Misplaced Pages

#161838

80-607: The Nabarlek Mine is a uranium mine in the Northern Territory of Australia which was productively worked only in 1979. The deposit sits within the Alligator Rivers Uranium Field approximately 62 kilometres (39 mi) northeast of Jabiru . It was discovered by Queensland Mines Limited in 1970 by following up an intense airborne radiometric anomaly . Prospecting rights over the future mine were first obtained by Gwendolyne Stevens ,

160-401: A reagent , heat, or simply washing with water. A summary of various leaching processes and their respective laboratory tests can be viewed in the following table: Some recent work has been done to see if organic acids can be used to leach lithium and cobalt from spent batteries with some success. Experiments performed with varying temperatures and concentrations of malic acid show that

240-677: A South Australian nurse and sheep farmer who had developed an interest in geology. She obtained rights over 1,282 square miles (3,320 km) of the Oenpelli Aboriginal reserve and named the area " nabarlek " after a local marsupial species. She negotiated an exploration program with Queensland Mines Limited, a subsidiary of Kathleen Investments Limited which owned the Mary Kathleen uranium mine in Queensland. Both companies were publicly listed, although Kathleen Investments

320-504: A functional group ( amidoxime group ) that selectively adsorbs heavy metals, and the performance of such adsorbents has been improved. Uranium adsorption capacity of the polymer fiber adsorbent is high, approximately tenfold greater in comparison to the conventional titanium oxide adsorbent. One method of extracting uranium from seawater is using a uranium-specific nonwoven fabric as an adsorbent. The total amount of uranium recovered from three collection boxes containing 350 kg of fabric

400-520: A leaching solution is pumped down drill holes into the uranium ore deposit where it dissolves the ore minerals. The uranium-rich fluid is then pumped back to the surface and processed to extract the uranium compounds from solution. In conventional mining, ores are processed by grinding the ore materials to a uniform particle size and then treating the ore to extract the uranium by chemical leaching . The milling process commonly yields dry powder-form material consisting of natural uranium, " yellowcake ", which

480-436: A method of extraction that does not produce the same occupational hazards, or mine tailings, as conventional mining. With regulations in place to ensure the use of high volume ventilation technology if any confined space uranium mining is occurring, occupational exposure and mining deaths can be largely eliminated. The Olympic Dam and Canadian underground mines are ventilated with powerful fans with radon levels being kept at

560-455: A sandstone body. Peneconcordant sandstone uranium deposits, also called Colorado Plateau –type deposits, most often occur within generally oxidized sandstone bodies, often in localized reduced zones, such as in association with carbonized wood in the sandstone. Precambrian quartz-pebble conglomerate-type uranium deposits occur only in rocks older than two billion years old. The conglomerates also contain pyrite. These deposits have been mined in

640-467: A very low to practically "safe level" in uranium mines. Naturally occurring radon in other, non-uranium mines, also may need control by ventilation. Heap leaching is an extraction process by which chemicals (usually sulfuric acid ) are used to extract the economic element from ore which has been mined and placed in piles on the surface. Heap leaching is generally economically feasible only for oxide ore deposits. Oxidation of sulfide deposits occurs during

720-464: A wastewater product/ raw materials. In the field of mineralogy, acid leaching is common to extract Metals such as vanadium, Cobalt, Nickel, Manganese, Iron etc. from raw materials/ reused materials. In recent years, there has been more attention given to metal leaching to recover precious metals from waste materials. For example, the extraction of valuable metals from wastewater. Due to the assortment of leaching processes there are many variations in

800-676: Is a naturally occurring process which scientists have adapted for a variety of applications with a variety of methods. Specific extraction methods depend on the soluble characteristics relative to the sorbent material such as concentration, distribution, nature, and size. Leaching can occur naturally seen from plant substances (inorganic and organic), solute leaching in soil, and in the decomposition of organic materials. Leaching can also be applied affectedly to enhance water quality and contaminant removal, as well as for disposal of hazardous waste products such as fly ash , or rare earth elements (REEs). Understanding leaching characteristics

880-459: Is concluded. Land reclamation after mining takes different routes, depending on the amount of material removed. Due to the high energy density of uranium, it is often sufficient to fill in the former mine with the overburden, but in case of a mass deficit exceeding the height difference between the previous surface level and the natural water table, artificial lakes develop when groundwater removal ceases. If sulfites, sulfides or sulfates are present in

SECTION 10

#1732773245162

960-406: Is controlled largely by the hydraulic conductivity of the soil, which is dependent on particle size and relative density that the soil has been consolidated to via stress. Diffusion is controlled by other factors such as pore size and soil skeleton, tortuosity of flow path, and distribution of the solvent (water) and solutes. Leaching can sometimes be used to extract valuable materials from

1040-435: Is extensively used to suppress airborne dust levels. Groundwater is an issue in all types of mining, but in open pit mining, the usual way of dealing with it – i.e. when the target mineral is found below the natural water table – is to lower the water table by pumping off the water. The ground may settle considerably when groundwater is removed and may again move unpredictably when groundwater is allowed to rise again after mining

1120-404: Is highly dependent on the characteristics of the soil, which makes modeling efforts difficult. Most leaching comes from infiltration of water, a washing effect much like that described for the leaching process of biological substances. The leaching is typically described by solute transport models, such as Darcy's Law , mass flow expressions, and diffusion -dispersion understandings. Leaching

1200-453: Is home to approximately 500 mineralized breccia pipes and Cripple Creek, Colorado, also is a site that contains breccia pipe ore deposits that is associated with a volcanic pipe. Olympic Dam mine , the world's largest uranium deposit, was discovered by Western Mining Corporation in 1975 and is owned by BHP . Uranium prospecting is similar to other forms of mineral exploration with the exception of some specialized instruments for detecting

1280-541: Is if pesticides are leached and carried through stormwater runoff ,; this is not only necessary to plant health, but it is important to control because pesticides can be toxic to human and animal health. Bioleaching is a term that describes the removal of metal cations from insoluble ores by biological oxidation and complexation processes. This process is done in most part to extract copper , cobalt , nickel , zinc , and uranium from insoluble sulfides or oxides . Bioleaching processes can also be used in

1360-484: Is important in preventing or encouraging the leaching process and preparing for it in the case where it is inevitable. In an ideal leaching equilibrium stage, all the solute is dissolved by the solvent, leaving the carrier of the solute unchanged. The process of leaching however is not always ideal, and can be quite complex to understand and replicate, and often different methodologies will produce different results. There are many types of leaching scenarios; therefore,

1440-399: Is in principle no different from any other hard rock mining and other ores are often mined in association (e.g., copper, gold, silver). Once the ore body has been identified a shaft is sunk in the vicinity of the ore veins, and crosscuts are driven horizontally to the veins at various levels, usually every 100 to 150 metres. Similar tunnels, known as drifts, are driven along the ore veins from

1520-432: Is now the accepted leading technique for uranium prospecting with worldwide applications for geological mapping, mineral exploration & environmental monitoring . Airborne gamma-ray spectrometry used specifically for uranium measurement and prospecting must account for a number of factors like the distance between the source and the detector and the scattering of radiation through the minerals, surrounding earth and even in

1600-534: Is nowadays commonly sold on the uranium market as U 3 O 8 . While some nuclear power plants – most notably heavy water reactors like the CANDU – can operate with natural uranium (usually in the form of uranium dioxide ), the vast majority of commercial nuclear power plants and many research reactors require uranium enrichment , which raises the content of U from the natural 0.72% to 3–5% (for use in light water reactors ) or even higher , depending on

1680-441: Is practically limitless with respect to world-wide demand. That is to say, if even a portion of the uranium in seawater could be used the entire world's nuclear power generation fuel could be provided over a long time period. Some proponents claim this statistic is exaggerated. Although research and development for recovery of this low-concentration element by inorganic adsorbents such as titanium oxide compounds has occurred since

SECTION 20

#1732773245162

1760-434: Is used for thinner, flatter ore bodies. In this method the ore body is first divided into blocks by intersecting drives, removing ore while so doing, and then systematically removing the blocks, leaving enough ore for roof support. The health effects discovered from radon exposure in unventilated uranium mining prompted the switch away from uranium mining via tunnel mining towards open cut and in-situ leaching technology,

1840-691: The Blind River – Elliot Lake district of Ontario, Canada, and from the gold-bearing Witwatersrand conglomerates of South Africa. Unconformity-type deposits make up about 33% of the World Outside Centrally Planned Economies Areas' (WOCA) uranium deposits. Hydrothermal uranium deposits encompass the vein-type uranium ores. Vein-type hydrothermal uranium deposits represent epigenetic concentrations of uranium minerals that typically fill breccias, fractures, and shear zones. Many studies have sought to identify

1920-1334: The Elkon mine at 71,300 tU, the Brazilian Itataia complex at 67,240 tU, the Marenica project at 62,856 tU, the Langer Heinrich Mine at 60,830 tU, the Dominion mine at 55,753 tU, the Inkai Uranium Project at 51,808 tU, the Kiggavik project at 51,574 tU, the Rössing mine at 50,657 tU, the Australian Yeleerie project at 44,077, and the Trekkopje mine at 42,243 tU. Many different types of uranium deposits have been discovered and mined. There are mainly three types of uranium deposits including unconformity-type deposits, namely paleoplacer deposits and sandstone-type, also known as roll front type deposits. Uranium deposits are classified into 15 categories according to their geological setting and

2000-1114: The Olympic Dam mine at 2981 tU, the Arlit mine at 1808 tU, the Rabbit Lake mine at 1400 tU, the Akouta mine at 1435 tU, and the McClean Lake mine at 1400 tU. The world's largest deposits include the Olympic Dam mine at 295,000 tU, the Imouraren mine at 183,520 tU, the McArthur River mine at 128,900 tU, the Streltsovsk mine at 118,341 tU, the Novokonstantinovka mines at 93,630, the Cigar Lake Mine at 80,500 tU, Uzbekistan mines at 76,000 tU,

2080-472: The western US ), Precambrian unconformities (in Canada), phosphate , Precambrian quartz -pebble conglomerate , collapse breccia pipes (see Arizona breccia pipe uranium mineralization ), and calcrete . Sandstone uranium deposits are generally of two types. Roll-front type deposits occur at the boundary between the up dip and oxidized part of a sandstone body and the deeper down dip reduced part of

2160-400: The "cut and fill" or "open stoping" method, the space remaining following removal of ore after blasting is filled with waste rock and cement. In the "shrinkage" method, only sufficient broken ore is removed via the chutes below to allow miners working from the top of the pile to drill and blast the next layer to be broken off, eventually leaving a large hole. The method known as "room and pillar"

2240-696: The 1960s in the United Kingdom, France, Germany, and Japan, this research was halted due to low recovery efficiency. At the Takasaki Radiation Chemistry Research Establishment of the Japan Atomic Energy Research Institute (JAERI Takasaki Research Establishment), research and development has continued culminating in the production of adsorbent by irradiation of polymer fiber. Adsorbents have been synthesized that have

2320-536: The GSC built a lighter weight, more practical unit in 1934. Subsequent models were the principal instruments used for uranium prospecting for many years, until geiger counters were replaced by scintillation counters . The use of airborne detectors to prospect for radioactive minerals was first proposed by G. C. Ridland, a geophysicist working at Port Radium in 1943. In 1947, the earliest recorded trial of airborne radiation detectors (ionization chambers and Geiger counters)

2400-461: The May, 2008 exchange rate, this was about $ 240/kg-U. In 2012, ORNL researchers announced the successful development of a new adsorbent material dubbed "HiCap", which vastly outperforms previous best adsorbents, which perform surface retention of solid or gas molecules, atoms or ions. "We have shown that our adsorbents can extract five to seven times more uranium at uptake rates seven times faster than

2480-536: The Queensland Mines share price to a peak of $ 46, up from $ 12 at the start of the year. It was widely reported that Nabarlek was the richest uranium deposit in the world. In August 1971, the technical committee of QML revised its estimated yield for Nabarlek to 9,000 tonnes, leading to calls for the resignation of Hudson and a steep fall in the share price. This in turn led to the collapse of investment house Mineral Securities Limited in 1972 and contributed to

Nabarlek Uranium Mine - Misplaced Pages Continue

2560-587: The Sengier reopened the Sinkolobwe mine with U.S. Army Corps of Engineers ' resources, and a $ 13 million investment from the United States. Sengier reported that uranium ore had been extracted from the mine down to a depth of 79 meters, but that another 101 meters of ore was available for extraction. This amounted to 10,000 tons of up to 60% triuranium octoxide . The project also acquired most of

2640-679: The Shinkolobwe mine, but closed down in the late 1930s as the radium market diminished. In May 1940, the Nazis invaded Belgium and seized Union Minière's uranium ore stored there. On 18 September 1942, 1250 t of Shinkolobwe uranium ore for the Manhattan Project was purchased from Union Minière's Edgar Sengier , who had stockpiled the ore in an Archer Daniels Midland warehouse near the Bayonne Bridge , Staten Island . In 1943,

2720-845: The Soviet Republics of Kazakhstan and the RSFSR would later become some of the leading uranium producers in the world, immediately after the end of World War II the availability of large uranium deposits in the USSR wasn't yet known and thus the Soviets developed immense mining operations in their satellite states East Germany and Czechoslovakia which had known uranium deposits in the Ore Mountains. The deliberately opaquely named SDAG Wismut (the German term "Wismut" for Bismuth should give

2800-423: The United States. A large mass of breccia is called a breccia pipe or chimney and is composed of the rock forming an irregular and almost cylinder-like shape. The origin of breccia pipe is uncertain but it is thought that they form on intersections and faults.  When the formations are found solid in ground host rock called rock flour, it usually is often a site for copper or uranium mining. Copper Creek, Arizona,

2880-399: The advances made in the efficiency of seawater uranium extraction, it was suggested that it would be economically competitive to produce fuel for light water reactors from seawater if the process was implemented at large scale. Uranium extracted on an industrial scale from seawater would constantly be replenished by both river erosion of rocks and the natural process of uranium dissolved from

2960-500: The air. In Australia, a Weathering Intensity Index has been developed to help prospectors based on the Shuttle Radar Topography Mission (SRTM) elevation and airborne gamma-ray spectrometry images. A deposit of uranium, discovered by geophysical techniques, is evaluated and sampled to determine the amounts of uranium materials that are extractable at specified costs from the deposit. Uranium reserves are

3040-436: The amounts of ore that are estimated to be recoverable at stated costs. As prices rise or technology allows for lower cost of recovery of known, previously uneconomic, deposits, reserves increase. For uranium this effect is particularly pronounced as the biggest currently uneconomic reserve – uranium extraction from seawater – is bigger than all known land based resources of uranium combined. From 2008 through at least 2024,

3120-515: The application. Enrichment requires conversion of the yellowcake into uranium hexafluoride and production of the fuel (again usually uranium dioxide, but sometimes uranium carbide , uranium hydride or uranium nitride ) from that feedstock. Before 1789, when Martin Heinrich Klaproth discovered the element, uranium compounds produced included nitrate, sulfate, phosphate, acetate and potassium- and sodium- diuranate . Klaproth detected

3200-606: The arduous task of rehabilitating the land impacted by mining was begun. The seventeen towns and mines under Wismut's control contributed 50 percent of the uranium used in the Soviet's first atomic bomb, Joe-1 , and 80 percent of the uranium used in the Soviet nuclear program. Of the 150,000 laborers, 1281 were killed in accidents and 20,000 suffered injuries. After Stalin's death in 1953, the Red Army turned over control of production to SDAG, and prison laborers were released, reducing

3280-421: The crosscut. To extract the ore, the next step is to drive tunnels, known as raises when driven upwards and winzes when driven downward, through the deposit from level to level. Raises are subsequently used to develop the stopes where the ore is mined from the veins. The stope, which is the workshop of the mine, is the excavation from which the ore is extracted. Three methods of stope mining are commonly used. In

Nabarlek Uranium Mine - Misplaced Pages Continue

3360-423: The data to be collected through laboratory methods and modeling, making it hard to interpret the data itself. Not only is the specified leaching process important, but also the focus of the experimentation itself. For instance, the focus could be directed toward mechanisms causing leaching, mineralogy as a group or individually, or the solvent that causes leaching. Most tests are done by evaluating mass loss due to

3440-698: The disseminated uranium deposit at Rossing , Namibia; uranium-bearing pegmatites , and the Aurora crater lake deposit of the McDermitt Caldera in Oregon. Disseminated deposits are also found in the states of Washington and Alaska in the US. Breccia uranium deposits are found in rocks that have been broken due to tectonic fracturing, or weathering. Breccia uranium deposits are most common in India, Australia and

3520-520: The element radium . Pierre advocated its usage as a cancer cure, which fostered a spa business for that town. In 1913, the Shinkolobwe , Katanga Province, was discovered. In 1931, the Port Radium deposit was discovered. Other significant discoveries included Beira Province , Tyuya Muyun , and Radium Hill . In 1922, Union Minière du Haut Katanga started producing medicinal radium from

3600-630: The element in pitchblende from the George Wagsfort mine, Ore Mountains , and established commercial use as glass coloring. Pitchblende from these mountains was mentioned as early as 1565, and 110 t of uranium was produced from 1825 until 1898. In 1852, the uranium mineral autunite from the Massif Central was identified. Around 1850, uranium mining began in Joachimsthal, Bohemia , where more than 620 t of uranium metal (tU)

3680-413: The extent of this topic is vast. In general, however, the three substances can be described as: Substance A and B are somewhat homogenous in a system prior to the introduction of substance C. At the beginning of the leaching process, substance C will work at dissolving the surficial substance B at a fairly high rate. The rate of dissolution will decrease substantially once it needs to penetrate through

3760-500: The geological process called weathering. Therefore, oxide ore deposits are typically found close to the surface. If there are no other economic elements within the ore a mine might choose to extract the uranium using a leaching agent, usually a low molar sulfuric acid. If the economic and geological conditions are right, the mining company will level large areas of land with a small gradient, layering it with thick plastic (usually HDPE or LLDPE ), sometimes with clay, silt or sand beneath

3840-542: The illusion of prospection for a metal the Soviets definitely weren't after) became the biggest employer in the Saxon Ore Mountains and remote mining towns like Johanngeorgenstadt swelled to ten times their population in a few years. The mining cost immense amounts of money and miners were on the one hand subject to heavier repression and surveillance but on the other hand allowed more generous supply with consumer goods than other East Germans. While production

3920-546: The insolvency of Patrick Corporation in 1975, both of which had made considerable investments at higher prices. Finance journalist Trevor Sykes has described this situation as analogous to the Poseidon bubble of 1970. In May 1973, the original licence-holder Gwendolyne Stevens transferred her rights to Queensland Mines in exchange for a royalty agreement. She died of a cerebral haemorrhage in March 1974. The proposed mine site

4000-604: The material, the solvent, and their availability. These specific properties can include, but are not limited to: The general process is typically broken up and summarized into three parts: Biological substances can experience leaching themselves, as well as be used for leaching as part of the solvent substance to recover heavy metals . Many plants experience leaching of phenolics, carbohydrates , and amino acids , and can experience as much as 30% mass loss from leaching, just from sources of water such as rain , dew , mist , and fog . These sources of water would be considered

4080-574: The mine. In the past mining companies would sometimes go bankrupt, leaving the responsibility of mine reclamation to the public. 21st century additions to US mining law require that companies set aside the money for reclamation before the beginning of the project. The money will be held by the public to insure adherence to environmental standards if the company were to ever go bankrupt. In-situ leaching (ISL), also known as solution mining, or in-situ recovery (ISR) in North America, involves leaving

SECTION 50

#1732773245162

4160-423: The more efficient acid leach. The Australian government has published a best practice guide for in situ leach mining of uranium, which is being revised to take account of international differences. The uranium concentration in sea water is low, approximately 3.3 parts per billion or 3.3 micrograms per liter of seawater. But the quantity of this resource is gigantic and some scientists believe this resource

4240-415: The native groundwater in the orebody which is fortified with a complexing agent and in most cases an oxidant. It is then pumped through the underground orebody to recover the minerals in it by leaching. Once the pregnant solution is returned to the surface, the uranium is recovered in much the same way as in any other uranium plant (mill). In Australian ISL mines ( Beverley , Four Mile and Honeymoon Mine )

4320-512: The now-exposed rocks acid mine drainage can be a concern for those newly developing bodies of water. Mining companies are now required by law to establish a fund for future reclamation while mining is ongoing and those funds are usually deposited in such a way as to be unaffected by bankruptcy of the mining company. If the uranium is too far below the surface for open pit mining, an underground mine might be used with tunnels and shafts dug to access and remove uranium ore. Underground uranium mining

4400-734: The only four countries that have reported non-domestic uranium exploration and development expenses are: China, Japan, France, and Russia. The U.S. is investigating whether China is circumventing a ban on Russian uranium imports by exporting its uranium to the U.S. while importing enriched uranium from Russia. This inquiry follows a spike in Chinese uranium exports to the U.S. after the December 2023 ban, which aimed to cut off funding for Russia's war in Ukraine. As with other types of hard rock mining there are several methods of extraction. In 2016,

4480-562: The ore stockpiled for milling. 546,437 t of ore were mined at an average grade of 1.84% U 3 O 8 . The mill commenced operation in June 1980 and ran until 1988, during which time 11,084 t U 3 O 8 were produced. A survey in 2006 concluded that revegetation had failed. Rehabilitation work is continuing. Uranium mine Uranium is mined by in-situ leaching (57% of world production) or by conventional underground or open-pit mining of ores (43% of production). During in-situ mining,

4560-429: The ore where it is in the ground, and recovering the minerals from it by dissolving them and pumping the pregnant solution to the surface where the minerals can be recovered. Consequently, there is little surface disturbance and no tailings or waste rock generated. However, the orebody needs to be permeable to the liquids used, and located so that they do not contaminate ground water away from the orebody. Uranium ISL uses

4640-514: The oxidant used is hydrogen peroxide and the complexing agent sulfuric acid. Kazakh ISL mines generally do not employ an oxidant but use much higher acid concentrations in the circulating solutions. ISL mines in the USA use an alkali leach due to the presence of significant quantities of acid-consuming minerals such as gypsum and limestone in the host aquifers. Any more than a few percent carbonate minerals means that alkali leach must be used in preference to

4720-546: The percentage of the mined uranium produced by each mining method was: in-situ leach (49.7 percent), underground mining (30.8 percent), open pit (12.9 percent), heap leaching (0.4 percent), co-product/by-product (6.1%). The remaining 0.1% was derived as miscellaneous recovery. In open pit mining, overburden is removed by drilling and blasting to expose the ore body, which is then mined by blasting and excavation using loaders and dump trucks. Workers spend much time in enclosed cabins thus limiting exposure to radiation. Water

4800-458: The plastic liner. The extracted ore will typically be run through a crusher and placed in heaps atop the plastic. The leaching agent will then be sprayed on the ore for 30–90 days. As the leaching agent filters through the heap, the uranium will break its bonds with the oxide rock and enter the solution. The solution will then filter along the gradient into collecting pools which will then be pumped to on-site plants for further processing. Only some of

4880-668: The population of laborers to 45,000. At its peak in 1953, the St. Joachimsthal mines had 16,100 inmates, half of whom were Soviet political prisoners. By 1975, 75% of global uranium ore production came from quartz - pebble conglomerates and sandstones located in the Elliot Lake area of Canada , Witwatersrand , and the Colorado Plateau . In 1990, 55% of world production came from underground mines, but this shrank to 33% by 1999. From 2000, new Canadian mines again increased

SECTION 60

#1732773245162

4960-416: The pores of substance A in order to continue targeting substance B. This penetration can often lead to dissolution of substance A, or the product of more than one solute, both unsatisfactory if specific leaching is desired. The physiochemical and biological properties of the carrier and solute should be considered when observing the leaching process , and certain properties may be more important depending on

5040-461: The presence of radioactive isotopes. The Geiger counter was the original radiation detector, recording the total count rate from all energy levels of radiation. Ionization chambers and Geiger counters were first adapted for field use in the 1930s. The first transportable Geiger–Müller counter (weighing 25 kg) was constructed at the University of British Columbia in 1932. H.V. Ellsworth of

5120-656: The production from the Eldorado Mine (Northwest Territories) . According to Richard Rhodes , referring to German uranium research, " Auer , the thorium specialists ... delivered the first ton of pure uranium oxide processed from Joachimsthal ores to the War Office in January 1940. In June 1940 ... Auer ordered sixty tons of refined uranium oxide from the Union Miniére in occupied Belgium." While

5200-740: The proportion of underground mining, and with Olympic Dam it is now 37%. In situ leach (ISL, or ISR) mining has been steadily increasing its share of the total, mainly due to Kazakhstan. In 2009, top producing mines included the McArthur River uranium mine at 7400 tU, the Ranger Uranium Mine at 4423 tU, the Rössing uranium mine at 3574 tU, the Moiynkum Desert mines at 3250 tU, the Streltsovsk mine at 3003 tU,

5280-493: The re-use of fly ash by recovering aluminum using sulfuric acid . Coal fly ash is a product that experiences heavy amounts of leaching during disposal. Though the re-use of fly ash in other materials such as concrete and bricks is encouraged, still much of it in the United States is disposed of in holding ponds, lagoons , landfills , and slag heaps. These disposal sites all contain water where washing effects can cause leaching of many different major elements , depending on

5360-458: The solvent in the leaching process and can also lead to the leaching of organic nutrients from plants such as free sugars , pectic substances, and sugar alcohols . This can in turn lead to more diversity in plant species that may experience a more direct access to water. This type of leaching can often lead to the removal of an undesirable component from the solid by water, this process is called washing. A major concern for leaching of plants,

5440-490: The source of uranium with hydrothermal vein-type deposits and the potential sources still remains a mystery, but are thought to include preexisting rocks that have been broken down by weathering and force that come from areas of long-term sediment build up. The South Chine Block is an example of a region that has been relying on vein-type hydrothermal uranium deposit demand for the past half century. Igneous deposits include nepheline syenite intrusives at Ilimaussaq , Greenland;

5520-404: The sulfuric acid. Heap leach is significantly cheaper than traditional milling processes. The low costs allow for lower grade ore to be economically feasible (given that it is the right type of ore body). US environmental law requires that the surrounding ground water is continually monitored for possible contamination. The mine will also have to have continued monitoring even after the shutdown of

5600-417: The surface area of the ocean floor, both of which maintain the solubility equilibria of seawater concentration at a stable level. Some commentators have argued that this strengthens the case for nuclear power to be considered a renewable energy . Leaching (chemistry) Leaching is the process of a solute becoming detached or extracted from its carrier substance by way of a solvent . Leaching

5680-599: The type of fly ash and the location where it originated. The leaching of fly ash is only concerning if the fly ash has not been disposed of properly, such as in the case of the Kingston Fossil Plant in Roane County , Tennessee. The Tennessee Valley Authority Kingston Fossil Plant structural failure lead to massive destruction throughout the area and serious levels of contamination downstream to both Emory River and Clinch River . Leaching in soil

5760-544: The type of rock in which they are found. This geological classification system is determined by the International Atomic Energy Agency (IAEA). Uranium is also contained in seawater but at present prices on the uranium market , costs would have to be lowered by a factor of 3–6 to make its recovery economical. Uranium deposits in sedimentary rocks include those in sandstone (in Canada and

5840-415: The uranium (commonly about 70%) is actually extracted. The uranium concentrations within the solution are very important for the efficient separation of pure uranium from the acid. As different heaps will yield different concentrations, the solution is pumped to a mixing plant that is carefully monitored. The properly balanced solution is then pumped into a processing plant where the uranium is separated from

5920-406: The world's best adsorbents," said Chris Janke, one of the inventors and a member of ORNL's Materials Science and Technology Division. HiCap also effectively removes toxic metals from water, according to results verified by researchers at Pacific Northwest National Laboratory . In 2012 it was estimated that this fuel source could be extracted at 10 times the current price of uranium. In 2014, with

6000-399: Was >1 kg of yellowcake after 240 days of submersion in the ocean. The experiment by Seko et al. was repeated by Tamada et al. in 2006. They found that the cost varied from ¥15,000 to ¥88,000 depending on assumptions and "The lowest cost attainable now is ¥25,000 with 4g-U/kg-adsorbent used in the sea area of Okinawa, with 18 repetitionuses [ sic ]." With

6080-448: Was conducted by Eldorado Mining and Refining Limited . (a Canadian Crown Corporation since sold to become Cameco Corporation ). The first patent for a portable gamma-ray spectrometer was filed by Professors Pringle, Roulston & Brownell of the University of Manitoba in 1949, the same year as they tested the first portable scintillation counter on the ground and in the air in northern Saskatchewan . Airborne gamma-ray spectrometry

6160-530: Was located 200 yards (180 m) from an Aboriginal sacred site known as Gabo Djang, associated with the Dreaming related to the green ant . The traditional owners of Nabarlek consequently opposed the mine. QML initially offered $ 7,425 in exchange for the mineral rights, which by 1974 had grown to a package of $ 891,000 in cash plus a royalty valued at $ 13.6 million, which was rejected. Open cut mining eventually took place between June and October 1979 with

6240-637: Was majority-owned by the Rio Tinto Zinc Corporation (RTZ). In early 1970, Queensland Mines began costeaning Nabarlek, revealing visible deposits of pitchblende . One 76-centimetre (30 in) sample was found to contain 72 percent uranium oxide, compared with averages of 0.1 percent on some American and Canadian mines. News of the positive results soon leaked, and on 1 September the company's chairman Roy Hudson announced an estimated yield of 55,000 tonnes of uranium oxide at an average grade of 540 pounds (240 kg) per tonne. This sent

6320-473: Was never able to compete with global uranium market prices, the dual use nature of the mined material as well as the possibility to pay miners in soft currency but sell uranium for hard currency or substitute imports which would have had to be paid for in hard currency tipped the scales in favor of continuing mining operations throughout the Cold War. After German reunification , mining was wound down and

6400-764: Was produced from 1850 and 1898, with 10,000 tU produced before closure in 1968. In 1871, uranium ore mining began in Central City, Colorado , where 50 t were mined before 1895. In 1873, the uranium mining began in the South Terras mine, St Stephen-in-Brannel , Cornwall, producing most of the 300 tU from that area in the 19th century. In 1898, carnotite was first mined in the Uravan Mineral Belt , yielding 10 tU annually. In 1898, Pierre Curie and Marie Skłodowska-Curie took delivery of 1 t of pitchblende from St. Joachimsthal, from which Marie identified

#161838