Browsing by All Authors "Timur, Servet"

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    ASSESSING CYANEX 272 and BINARY EXTRACTANTS for the SEPARATION of PRASEODYMIUM and NEODYMIUM in EXTRACTION of ESKİŞEHİR – BEYLİKOVA RARE EARTH ORES
    (Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-04-26) Gezici, Utku Orçun; Baştürkcü, Esra; Arslan-Kaba, Mehtap; Ertürk, Selim; Sözer, Belma Soydaş; Kartal Şireli, Güldem; Timur, Servet
    Rare earth elements (REEs) are essential in various industrial applications due to their high magnetic susceptibility, low density, and thermal stability. Praseodymium is used in producing yellow pigments for glass and ceramics, while Neodymium is crucial in producing powerful permanent magnets and laser applications. Technological advancements have driven the demand for Pr and Nd and increased the need for a reliable supply chain. The primary sources of Pr and Nd are minerals like monazite, bastnasite, and xenotime, which require complex separation processes due to their mixed contents. The main secondary sources include electronic waste, particularly from permanent magnets. The difficulty in the extraction of REEs lies in their closely related chemical and physical properties. Solvent extraction (SX), based on differences in ionic radii, is a widely used method for REE separation in industrial applications. Nevertheless, the similarity in Pr and Nd ionic radius complicates their separation compared to other REEs. This research examined the effectiveness of Cyanex 272 in the SX process for separating Pr and Nd, as well as its potential for improvement through the use of binary extractant combinations viz. Cyanex 572, Cyanex 801, Cyanex 923, as well as DEHPA. The synthetically prepared aqueous solution was composed of 400 ppm Pr and 800 ppm Nd. The extraction efficiency and selectivity were determined by using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The findings revealed that the loading efficiencies for Pr and Nd varied with the concentration of Cyanex 272, namely Pr loading efficiencies ranging from 5.5% to 24.4%, and Nd from 6.7% to 31.3%. Notably, binary extractant experiments indicated that mixtures incorporating Cyanex 272 with DEHPA, Cyanex 572, and Cyanex 801 exhibited enhanced extraction efficiencies compared with the sole Cyanex 272. On the other hand, the combination of Cyanex 272 and Cyanex 923 resulted in a diminished extraction efficiency. These obtained outcomes could potentially adapt to the development of domestic technology for the extraction of REEs from the Eskişehir Beylikova REE Ores.
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    Production of Metallic Lanthanum from Its Oxide Form via Molten Salt Electrolysis
    (Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-04-26) Özer, Osman Can; Arslan Kaba, Mehtap; Kartal Şireli, Güldem; Soydaş Sözer, Belma; Timur, Servet
    Lanthanides, including the elements with the atomic number of 57 to 71, scandium, and yttrium are the seventeen chemically related elements known as rare earth elements (REEs). Despite their misleading name, “rare earth”, these elements are not rare in the Earth’s crust. Instead, the term refers to the challenge of separating and obtaining them in their pure form due to their similar chemical properties. REEs are crucial in a variety of high-technology applications, namely the military, the automobile industry, electrical engineering, optics, catalysts, wind turbines, and other sustainable energy systems, due to their exceptional physical and chemical properties. Because of the growing demand for REEs in functional materials, the recovery of REEs from secondary resources has become critical to the transition to a green economy. The primer REEs extraction process consists of mining, physical beneficiation, chemical treatments, separation, and reduction. In the reduction step, where REEs reduce to metal form, electrolytic methods (molten salt electrolysis) and metallothermic methods are prominently discussed in the open literature. Electrolytic methods can operate continuously and outperform metallothermic techniques in terms of production capacity and controllability, as well as product purity. Nowadays, two types of electrolytes are commonly used in the electrolytic production of REEs: fluoride- and chloride-based molten salts. The main issues with the widely used electrochemical extraction of rare earth oxides in fluoride-based molten electrolytes are lower solubility and lower energy efficiencies, as well as higher emissions of greenhouse gases, such as CO2 and perfluorocarbons, which are extremely harmful to the environment. Given the current limitations of fluoride systems, molten chloride-based electrolytes appear to be a preferable option. To achieve lower melting points (e.g., 650 °C) and higher product purities (i.e., 99%), common chloride electrolytes are composed of RECl3 (RECl3= rare earth chlorides) and additional chlorides, such as NaCl, KCl, BaCl2, and CaCl2. Thus, we concentrated on molten salts based on chlorides containing RECl3. To overcome the low solubility of rare earth oxides in molten chloride salts and toxic oxychloride formations, RECl3 salts were used. RE2O3 was converted to RECl3 in a separate system through chlorination. Furthermore, the need to work in a controlled atmosphere due to REEs high oxygen affinity made the electrolysis cell design critical. As a result, the electrochemical cell was designed and installed, and the effects of process parameters such as electrolyte composition, temperature, current efficiency, and electrolysis time were investigated systematically. X-ray diffractometry (XRD) and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) were used to characterize the produced La. The maximum current efficiency was found to be 73.5%. These obtained results could potentially be implemented during the development of domestic technology for the electrolytic extraction of REEs from Turkey Eskişehir Beylikova REEs ores.
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    SELECTIVE SEPARATION OF SAMARIUM FROM LIGHT RARE EARTH ELEMENTS via pH-CONTROLLED SOLVENT EXTRACTION
    (Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-04-26) Tunç, Melike; Gezici, Utku Orçun; Baştürkcü, Esra; Ertürk, Selim; Soydaş Sözer, Belma; Kartal Şireli, Güldem; Timur, Servet
    Rare Earth Elements (REEs) are essential for advanced technologies due to their unique properties. This study presents a pH-controlled solvent extraction method to separate Samarium (Sm) from light REEs simulating Beylikova REE leaching liquid. The process, utilizing 0.75 M DEHPA in kerosene, showed that Sm achieved a 59% extraction efficiency at pH 0.5, significantly higher than La, Pr, and Nd. This pH optimization enhances the sustainability and efficiency of REE extraction, promoting the effective utilization of Turkey's REE resources and domestic technologies.