Sürdürülebilir Kalkınma Amaçları
Araştırmacılar(18)
Birim yayınları
106 →- MakaleAçık Erişim2026Mercury Removal from Glycine Leach Solutions Using Sodium Sulfide (Na2S) Precipitation
Kantarci, Sadiye; Alp, Ibrahim; Youpoungam, Abdou Azizi; Sivircik, Salih
Amino acid leaching has been considered an environmentally friendly alternative for gold recovery; however, the dissolution of mercury (Hg) during the leaching of amalgamation tailings remains a major challenge. This study is a novelty study that focuses on Hg removal by passing the Hg-containing tailings, previously processed by amalgamation, into solution via glycine (NH(2)CH2COOH) leaching. In this regard, a precipitation method using sodium sulfide (Na2S) was developed to remove Hg from solutions obtained after glycine leaching. The effects of precipitation time, pH, Na2S dosage, and temperature were investigated. The effects of pH, precipitation time, and temperature were found to be limited within the investigated ranges. The results showed that Na2S dosage was the most effective parameter in mercury removal. The initial Hg concentration of 12,160 ppb was reduced to 223 ppb at a Na2S:Hg molar ratio of 60, corresponding to approximately 98% removal efficiency under the selected operating conditions. Increasing the Na2S:Hg ratio to 80 resulted in a slightly higher removal efficiency (similar to 99%) with a final Hg concentration of 144 ppb; however, a ratio of 60 was considered optimal in terms of reagent consumption and process efficiency. The outcomes indicate that Hg removal with Na2S is a rapid and effective process under alkaline conditions, while Au remains in solution and Cu and Ag are partially removed, indicating limited selectivity and the need for further optimization. Therefore, this study provides a basis for developing more environmentally friendly processes for amalgamation tailings.
- MakaleAçık Erişim2026Aluminum Recovery and Process Optimization from High-Silica Kemiklitepe (Türkiye) Bauxite Ore by the Alkaline Roasting-Water Leaching Method
Uysal, Turan
In this study, an innovative and environmentally friendly alternative method was investigated for aluminum recovery from diasporic bauxite, classified as a critical raw material, without using caustic soda. Within this context, the alkaline roasting–water leaching combination was applied to enhance aluminum recovery from high-silica bauxite ore. Optimization of the process parameters was carried out using Response Surface Methodology (RSM). The effects of key parameters, roasting temperature, milling time, and ball-to-powder/ore ratio (BPR), on Aluminum (Al) dissolution were systematically evaluated through the RSM design. The reliability of the model was confirmed by ANOVA analysis, and the regression results indicated that the coefficient of determination (R²) exceeded 90% for all responses, demonstrating a strong model fit. According to the optimization outcomes, the optimum conditions were determined as a roasting temperature of 919 °C, a milling time of 90 minutes, and a BPR of 23. Water leaching results revealed that aluminum recovery increased by approximately 26% in the ore roasted at 1000 °C compared to the raw (unroasted) ore. Overall, the findings indicate that the alkaline roasting–water leaching method is a promising alternative for processing high-silica bauxite deposits.
- MakaleYalnız künye2026Selective extraction of rare earth elements from end-of-life NdFeB magnets via low-temperature NH4Cl-based chlorination roasting and water leaching
Kumas, Cavit; Prasetia, Hendra; Sumardi, Slamet; Astuti, Widi; Mufakhir, Fika Rofiek; Daulay, Amru; Wicaksono, Mahruri Arif
Neodymium-iron-boron (NdFeB) magnets are critical components in the transition to a low-carbon energy economy due to their superior magnetic properties. They have significantly higher rare earth element (REE) content (25-35%) compared to natural resources (0.15-2%), making end-of-life NdFeB magnets a valuable secondary REE source. In this study, the selective recovery of REEs from end-of-life NdFeB magnets was investigated using water leaching following chlorination roasting with NH4Cl. A series of experiments was conducted to evaluate the effect of NH4Cl on the NdFeB magnet ratio, roasting temperatures, and roasting duration. Under optimal conditions (300 degrees C, 3 h, NH4Cl at twice the stoichiometric requirement), the roasted products were subjected to water leaching (500 rpm, 90 degrees C, liquid - solid ratio of 20 mL/g, 1 h). resulting in over 95% REE dissolution. Rare earth oxalates were precipitated from the pregnant leach solution with 90% efficiency using 1.5 times the stoichiometric requirement of oxalic acid. Subsequent calcination at 850 degrees C for 2 h yielded rare earth oxides with 99.8% REE purity. Moreover, the dissolution of iron was effectively suppressed through a simple two-stage Fe(OH)3 precipitation step, providing a more economical and selective recovery route. Les aimants de n & eacute;odyme-fer-bore (NdFeB) sont des composants critiques de la transition vers une & eacute;conomie & eacute;nerg & eacute;tique & agrave; faible carbone gr & acirc;ce & agrave; leurs propri & eacute;t & eacute;s magn & eacute;tiques sup & eacute;rieures. Ils ont une teneur en & eacute;l & eacute;ments de terres rares (ETR) sup & eacute;rieures (25-35%) aux ressources naturelles (0.15-2%), ce qui rend les aimants de NdFeB en fin de vie une source secondaire pr & eacute;cieuse d'ETR. Dans cette & eacute;tude, on a examin & eacute; la r & eacute;cup & eacute;ration s & eacute;lective des ETR des aimants de NdFeB en fin de vie par lixiviation aqueuse apr & egrave;s grillage chlorurant avec du NH4Cl. On a effectu & eacute; une s & eacute;rie d'exp & eacute;riences pour & eacute;valuer l'effet du rapport NH4Cl/aimant de NdFeB, des temp & eacute;ratures et de la dur & eacute;e de grillage. Dans des conditions optimales (300 degrees C, 3 h et une concentration de NH4Cl deux fois sup & eacute;rieure & agrave; la st oe chiom & eacute;trie requise), on a soumis les produits grill & eacute;s & agrave; une lixiviation aqueuse (500 tr/min, 90 degrees C, rapport liquide/solide de 20 mL/g, 1 h) conduisant & agrave; une dissolution de plus de 95% des ETR. On a pr & eacute;cipit & eacute; les oxalates de terres rares & agrave; partir de la solution de lixiviation enrichie avec une efficacit & eacute; de 90% en utilisant 1.5 fois la quantit & eacute; st oe chiom & eacute;trique requise d'acide oxalique. Une calcination ult & eacute;rieure & agrave; 850 degrees C pendant 2 h a produit des oxydes de terres rares d'une puret & eacute; de 99.8%. De plus, la dissolution du fer & eacute;tait efficacement supprim & eacute;e par une simple & eacute;tape de pr & eacute;cipitation de Fe(OH)3 en deux phases, offrant une voie de r & eacute;cup & eacute;ration plus & eacute;conomique et plus s & eacute;lective.
- MakaleYalnız künye2026An 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 Erişim2026Variability of Schmidt Rebound Values in Volcanic Rocks (Basalt and Lapilli Tuff): Comparative Effect of Surface Roughness, Alteration, and Testing Methods
Karaman, Kadir; Külekçi, Gökhan; Çakır, Yaşar; Kolaylı, Hasan
Enhancing the sustainability and safety of rock engineering requires understanding how micro-structural and alteration conditions influence the geomechanical properties of rocks in geotechnical projects. The determination of surface hardness using the Schmidt Hammer is an interdisciplinary experimental method employed in mining, geology, and civil engineering. This study quantitatively evaluates the effects of surface roughness, weathering degree, and evaluation procedures on Schmidt rebound values obtained from basalt and lapilli tuff. Field measurements on eight surfaces produced rebound values between 10 and 60, with standard deviations ranging from 2.4 to 11, reflecting substantial variability related to roughness and alteration. Laboratory results showed that cut surfaces yielded the highest hardness values (Mean ≈ 57–58) with very low variability (SD ≈ 1.1–1.6), whereas natural surfaces exhibited markedly lower rebound values (Mean ≈ 19–22) and greater scatter (SD ≈ 4–4.5). A strong correlation (R2 > 0.97) was observed between JRC roughness and rebound values in laboratory-prepared samples. The percentage difference among the USBR, ASTM, and Sumner & Nel methods remained below 5% when the standard deviation of measurements was under 2, indicating that method selection becomes critical only for heterogeneous surfaces. Mineralogical heterogeneity further increased variability in lapilli tuff, whereas basalt provided highly consistent responses. Overall, this study introduces quantitative thresholds linking roughness, weathering, and statistical variability, offering a more rigorous and reproducible framework for interpreting Schmidt hardness measurements.
- MakaleYalnız künye2026Cenozoic Lamprophyres From NE Türkiye: New Constraints on Post-Collisional Metasomatism and Alkaline Magma Origin in the Juvenile Subcontinental Lithospheric Mantle
Arslan, Mehmet; Temizel, İrfan; Krmíček, Lukáš; Yücel, Cem
The Middle Eocene (~43 Ma) and Late Miocene (~6 Ma) lamprophyres cropping out as sills from NE Türkiye can be classified as alkaline lamprophyres. These lamprophyres exhibit moderate contents of K2O (2.22–2.59 and 2.58–2.98 wt%), K2O/Na2O ratios (0.78–1.14 and 0.62–0.94) and Mg# (40.55–46.32 and 56.93–61.52), respectively, and low concentrations of mantle compatible elements. The lamprophyres also have a moderate to relatively high abundance of rare earth elements (ΣREEs = 140–159 and 547–604 ppm, respectively) with significantly fractionated REE patterns (LaN/YbN = 6.82–9.10 and 65.17–71.31, respectively), and are enriched in large-ion lithophile and light REEs but depleted in high-field-strength and heavy REEs. The lamprophyres have homogeneous and moderately low (87Sr/86Sr)i of 0.705048–0.705474 and 0.705252–0.705401, and nearly uniform εNd(i) values varying from −0.47 to 0.20 and 0.54 to 0.79 and εHf(i) values varying from 4.51–6.71 and 5.83–6.18, respectively. They also have a narrow and moderately high Δ7/4Pb range of 6.19–15.41 and 10.62–10.88 and Δ8/4Pb range of 49.56–56.14 and 46.86–47.99, respectively. Petrological modelling suggests that the parental magmas of both the Eocene and Miocene lamprophyres were generated by the low-degree partial melting of phlogopite-bearing spinel-garnet and amphibole-bearing garnet lherzolite sources, respectively. By integrating whole-rock trace elements and isotope compositions with regional geological observations, we propose that the post-collisional Middle Eocene and Late Miocene lamprophyres in the Eastern Pontides Orogenic Belt originated from the juvenile subcontinental lithospheric mantle sources metasomatized initially by Neotethyan subduction-related fluids during the Eocene, and subsequently overprinted by delaminated lithosphere-derived carbonate components in the Miocene. The lamprophyres likely record a temporal magmatic response to lithospheric delamination and regional thermal upwelling associated with Eocene extensional tectonics, followed by lithospheric thinning during the Miocene in a post-collisional tectonic setting.
- MakaleYalnız künye2026Improving the hydrothermal reduced graphene oxide supercapacitor with heat-moisture-treated potato starch as binder
Daulay, Amru; Yassaroh, Yassaroh; Samada, Lukmanul Hakim; Amrulloh, M. Hanif; Kumaş, Cavit; Nariswari, Mentari Kirana; Putri, Devi Mariska; Chambioso, Yugo
Alternative binders that can be processed in water are still in the early stages of development for more efficient and sustainable supercapacitors. However, their electrochemical performance is still below average. This study uses heat-moisture-treated starch (starch HMT) as a binder for reduced graphene oxide (rGO) supercapacitors. Starch HMT has been fabricated at 120 °C. The XRD diffractogram exhibits peaks at 2θ angles of 15°, 17°, 22°, and 24°. The 2θ values indicate that potato starch is of type B. FTIR spectra show the formation of OH, C–O–C, C-O, C–O–C, and C-H bonds. SEM images show cracks in the morphology. Electrochemical testing shows a specific capacity of 230 F/g at a current density of 1 A/g. The charge–discharge stability of the electrodes at 5000 cycles is 90%. These results offer a framework for developing electrode materials and binders for supercapacitors.
- Derleme MakaleYalnız künye2026Activated Carbon Derived from Coal and its Application for Wastewater Treatment
Daulay, Amru; Yassaroh, Yassaroh; Huda, Miftahul; Sumardi, Slamet; Prasetia, Hendra; Kumaş, Cavit; Yusmiati; Lestari, Devi
Coal is used to produce fuels, chemicals, and other high-value-added products to improve efficiency. Activated carbon (AC) derived from coal is an important part of coal’s resource utilization and is high-value-added. This study presents relevant research on AC derived from coal, including raw material selection, preparation methods, modification techniques, and regeneration methods. The potential applications of AC derived from coal for the adsorption of contaminants, including heavy metals, pesticides, pharmaceutical compounds, and organic and inorganic compounds, are reviewed. One of the advantages of using AC derived from coal in wastewater treatment is high adsorption, low cost, and sustainability.
- MakaleYalnız künye2026Comparison of Zn recovery prediction from carbonate ores with machine-learning methods
Erkan, Ilker; Günen, Mehmet Akif
This study addresses the challenge of predicting zinc (Zn) recovery from carbonate ores via sodium hydroxide (NaOH) leaching. This complex process influenced by variable ore composition, surface passivation effects, and nonlinear reaction dynamics, which complicate reagent optimization and process control in hydrometallurgical operations. To tackle this, a dataset containing 422 experimental observations was compiled from previous studies, incorporating ore composition and process parameters, such as NaOH concentration, leaching time, temperature, and solid-to-liquid ratio. Four regression models (decision tree, neural network, generalized additive model, and random forest) were trained and evaluated using performance metrics, such as coefficient of determination (R2), root mean squared error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and symmetrical mean absolute percentage error (SMAPE). Among these, the random forest model achieved the best predictive accuracy, with R2 value of 0.8541 on the test set and the lowest error rates, demonstrating its effectiveness in capturing the complex relationships between input variables and Zn recovery. Explainable artificial intelligence, particularly SHapley additive exPlanations (SHAP) analysis, revealed that NaOH concentration, leaching time, and solid-to-liquid ratio had the most positive influence on Zn recovery, whereas elements such as Ca, Fe, and Pb had inhibitory effects. These findings align with known geochemical behavior and provide valuable insights for reagent optimization and process efficiency in leaching processes. This study demonstrates the practical potential of machine learning in mineral processing, offering a scalable framework for optimizing Zn recovery from non-sulfide ores and a data-driven approach to enhance decision-making in hydrometallurgical applications.
- MakaleYalnız künye2026Variable-speed retrofit of a legacy slurry pumping duty: Measured energy reduction with proxy-based operability assessment
Külekçi, Gökhan; Aygün, Muhammet; Göller, Zafer; Yildiz, Onur
Legacy ore beneficiation plants often operate slurry pumps at fixed speed despite variable sump inflow and slurry conditions, which can increase electricity demand and complicate level control. This study evaluates a variable-speed retrofit in which a variable frequency drive was integrated with level feedback and proportional-integral control for a legacy slurry pumping duty. Measured average operating power decreased from 25.6 kW before retrofit to 11.6 kW after implementation, documenting a substantial reduction in electrical demand under the observed operating regime. Because hydraulic-duty data were unavailable for both periods, this result is not presented as a duty-normalised specific-energy reduction. Process interpretation was supported by a bounded proxy framework based on a flowsheet-consistent solids band over 177 days. The proxy analysis linked solids variability to derived slurry density behaviour and operability implications. Overall, the study documents measured electrical-demand reduction and provides a framework for discussing retrofit performance where plant instrumentation is limited.
Tam Kayıt
| Alan | Değer | Dil |
|---|---|---|
| dc.date.accessioned | 2026-10-22T08:47:34.532240200Z | |
| dc.date.available | 2026-10-22T08:47:34.532240200Z | |
| dc.identifier.uri | https://rdlopen.rawdatalibrary.net/r/gumushane/10054 | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.title | Maden Mühendisliği Bölümü | tr |
| dc.title | Department of Mining Engineering | en |
| dspace.entity.type | OrgUnit | |
| organization.identifier.code | gumushane-muhendislik-ve-doga-bilimleri-maden-muhendisligi | |
| organization.unitType | department | |
| rdl.unit.alias | \bmaden muhendisligi bolumu\b | |
| rdl.unit.alias | \bmin(ing)? eng(ineering|n|g)?\b |