The purpose of this study was to determine the kinetics of the dissolution of a uranium residue in ammonium carbonate media. The residue is generated in the production of medical isotopes. The effects of parameters, such as varying peroxide and carbonate concentrations, dissolution time as well as temperature on the extraction rate have been separately studied. Results indicate complete dissolution of the residue at 60 °C, after 30 min, in ammonium carbonate solution enriched with hydrogen peroxide. The yield and rate of uranium extraction were found to increase as a function of both temperature, in the range of 25-60 °C, and hydrogen peroxide concentration. The extraction process was governed by chemical reaction as the activation energy was found to be 45.5 kJ/mol. The order of reaction with respect to uranium concentration was found to be approximately first order.
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http://dx.doi.org/10.1007/s10967-014-3396-3 | DOI Listing |
J Med Case Rep
December 2024
Department of Internal Medicine, Woldia Comprehensive Specialized Hospital, Woldia, Ethiopia.
Introduction: Aluminum phosphide is a cheap and commonly used rodenticide that is also an effective solid fumigant and frequently used for grain preservation. The pill contains around 44% inert elements (ammonium carbonate) to avoid disintegration of the tablet, while the rest (about 56%) is aluminum phosphide. Because it is freely available on the market, it is one of the commonly used agents for self-poisoning in different parts of the developing world.
View Article and Find Full Text PDFGels
December 2024
Biophysics and Biotechnology Department, Voronezh State University, 1 Universitetskaya Square, 394018 Voronezh, Russia.
Carboxymethyl cellulose sodium salt (CMC)-based superabsorbents are promising materials for the development of agricultural matrices aimed at water management and slow-release fertilizer production. However, an increase in the CMC content tends to reduce their water-absorbing capacity. This study aims to develop a cost-effective method for producing eco-friendly superabsorbents with enhanced water-absorbing capacity by incorporating a porogen and employing lyophilization.
View Article and Find Full Text PDFSensors (Basel)
November 2024
Zijin School of Geology and Mining, Fuzhou University, Fuzhou 350108, China.
This study investigates the ethanol gas-sensing mechanisms of ZnO nanocrystals with distinct morphologies, synthesized via a hydrothermal method using various alkali sources. Significant differences in the gas-sensing performance and morphology of ZnO samples synthesized with ammonium carbonate (NaCO), hexamethylenetetramine (HMTA), ammonia solution (NH·HO), and sodium hydroxide (NaOH) were observed. ZnO were confirmed to be impurity-free through XRD analysis, and their morphological features were characterized by SEM.
View Article and Find Full Text PDFMaterials (Basel)
September 2024
China Nonferrous Metal Innovation Research Institute (Tianjin) Co., Ltd., No. 86 Ziguang Road, Zhongbei Industrial Park, Xiqing District, Tianjin 300380, China.
This paper describes a highly alkaline low-grade copper oxide ore. Copper can be selectively leached out while other metals are retained. A thermodynamic model of the CuO-(NH)SO-NH-HO system was established for the leaching of tenorite (CuO) under conditions of mass and charge conservation.
View Article and Find Full Text PDFInt J Mol Sci
September 2024
Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, pr. Torez 44, St. Petersburg 194223, Russia.
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