Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ4Solvent Extraction of Copper from Sulfate Solutions Using Acorga OPT5510; [Extracción de cobre de soluciones de sulfato mediante solventes con Acorga OPT5510]
Karacahan, Mehmet Kayra
This study used a solvent extraction technique with AcorgaOPT5510 extractant in kerosene to examine the extraction of copper ions from the actual leach solution produced after leaching malachite ore in sulfuric acid solutions. On the Cu/Fe separation factor and the effectiveness of copper extraction, the impacts of significant parameters, including stirring speed, contact duration, extractant concentration, beginning solution pH, and temperature, were examined. The following values were chosen as the optimal ones: 1:1, 1.5, 12%, 20 °C, 10 min, 10 min, and 500 rpm for maximum Cu2+ extraction from the aqueous-phase, aqueous/organic phase ratio, equilibrium pH of the aqueous phase, extractant concentration, temperature, contact time, settling time, and stirring speed. Under these conditions, 94% of the copper in the leach solution was removed, yielding about 40.09 Cu/Fe separation factor. A McCabe-Thiele plot was revealed, and it was shown that a two-step extraction procedure would yield the best results. Furthermore, employing a sulfuric acid concentration of 4 mol·L-1 for 10 minutes, the loaded organic phase was stripped and recovered 91% copper.
- MakaleAçık Erişim2024Scopus SJRQ1Optimization and Kinetic Study of Manganese Leaching from Pyrolusite Ore in Hydrochloric Acid Solutions with Oxalic Acid
Karacahan, Mehmet Kayra
The leaching behavior of pyrolusite minerals was examined in hydrochloric acid solutions, including oxalic acid, to evaluate the influence of various experimental conditions. The optimum parameters for the leaching process were found in the first stage, and the process's kinetics were assessed in the second. The concentrations of oxalic acid, hydrochloric acid, and temperature were chosen as independent variables in the optimization experiments, with the central composite design used to analyze the experimental data. The optimum concentrations for oxalic acid, hydrochloric acid, and temperature were determined to be 0.75 mol/L, 1.2 mol/L, and 60 °C, respectively. The leaching rate was determined to be 97.4% for 120 min of response time in optimum situations. The kinetic assessment experiments studied the effects of solid/liquid ratio, particle size, stirring speed, and temperature on the manganese leaching rate from pyrolusite. In the studies, the leaching rate was shown to rise with increasing temperature and stirring speed, as well as with decreasing particle size and solid/liquid ratio. The kinetic analysis revealed that the leaching kinetics matched the mixed kinetic model, and a mathematical model for the leaching process was developed. This process's activation energy was determined to be 29.05 kJ/mol. Graphical Abstract: (Figure presented.)
AtıfScopus17WoS15OpenAlex18
İncele - MakaleAçık Erişim2023Investigation of Recovery of Zinc Ions from Zinc-Containing Leached Malachite Ore by D2EHPA Extractant
Karacahan, Mehmet Kayra
In this study, the recovery of Zn2+ from the actual leach solution obtained after leaching smithsonite ore in sulfuric acid solutions was investigated by applying the solvent extraction method. The organic phase was prepared using D2EHPA and kerosene. The effects of the initial pH of the solution, extractant concentration, stirring time, and stirring speed on the extraction process were investigated. It was determined that the extraction efficiency increased with the increase in the extractant concentration, the initial pH of the aqueous solution, the stirring speed, and the stirring time. In order to selectively increase the transfer of Zn2+ from the aqueous phase to the organic phase, the optimal values for the initial pH of the aqueous phase, extractant concentration, stirring time, and stirring speed were determined as 3.5, 0.1 mol/L, 10 min, and 500 rpm, respectively. The stoichiometry and mechanism of the extraction process were determined by applying the equilibrium slope method.
- Kitap BölümüYalnız künye2023A Multi-parameter Occupational Safety Risk Assessment Model for Chemicals in the University Laboratories by an MCDM Sorting Method
Gul, Muhammet; Yucesan, Melih; Karacahan, Mehmet Kayra
University laboratories are high-risk working environments where many chemicals coexist to conduct teaching and scientific research. The frequent occurrence of such chemical-related occupational accidents in recent times highlights the importance of ensuring these units’ safety in universities for researchers, students, workplaces, and institutions. In occupational safety risk assessment, very few studies have grouped risks. Many of them also ignored some important risk parameters. Overcoming these disadvantages, this study developed a multi-parameter and multi-criteria decision-making (MCDM) sorting-based methodology for the occupational safety risk assessment of chemicals in a university laboratory. First, six different risk parameters (probability, severity, exposure, detectability, worsening factor, sensitivity to non-usage of personal protective equipment) were determined. The weight value was calculated using the best–worst method (BWM). Then, a risk priority value and classification for each chemical with TOPSIS-Sort, the MCDM sorting method. Finally, some control measures are recommended to reduce the safety risk of the laboratory. The applicability of the proposed methodology has been tested with a real case study. The methodology is intended to adapt to university laboratories’ risk assessment and become a primary reference for university safety analysts.
AtıfScopus2OpenAlex1İncele - MakaleYalnız künye2023Scopus SJRQ2Investigation of Leaching Kinetics of Molybdenum from MoO3 Concentrate in Ammonia–Ammonium Nitrate Solutions
Karacahan, Mehmet Kayra
MoO3 is a widely accessible foundation material and the primary compound used to produce numerous molybdenum products. The ore was first roasted, and the leaching behavior of concentrated molybdenite mineral was assessed. The optimal conditions for the leaching process were identified in the second step, and in a subsequent stage, the process' kinetics were assessed. Ammonia and ammonium nitrate concentration were used as independent variables in the trials, and the central composite design approach was used to analyze the results. At the conclusion of the tests, the optimum concentrations of ammonia and ammonium nitrate were found to be 2.42 mol/L and 1.86 mol/L, respectively. On the rate at which molybdenum leached from MoO3, the influences of temperature, stirring speed, solid-to-liquid ratio, and particle size were investigated. It was found that the leaching rate increased when temperature and stirring speed increased, along with decreasing the solid-to-liquid ratio and particle size. Leaching efficiency of molybdenum (93%) such as temperature 20 °C, 1.859 mol/L ammonium nitrate concentration, 2.419 mol/L ammonia concentration, solid/liquid ratio 6/100 g/mL, stirring speed 400 rpm, and average particle size 0.115 mm optimum conditions have been achieved. The kinetic study proposed a mathematical model for the leaching process, which revealed that the leaching kinetics matched the Avrami model. This process' activation energy was determined to be 22.66 kJ/mol. Calcium molybdate is used in various fields, such as construction, transportation, anti-corrosion pigments, and flame retardants. Graphical Abstract: [Figure not available: see fulltext.]
AtıfScopus8WoS7OpenAlex9İncele - MakaleAçık Erişim2022Ponza ile bakır ve kurşun iyonlarının adsorpsiyon karakteristikleri
Karacahan, Mehmet Kayra; Demirkiran, Nizamettin; Tanaydın, Zümra Bakıcı; Ince, Muharrem
Bu çalışmada, kesikli sistemde, ponza kullanılarak çözeltilerden Cu(II) ve Pb(II) iyonlarının uzaklaştırılması amaçlanmıştır. Adsorban miktarı etkisi (0.1-0.5g), Cu(II) ve Pb(II) iyon çözeltilerinin derişim etkisi (Cu(II) için; 3.2-31.8 ppm, Pb(II) için; 10.2-103.6 ppm), çözeltilerin pH etkisi (Cu(II) için 3-6.1(doğal pH), Pb(II) için 3-5.25(doğal pH)) gibi değişken parametrelerin etkileri incelenmiştir. Adsorban miktarının 0.4 g, çözelti iyon derişiminin 6.4 ppm ve pH değerinin 6.1 olduğu optimum şartlarda %91 bakır giderim verimi elde edilirken adsorban miktarının 0.4 g, çözelti iyon derişiminin 20.7 ppm ve pH değerinin 5.2 olduğu optimum şartlarda %97.7 kurşun giderim verimi elde edilmiştir. Deneysel olarak bulunan adsorpsiyon verilerine Langmuir, Freundlich, Temkin ve Harkins-Jura izoterm modelleri uygulanarak modellenmiş ve izoterm sabitleri hesaplanmıştır. Bakır ve kurşun iyonlarının adsorpsiyonunda Freundlich izoterm modeli deney verilerine en uygun model olarak belirlenmiştir. Bakır için ponzanın maksimum adsorplama kapasitesi 2.55 mg g⁻¹, kurşun için bu değer 10.28 mg g⁻¹ olarak bulunmuştur. Adsorpsiyon kinetiklerinin yalancı ikinci mertebeden kinetik modeline daha uyumlu olduğu belirlenmiştir. Farklı sıcaklıklarda standart serbest enerji değişimi (ΔG°), entalpi (ΔH°) ve entropi (ΔS°) değerleri belirlenmiştir. Yapılan çalışmada elde edilen sonuçlar, diğer adsorbanlarla karşılaştırıldığında ponzanın sulu çözeltilerden ağır metallerin gideriminde etkin, ekonomik ve alternatif bir adsorban malzemesi olabileceğini göstermiştir.
AtıfOpenAlex1TR Dizin1
İncele - Derleme MakaleAçık Erişim2021Acquisition of Rare Earth Elements by Application of Hydrometallurgical Methods
Karacahan, Mehmet Kayra
The demand for rare earth elements in the world is increasing rapidly, but the supply amounts of these elements are decreasing due to export quotas imposed by the Chinese government and illegal mining operations. Many countries have accelerated their efforts to obtain rare earth elements from primary and secondary sources in order to meet their future needs by taking measures. Rare earth elements are the most important components necessary both for the design and development of high-tech products that we use in our daily lives and for the advancement of modern industry. These elements, which have become indispensable materials of our lives, are generally not found in pure form in nature, but in complex structures in ores. Rare earth elements have close to 250 known minerals, but ores such as bastnasite, monazite and xenotime are commercially exploited. It is usually physically enriched by flotation, gravity, electrostatic or magnetic separation processes to obtain bastnasite, monazite and xenotime concentrates. In order to develop viable and environmentally friendly processes, studies are carried out for the extraction of rare earth elements from leaching solutions (chloride, nitrate, sulfate, thiocyanate, etc.) and the use of different cationic, anionic and neutral extractants depending on the solution medium. Commercial extraction of rare earth elements D2EHPA, Cyanex 272, PC-88A, Versatic 10, TBP, Aliquat 336 etc. carried out using different extractants. In this work, hydrometallurgical methods used for the recovery of rare earth elements from primary sources are examined. These methods are hydrometallurgical methods consisting of leaching with acids and alkalis followed by processes such as solvent extraction, ion exchange or precipitation and reduction. With the application of hydrometallurgical processes, processes that may be beneficial for the recovery of rare earth elements under various conditions have been evaluated.
AtıfOpenAlex1TR Dizin1İncele - MakaleAçık Erişim2020Adsorption of Copper and Cadmium with Perlite and Comparison of Adsorption Properties
Karacahan, Mehmet Kayra; Demirkiran, Nizamettin; Ince, Muharrem; Bakıcı Tanaydın, Zümra
This study, the effectiveness of perlite for the removal of Cu (II) and Cd (II) ions from aqueous medium was investigated by adsorption method. Using perlite adsorbent, parameters such as initial concentration, initial pH, adsorbent dosage and contact time affecting Cu (II) and Cd (II) ions adsorption from aqueous solutions were investigated. Initial concentration of copper (II) ions, initial pH value, adsorbent amount, contact time respectively 3.2 ppm, natural pH 6.49, 2 g, during the 180 minutes adsorption 94% of copper ions adsorbed, the initial concentration of cadmium (II) ions solution, initial pH, adsorbent amount, contact time 5.6 (ppm), natural pH 5.25, 2 g, 180 minutes, respectively, 77% adsorbed. It was determined that the adsorption data fit the Langmuir isotherm for copper ions and Freundlich isotherm for cadmium ions, and the kinetic data of copper and cadmium ions fit the false second order model. Including the thermodynamic parameters of adsorption, Gibbs free energy change (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) values calculated at 20oC are for copper 3.1 kJ mol-1, -55.52 kJ mol-1, -0.2 kJ mol-1 K-1 , respectively and for cadmium, 7.14 kJ mol-1, -28.02 kJ mol-1, -0.12 kJ mol-1 K-1, respectively. The results showed that the adsorption of these metal ions on the perlite is exothermic and feasible at 20-50°C.
AtıfTR Dizin6İncele - MakaleAçık Erişim2018Effect of Dehydration Treatment on Dissolution of Ulexite in Ammonium Sulfate Solutions
Karacahan, Mehmet Kayra; Demirkiran, Nizamettin; Turhan Özdemir, G.Deniz
Ulexite is commercially one of important boron minerals, and it is found abundantly in Turkey. Ulexite is generally available together with other borates, and it can be used as a raw material in the production of boron compounds. It includes a significant amount of hydration water. When ulexite is subjected a dehydration process, it loses some part of hydrate water depending upon applied temperature. A porous solid is obtained in consequence of dehydration treatment, and the solid material becomes more chemically active. The resulting porous structure allows occurring more readily the reaction between solid and fluid, and the dissolution rate increases. In this study, the dissolution kinetics of calcined ulexite in ammonium sulfate solutions was examined. In the experiments, the effects of the dehydration temperature, solution concentration, reaction temperature, solid-to-liquid ratio, and stirring speed on
AtıfOpenAlex1İncele - MakaleYalnız künye2017Malahit Cevherinin Perklorik Asit Çözeltilerindeki Çözünürlüğünün İncelenmesi
Karacahan, Mehmet Kayra; Demirkiran, Nizamettin
Hidrometalurji sulu çözeltilerde kimyasal reaksiyonlar vasıtasıyla metal, metal tuzları ve bileşiklerinin üretimini kapsar. Oksitli bakır cevherlerindeki bakır, hidrometalurjik yöntemler yardımıyla kazanılabilir. Sözü edilen metodun ilk aşaması katı-sıvı kütle transferini içeren liç prosesidir. Bu proseste katı cevher uygun bir çözücü ile çözündürülür ve metal değerler çözelti ortamına transfer edilir. Mevcut çalışmada, oksitli bir bakır cevheri olan malahitin sulu perklorik asit çözeltilerindeki çözünürlüğü incelenmiştir. Malahit cevherindeki bakır, çinko ve demirin çözünme davranışı belirlenmiştir. Cevherdeki bakırın çözünürlüğü üzerine asit derişimi, reaksiyon sıcaklığı, ortalama katı tanecik boyutu, katı/sıvı oranı ve karıştırma hızının etkileri araştırılmıştır. Bütün deneysel parametrelerin bakırın çözünmesi üzerinde önemli bir etkiye sahip oldukları gözlenmiştir. Asit derişimi, reaksiyon sıcaklığı ve karıştırma hızının artmasıyla, katı/sıvı oranı ve katı tanecik boyutunun ise azalmasıyla cevherdeki bakır liçinin arttığı tespit edilmiştir. Cevherdeki demirin çözünürlüğünün asit derişiminden oldukça etkilendiği gözlenmiştir. Reaksiyon koşullarının kontrol edilmesiyle çözelti ortamına geçen bakır miktarının yüksek, demir miktarının ise düşük seviyelerde tutulabileceği belirlenmiştir. Liç prosesi ile ilgili kinetik analiz yapılmış ve reaksiyon hızının karışık kinetik kontrollü modele uyduğu belirlenmiştir. Liç prosesinin aktivasyon enerjisi 30,94 kJ/mol olarak hesaplanmıştır