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Öğe Çinkur'da üretilen klinkerden Zn, Cu, Ni, Co, Cd, Ge ve In'un solvent ekstraksiyonla seçimli kazanılması araştırmaları(2008) Canbazoğlu, Mehmet; Kul, Mehmet; Kaya, Özlem; Kulaksız, M. İbrahim[Abstract Not Available]Öğe Effect of Process Parameters on the Electrodeposition of Zinc on 1010 Steel: Central Composite Design Optimization(Esg, 2020) Kul, Mehmet; Oskay, Kursad Oguz; Erden, Fuat; Akca, Erdem; Katirci, Ramazan; Koksal, Erkan; Akinci, EvindarIn the present work, we studied the effect of critical electrogalvanizing parameters on the quality of electrodeposited Zn films. The current density, electrodeposition time, and ZnCl2 concentration of electrolyte were optimized to maximize current efficiency and brightness, and also, to minimize the surface roughness. Importantly, regression models of the response variables were developed. These models could help industrial applications by providing definitive process conditions to obtain Zn coatings at a desired thickness, roughness and brightness with a high current efficiency. First, preliminary studies were conducted to determine the initial levels of the designated factors. Then, the optimization was conducted through the Central Composite Design by Design -Expert (trial version). Upon completion of the optimization, analysis of variance was also performed. The optimum values of current density, coating duration and ZnCl2 concentration were determined as 3.7 A/dm(2), 4.4 minutes, and 50 g/L, respectively, at a thickness of 6 mu m. Finally, a set of Zn films were deposited at this optimum conditions. The characterization of these films showed that the experimental results were in good accordance with model predictions, providing a bright (L*=83.69) and smooth (Ra=0.75 mu m) coating with excellent adhesion to steel substrate (pull-off strength > 29.41 MPa) at a current efficiency of 98.7%.Öğe Efficient Zinc Removal from Blast Furnace Sludge Using Choline Chloride-Malonic Acid: Towards Sustainable Recycling of Iron Extraction Waste(Springer, 2023) Kul, Mehmet; Oskay, Kuersad O.; Dogan, Mehmet; Aslan, NevzatChemical components of blast furnace sludge (BFS) of iron blast furnaces become a recyclable raw material in the furnace when a few contents including zinc (Zn) are selectively removed. Out of four deep eutectic solvents (DES) preselected from the literature for their potential selective Zn leaching performances, choline chloride-malonic acid was determined to be the most efficient DES for its efficiency in removing Zn from BFS in the presence of iron (Fe). Further preliminary tests were conducted via iterations of leaching parameters to determine their individual effects on the leaching efficiencies for Zn, Ca, and Fe. Parameters like DES concentration, leaching period, and solid/liquid ratio were found to be the most accountable, as agitation speed and temperature showed only a slight influence on the efficiencies. For a maximum Zn removal of about 85% with the least amount of Fe of around 15%, the empirical parameters without any extra optimization were estimated to be 30 vol.% malonic acid concentration, 1/4 (g/mL) solid/liquid ratio, 100 rpm agitation speed, 60 & DEG;C leaching temperature, and 3.0 h leaching period.Öğe Electrical and mechanical properties of reduced graphene oxide/CuCrZr composites(Taylor & Francis Ltd, 2024) Kul, Mehmet; Kurt, Nida; Yartasi, Ekrem; Erden, FuatThe present work investigates electrical and mechanical properties of reduced graphene oxide (rGO)/CuCrZr composites. Briefly, CuCrZr alloys were prepared by high-energy ball milling, and the milling parameters and the alloy composition were optimised. Following this, different amounts of rGO were introduced to hexadecyltrimethylammonium bromide-modified CuCr0.5Zr0.05 through solution mixing, and the rGO/CuCrZr pellets were then prepared by cold isostatic pressing and sintering. Furthermore, the composite samples were compacted two more times under 350 MPa and then 700 MPa. The electrical conductivity and hardness were studied on sintered, 350 MPa-compacted and 700 MPa-compacted samples. Apparent porosity was also determined, and the importance of compaction pressure and porosity was highlighted. Overall, the optimum combination of electrical conductivity and hardness was realised in the rGO/CuCr0.5Zr0.05 composite with 0.3% rGO.Öğe An Electrochemical Procedure to Form Metal Powders from Recycled Hard Particle Embedded Composite Cutting Tools(ELECTROCHEMICAL SOC INC, 2017) Altunbasak, Tansu; Kul, Mehmet; Karakaya, Ishak; Manivannan, M; Narayan, S; Kostecki, R; Johnson, C; Atanassov, PBUsed valuable particle embedded composite cutting tools, obtained by powder metallurgy techniques by mixing metallic powders with hard, abrasive particles were electrolyzed for reclamation of metallic powders and valuable particles. The effects of copper ion and sulfuric acid concentrations and pH of the electrolyte, current density and temperature on microstructure of produced copper powders were investigated in detail. Copper powders were characterized by X-Ray diffraction (XRD) and scanning electron microscopy (SEM). SEM results indicated that dendritic structure of copper powders turn into compact, dense powders by controlling the electrodeposition conditions.Öğe Elektro Çözündürme-Biriktirme İle Elmas Testere Hurda Soketlerinden Elmas Geri Kazanımı Ve Toz Metal Üretimi(2019) Kul, Mehmet; Bektaş, Hacı Ali; Şimşir, Mehmet; Karakaya, İshak; Kumruoğlu, Levent CenkElmas testere, soket adı verilen kesici uçların dairesel bir çelik gövdeye kaynatılması ile elde edilir. Soketler bir takım metal tozlarının ve sanayi elmaslarının karısımı olup, yüksek ısı ve basınca tabi tutularak (sinterlenerek) elde edilir. Elmas testerelerin kullanımı sırasında soketler asınmakta ve kırılmaktadır, islevini yitiren soketler (üretim sırasında hasarlı çıkanlar, çalısma boyundan daha kısa duruma gelen soketler) herhangi bir islemle yeniden kullanılır duruma dönüstürülmemektedir. Proje kapsamında elektro çözündürme-biriktirme prosesi kullanılarak elmas soketlerin geri kazanımına iliskin çalısmalar yapılmıstır. Bu çalısmalarda anot olarak baglanan elmas soketler çözündürülürken, katotta ise toz biriktirmek amaçlanmıstır. Soket içerisinde bulunan elmas partikülleri ise hücre içerisinden toplanmaktadır. Proje kapsamında bakır, kobalt ve bronz esaslı olmak üzere üç farklı soket kompozisyonu ile çalısılmıstır. Soketlerin geri dönüsümü için iyonik ve sulu elektrolitler ile çalısmalar yapılmıstır. Sulu elektrolit olarak sülfatlı ve klorürlü elektrolitler denenmistir. Iyonik çözelti olarak choline chloride + ethylene glycol, choline chloride + üre ve choline chloride + malonik asit olmak üzere üç farklı iyonik sıvı ile denemeler yapılmıstır. Bu denemelerde ethaline (choline chloride + ethylene glycol) elektroliti ile en iyi sonuçlar elde edilmistir. Ethaline iyonik sıvısının viskozitesini düsürmek için saf su eklenerek yapılan çalısmalar da yapılmıstır. Bu çalısmalarda saf ethaline elektrolitinden daha iyi anodik ve katodik verim degerlerine ulasılmıstır. Deneysel çalısmalarda anodik ve katodik verimi, üretilen tozların tane boyutunu etkileyen akım yogunlugu, elektrolit metal ve asit konsantrasyonu gibi birçok faktör incelenmistir. Ön deneylerden elde edilen veriler kullanılarak anodik ve katodik verimi arttırmaya yönelik optimizasyon çalısmaları yapılmıstır. Proje kapsamında endüstride kullanılabilecek bir prototip tasarlanmıs ve imal edilmistir. Optimizasyon verileri kullanılarak prototipte çalısmalar yapılmıstır. Bu prototipte hurda elmas soketler çözündürülerek basarılı bir sekilde bakır, kobalt ve bronz tozları üretilmis ve elmas geri kazanılmıstır. Prototipte üretilen bakır ve bronz tozlarının oksitlendigi XRD analizi ile belirlenmistir. Bu tozlar argon-H2 gazı karısımı atmosferinde indirgenerek metalik toz üretilmistir. Üretilen tozlardan ticari bir soket üretilmistir. Üretilen soketin sertlik ve yogunluk degerlerinin ticari tozlarla üretilen soketlere benzer özellikler gösterdigi tespit edilmistir.Öğe Elektrolitik metal kaplama yıkama banyolarındaki Ni, Cu, Cr, ve Zn metallerinin solvent ekstrasiyonla seçimli kazanımı ve kaplama banyosuna eklenebilirliğinin araştırılması(2010) Kul, Mehmet[Abstract Not Available]Öğe Optimization of selective leaching of Zn from electric arc furnace steelmaking dust using response surface methodology(ELSEVIER SCIENCE BV, 2015) Kul, Mehmet; Oskay, Kursad Oguz; Simsir, Mehmet; Subutay, Halit; Kirgezen, HabipThe aim of this work is to investigate and optimize the effects of the leaching parameters on the selective leaching of zinc from electric arc furnace steelmaking dust (EAFD). The response surface method was applied on the basis of a three-level Box-Behnken experimental design method for optimization of selective leaching parameters of zinc from EAFD. The leaching recoveries of zinc (Y-Zn) and iron (Y-Fe) were taken as the response variables, where the concentration of sulphuric acid (X-1, mol/L), leaching temperature (X-2, degrees C), leaching time (X-3, min), and liquid/solid ratio (X-4, mL/g) were considered as the independent variables (factors). The mathematical model was proposed. Statistical ANOVA analysis and confirmation tests were applied. A maximum of 79.09% of zinc was recovered while the minimum iron recovery was 4.08% under the optimum conditions of leaching time 56.42 min, H2SO4 concentration 2.35 mol/L, leaching temperature 25 degrees C and liquid/solid ratios. By using ANOVA, the most influential factors on leaching of zinc and iron were determined as H2SO4 concentration and leaching temperature, respectively. The proposed model equations using response surface methodology show good agreement with the experimental data, with correlation coefficients (R-2) of 0.98 for zinc recovery and 0.97 for iron recovery.Öğe Optimizing the recovery of copper from electroplating rinse bath solution by hollow fiber membrane(IWA PUBLISHING, 2015) Oskay, Kursad Oguz; Kul, MehmetThis study aimed to recover and remove copper from industrial model wastewater solution by non-dispersive solvent extraction (NDSX). Two mathematical models were developed to simulate the performance of an integrated extraction-stripping process, based on the use of hollow fiber contactors using the response surface method. The models allow one to predict the time dependent efficiencies of the two phases involved in individual extraction or stripping processes. The optimal recovery efficiency parameters were determined as 227 g/L of H2SO4 concentration, 1.22 feed/strip ratio, 450 mL/min flow rate (115.9 cm/min. flow velocity) and 15 volume % LIX 84-I concentration in 270 min by central composite design (CCD). At these optimum conditions, the experimental value of recovery efficiency was 95.88%, which was in close agreement with the 97.75% efficiency value predicted by the model. At the end of the process, almost all the copper in the model waste water solution was removed and recovered as CuSO4 center dot 5H(2)O salt, which can be reused in the copper electroplating industry.Öğe Recovery of copper by LIX 984N-C from electroplating rinse bath solution(ELSEVIER SCIENCE BV, 2009) Kul, Mehmet; Cetinkaya, UemitDevelopment of a complete hydrometallurgical process at the laboratory scale for recovering copper from the copper electroplating second rinse bath solution containing similar to 2.5 g/L copper (CESRBS) by solvent extraction route using LIX 984N-C dissolved in commercial kerosene was investigated. By using LIX 984N-C, an electrolyte from CESRBS with similar to 97 g/L copper content, which was addable to the copper electroplating bath, was generated by 30 vol.% LIX 984N-C in commercial kerosene at the O/A ratio of 1/8 and equilibrium pH value of 2 with two-stage counter-current extraction, and stripping of loaded organic by copper electroplating first rinse bath solution (7.8 g/L Cu) with 550 g/L sulfuric acid addition and with the O/A ratio of 2 at two-stage countercurrent stripping process. The copper in stripping solution precipitated as CuSO4 3H(2)O salt. If the copper sulfate is produced without contaminated with organic phase, it could be recycled to the copper electroplating bath. A complete flow sheet of 30 vol.% LIX 984N-C process for the recovery of copper from CESRBS was demonstrated. (C) 2009 Elsevier B.V. All rights reserved.Öğe Recovery of Nickel by Solvent Extraction from Electroplating Rinse Bath Solution(TAYLOR & FRANCIS INC, 2010) Kul, Mehmet; Cetinkaya, UemitDevelopment of a complete solvent extraction process at the laboratory scale for recovering nickel from nickel electroplating second rinse bath solution (NESRBS) by solvent extraction route using DEHPA and LIX 984N-C dissolved in commercially available kerosene has been investigated. An electrolyte from NESRBS containing,48 g/L nickel, suitable for recycle to the nickel electroplating bath, was generated by 0.5M DEHPA in commercial kerosene at the O/A ratio of 1/5 and 5.00 +/- 0.25 equilibrium pH value with two-stage counter-current extraction. Stripping of loaded organic was done using nickel electroplating first rinse bath solution (16 g/L Ni) with 150 g/L sulfuric acid addition at two-stage counter-current stripping process. LIX 984N-C can also be used for this purpose, but it is not recommended due to a solid stabilized emulsion formation at high equilibrium pH value and nickel concentration. A complete flow sheet of 0.5 M DEHPA extraction process for the recovery of nickel from NESRBS was developed.Öğe Recovery of Zinc by LIX 984N-C from Electroplating Rinse Bath Solution(TAYLOR & FRANCIS INC, 2009) Kul, Mehmet; Cetinkaya, UemitThe development of a complete solvent extraction process at the laboratory scale for recovering zinc from the zinc electroplating first rinse bath solution (alkali solution) containing 1.9g/L zinc (ZEFRBS) by a solvent extraction route using LIX 984N-C, which is a new SX reagent developed by Cognis, and dissolved in commercial kerosene was investigated. By using LIX 984N-C, an electrolyte from ZEFRBS with 12g/L zinc content, which was addable to the alkali zinc electroplating bath, was generated by 10 vol.% LIX 984N-C in commercial kerosene at the O/A ratio of 1/4 and equilibrium pH value of 8.00 +/- 0.05 with a two-stage countercurrent extraction, and stripping of the loaded organic by a strip solution with 150g/L sulfuric acid and with the O/A ratio of 1.5 at a two-stage countercurrent stripping process. A new complete flow sheet of 10 vol.% LIX 984N-C process for the recovery of zinc from ZEFRBS has been demonstrated.Öğe Separation and recovery of valuable metals from real mix electroplating wastewater by solvent extraction(ELSEVIER SCIENCE BV, 2015) Kul, Mehmet; Oskay, Kursad OguzRecycling of electroplating wastewater is very important because of the large amounts of wastewater generated, the enormous economic value and large environmental concerns when conventional neutralization precipitation processes are used to dispose of the wastewater. This work describes the recovery of valuable metals from industrial wastewater collected at a galvanizing industrial site using a solvent extraction process. Several extractants such as DEHPA, TBP, LIX 984N-C, Cyanex 272 and Aliquat 336 were tried for the separation and recovery of valuable metals from the wastewater. Optimum extraction parameters for zinc, copper, iron, nickel and chromium were determined as 10% Aliquat 336, 5% LIX 984N-C, 10% DEHPA, 15% LIX 984N-C and 10% Cyanex 272 in kerosene at equilibrium pH 1.45, 1.20, 1.00, 5.25 and 6.00 with 99.6%, 100%, 100%, 99.9% and 100% extraction efficiencies at almost 100% selectivity, respectively. These extraction efficiencies were attained at two extraction stages for zinc, copper and chromium and at one extraction stage for iron and nickel. Copper-loaded LIX 984N-C, iron-loaded DEHPA, nickel-loaded LIX 984N-C and chromium-loaded Cyanex 272 were stripped with 450 g/L, 2 M, 150 g/L and 1 M H2SO4 respective strip solutions with relative 100% stripping efficiencies. A two-stage process stripped the zinc-loaded Aliquat 336 with a 2 M NaOH solution with 100% efficiency. Based on the data, a flow sheet for the separation of the five metal ions is provided. (C) 2015 Elsevier B.V. All rights reserved.
