Browsing by Category "Konferans Ögesi- Uluslararası- Kurum Öğretim Elemanı"

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    Efficient Purification and Production of Rare Earth Metals from Bastnasite Ore: Beneficiation, Leaching, Solvent Extraction, and Metallothermic Reduction Approaches
    (Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-10-30) Koç Delice, Tülay; Türker, Gülşah; Kutluata, Onur Berk; Şeşen, Halil; Soydaş Sözer, Belma; Pıtıcescu, Radu Robert; Bogdanescu, Cristian
    Rare earth elements (REE) are one of the indispensable raw materials of modern technologies and are used in many critical applications such as magnetic materials, catalysts and batteries. The economic and efficient recovery of REE from ores is of great importance to reduce global supply risks [1,2] This study investigates the production of high purity rare earth metals by physical pre-benefication, leaching, solvent extraction and metallothermic reduction steps applied in the process of recovery of rare earth elements from bastnasite ore containing rare earth elements. Bastnasite occurs naturally with fluorite, barite, calcite, quartz, hematite and some silicates. Various methods, mainly gravity separation, magnetic separation, flotation and electrical separation, can be used to extract these gangue minerals [3]. In the present study, bastnasite ore was subjected to crushing-grinding-sieving processes and pre-enrichment process was carried out. The direct leaching and roasting methods were applied to the screened ore and the pre-beneficatio ore sample with a particle size of -45 µm was then subjected to mineral acid leaching with and without roasting. The effects of roasting temperature, roasting type, acid type, acid concentration on the leaching efficiency of the pre-enriched ore concentrate were investigated. Solvent extraction parameters were investigated for the purification and selective recovery of REEs from the REE loaded solution obtained. In the following stage of the study, we focused on the production of high purity rare earth metals from rare earth oxides purified by solvent extraction by metallothermic method. The metallothermic process is based on a reduction reaction, usually using reactive metals such as Ca or Mg. In this study, neodymium metal (Nd) production by metallothermic reduction method using neodymium oxide (Nd₂O₃) obtained after solvent extraction process with 95%-97% Nd content is discussed. Mg was selected as the reactive metal. The reduction reaction was carried out in vacuum under high temperature conditions (800-1000°C). As a result of metallothermic reduction, high purity neodymium sponge was obtained.
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    RECOVERY OF PLATINUM GROUP METALS FROM SCRAP AUTOMOTIVE CATALYSTS BY HYDROMETALLURGICAL METHOD
    (IMNR, 2024-10-30) Kaya, Yasemin; Arda, Tuğba; Güldür, Fatma Çiğdem
    Based on their economic importance and supply risk, platinum group metals (PGMs) are classified as critical elements by the European Commission. Meeting the increasing demand for PGMs is becoming more and more difficult due to the limited natural resources and depletion of high-grade ores [1,2]. A catalytic converter contains 0.1-0.5% PGMs such as Pt, Pd, and Rh, and the PGM content in catalytic converters is approximately a thousand times higher than the amount found in the ore [2]. For this reason, it is of great importance to obtain PGMs from non-traditional materials, such as scrap autocatalytic converters. This work aims to obtain high-efficiency, environmentally friendly, and economical PGM from the scrap catalytic converters with hydrometallurgical method. The scrap catalytic converter sample purchased from a Turkish supplier company in ground form was analysed to determine its PGM content. In order to investigate the roles of leaching temperature, T, solid to liquid ratio, S/L, and leaching time, t, the samples were treated with HCl and H2O2 solution under different leaching conditions. During leaching step, more than 98% Pt and Pd were taken into solution while Rh was leached more than 60% efficiency. Following the leaching step, the elements were separated from the leach solution by precipitation.