Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2026Scopus SJRQ2/r/munzur/4383
  An 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.

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  İncele
• MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/802
  Solvent 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.

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  AtıfScopus1·WoS3·OpenAlex1

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• MakaleAçık Erişim2025Scopus SJRQ3/r/munzur/2071
  Optimization 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.

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  AtıfScopus3·OpenAlex4

  İncele
• MakaleAçık Erişim2023/r/munzur/5765
  Pirofillit Cevherinden Alümina Üretimine Zenginleştirme Yöntemlerinin Etkisi

  Erdemoğlu, Murat; Uysal, Turan; Aydoğmuş, Ramazan

  Bu çalışmada, pirofillit cevherinden alüminyum (Al) kazanımı üzerine farklı zenginleştirme yöntemlerinin etkisi araştırılmıştır. Zenginleştirme yöntemleri pirofillitin doğal hidrofob yapısından dolayı flotasyon yöntemi, kırılganlık farklılığından dolayı ise Aşındırmalı Yıkama (AY) yöntemi kullanılmıştır. Zenginleştirme sonucu konsantre numunelere HCl ile liç işlemi yapılmış, liç sonucu çözeltiye geçen Al miktarları karşılaştırılarak değerlendirilmiştir. Pirofillit cevherinin AY yöntemi ile zenginleştirilmesi sonucu %54.79 verimle %27.44 Al2O3 tenörlü bir konsantre, flotasyon yöntemi ile ise %30.49 verimle %28.05 Al2O3 tenörlü bir konsantre elde edilmiştir. Buna göre zenginleştirme verimi açısından AY yöntemi daha verimli iken liç verimi açısından ise flotasyon yönteminin daha verimli olduğu belirlenmiştir. Tüvenan cevhere göre nihai alümina miktarı ve saflığı birlikte değerlendirildiğinde doğrudan liç ve AY konsantresi değerlerinin birbirine yakın olduğu belirlenmiştir. Sonuç olarak pirofillit cevherinden alümina üretimi için ayrıntılı ekonomik analiz yapılarak uygun yöntemin belirlenmesinin daha doğru olacağı değerlendirilmektedir.

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  İncele
• MakaleYayıncıda açık erişim2023Scopus SJRQ3/r/munzur/2611
  Potassium chloride recovery from mechanically activated microcline through the chlorination roasting and leaching route

  Alyosif, Bahaa; Uysal, Turan; Erdemoğlu, Murat

  In this study, effects of mechanical activation in the chlorination roasting and water leaching route known as CaCl2 process and developed for the production of potassium chloride (KCl) from potassium feldspar ores were studied. A microcline containing K-feldspar ore with 10.89% K2O was first intensively dry milled by a planetary ball mill and mixed with calcium chloride (CaCl2) and then roasted at temperatures up to 1000 °C to obtain KCl that will be finally dissolved by the water leaching. Potassium recovery by water leaching increased rapidly up to 800 °C. At higher temperatures, the recovery decreased fast due to the evaporation of KCl. According to the K recovery values per unit energy consumed, the optimum roasting temperature was determined as 750 °C and the milling time was 15 min. It was concluded that intensive milling causes mechanical activation of the microcline to reduce the chlorination roasting temperature, which triggers a rise in the K recovery by the water leaching.

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  AtıfScopus9·WoS8·OpenAlex7

  İncele
• Derleme MakaleYalnız künye2023Scopus SJRQ1/r/munzur/2455
  Hydrometallurgical 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.

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  AtıfScopus46·WoS46·OpenAlex51

  İncele
• MakaleYalnız künye2023Scopus SJRQ2/r/munzur/2328
  Aluminum Recovery by Acid Leaching of Variously Enriched Pyrophyllite Ore: Effects of Pre-treatment Methods for Activation

  Aydoğmuş, Ramazan; Erdemoğlu, Murat; Uysal, Turan

  Effects of pre-treatment methods such as calcination for thermal activation and intensive milling for mechanical activation on the aluminum (Al) recovery by acid leaching of preliminarily enriched pyrophyllite ore via attrition scrubbing and froth flotation were investigated. XRD patterns of the calcined and the intensively milled samples were compared to determine the changes during the pre-treatment processes. Hot HCl solution was used for dissolution of aluminum to determine the Al recoveries from variously enriched and variously pre-treated pyrophyllite ore samples. Specific thermal and milling energies consumed per unit amount of ore were calculated, and the ideal activation method was suggested by comparing the activation methods in terms of energy consumption. Mechanical activation of the pyrophyllite concentrate obtained by attrition scrubbing rather than froth flotation was suggested for higher recoveries of aluminum from by acidic leaching. It was determined that operating cost (in terms of energy) of the mechanical activation is lower and aluminum recovery is higher than thermal activation. It was concluded that mechanical activation instead of thermal activation is more economical and environmentally friendly method.

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  AtıfScopus5·WoS4·OpenAlex5

  İncele
• MakaleAçık Erişim2023Scopus SJRQ3/r/munzur/2321
  Optimization of shape factor by the response surface method, and the effect on sphalerite flotation recovery

  Uysal, T.

  Various morphological parameters that affect the flotation recovery of sphalerite were modelled and optimized using the response surface method (RSM). The effects of roughness value, shape factor, and collector concentration were investigated using the central composite full design method. The results were evaluated by analysis of variance. The optimum roughening time was found to be 25 minutes, the optimum roughness value was 2.9071 μm, and the optimum collector concentration was 0.001 M. Using these values, a flotation recovery of 98.01% was obtained. Similarly, in shape factor studies, the optimum grinding time was 15 seconds, the optimum roundness value 0.7421, and the optimum collector concentration 0.0009 M, which resulted in a flotation recovery of 94.30%. The average error between the optimization results and the experimental results was estimated to be less than 6%, and the R2 values were greater than 90%. The study shows that RSM can be effectively applied in finding the economic optimum condition for obtaining maximum flotation recovery with minimum reagent consumption.

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  AtıfScopus2·WoS2·OpenAlex2

  İncele
• MakaleYalnız künye2023Scopus SJRQ2/r/munzur/1765
  Contribution of Mechanical Activation for Obtaining Potassium Chloride from Microcline

  Alyosif, Bahaa; Uysal, Turan; Aydemir, Muhammet Kürşat; Erdemoğlu, Murat

  The effect of intensive milling on the conversion of microcline (KAlSi3O8) to potassium chloride (KCl) occurred during the chlorination roasting process for artificial KCl production was investigated. A feldspar ore with 10.89% K2O grade and containing microcline was dry milled by a planetary ball mill for mechanical activation. Milled ore mixed with calcium chloride was roasted at temperatures between 500 and 1000 °C to get the chlorination roasting process. The product was then leached in water to dissolve KCl occurring during the roasting, which will be precipitated from the pregnant leach solution by evaporation. Results showed that potassium recovery from the unmilled ore increased rapidly up to 800 °C, and dramatically decreased at higher temperatures due to the removal of KCl from the furnace by means of evaporation. A potassium recovery of 31.95% was achieved by the unmilled ore, whereas it was 88.43% when 15 min milled ore was roasted at 750 °C. It was concluded that intensive milling caused mechanical activation of microcline to reduce the roasting temperature of the chlorination roasting process.

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  AtıfScopus12·WoS11·OpenAlex10

  İncele
• MakaleAçık Erişim2022/r/munzur/6527
  Tane şeklinin galen cevherinin flotasyonuna ve topaklanmasına etkisi

  Guven, Onur; Uysal, Turan

  Farklı şekil faktörlerine sahip tanelerle yürütülen flotasyon çalışmalarında daha köşeli tanelerin yuvarlak tanelere nazaran daha yüksek verimle kazanıldığı bilinmektedir. Bu durum flotasyon işlemlerinde şekil faktörlerinin rolünü göstermekte olup, uygulamalarda uygun tane morfolojisi ile önemli kazanımlar sağlanılabilmektedir. Bu çalışmada ise galen flotasyonu üzerine tane şeklinin etkisi çalışılmıştır. Bu amaçla galen -74+38 µm boyutunda şekil faktörü analizi yapılmıştır. Farklı şekil faktörüne sahip numuneler farklı KAX konsantrasyonlarında mikro-flotasyon ve agregasyon işlemleri yapılmıştır. Mikro-flotasyon sonuçlarına göre KAX konsantrasyonu arttıkça şekil faktörünün etkisinin arttığı ancak yüksek konsantrasyonlarda bu etkinin tam olarak gözlenmediği saptanmıştır.

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