Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu Kurumsal Araştırma Arşivi

Kurum yayınları ve kurum çalışanlarının yayınları “Açık Erişim” kapsamında yayınlanmaktadır. Açık Erişim “evrensel nitelikteki bilimsel bilginin insanlığın yararına sunulması” amacını taşır. Tezler, konferans bildirileri ve sunumlar ile makaleler kurum çalışanları tarafından sisteme girilmektedir.Tezler için; YÖK'ten alınan görüş doğrultusunda tez sahibinin izin vermesi yeterlidir. Konferans bildirileri ve sunumların yayına gönderildiği son hali arşive konulabilir.Makaleler için ise; hakem onayından geçmiş, yayına gönderildiği son halinin (post-print) Açık Erişime sunulmasına yayıncılar %90 oranında izin vermektedir. Arşivde şu an 1.639 yayın bulunmaktadır, çalışma bitiminde bu sayı yaklaşık 2.000 yayın sayısına ulaşacaktır.

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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.

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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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SELECTIVE SEPARATION of LANTHANUM USING DEHPA: INVESTIGATING THE POTENTIAL of EXTRACTING RARE EARTH ELEMENTS from ESKISEHIR BEYLIKOVA ORES

(Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-04-26) Tunç, Melike; Gezici, Utku Orçun; Özer, Osman Can; Arslan Kaba, Mehtap; Soydaş Sözer , Belma; Kartal Şireli, Güldem; Kartal Şireli, Güldem; Timur, Servet İ.

Rare Earth Elements (REEs) are essential components of advanced technology applications such as renewable energy, electronics, and defense. Their unique magnetic, catalytic, and luminescent properties render them essential for the development of high-performance materials. However, efficient and selective separation of individual REEs is a significant challenge owing to their chemical and physical similarities. This study focuses on the selective separation of lanthanum (La) from complex mixtures of REEs as it is crucial for the sustainable extraction of Eskişehir Beylikova Rare Earth Ore. In this study, solvent extraction (SX), a critical method for separating REEs, was carried out by using di (2-ethylhexyl) phosphoric acid (DEHPA) as the extractant. The selection of DEHPA was done based on its proven efficiency in REE SX processes, which offers a balance between selectivity and extraction capacity. For this purpose, various DEHPA concentrations in the organic phase were studied to obtain the optimal conditions for the selective separation of La from the leach liquor. The synthetically prepared leach liquor contained 5000 ppm La, 400 ppm Pr, 800 ppm Nd, and 200 ppm Sm. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) was utilized to determine the precise ion concentrations in the initial and extracted aqueous phases which ensured the accurate assessment of the extraction efficiency and selectivity. These initial findings revealed that the loading pattern is as follows: initial larger ionic radius La3+ (1.16 Å) loaded than after Pr3+ (1.13 Å), Nd3+ (1.11 Å), and Sm3+ (1.08 Å) came. The organic concentration was prepared ranging from 0.03M to 0.9M in kerosene. The loading efficiencies for La varied from 1.95% to 84.5%, whereas those for Sm, Pr, and Nd varied from 77.61% to 100%, from 41.69% to 99.17%, and from 27.78% to 97.68%, respectively, with increasing DEHPA concentrations. The outcomes demonstrated the feasibility of selective separation of La from other REEs using 0.03M DEHPA. The obtained results could be potentially adopted for the domestic production of REEs in the Eskişehir Beylikova Rare Earth 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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Synthesis, Characterizations and Applications of Organo-Rare-Earth-Metal Complexes for Organic Light Emitting Diode Applications

(Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-04-26) MARAŞLIOĞLU, Cem; CEVHER, Şevki Can; CANIMKURBEY, Betül; CAMCI, Merve Taner; ÇIRPAN, Ali

Lighting technologies are an indispensable part of this era and cover a wide area in many fields such as primary lighting and lighting in imaging sectors. Among these lighting technologies, organic light emitting diodes (OLEDs) attract attention due to their low potential operation, easy application to large areas, flexibility, lightness and high resolution. On the other hand, it is seen in the literature that organometallic complexes synthesized by using transition metals and some rare earth metals operate with high efficiency. This study is initiated by the motivation to increase the diversity in OLED applications and to synthesize applicable electroluminescent organometallic materials with high performance criterias. While imidazole derivatives, which are known to emit blue light are easy to synthesize and derivatize, were chosen as organic components, Europium (Eu), Lanthanium (La) and Terbium (Tb) metals were preferred as metals to be used in organometallic complexes. Imidazole-derivatives, which have electroluminescence alone, are expected to have high-intensity and narrow emission band possessing emission in their metal complexes taking advantage of the shielding properties of electrons in the outer orbit of rare earth metals (REMs) and inhibition of f-f electron transition. Structural characterizations are done by using infrared (IR) spectroscopy, 1H-NMR and 13C-NMR, optical characterizations are performed by UV-Vis spectroscopy (UV) and photoluminescence (PL) spectroscopy, electronical characterizations are completed by Cyclic Voltammetry (CV). Finally, the OLED applications has been completed and measured as external quantum efficiencies (EQEs), photoluminescence quantum yields (PLQYs), turn-on voltages and current density-voltage curves.

Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu Kurumsal Araştırma Arşivi

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