In this work, a novel procedure was developed to separate thorium from uranium ore, consisting of leaching, liquid–liquid extraction, precipitations and ion exchange chromatography. The final product was 91.32 ± 0.77 mg of thorium with a purity of 99.5 ± 1.2 wt%. Of that, 7.65 ± 0.10 mg was 230 Th and the remainder 232 Th.
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Nitric acid leaching of radium and other significant radionuclides from uranium ores and tailings. Nitric acid leaching of representative uranium ores and mill tailings from the western U.S. mining districts removes up to 98% of the /sup 226/Ra and /sup 230/Th, yielding a residue containing 17 to….
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Uranium minerals are always associated with more radioactive elements such as radium and radon in the ore which arise from the radioactive decay of uranium over a few million of years. Therefore, although uranium itself is barely radioactive, the ore which is mined, especially if it is very high-grade such as in some Canadian mines, is handled ...
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Ferric chloride leaching, at temperatures around 74°C, is found to remove up to remove up to 97% of the uranium from ores occurring in the Elliot Lake area of Canada. Radium removal is poor due to the formation of sulphates from the sulphides present in the ore. However, if the sulphides are removed initially by flotation, then ferric …
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Radium removal from uranium ores and mill tailings. U.S. Bureau of Mines, Rept. of inv. 8099. (1975) B. Havlik et al. Radium-226 liberation from uranium ore …
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1. Introduction. Phosphogypsum (PG) is a hazardous waste associated with the phosphoric acid production using the wet process [1].PG is considered a relatively high level natural uranium series radionuclide material, which provokes a negative environmental impact and many restrictions on the use of the PG waste (only 15% of the …
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Uranium Ore (Carnotite). Milling: This process takes place at a mill after the ore containing uranium is removed from the Earth through open pit or underground mining.The ore is brought to a mill, crushed, and ground up before chemicals are added to dissolve the uranium. The uranium is then separated from the chemical solution, …
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NSF 58-Certified Reverse Osmosis Systems Remove Radium and Other Contaminants. If radium is one of multiple contaminants in your water, an RO system with NSF 58 certification is your best bet. RO systems force water through a semipermeable membrane that removes contaminants, including radium-226 and -228.
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The leaching of uranium ore and mill tailings to remove radium was studied. A few scouting tests were performed to obtain data on the recovery of radium, thorium, and uranium from leach liquors and on the recycle of leaching agents. ... Uranium ore was treated with soluble barium at concentrations of 10, 25, 50, and 100 mg per litre of slurry ...
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Acid pressure leaching of a sulphidic uranium ore with emphasis on radium extraction. Hydrometallurgy, 15 : 219--242. A pressure leaching study of a pyrite-containing uranium ore from Elliot Lake, On- tario was conducted to effect simultaneous extraction of uranium and radium there- by producing tailings with reduced environmental impact.
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It was found, that 95- of radium bound in sediments was reIeased in 1 N solutions of KCl and NaCl salts, dependent on their structure and mineralogical composition. The control of the radioactivity level of surface water contaminated by radioactive waste from uranium ore mining and processing revealed higher concentration of dissolved radium in places …
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Radium removal from uranium ores and mill tailings. S. Borrowman, P. T. Brooks. Published 1975. Environmental Science, Engineering. Mill tailings from conventional …
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The purification of radium waters has been the subject of numerous studies mainly due to the fact that sewage from mines and uranium ore processing plants was …
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Uranium reserve estimates in ore deposits can be significantly impacted by 226 Ra/ 238 U disequilibria arising from the differential mobility of uranium and radium during groundwater transport. 1D reactive transport models were developed to investigate the long-term effects of retention processes (UO 2(am) precipitation, U(VI) and Ra …
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The removal rates with membrane filtration processes have been in the order of 90-99.9% for uranium [56] and for radium in the order of 43-99% (strongly dependent on the initial concentration) [13 ...
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The radium leaching characteristics from both ore and sulfate-leached tailings were investigated. Several 1 M salt solutions showed poor to moderate RaSO 4 dissolution from "slimes solids" tailings, while 3 M HNO 3 or HCl solutions dissolved approximately 95% of the radium content of either ore or tailings. Tests are reported in …
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A pressure leaching study of a pyrite-containing uranium ore from Elliot Lake, Ontario was conducted to effect simultaneous extraction of uranium and radium thereby producing tailings with reduced environmental impact. This investigation was carried out in two parts. In Part I, pressure leaching with oxygen gas only was studied.
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Low Energy Gamma Spectrometry (L.E.G.S.) has proven to be a rapid and cost effective method of determining uranium, thorium and the uranium daughter products Radium-226 and Lead-214 in samples of ...
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Radium is a naturally occurring radioactive element found in nature. Radium has no non-radioactive isotopes. It is one of the products of the radioactive decay of uranium (U). The longest lived isotope is Ra-226 which is formed in the natural decay of U-238. The other major radium isotope is Ra-228. It is produced from the decay of radioactive ...
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Radium in uranium mill tail- ings- Some observations on retention and removal. Hydrometallurgy, 12: 151--176. The various mechanisms by which radium can be retained by uranium mill tailings are discussed. These include coprecipitation (solid solutions), adsorption on silica and hy- droxides, ion exchange in clay minerals, and …
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During chemical processing of uranium ore, most of the radium isotopes remain with the insoluble tailings. Consequently, the radium present in the liquid effluents at later times will consist largely of the 11.43-day radium-223 that will have ingrown from its thorium-227 parent remaining in the effluent rather than the 1600-year radium-226 that ...
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DOI: 10.1016/0304-386X(84)90032-X Corpus ID: 96245629; Radium in uranium mill tailings - Some observations on retention and removal @article{Nirdosh1984RadiumIU, title={Radium in uranium mill tailings - Some observations on retention and removal}, author={Inderjit Nirdosh and S. V. Muthuswami and Malcolm H. I. Baird}, …
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The radium content of a representative sandstone type of uranium ore was found to be distributed uniformly according to particle size before leaching, but in sulfuric acid-leached tailings was found predominantly in the −325 mesh fraction. ... In several collieries the radium removal from mine water was necessary to mitigate negative …
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Chabalala and Chirwa found reductive functional bacteria isolates from the soil have strong tolerance to uranium; within 24 h, uranium with a concentration of 200 …
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ritchie, c. f. separation of radium from uranium by co-precipitation from nitric acid solutions of pitchblende ore.united states: n. p., 1946. web. doi:10.2172/4335966.
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DOI: 10.1016/0304-386X(83)90004-X Corpus ID: 95475670; Radium removal from elliot lake uranium-mill solids by EDTA leaching @article{Nixon1983RadiumRF, title={Radium removal from elliot lake uranium-mill solids by EDTA leaching}, author={Allen C. Nixon and D. Keller and Klaus Fritze and Alice Pidruczny and Alfio.
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Ferric chloride leaching at temperatures in the range 47-74/sup 0/C. is found to remove up to 97% of the uranium from ores occurring in the Elliot Lake area of Canada, but radium removal was found to be poor due to the formation …
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Uranium Extraction. Uranium leaching is the process by which the uranium is extracted from the raw ore by reacting the material with acid or base. Fig. 2 shows a general process flow for the uranium extraction …
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A process is presented for extracting uranium and radium values from a uranium ore which comprises leaching the ore with a ferric chloride solution at an elevated temperature of above 50 deg C and at a pH less than 4; separating the ore residue from the leaching solution by filtration; precipitating the excess ferric iron present at a pH of less than 5 by …
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95% removal of 238U is also 95% removal of 235U when they are present together regardless of the ratio of their activities. Radium removal by ion-exchange softening …
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Many of the findings related to occupational exposures and adverse health outcomes presented in this chapter are based on studies of uranium and hard-rock miners (e.g., worker-based radon studies) for periods of disease risk when the magnitude of the exposures was much greater than the exposures reported at most mines and processing …
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Radium was discovered in 1898 by Marie Curie and Pierre Curie. They managed to extract 1 mg of radium from ten tonnes of the uranium ore pitchblende (uranium oxide, U 3 O 8), a considerable feat, given the chemically methods of separation available to them. They identified that it was a new element because its atomic spectrum revealed new lines.
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Ferric chloride leaching at temperatures in the range 47-74/sup 0/C. is found to remove up to 97% of the uranium from ores occurring in the Elliot Lake area of Canada, but …
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LEACHING OF RADIUM 226 FROM URANIUM MILL TAILINGS 367 CONCLUSIONS During the extraction of uranium from ore by hot sulfuric acid, there is evidence of considerable solubilization of radium from the ore and of redis- tribution of this dissolved radium to the tailings solids. The present study has focused on the hosts of …
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DOI: 10.1016/0304-386X(83)90059-2 Corpus ID: 96795284; Coextraction of uranium and radium from ore with ferric chloride @article{Nirdosh1983CoextractionOU, title={Coextraction of uranium and radium from ore with ferric chloride}, author={Inderjit Nirdosh and Malcolm H. I. Baird and S. V. Muthuswami and S. S. Banerjee}, …
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Tests also showed that the hexametaphosphate interferes with uranium extraction from the ore and solubilizes thorium-230 and radium-226 from neutral residues left after acid leaching. This approach was tested further, and 70-80% removal of thorium and radium from the slimes (-200 mesh) fraction of the tailings was achieved.
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uranium ore and mill tailings to remove radium. performed to obtain data on the r ry of radium, thorium, and ch liquors and on the recycle of leaching agents. A few scou hydrochl or? G aci d, ethyl en c acid (EDTA), tri ami nepentaaceti c acid ( sample of a western U.S. ore and tw les of tailings ined from different uranium mills th
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To improve the utilisation of uranium resources while reducing the radioactive contamination of uranium slag by ^226Ra, the effects of various factors on uranium–radium co-leaching from uranium ore were investigated. For nitric acid agitation leaching, the optimal performance was achieved using 80 mesh ore in 4 mol L^−1 nitric …
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Abstract. Mill tailings from conventional uranium extraction processes contain nearly all of the radium originally in the ore. Such tailings require controlled storage in perpetuity to …
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Previous work on radium removal from mill tailings and on radioactive disequilibrium in uranium deposits is critically reviewed in relation to these mechanisms. …
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