The Experts below are selected from a list of 30762 Experts worldwide ranked by ideXlab platform
Sh. G. Beheir - One of the best experts on this subject based on the ideXlab platform.
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Studies on uranium recovery from a uranium-bearing phosphatic sandstone by a combined heap leaching-liquid-Gel Extraction process. 2—Liquid-Gel Extraction
Hydrometallurgy, 1992Co-Authors: K. Shakir, M. Aziz, Sh. G. BeheirAbstract:Abstract Liquid-Gel Extraction of uranium from the liquors obtained by the heap leaching of a local phosphatic sandstone was investigated using Gels composed of styrene divinyl benzene copolymer incorporating di-(2-ethylhexyl)-phosphoric acid. The different factors that can affect the process were studied. Incorporation of TBP into the Gel was found to enhance uranium Extraction. Uranium sorbed on the Gel could be efficiently eluted by a Fe(II) H 3 PO 4 solution. A laboratory experiment combining heap leaching and liquid-Gel Extraction proved the feasibility of the use of the combined process for uranium recovery from the mineralization under test.
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Studies on uranium recovery from a uranium-bearing phosphatic sandstone by a combined heap leaching-liquid-Gel Extraction process. 1—Heap leaching
Hydrometallurgy, 1992Co-Authors: K. Shakir, M. Aziz, Sh. G. BeheirAbstract:Abstract In the mineralization under investigation uranium does not form a definite mineral but it is hosted by apatites. The batch used in the present work assays between 0.045 and 0.048% uranium. Heap leaching was first tried with a Fe 2 ( SO 4 ) 3 H 2 SO 4 solution of pH 1.7 but the results were discouraging. Leaching with H 2 SO 4 solutions of moderate acidity containing a low concentration of HNO 3 was next tried. The process was found to proceed in two distinct stages, dissolution and a step called rinsing. The factors that affect uranium recovery and acid consumption during the dissolution stage were investigated and the optimal conditions for uranium recovery were determined.
K. Shakir - One of the best experts on this subject based on the ideXlab platform.
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Studies on uranium recovery from a uranium-bearing phosphatic sandstone by a combined heap leaching-liquid-Gel Extraction process. 2—Liquid-Gel Extraction
Hydrometallurgy, 1992Co-Authors: K. Shakir, M. Aziz, Sh. G. BeheirAbstract:Abstract Liquid-Gel Extraction of uranium from the liquors obtained by the heap leaching of a local phosphatic sandstone was investigated using Gels composed of styrene divinyl benzene copolymer incorporating di-(2-ethylhexyl)-phosphoric acid. The different factors that can affect the process were studied. Incorporation of TBP into the Gel was found to enhance uranium Extraction. Uranium sorbed on the Gel could be efficiently eluted by a Fe(II) H 3 PO 4 solution. A laboratory experiment combining heap leaching and liquid-Gel Extraction proved the feasibility of the use of the combined process for uranium recovery from the mineralization under test.
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Studies on uranium recovery from a uranium-bearing phosphatic sandstone by a combined heap leaching-liquid-Gel Extraction process. 1—Heap leaching
Hydrometallurgy, 1992Co-Authors: K. Shakir, M. Aziz, Sh. G. BeheirAbstract:Abstract In the mineralization under investigation uranium does not form a definite mineral but it is hosted by apatites. The batch used in the present work assays between 0.045 and 0.048% uranium. Heap leaching was first tried with a Fe 2 ( SO 4 ) 3 H 2 SO 4 solution of pH 1.7 but the results were discouraging. Leaching with H 2 SO 4 solutions of moderate acidity containing a low concentration of HNO 3 was next tried. The process was found to proceed in two distinct stages, dissolution and a step called rinsing. The factors that affect uranium recovery and acid consumption during the dissolution stage were investigated and the optimal conditions for uranium recovery were determined.
M. Aziz - One of the best experts on this subject based on the ideXlab platform.
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Studies on uranium recovery from a uranium-bearing phosphatic sandstone by a combined heap leaching-liquid-Gel Extraction process. 2—Liquid-Gel Extraction
Hydrometallurgy, 1992Co-Authors: K. Shakir, M. Aziz, Sh. G. BeheirAbstract:Abstract Liquid-Gel Extraction of uranium from the liquors obtained by the heap leaching of a local phosphatic sandstone was investigated using Gels composed of styrene divinyl benzene copolymer incorporating di-(2-ethylhexyl)-phosphoric acid. The different factors that can affect the process were studied. Incorporation of TBP into the Gel was found to enhance uranium Extraction. Uranium sorbed on the Gel could be efficiently eluted by a Fe(II) H 3 PO 4 solution. A laboratory experiment combining heap leaching and liquid-Gel Extraction proved the feasibility of the use of the combined process for uranium recovery from the mineralization under test.
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Studies on uranium recovery from a uranium-bearing phosphatic sandstone by a combined heap leaching-liquid-Gel Extraction process. 1—Heap leaching
Hydrometallurgy, 1992Co-Authors: K. Shakir, M. Aziz, Sh. G. BeheirAbstract:Abstract In the mineralization under investigation uranium does not form a definite mineral but it is hosted by apatites. The batch used in the present work assays between 0.045 and 0.048% uranium. Heap leaching was first tried with a Fe 2 ( SO 4 ) 3 H 2 SO 4 solution of pH 1.7 but the results were discouraging. Leaching with H 2 SO 4 solutions of moderate acidity containing a low concentration of HNO 3 was next tried. The process was found to proceed in two distinct stages, dissolution and a step called rinsing. The factors that affect uranium recovery and acid consumption during the dissolution stage were investigated and the optimal conditions for uranium recovery were determined.
Liang Li - One of the best experts on this subject based on the ideXlab platform.
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observation of sodium Gel induced protein modifications in dodecylsulfate polyacrylamide Gel electrophoresis and its implications for accurate molecular weight determination of Gel separated proteins by matrix assisted laser desorption ionization tim
Journal of the American Society for Mass Spectrometry, 1999Co-Authors: Michael A Jeannot, Jing Zheng, Liang LiAbstract:Matrix-assisted laser desorption ionization (MALDI) time-of-flight mass spectrometry (TOFMS) can potentially provide accurate molecular weight information of proteins separated by sodium dodecylsulfate polyacrylamide Gel electrophoresis (SDS-PAGE). Several issues related to resolution and accuracy of molecular weight measurement are investigated by using a time-lag focusing MALDI-TOF mass spectrometer. The effects of the Gel components SDS, glycerol, and tris buffer on the mass spectral signals are studied systematically. Glycerol and tris buffer are shown to have little or no effect on resolution and mass accuracy, whereas SDS degrades sensitivity, resolution, and mass accuracy even at low concentrations. A simple and fast Gel Extraction technique is presented which is capable of detecting proteins loaded at the low-picomole level on the Gel. The sample preparation procedure used in this work appears to remove most of SDS from the Gel, thereby reducing the peak broadening effect caused by SDS and resulting in high resolution and accurate measurement of proteins. However, for proteins containing cysteines, the molecular ions are composed of a distribution of acrylamide-protein adducts likely formed by reaction with unpolymerized acrylamide in the Gel during the Gel separation process. The implications of Gel-induced protein modifications on the accurate molecular weight measurement of Gel-separated proteins are discussed.
Stevin H. Gehrke - One of the best experts on this subject based on the ideXlab platform.
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Chemical aspects of Gel Extraction
Chemical Engineering Science, 2001Co-Authors: Stevin H. Gehrke, Gerald P. Andrews, Edward L CusslerAbstract:Abstract Dilute aqueous solutions can be effectively concentrated with crosslinked partially hydrolysed polyacrylamide Gels. Because the Gels are near their critical point, they can be regenerated with small changes in pH. The selectivity of concentrating nonelectrolyte solutes can be adjusted by changes in Gel crosslinking; the selectivity of separating electrolytes seems larGely the result of Donnan equilibria. The regeneration of the Gels is effected larGely by altering the ionization of carboxylic acid groups within the Gel, and less influenced by ion pairing. The regeneration is compromised at high salt concentrations which reduce the Gel's swelling.
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Dewatering Fine Coal Slurries by Gel Extraction
Separation Science and Technology, 1998Co-Authors: Stevin H. Gehrke, Lii-hurng Lyu, Kristopher BarnthouseAbstract:ABSTRACT Gel Extraction is evaluated as a novel technique for dewatering fine coal slurries. This technique uses temperature-responsive Gels to absorb water from slurries at low temperatures; after separation of the swollen Gel from the dewatered slurry, the Gel is heated slightly above ambient temperature, which causes it to release the water it absorbed. The Gel can then be recycled. The equilibrium and kinetic properties of poly(N-isopropylacrylamide) Gel were evaluated for utility in this process. The Gels effectively dewatered slurries to around 70 wt% solids; performance was not a strong function of particle size, though coarser slurries (−16 mesh) could be dewatered to greater extents than the finer slurries (325 = 400 mesh). The Gels showed no sign of deterioration over a period of 2 months and 20 cycles.
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Dewatering fine coal slurries by Gel Extraction. Final report
1990Co-Authors: Stevin H. Gehrke, Lii-hurng LyuAbstract:A new technology called Gel Extraction has been evaluated to determine its economic viability in dewatering the fine and ultrafine coal slurries generated upon separation of sulfur and ash from clean coal during the physical coal cleaning process. Water must be removed from such slurries prior to transportation and combustion but the dewatering costs are substantial, especially for the fine particles below 28 mesh (0.6 mm). Gel Extraction is a potential breakthrough in slurry dewatering technology. The goal of this project was to acquire the qualitative and quantitative data needed to estimate the potential of Gel Extraction for dewatering coal slurries. The specific objectives were to determine the maximum extents of dewatering (minimum surface moisture in the coal product), the clarity of the water removed (minimum solids content), the speed of the dewatering cycles, the service lifetime of the Gels, and the factors which influence all of these. With the results obtained, an economic analysis of Ohio coal cleaning plant dewatering technologies was carried out. The polymer Gel at the heart of this project, poly (N-isopropylacrylamide) (PNIPA), can swell several times its shrunken weight at 32{degrees}C by absorbing water at 25{degrees}C. In Gel Extraction, a shrunken NIPA Gel is contactedmore » with a slurry at ambient temperature or cooler; the Gel swells by absorbing water from the slurry. The Gel is then removed from the dewatered slurry and warmed above its critical temperature of 33{degrees}C, which returns it to the shrunken state by releasing the absorbed water. The facts that the Gel is reusable and the process is simple and driven by low-grade energy (warm temperatures), and not inherently limited by particle size, made the process an attractive possible alternative to centrifugation, screening, filtration, etc. for slurry dewatering.« less
