Solvent Extraction and Ion Exchange Applications in Africa's Resurging Uranium Industry: A Review

Sole, Kathryn C.; Cole, Peter M.; Feather, Angus M.; Kotze, Marthie H.

doi:10.1080/07366299.2011.581101

Cited by 34 publications

(20 citation statements)

References 8 publications

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“…Due to its potential toxicological effects, it has been become necessary and urgent to remove chromium from drinking water. Many treatment techniques such as ion exchange, chemical precipitation, reverse osmosis, membrane separation, solvent extraction and filtration [10][11][12][13][14] have been suggested for removal and up take of dichromate from water. Adsorption is considered as an effective, economical and environmentally friendly method for removal of heavy metal ions from aqueous solutions and attracts significant attention in the treatment of water 15 .…”

mentioning

confidence: 99%

Novel synthesis of Ni/Fe layered double hydroxides using urea and glycerol and their enhanced adsorption behavior for Cr(VI) removal

El-Reesh

Farghali

Taha

et al. 2020

Sci Rep

133

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Novel modified Ni/Fe layered double hydroxides with different morphology of spherical-like shape were fabricated via using urea as a ligand and glycerol (Ni/Fe LDH/GL) with Ni:Fe molar ratios of 2:1 by the simplest co-precipitation method. Also, for comparison purposes, Ni/Fe LDH was synthesized to be used as a control one. A suggested interpretation for the morphology change was also given. The materials were characterized by X-ray diffraction (XRD), The Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), EDX for elemental analysis, high resolution transmission electron microscopy (HRTEM), Brunauer, Emmett, and Teller (BET) equation, particle size distributions and Zeta potential measurements. In addition, the synthesized materials were used as adsorbents for removal of potassium dichromate from aqueous solutions under various experimental conditions. The adsorption of Cr (VI) was strongly pH dependant and the pH PZC was studied. Kinetic studies were evaluated through different models including, pseudo first and second orders, mixed 1, 2 orders, intra particle diffusion and Avrami models. For adsorption isotherms, twoparameter models (Langmuir, Freundlich and Temkin) and three parameter models (Sips, Langmuir-Freundlich and Tooth) were investigated showing maximum adsorption capacity of 50.43 mg/g and 136.05 mg/g for Ni/Fe LDH and Ni/Fe LDH/GL, respectively. Also, the effect of temperature was investigated at (23, 35, 45, 55 °C) and the thermodynamic parameters (∆H°, ∆S° and ∆G°) were calculated showing exothermic and spontaneous adsorption process. The effect of coexisting anions (cl − , So 4 2− and HPO 4 2−) and humic acid at different concentrations on the removal efficiency of dichromate ions was investigated. Chemical stability and recyclability of these adsorbents were also studied. The intermolecular hydrogen bonds formation between dichromate ion, urea, glycerol, LDH was explored by Monte Carlo simulation This study suggested that the modified Ni/Fe LDH/GL materials were promising nanoadsorbents for efficient potassium dichromate removal. Water is the most precious natural source important for human beings, agriculture, and industrial activities. Recently, water bodies are potentially contaminated and polluted by many hazardous materials such as nuclear and industrial wastes, pharmaceuticals, organic contaminants and heavy metals. Heavy metals like cadmium, zinc, copper, lead, arsenic, mercury and chromium have significant threat to human health due to its potentially toxic effects 1,2. Chromium is one of heavy metals widely used in many industrial processes such as electroplating, dyes, mining, photography, textile and leather 3. Chromium present in water in a trivalent and hexavalent oxidation state, it is established that hexavalent chromium exhibits high toxicity toward living organisms than trivalent chromium which in contrast is a micronutrient 4. Hexavalent chromium is reported as a cause of respiratory cancers 5,6 and mutations and chromosomal dam...

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mentioning

confidence: 99%

Novel synthesis of Ni/Fe layered double hydroxides using urea and glycerol and their enhanced adsorption behavior for Cr(VI) removal

El-Reesh

Farghali

Taha

et al. 2020

Sci Rep

133

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“…Thus, in summary, the technologies required for the bio-processing of more complex, polymetallic ores and other materials have been developed, piloted and/or demonstrated. In addition, the advances briefly described above have been underpinned by concomitant progress in the separation and purification of many of the elements in the periodic table using solvent extraction or ion-exchange technologies [191][192][193][194]. Given the technology developments and the remarkable resilience and adaptability of acidophilic microorganisms, it is not surprising that numerous studies on the application of biohydrometallurgy to many different metal-rich materials from primary mineral resources, secondary mining products and numerous "manufactured" resources have been described.…”

Section: Technology Developmentsmentioning

confidence: 99%

Review of Biohydrometallurgical Metals Extraction from Polymetallic Mineral Resources

Watling

2014

Minerals

138

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This review has as its underlying premise the need to become proficient in delivering a suite of element or metal products from polymetallic ores to avoid the predicted exhaustion of key metals in demand in technological societies. Many technologies, proven or still to be developed, will assist in meeting the demands of the next generation for trace and rare metals, potentially including the broader application of biohydrometallurgy for the extraction of multiple metals from low-grade and complex ores. Developed biotechnologies that could be applied are briefly reviewed and some of the difficulties to be overcome highlighted. Examples of the bioleaching of polymetallic mineral resources using different combinations of those technologies are described for polymetallic sulfide concentrates, low-grade sulfide and oxidised ores. Three areas for further research are: (i) the development of sophisticated continuous vat bioreactors with additional controls; (ii) in situ and in stope bioleaching and the need to solve problems associated with microbial activity in that scenario; and (iii) the exploitation of sulfur-oxidising microorganisms that, under specific anaerobic leaching conditions, reduce and solubilise refractory iron(III) or manganese(IV) compounds containing multiple elements. Finally, with the successful applications of stirred tank bioleaching to a polymetallic tailings dump and heap bioleaching to a polymetallic black schist ore, there is no reason why those proven technologies should not be more widely applied.

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“…Although this device has some merits like a simple structure, low cost and is effective to some extent, there are still problems such as low efficiency [13], too many extraction stages, emulsifying easily [14][15][16][17] and occupation and fire risks [18].…”

Section: Introductionmentioning

confidence: 99%

Solvent extraction of In3+ with microreactor from leachant containing Fe2+ and Zn2+

Ju¹,

Peng²,

Wei³

et al. 2014

Green Processing and Synthesis

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The microreactor has been developed for a wide range of applications because of many advantages, such as high mass transfer efficiency, low energy consumption and the closed and safe system. The application of microreactors in the traditional hydrometallurgy extraction process is expected to overcome difficulties such as coextraction of impurities, large consumption of extractant and hidden fire risks. In this study, the extraction and separation efficiency of In 3+ from a complex sulfate solution containing impurities, such as Fe 2+ and Zn 2+ , were studied. The microreactor extraction was carried out in a Pyrex microchip, and the organic phase was prepared with the extractant di(2-ethylhexyl) phosphoric acid (D2EHPA) diluted in 260# kerosene. The results showed that with only 0.55 s contact between the organic and aqueous phases, the extraction ratio of In 3+ can reach 90.80%, while only 0.16% of Fe 2+ and 0.22% of Zn 2+ were co-extracted; the average mass transfer speed of In 3+ was calculated as high as 0.34 g·m -2 ·s -1 . Compared with the traditional mixing settler process, microreactor extraction has advantages of higher extraction ratio of In 3+ , lower trend of co-extraction of the impurities and emulsification.

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Solvent Extraction and Ion Exchange Applications in Africa's Resurging Uranium Industry: A Review

Cited by 34 publications

References 8 publications

Novel synthesis of Ni/Fe layered double hydroxides using urea and glycerol and their enhanced adsorption behavior for Cr(VI) removal

Novel synthesis of Ni/Fe layered double hydroxides using urea and glycerol and their enhanced adsorption behavior for Cr(VI) removal

Review of Biohydrometallurgical Metals Extraction from Polymetallic Mineral Resources

Solvent extraction of In3+ with microreactor from leachant containing Fe2+ and Zn2+

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