| 1. |
- Kaya, Şerif, et al.
(författare)
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Scandium Recovery from an Ammonium Fluoride Strip Liquor by Anti-Solvent Crystallization
- 2018
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Ingår i: Metals. - : MDPI. - 2075-4701. ; 8:10
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the crystallization of scandium from ammonium fluoride strip liquor, obtained by solvent extraction, was investigated using an anti-solvent crystallization technique. Acetone, ethanol, methanol and isopropanol were added individually to the strip liquor as the anti-solvent and scandium was precipitated and obtained in the form of (NH4)3ScF6 crystals. The results show that scandium can be effectively crystallized from the strip liquor to obtain an intermediate, marketable scandium product. Yields greater than 98% were obtained using an anti-solvent to strip liquor volumetric ratio of 0.8. Acetone had the least performance at lower anti-solvent to strip liquor volumetric ratios, possibly due to its limited H bonding capability with water molecules when compared to alcohols.
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| 2. |
- Köroğlu, Münevver, et al.
(författare)
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One step production of silver-copper (Agcu) nanoparticles
- 2021
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Ingår i: Metals. - : MDPI AG. - 2075-4701. ; 11:9
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Tidskriftsartikel (refereegranskat)abstract
- AgCu nanoparticles were prepared through hydrogen-reduction-assisted Ultrasonic Spray Pyrolysis (USP) and the Hydrogen Reduction (HR) method. The changes in the morphology and crystal structure of nanoparticles were studied using different concentrated precursors. The structure and morphology of the mixed crystalline particles were characterized through X-ray diffraction analysis (XRD), scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM) and Energy-dispersive X-ray spectroscopy (EDS). The average particle size decreased from 364 nm to 224 nm by reducing the initial solution concentration from 0.05 M to 0.4 M. These results indicate that the increase in concentration also increases the grain size. Antibacterial properties of nanoparticles against Escherichia coli were investigated. The obtained results indicate that produced particles show antibacterial activity (100%). The AgCu nanoparticles have the usage potential in different areas of the industry.
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| 3. |
- Ma, Yiqian, et al.
(författare)
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A cleaner approach for recovering Al and Ti from coal fly ash via microwave-assisted baking, leaching, and precipitation
- 2021
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Ingår i: Hydrometallurgy. - : Elsevier. - 0304-386X .- 1879-1158. ; 206
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Tidskriftsartikel (refereegranskat)abstract
- Coal fly ash (CFA) is a potential mineral resource from which to recover Al and other valuable metals. In this study, a new processing technology for the recovery of Al and Ti from CFA has been developed and comprehensively investigated. The baking process applied in previous work has been improved by using microwave heating and a mixture of H2SO4 + NH4HSO4 as the extractant. This method enhanced the Al and Ti extraction efficiencies, while decreasing energy consumption and gas emissions relative to other acidic baking processes. When employing the optimized baking and leaching parameters (baking conditions: 280 degrees C, 1.2 times the theoretical amount of reagents, 60 min; leaching conditions: 60 degrees C, L/S: 5 g water to 1 g baked ash, 30 min) 82.4% Al and 55.6% Ti could be extracted. Scanning electron microscopy images and X-ray diffraction analysis indicated that most of the mullite (3Al(2)O(3).2SiO(2)) in the CFA was transformed into godovikovite (NH4Al(SO4)(2)) and quartz (SiO2) after microwave-assisted baking. The soluble salts were then leached into solution, while the quartz remained in the residue. Precipitation allowed for the recovery and separation of Al and Ti from the leach solution. Al was selectively recovered via NH4Al(SO4)(2)center dot 12H(2)O precipitation after maintaining the solution at 0 degrees C for 10 h. A high-quality product of alumina was obtained from the NH4Al(SO4)(2)center dot 12H(2)O. After reducing the iron in the solution from Fe3+ to Fe2+, Ti was recovered via hydrolysis after increasing the pH to 3.1. The Ti precipitate contained 44.2% Ti with a small amount of impurity. The developed approach was cleaner and more efficient than those reported to date for the recovery of Al and Ti from stable CFA.
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| 4. |
- Ma, Yiqian, et al.
(författare)
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Basic Sulfate Precipitation of Zirconium from Sulfuric Acid Leach Solution
- 2020
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Ingår i: Metals. - : MDPI AG. - 2075-4701. ; 10:8, s. 1099-
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Tidskriftsartikel (refereegranskat)abstract
- H2SO4 was ensured to be the best candidate for Zr leaching from the eudialyte. The resulting sulfuric leach solution consisted of Zr(IV), Nb(V), Hf(IV), Al(III), and Fe(III). It was found that ordinary metal hydroxide precipitation was not feasible for obtaining a relatively pure product due to the co-precipitation of Al(III) and Fe(III). In this reported study, a basic zirconium sulfate precipitation method was investigated to recover Zr from a sulfuric acid leach solution of a eudialyte residue after rare earth elements extraction. Nb precipitated preferentially by adjusting the pH of the solution to around 1.0. After partial removal of SO42− by adding 120 g of CaCl2 per 1L solution, a basic zirconium sulfate precipitate was obtained by adjusting the pH to ~1.6 and maintaining the solution at 75 °C for 60 min. Under the optimum conditions, the loss of Zr during the SO42− removal step was only 0.11%, and the yield in the basic zirconium sulfate precipitation step was 96.18%. The precipitate contained 33.77% Zr and 0.59% Hf with low concentrations of Fe and Al. It was found that a high-quality product of ZrO2 could be obtained from the basic sulfate precipitate.
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| 5. |
- Vieceli, Nathalia Cristine, 1989, et al.
(författare)
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Recycling of Li-Ion Batteries from Industrial Processing: Upscaled Hydrometallurgical Treatment and Recovery of High Purity Manganese by Solvent Extraction
- 2023
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Ingår i: Solvent Extraction and Ion Exchange. - : Informa UK Limited. - 0736-6299 .- 1532-2262. ; 41:2, s. 205-220
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Tidskriftsartikel (refereegranskat)abstract
- Manganese plays a central role in lithium-ion batteries (LIBs) but its recycling is rarely addressed when compared to other valuable metals present in LIBs, such as Co and Ni. Thus, the main goal of this work was to study and achieve the separation of Mn from Co and Ni by solvent extraction from a leachate obtained from LIBs using hydrochloric acid in an upscaled reactor, which is an innovative aspect of this work. The results confirmed the high selectivity of D2EHPA towards Mn, which could be completely extracted in two stages (0.5 M D2EHPA at pH 2.5). The main co-extracted metals were Al, Cu and Co, but with lower concentrations than Mn. The behavior of minor impurities such as Zn and Mg was also monitored. Scrubbing using manganese chloride was crucial to remove impurities from the loaded organic and prevent their presence in the stripping product, and high O:A ratios negatively affected the scrubbing efficiency. Keeping the concentration of HCl up to 0.5 M in the stripping stage helped to limit the stripping of impurities. Manganese oxide was precipitated as a product with 99.5% purity (with traces of Zn, Cu and Co), which could be reused in the battery value chain.
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| 6. |
- Vieceli, Nathalia Cristine, 1989, et al.
(författare)
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Solvent extraction of cobalt from spent lithium-ion batteries: Dynamic optimization of the number of extraction stages using factorial design of experiments and response surface methodology
- 2023
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Ingår i: Separation and Purification Technology. - : Elsevier BV. - 1873-3794 .- 1383-5866. ; 307
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Tidskriftsartikel (refereegranskat)abstract
- The optimization of lithium-ion batteries (LiBs) recycling is crucial not only from a waste management perspective but also to decrease the dependence on imports of critical raw materials. In addition, the diversification of the recycling technologies is very important for better flexibility of the market. This study aims at investigating the recovery of Co from spent LiBs using solvent extraction from a real chloride-based solution obtained after the removal of Mn, which is very rarely reported. Cyanex 272 was used as the extractant and the effect of several variables on the extraction efficiency was considered to model and optimize the separation of Co and Ni. The number of extraction stages directly affects not only the process efficiency but also its cost. Thus, in this work, a novel approach was developed to assist in the selection of the number of extraction stages using a dynamic method based on the factorial design of experiments and response surface methodology combined with the Kremseŕs Equation. This method can assist the process design, decrease the overall cost of the operation, and optimize the separation of Co and Ni in a reduced number of extraction stages. The concentration of Co and Ni in the feed solutions is ∼ 8.3 g/L and 1.9 g/L, respectively. Based on the results, 98% extraction efficiency for Co can be achieved in 1 to 2 extraction stages with low co-extraction of Ni (<5%) when using 0.6–0.8 M Cyanex 272, O:A ratio below 1 and pH ∼ 5, but several combinations of conditions could provide similar results.
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| 7. |
- Özcelik, Duygu Yeşiltepe, et al.
(författare)
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Mixed oxides NiO/ZnO/Al 2 O 3 synthesized in a single step via ultrasonic spray pyrolysis (USP) method
- 2022
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Ingår i: Metals. - : MDPI AG. - 2075-4701. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Mixed oxides have received remarkable attention due to the many opportunities to adjust their interesting structural, electrical, catalytic properties, leading to a better, more useful performance compared to the basic metal oxides. In this study, mixed oxides NiO/ZnO/Al2O3 were synthesized in a single step via the ultrasonic spray pyrolysis method using nitrate salts, and the temperature effects of the process were investigated (400, 600, 800 °C). The synthesized samples were characterized by means of scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and Raman spectroscopy analyses. The results showed Al2O3, NiO–Al2O3 and ZnO–Al2O3 systems with spinel phases. Furthermore, the Raman peaks supported the coexistence of oxide phases, which strongly impact the overall properties of nanocomposite.
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