Sürdürülebilir Kalkınma Amaçları
Yayınları
9 →- MakaleYalnız künye2026Scopus SJRQ2An integrated process for rare earth elements recovery and silica production from Turkish bauxite-related ores
Uysal, Turan; Erüst, Ceren; Erdemoglu, Murat; Sis, Hikmet
The evaluation of bauxite-associated shales as a secondary source of rare earth elements (REEs) is strategically important for securing a sustainable supply of critical raw materials used in advanced technologies. In this study, shale ore associated with bauxite, unsuitable for aluminium production due to its high silica content, was investigated as a potential resource for valuable REEs. The effect of thermal activation on REE recovery was examined, and the potential use of the leach residue as a silica source was assessed. Based on acid leaching results, the optimum calcination temperature was identified as 700 degrees C. Under these conditions, high REE recoveries were achieved: 92.9% La, 89.9% Ce, 89.0% Pr, 88.7% Nd, and 73.0% Sm. After leaching, the residue was enriched in alumina and silica. To improve silica purity and recover remaining REEs and Al, a second-stage leaching process was applied. This resulted in a byproduct containing 55% SiO2 with a specific surface area of 48 m2 g-1, indicating its potential as a silica source. The results demonstrate that bauxite-associated shale can be sustainably valorised through intensive milling, calcination, and acid leaching, enabling efficient REE recovery and the production of a silica-rich byproduct. L'& eacute;valuation de schistes associ & eacute;s & agrave; la bauxite comme source secondaire d'& eacute;l & eacute;ments de terres rares (ETR) est strat & eacute;giquement importante pour garantir un approvisionnement durable en mati & egrave;res premi & egrave;res critiques utilis & eacute;es dans les technologies avanc & eacute;es. Dans cette & eacute;tude, on a examin & eacute; le minerai de schiste associ & eacute; & agrave; la bauxite, inappropri & eacute; & agrave; la production d'aluminium en raison de sa teneur & eacute;lev & eacute;e en silice, comme ressource potentielle d'ETR pr & eacute;cieux. On a examin & eacute; l'influence de l'activation thermique sur la r & eacute;cup & eacute;ration des ETR et l'on a & eacute;valu & eacute; l'utilisation potentielle du r & eacute;sidu de lixiviation comme source de silice. D'apr & egrave;s les r & eacute;sultats de la lixiviation acide, on a identifi & eacute; la temp & eacute;rature optimale de calcination & agrave; 700 degrees C. Dans ces conditions, on a obtenu des r & eacute;cup & eacute;rations d'ETR & eacute;lev & eacute;es: 92.9% de La, 89.9% de Ce, 89.0% de Pr, 88.7% de Nd et 73.0% de Sm. Apr & egrave;s la lixiviation, le r & eacute;sidu & eacute;tait enrichi en alumine et en silice. Afin d'am & eacute;liorer la puret & eacute; de la silice et de r & eacute;cup & eacute;rer les ETR et l'Al restants, on a appliqu & eacute; une deuxi & egrave;me & eacute;tape de lixiviation. Cela a engendr & eacute; un sous-produit contenant 55% de SiO2 et pr & eacute;sentant une surface sp & eacute;cifique de 48 m2/g, indiquant son potentiel en tant que source de silice. Les r & eacute;sultats d & eacute;montrent que le schiste associ & eacute; & agrave; la bauxite peut & ecirc;tre valoris & eacute; de mani & egrave;re durable par broyage intensif, calcination et lixiviation acide, permettant une r & eacute;cup & eacute;ration efficace des ETR et la production d'un sous-produit riche en silice.
- MakaleAçık Erişim2026Scopus SJRQ3Optimized bioleaching of spent FCC catalysts for the recovery of critical metals
Erust, Ceren; Altındaş, Mediha Demet Okudan
Spent fluid catalytic cracking (FCC) catalysts, generated in large volumes by petroleum refining, represent a promising secondary source of critical metals such as lanthanum, cerium, titanium, and vanadium. In this study, a biohydrometallurgical approach was applied to recover these metals using Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans. The spent FCC catalyst, supplied by petroleum refinery, was characterized through WD-XRF, XRD, SEM-EDS, and ICP-OES analyses, confirming significant concentrations of La2O3 (1.44%), TiO2 (1.43%), and CeO2 (0.23%). Bioleaching experiments were conducted under varying initial ferrous ion concentrations (1–9 g/L) and pulp densities (5–20% w/v) at 35°C over 14 days. Results revealed that the optimal conditions for maximum recovery occurred at 5 g/L Fe2+ and 10% pulp density, achieving leaching efficiencies of 95.5% for La, 90.5% for Ce, 92.5% for Ti, and 60.8% for V within seven days. Beyond this period, efficiency decreased due to jarosite formation and microbial activity constraints. The findings confirm that bioleaching is a cost-effective and sustainable route that aligns with circular economy principles by reducing reliance on virgin rare earth mining while mitigating the environmental impact of catalyst disposal.
- MakaleYalnız künye2026Scopus SJRQ2Kinetic investigation on the recovery of copper and cobalt from sulphuric acid plant electrofilter dust
Erust, Ceren
Several waste dusts collecting equipment options are available for air pollution control in plants, the most commonly used being the electrofilter. Industrial wastes such as electrofilter dust are evaluated as a secondary resource owing to their critical metal contents. In this work, the results of studies on the extraction of cobalt and copper from electrofilter dust generated in sulphuric acid production plants are presented. The chemical and mineralogical compositions of the dust were investigated using instrumental analytical methods. The electrofilter dust consists of the main phases of haematite, quartz, and anhydrite. Also, electrofilter dust contains 1.43% copper and 0.28% cobalt. It was found that the process of copper and cobalt dissolution is characterized by chemical kinetics. When the acid leaching was applied in 1 M sulphuric acid in the presence of 0.05 M hydrogen peroxide, with the temperature 80°C and 2 h of leaching time, stirring rate of 200 rpm and liquid to solid ratio 20/1 v/w, cobalt and copper extraction achieved 88% and 98% respectively. As a result of studying the kinetics of acid leaching with sulphuric acid in the presence of oxidant hydrogen peroxide, activation energy and the type of reaction to chemical controlled model were determined.
AtıfScopus2WoS2OpenAlex1
İncele - MakaleAçık Erişim2026Scopus SJRQ2Solvent extraction of rare earth elements and α-alumina production from pregnant leaching solution obtained from Turkish bauxite-related ore
Erust, Ceren; Uysal, Turan
The use of bauxite-related shales as a secondary source for the extraction of rare earth elements (REEs) is very important to meet the raw material supply, which is the keystone of advanced technology applications. This study presents the investigation into the recovery of REEs from Kızıldağ shale ore and the potential utilization of its leach residue as a silica source. Mineralogical analysis revealed that the ore predominantly consists of paragonite, muscovite, quartz, pyrophyllite, and calcite. Calcined ore was subjected to acid leaching, and the resulting pregnant solution was purified using solvent extraction to separate from aluminum the ∑REEs with a content of 1887.35 ppm. Optimal solvent extraction conditions 1.5 M D2EHPA, 50% O/A ratio, pH 1.5, and 15-minute mixing time achieved 95% total REE extraction, with efficiency in the order Pr > La > Nd > Ce > Dy > Y > Sc. To purify Al from the Fe- and K-rich solution post-SX, electrolysis was performed, resulting in 97.16% precipitation efficiency of Al as Al(OH)3 at pH 5. The precipitate was subsequently roasted at 1100°C to produce α-alumina with 75.2% Al2O3 content. These findings confirm the technical feasibility of recovering REEs and producing coarse-purity alumina from Kızıldağ shale ore.
AtıfScopus1WoS3OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ3Optimization of rare earth elements recovery from Kızıldag (Karaman-Türkiye) shale ore using response surface methodology
Uysal, Turan; Ünal, Ceren Erust; Akça, Muhammet Esat; Sis, Hikmet; Erdemoğlu, Murat
In this study, the usability of bauxite-related shale ore, rich in Rare Earth Elements (REEs), to produce REEs, which have high added value and critical importance, was investigated. In this context, Kızıldag (Karaman-Türkiye) shale ore, was prepared for tests through size reduction and sampling processes. HCl leaching was performed at different acid concentrations, leaching times, leaching temperatures, and liquid/solid ratios to determine the optimum leaching conditions for the milled ore. The modeling and optimization parameters related to leaching recovery were investigated using the response surface method (RSM). The results were evaluated using analysis of variance, three-dimensional graphs were drawn, and the accuracy of the models was discussed. Accordingly, optimum values were found, and the REE leaching recovery corresponding to these optimum values was 49.13%. It was concluded that the optimization results were compatible with the experimental results, and the average error rate (6.35%) was low.
AtıfScopus3OpenAlex4İncele - MakaleYalnız künye2025Scopus SJRQ1The Extraction of Rare-Earth Elements (REEs) from Spent Nickel–Metal Hydride (Ni–MH) Batteries by Bifunctional Ionic Liquids (Bif-ILs): Process Optimization and Kinetics Modeling
Erust, Ceren
The cathode material of nickel–metal hydride (Ni–MH) batteries includes nickel, cobalt, and rare-earth elements (REEs) such as La, Ce, Nd, and Pr, which are among the critical raw materials (CRMs). Ionic liquids as the environmentally friendly approaches are proposed by various investigations for the extraction of critical metals from spent Ni–MH batteries. In this study, three different Bifunctional Ionic Liquids (Bif-ILs) were designed for comparative studies, namely Aliquat 336–Cyanex 272 (AL–CY), Aliquat 336–PC88A (AL–PC), and Aliquat 336–D2EHPA (AL–D2). The extraction results indicated that temperature has a direct effect on the extraction of critical metals in the presence of all Bif-ILs. Among three types of Bif-ILs, AL–D2 has an optimal extraction power (La: 98.8%, Ce: 94.2%, Nd: 99.2%, and Pr: 98.4%) after precipitation of 99.99% of Ni and Co. Furthermore, kinetics modeling is used for reaction mechanisms investigation. Results indicated that the mixed controlled model by shrinking core model (diffusion controlled and chemical reaction controlled) was the best model fitted to all data (coefficient of determination (R2) > 0.90). according to the Arrhenius equation, activation energies for all REEs in the presence of all Bif-ILs are between 13 and 42 kJ/mol that reflects a mixed controlled reaction.
AtıfScopus2OpenAlex2İncele - Derleme MakaleYalnız künye2023Scopus SJRQ1Hydrometallurgical Roadmaps and Future Strategies for Recovery of Rare Earth Elements
Erust, C.; Karacahan, M.K.; Uysal, T.
Increasing demand for low carbon technologies and renewable energy sources requires our resources and economies to be circular. Many countries agree that the responsible consumption, production, and recycling of rare-earth-containing products is essential as a way to achieve the sustainable development goals also set out in the European Green Deal. Sustainable sourcing is targeted with carefully designed roadmap for cost efficient REE production from end-of-life products (EoLs) in addition to mining activities as providing primary sources. Hydrometallurgical methods, such as roasting, leaching, precipitation, crystallization, solvent extraction, and ion exchange includes fast developing, selective, eco-friendly, and cost-effective technologies especially for the extraction of REEs. This article provides an overview of primary and secondary resources and summarizes presents case scenario of studies carried out on the use of some promising methods, which could serve as an economical means for recovering REEs.
AtıfScopus46WoS46OpenAlex51İncele - MakaleAçık Erişim2022Scopus SJRQ4Biyo-hidrometalurjik yöntemler ile kullanılmış vanadyum katalizörlerden vanadyumun geri kazanımı ve pilot ölçekli uygulamalar için tekno-ekonomik analiz
Erüst, Ceren
Sülfürik asit üretiminde katalitik indirgemeyi sağlayan vanadyum katalizörlerinin yaygın kullanımı, tehlikeli atık olarak kabul edilen kullanılmış katalizörlerin zamanla daha da artmasına neden olmaktadır. Kullanılmış vanadyum katalizörler (KVK), yüksek oranda SiO₂ ve ağır metal içeriğinin yanında kritik metal listesinde yer alan vanadyumu da içermektedir. Döngüsel ekonomi politikası uygulamalarına yönelik artan talep, bu atıklardan vanadyumun kazanımı için tekno-ekonomik açıdan uygun bir yol geliştirmeyi gerektirmektedir. Bu çalışmada, kimyasal liç (1 M sülfürik asit ve %1 h/h hidrojen peroksit) ve biyoliç (Acidithiobacillus ferrooksidans, Acidithiobacillus thiooxidans ve Leptospirillum ferrooxidans içeren karışık bakteri kültürü) yöntemleri kullanılmış ve KVK’lardan vanadyum kazanımı değerlendirilmiştir. Katalizörlerde bulunan vanadyum, hidrometalurjik ve biyohidrometalurjik yöntemlerle yüksek verimle (%96,8 ve %97,1) kazanılmıştır. Geliştirilen modelleme de biyohidrometalurjik yöntemin yatırım maliyetinin 3,8 yılda geri karşılanacağı ve geri ödeme yüzdesi %89,32 olarak öngörülmüştür. Hidrometalurjik yöntemde ise, yatırım maliyetinin 1,2 yılda karşılanacağı ve geri ödeme yüzdesinin %80,3 olduğu belirlenmiştir. Bu sonuçlar hidrometalurjik yaklaşımın daha hızlı, biyohidrometalurjik yaklaşımın ise daha ekonomik bir yöntem olduğunu göstermiştir.
- Derleme MakaleAçık Erişim2022Scopus SJRQ4Kritik Hammaddelerin Geri Dönüşüm ile Döngüsel Ekonomiye Kazandırılması
Okudan, Mediha Demet; Akcil, Ata; Erust, Ceren
Endüstri 4.0 devrimi ve Nesnelerin İnterneti (IoT) gibi teknolojilerle dijitalleşme, kaynaklarımızın ve ekonomilerimizin döngüsel olmasını gerektirmektedir. Başta Avrupa Birliği olmak üzere tüm ülkeler, kritik hammaddelerin sorumlu tüketiminin, üretiminin ve geri dönüşümünün sürdürülebilir kalkınma hedeflerine ulaşmanın bir yolu olarak çok önemli olduğu konusunda hemfikirdir. Ömrünü tamamlamış ürünlerden kritik hammaddelerin geri kazanılması için uygun maliyetli bir geri dönüşüm yöntemi, madencilikten çok daha az çevresel etkiye sahiptir. Biyo & hidrometalurjik yöntemler, kritik hammaddelerin, özellikle nadir toprak elementlerinin (NTE) çıkarılması için hızlı gelişen, seçici, çevre dostu ve uygun maliyetli teknolojilerdir. Bu makale, ikincil kaynaklara genel bir bakış sağlamakta ve kritik hammaddelerin kazanımı için ekonomik bir yol olarak hizmet edebilecek bazı umut verici yöntemlerin kullanımına ilişkin yürütülen çalışmaların senaryosunu özetlemektedir.
AtıfOpenAlex4TR Dizin1
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Tam Kayıt
| Alan | Değer | Dil |
|---|---|---|
| dc.date.accessioned | 2026-10-28T14:53:49.153410970Z | |
| dc.date.available | 2026-10-28T14:53:49.153410970Z | |
| dc.identifier.uri | https://rdlopen.rawdatalibrary.net/r/munzur/1004 | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.title | Erust, Ceren | |
| person.affiliation.name | Rare Earth Elements Application and Research Centre, Munzur University, Tunceli, Turkey | |
| person.familyName | Erust | |
| person.givenName | Ceren | |
| person.identifier.scopus | 55917754600 | |
| person.name.variant | Ünal, Ceren Erust | |
| person.name.variant | Erust, C. | |
| person.status | unverified |