can be easily dissolved, transported and precipitated within groundwater by subtle changes in oxidation conditions. Uranium does not usually form very insoluble mineral species, which is a further factor in

3285-492: The largest of the surficial deposits. They are interbedded with Tertiary sand and clay, which are usually cemented by calcium and magnesium carbonates. Surficial deposits also occur in peat bogs , karst caverns and soils. Surficial deposits account for approximately 4% of world uranium resources. The Yeelirrie deposit is by far the world's largest surficial deposit, averaging 0.15% U 3 O 8 . Langer Heinrich in Namibia

3358-602: The late phase of magmatic activity when hot fluids derived from the magma precipitate uranium on cracks within the newly formed granite. Such mineralisation contributed much to the uranium production of France. Veins hosted by metasedimentary units in the exocontact of granites are the most important sources of uranium mineralisation in central Europe including the world class deposits Schneeberg-Schlema-Alberoda in Germany (96,000 t uranium content) as well as Pribram (50,000 t uranium content) and Jachymov (~10,000 t uranium content) in

3431-554: The mine was reopened with the help of the United States Army Corps of Engineers , which involved draining the water and retooling the facility. Finally, the Office of Strategic Services were enlisted to deal with the threat of smuggling to Germany. American interest in the Shinkolobwe mine for the purpose of developing of nuclear weapons led to the implementation of extensive security measures. Shinkolobwe's location

3504-483: The mine's operation, from unofficial sources. In 1950, a uranium processing plant was said to be under construction near the mine. At the time, Shinkolobwe was believed to contain roughly half of the world's known reserves of uranium. In 1947, the US received 1,440 tons of uranium concentrates from the Belgian Congo, 2,792 in 1951, and 1,600 in 1953. A processing plant was added nearby, and for increased security,

3577-578: The mine, which caused the sealing of the mine by Union Minière. In what was termed Operation Plumbat , Israel, in 1968, obtained yellowcake (processed uranium ore ) to support the Israeli nuclear weapons effort in a clandestine operation after France stopped supplying it with uranium fuel for the Dimona nuclear reactor in reaction to the 1967 Arab-Israeli War . Numerous sources believe that in 1968 Israel managed to obtain 200 tonnes of yellowcake from

3650-511: The mine. The UNEP/OCHA concluded: Shinkolobwe is representative of similar situations in Africa and elsewhere in the developing world. A strong link exists between rural poverty, environmental protection and this type of livelihood activity. Alternative income opportunities must be developed and integrated in parallel to artisanal exploitation if new livelihood options are to be found for these rural poor. A holistic, multidisciplinary approach within

3723-556: The old mine collapsed . Although industrial production has ceased with cement lids sealing off the mine shafts, there is evidence that some artisanal mining still goes on here. A United Nations inter-agency mission, led by the UN Office for Coordination of Humanitarian Affairs (OCHA) and the United Nations Environment Programme (UNEP), and organised through their Joint Environment Unit, visited

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3796-496: The ore still "on the docks". However, of the 1200 tons confiscated, the Alsos Mission was able to recover most of this uranium in 1945. Open-cut operations restarted in 1944, and underground in 1945, which required pumping the mine dry since the water table was at about 45 m. The 255 m level was reached in 1955. The United States used Shinkolobwe's uranium resources to supply the Manhattan Project to construct

3869-642: The pipe. Resources within individual pipes can range up to 2500 tonnes U 3 O 8 at an average grade of between 0.3 and 1.0% U 3 O 8 . The best known examples of this deposit type are in the Arizona breccia pipe uranium mineralization in the US, where several of these deposits have been mined. Volcanic deposits occur in felsic to intermediate volcanic to volcaniclastic rocks and associated caldera subsidence structures, comagmatic intrusions, ring dykes and diatremes . Mineralization occurs either as structurally controlled veins and breccias discordant to

3942-423: The quartz-hematite breccias. The breccias in the area host a low grade resource of about 31,400 t U 3 O 8 at 615 ppm in average. Vein deposits play a special role in the history of uranium: the term "pitchblende" (" pechblende ") originates from German vein deposits when they were mined for silver in the 16th century. Franz Ernst Brückmann made the first mineralogical description of the mineral in 1727, and

4015-464: The regional scale are normal faults while on the deposit scale are bedding parallel shears and thrusts. Textural evidence indicates that the uranium and gold have been remobilized to their current sites; however the debate continues if the original deposition was detrital or was entirely hydrothermal, or alternatively related to high grade diagenesis . Uranium minerals are typically uraninite with lesser uranothorite, brannerite, and coffinite. The uranium

4088-404: The same rate they decay by the bombardment of Earth with cosmic rays . Uranium has the highest atomic weight of the naturally occurring elements and is approximately 70% denser than lead , but it is not as dense as tungsten , gold , platinum , iridium , or osmium . It is always found combined with other elements. Along with all elements having atomic weights higher than that of iron , it

4161-501: The sandstone/mudstone sequence. Mineralisation forms tongue-shaped ore zones along the permeable sandstone layers adjacent to the fault. Often there are mineralised zones 'stacked' vertically on top of each other within sandstone units adjacent to the fault zone. Quartz pebble conglomerate hosted uranium deposits are of historical significance as the major source of primary production for several decades after World War II . This type of deposit has been identified in eight localities around

4234-632: The sedimentary sequence and often occur immediately above and below the mineralised horizon. Uranium is mobile under oxidising conditions and precipitates under reducing conditions, and thus the presence of a reducing environment is essential for the formation of uranium deposits in sandstone. Primary mineralization consists of pitchblende and coffinite, with weathering producing secondary mineralization. Sandstone deposits constitute about 18% of world uranium resources. Orebodies of this type are commonly low to medium grade (0.05–0.4% U 3 O 8 ) and individual orebodies are small to medium in size (ranging up to

4307-507: The stratigraphy and less commonly as stratabound mineralization either in extrusive rocks or permeable sedimentary facies . Mineralization may be primary, that is magmatic-related or as secondary mineralization due to leaching, remobilization and re-precipitation. The principal uranium mineral in volcanic deposits is pitchblende, which is usually associated with molybdenite and minor amounts of lead, tin and tungsten mineralization. Volcanic hosted uranium deposits occur in host rocks spanning

4380-588: The then Belgian colony of Congo , had a virtual monopoly of the world uranium market (holding most of the deposits known at the time). The uranium mined in Congo was mostly transported to the UMHK refinery for uranium ore which was located in Olen. Some 1200 tonnes of uranium stored at the Olen refinery were captured by the Germans during the invasion and occupation of Belgium in 1940, and only recovered by US troops at

4453-483: 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. Sandstone deposits are contained within medium to coarse-grained sandstones deposited in a continental fluvial or marginal marine sedimentary environment . Impermeable shale or mudstone units are interbedded in

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4526-519: The uniqueness of Sengier's stockpile, after the war the MED and the AEC considered ore containing 0.3 percent as a good find. Without Sengier's foresight in stockpiling ore in the United States and aboveground in Africa, we simply would not have had the amounts of uranium needed to justify building the large separation plants and the plutonium reactors. In 1940, 1,200 tons of stockpiled uranium ore were shipped to

4599-563: The uranium was transported from Lubumbashi by road through Zambia to the United Republic of Tanzania. Attempts via Interpol to learn the precise origin within the Democratic Republic of the Congo have remained inconclusive. On August 9, 2006, the British Sunday Times published a report claiming that Iran was seeking to import "bomb-making uranium" from the Shinkolobwe mine, providing no evidence but quoting

4672-551: The vein areas carry mineralization and although massive lenses of pitchblende can occur, the overall ore grade is only about 0.1% uranium. The Bohemian Massif contains shear zone hosted uranium deposits with the most important one being Rozna-Olsi in Moravia northwest of Brno . Rozna is currently the only operating uranium mine in central Europe with a total uranium content of 23,000 t and an average grade of 0.24%. The formation of this mineralisation occurred in several stages. After

4745-701: The vein deposit Jachymov in the Czech Republic became the type locality for uraninite. In 1789 German chemist Martin Heinrich Klaproth discovered the element uranium in a sample of pitchblende from the Johanngeorgenstadt vein deposit. The first industrial production of uranium was made from the Jachymov deposit, and Marie and Pierre Curie used the tailings of the mine for their discovery of polonium and radium . Vein deposits consist of uranium minerals filling in cavities such as cracks, veins, fractures, breccias, and stockworks associated with steeply dipping fault systems. There are three major subtypes of vein style uranium mineralisation: Intragranitic veins form in

4818-492: The water evaporates. Some particularly rich uranium deposits are formed in palaeochannels which are filled in the lower parts by lignite or brown coal , which acts as a particularly efficient reductive trap for uranium. Sometimes, elements such as scandium , gold and silver may be concentrated within these lignite-hosted uranium deposits. The Frome Embayment in South Australia hosts several deposits of this type including Honeymoon , Oban, Beverley and Four-Mile (which

4891-426: The water table and the formation of uranyl minerals. Below the water table, hypogene ores include uraninite (pitchblende), cobalt-nickel sulfides and selenides . The first mine was opened in the Belgian Congo in 1921. Uranium-bearing ore was initially exported to Olen, Belgium for the extraction of radium , and uranium. Only the richest ore was sent to Olen, with the remainder held in reserve. Open-cut mining

4964-762: The wide variety of geological conditions and places in which uranium mineralization may accumulate. Uranium is an incompatible element within magmas , and as such it tends to become accumulated within highly fractionated and evolved granite melts, particularly alkaline examples. These melts tend to become highly enriched in uranium, thorium and potassium, and may in turn create internal pegmatites or hydrothermal systems into which uranium may dissolve. The International Atomic Energy Agency (IAEA) assigns uranium deposits to 15 main categories of deposit types, according to their geological setting and genesis of mineralization, arranged according to their approximate economic significance. The IAEA classification scheme works well but

5037-632: The world. The most significant deposits are in the Huronian Supergroup in Elliot Lake , Ontario , Canada and in the Witwatersrand Supergroup of South Africa . These deposits make up approximately 13% of the world's uranium resources. Quartz pebble conglomerate hosted uranium deposits formed from the transport and deposition of uraninite in a fluvial sedimentary environment and are defined as stratiform and stratabound placer deposits . Host rocks are typically submature to supermature, polymictic conglomerates and sandstones deposited in alluvial fan and braided stream environments. The host conglomerates of

5110-422: Was developed by the International Atomic Energy Agency and subdivides deposits into 15 categories. Uranium is a silvery-gray, weakly radioactive metallic chemical element . It has the chemical symbol U and atomic number 92. The most common isotopes in natural uranium are U (99.274%) and U (0.711%). All uranium isotopes present in natural uranium are radioactive and fissionable , and U

5183-419: Was officially closed in 2004. The mine's name was taken from the long-gone nearby village of Shinkolobwe. It is also slang for "a man who is easygoing on the surface but who becomes angry when provoked". The mineral deposits at Shinkolobwe were discovered in 1915 by the English geologist Robert Rich Sharp (1881–1960). The formations of the Shinkolobwe ore deposit form a spur of the Mine Series wedged into

5256-586: Was removed from maps and journalists were denied access to the mine and official information. Just as a lack of uranium ore impeded the German and Japanese attempts to make an atomic bomb, the Americans wanted to maintain their monopoly against the Soviets. Security measures were slightly more relaxed in the wake of World War II, but in the 1950s, most journalists were able to gather only scraps of information on

5329-538: Was suspended at level 57 m (187.0 ft) and at the level 79 m (259.2 ft) underground in 1936, though exploration had commenced at level 114 m (374.0 ft), and water pumps installed at level 150 m (492.1 ft). Both Britain and France expressed interest in the Belgium inventory of uranium ore in 1939. Nothing further happened though after the Nazis occupied Belgium in 1940 and got control of

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