نتایج جستجو برای: Uranium ore

تعداد نتایج: 18938  

2008
R. M. Tripathi S. K. Sahoo V. N. Jha Rajesh Kumar A. K. Shukla V. D. Puranik

Mining and ore processing activities are associated with changes in the surrounding environment and may pose a risk to human health, if adequate safety measures are not taken. The uranium ore generally varies worldwide between 0.03 – 3% U3O8, except for a few deposits where higher levels of uranium is reported. More than 95% of the ore is converted into waste material called “tailings”. Around ...

Journal: :Journal of environmental management 2016
James A Saunders Bruce E Pivetz Nathan Voorhies Richard T Wilkin

Sandstone-hosted roll-front uranium ore deposits originate when U(VI) dissolved in groundwater is reduced and precipitated as insoluble U(IV) minerals. Groundwater redox geochemistry, aqueous complexation, and solute migration are important in leaching uranium from source rocks and transporting it in low concentrations to a chemical redox interface where it is deposited in an ore zone typically...

2008
ZHANG Jie-lin

Based on hyper spectral data mining techniques, field spectra data is used to study the diagnosable spectral signatures of uranium mineralization factors in this paper, and the spectral features of pluton, ore-controlling fault and hydrothermal alteration including alkali metasomatism, hematitization, chloritization and hydromicazation are acquired and analyzed, the diagnosable spectra identifi...

2004

The northern Asia, including the southern territories of Russia, Kazakhstan, Uzbekistan, Mongolia and the northern China is known as an important distribution region of uranium deposits and occurrences. Since the 60s of 20th century, after the successful development of in-situ leach technology for sandstone-hosted uranium deposits, numerous uranium deposits previously discovered in Kazakhstan a...

2005
Maozhong Min Jia Chen Jinpeng Wang Guanhui Wei Mostafa Fayek

We present a first paragenetic study of the Wuyier, Wuyisan, Wuyiyi and Shihongtan sandstone-hosted roll-front uranium deposits, northwest China. The mineralization is hosted by Lower–Middle Jurassic coarseto medium-grained sandstones, which are dark-gray to black due to a mixture of ore minerals and carbonaceous debris. The sandstone is alluvial fan-braided river facies. Minerals associated wi...

2017
Zsolt Varga Judit Krajkó Maxim Peńkin Márton Novák Zsuzsanna Eke Maria Wallenius Klaus Mayer

The paper describes the applicability of different characteristics (signatures) in nuclear safeguards and forensics for assessment of uranium material provenance in terms of production process. The study follows a uranium ore concentrate production from an ore to a U3O8 product. It turned out that rare-earth elemental pattern, radiochronometry (age of ore body and material production date), sul...

2007
R. Gupta A. K. Sarangi

From the modest beginning in 1948, the atomic energy programme of India has grown to vast dimensions with mosaic of many interrelated programmes. The uranium ore mining and processing industry of the country began at Jaduguda in 1968. It has made a very impressive growth during these years with four operating mines and meeting the entire fuel requirement of the country. The country now has a de...

Journal: :Bioresource technology 2013
Abhilash B D Pandey

Bioreactor leaching using enriched culture of Acidithiobacillus ferrooxidans and Leptosprillium ferrooxidans was investigated for the apatite rich Indian (Narwapahar) uranium ore. Bioreactor leaching of Narwapahar ore of <45 μm size at pH 2.0 and 10% (w/v) PD using 10% (v/v) inoculum of the bacterium at 35 °C (A. ferrooxidans) and 40 °C (L. ferrooxidans), solubilised 57% and 63% uranium in 5 da...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2011
mahmoud abdollahy sayed abbas shojaosadati hasan zare tavakoli ali valivand

this study deals with bioleaching of the low grade uranium ore of saghand mine in iran using a mixed culture of mesophilic bacteria (acidithiobacillus ferrooxidans, acidithiobacillus thiooxidans and leptospirillum ferrooxidans). experiments were carried out in shaking flask examining the effect of temperature, initial ferrous ion concentration, pulp density and particle size. variations of ph, ...

Journal: :Food additives and contaminants 2007
Şenol Sert

A comparison method for the determination (without sample pre-concentration) of uranium in ore by inductively coupled plasma optical emission spectrometry (ICP-OES) has been performed. The experiments were conducted using three procedures: matrix matching, plasma optimization, and internal standardization for three emission lines of uranium. Three wavelengths of Sm were tested as internal stand...

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