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Öğe Bazı kayaçların mekanik özellikleri ile öğütülebilirliğinin ilişkilendirilmesi(Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2009) Aras, Ali; Aydoğan, SalihBu tez çalışmasında; kalsit, barit, kolemanit ve boksitin mekanik dayanım değerleri, kırılma parametreleri ve öğütülebilirlik - Bond iş indeksi değerleri arasındaki ilişkiler araştırılmıştır. İlk aşamada, kaya mekaniği deneyleri gerçekleştirilmiştir. İkinci aşamada, farklı besleme boyut fraksiyonlarına sahip numuneler, çelik bilyalı değirmende öğütülerek özgül kırılma hızı (Si) ve toplam kırılma dağılım fonksiyonu (Bi,j) parametreleri belirlenmiştir. Üçüncü aşamada ise standart Bond değirmeninde öğütme işlemi yapılarak öğütülebilirlik ve Bond iş indeksi değerleri belirlenmiştir. Daha sonra ise belirlenen bütün değerler arasında ilişkiler araştırılmıştır. Deneysel çalışmalardan elde edilen sonuçların birbirleri ile ilişkilendirilmesi neticesinde genel olarak, mekanik dayanım değerlerinin artışı ile özgül kırılma hızı (Si) ve aT değerlerinin azaldığı belirlenmiştir. Ayrıca, mekanik dayanımın artışına bağlı olarak, Bi,j parametresi ? değeri artmakta yani ürünlerin boyut dağılımı irileşmektedir. Öğütülebilirlik (G) değerlerinin mekanik dayanım değerlerinin artışı ile azaldığı ve buna bağlı olarak Bond iş indeksi (Wi) değerlerinin arttığı belirlenmiştir. Diğer taraftan, kırılma parametreleri özgül kırılma hızı (Si) ve aT değerlerinin artışı ile öğütülebilirlik (G) değerlerinin arttığı, Bond iş indeksi (Wi) değerlerinin ise azaldığı belirlenmiştir.Öğe Correlations of Bond and Breakage Parameters of Some Ores with the Corresponding Point Load Index(WILEY-V C H VERLAG GMBH, 2012) Aras, Ali; Ozkan, Alper; Aydogan, SalihThis paper presents significant correlations of the Bond parameter (work index, Wi and grindability, G) and the breakage parameters (specific rate of breakage, Si and the fineness value, ?) with the point load index (Is(50)). The experimental results obtained from calcite, barite, colemanite and bauxite samples have demonstrated that the Bond and breakage parameters were closely correlated with the point load index. That is, the values of G, Si and aT parameters decreased with the increase in the values of the point load index; however, the ? parameter of Bi,j increased with increasing Is(50) values.Öğe Dissolution Kinetics of Celestite (SrSO4) in HCl Solution with BaCl2(Elsevier Science Bv, 2006) Aydoğan, Salih; Erdemoğlu, Murat; Aras, Ali; Uçar, Gökhan; Özkan, AlperLeaching of celestite (SrSO4) in hydrochloric acid solution with BaCl2 was investigated to produce SrCl2 in solution, which is the main source for SrCO3. The effects of variables such as stirring speed, BaCl2 and HCl concentrations, and temperature and particle size, and also the presence of NaCl in the leaching solution were studied. The leaching was modeled according to the shrinking core model. The activation energy for the leaching process in 8.25 x 10(-3) M BaCl2 solution equilibrated with 0.5 M HCl was found as 68.8 U mol(-1). This value reveals that the dissolution of celestite is a chemical reaction controlled process. In agreement with the model, the reaction rate is inversely proportional to the particle size and increases as 0.73, 0.70 and 0. 19 powers of the H+, Cl- and Ba2+ concentrations, respectively.Öğe Dissolution kinetics of galena in acetic acid solutions with hydrogen peroxide(ELSEVIER SCIENCE BV, 2007) Aydogan, Salih; Aras, Ali; Ucar, Goekhan; Erdemoglu, MuratThe kinetics of leaching lead from galena in acetic (ethanoic) acid solutions with hydrogen peroxide are investigated with regard to stirring speed, temperature and concentration of HAc and H(2)O(2) concentration. Oxidation of galena with H(2)O(2) to produce lead sulphate which dissolves by complexing Ph(2+) with acetate anion (PbCH(3)COO(+) and Pb(CH(3)COO)(2)). Results indicate that the rate of galena dissolution is controlled by a surface chemical reaction with an apparent activation energy is 65.6 kJ mol(-1)I in the temperature range 30-70 degrees C. Both HAc and H(2)O(2) affect the rate of extraction of lead as an acetate complex. The order of reaction was 0.79 and 0.31 for H(2)O(2) and HAc concentrations, respectively. (C) 2007 Elsevier B.V. All rights reserved.Öğe Dissolution kinetics of nickel from Gördes (Manisa-Turkey) lateritic ore by sulphuric acid leaching under effect of sodium fluoride(Selçuk Üniversitesi Mühendislik Fakültesi, 2017) Ağaçayak, Tevfik; Aras, AliIn this study, dissolution kinetics of nickel from Gördes (Manisa-Turkey) lateritic ore by sodium fluoride in sulphuric acid solution was investigated. The effects of stirring speed, sulphuric acid concentration, sodium fluoride concentration and temperature on nickel extraction were examined. To determine the dissolution kinetics of nickel in sulphuric acid medium under effect of sodium fluoride, shrinking core model was applied to dissolution recoveries. As a result of kinetic studies, it was determined that mixed kinetic model was appropriate. The activation energy (Ea) for the dissolution was calculated as 41.24 kJ/mol.Öğe Geological and geomechanical properties of some carbonate marbles and basalt stone from Morocco(Selçuk Üniversitesi Mühendislik Fakültesi, 2017) Zedef, Veysel; Koçak, Kerim; Zaghloul, Najib Mohamed; Döyen, Adnan; Söğüt, Ali Rıza; Özşen, Hakan; Kekeç, Bilgehan; Aras, Ali; Doğan, Kemal; Ağaçayak, TevfikThe natural rocks used today as well as in the history for a variety of purposes were a subject of different alteration, weathering and deterioration conditions. These conditions are strictly controlled by environment and nature of rock varieties (marble and stone). This study is a first approach to understand the relation between some geological features and behavior against salt (Na2SO4) decay of Moroccan marbles and stones. For this purpose, widely used four dolomitic limestones, two crystalline limestones, one limestone and one basalt sample (total 8) were chosen from Morocco. Extra attention paid to choose locations being a representative of all Moroccan country. The carbonate samples (limestone and dolomite) consist of mainly dolomite and calcite with micritic and sparitic cement. The sole, non-carbonaceous sample is basalt of Khenifra containing mainly plagioclase and pyroxene. In general, both bulk-dry and powder density values of the studied rock samples are homogeneous. The limestone of Bir Jdid has the highest (10.81 %) effective porosity and dry weight loss value (4.61 %). The loss on ignition value of the Khenifra basalt has the lowest value with 1.26 %. The loss on ignition values are also relatively uniform. The obtained data indicate that outdoor uses (especially in coastal areas) of limestones of Bir Jdid and dolomitic limestones of Taza are more risky than the others.Öğe Kinetic study on leaching of nickel from Turkish lateritic ore in nitric acid solution(JOURNAL OF CENTRAL SOUTH UNIV, 2016) Ağaçayak, Tevfik; Zedef, Veysel; Aras, AliDissolution kinetics of nickel from lateritic ore in nitric acid solution was investigated. Experimental parameters used were stirring speed (100-600 r/min), temperature (40-96 A degrees C), nitric acid concentration (0.1-2 mol/L) and particle size (< 106 A mu m). The shrinking core model was applied to the results of experiments investigating the effects of leaching temperature in the range of 40-90 A degrees C and nitric acid concentration in range of 0.1-2 mol/L on nickel dissolution rate. The kinetic analysis shows that the nickel dissolution from lateritic ore could be described by diffusion model. The activation energy (E (a)) for the dissolution reaction is calculated as 79.52 kJ/mol.Öğe Kinetics of galena dissolution in nitric acid solutions with hydrogen peroxide(ELSEVIER SCIENCE BV, 2007) Aydogan, Salih; Erdemoglu, Murat; Ucar, Goekhan; Aras, AliThe extraction of lead from a galena concentrate in nitric acid solutions with additional hydrogen peroxide was studied taking stirring speed, temperature, hydrogen peroxide and nitric acid concentrations, and particle size as dissolution parameters. The dissolution curves followed the surface chemical reaction controlled shrinking core model over the whole range of parameters, except at high nitric acid concentrations where the reaction was diffusion-control led. The activation energy of 42 KJ mol(-1) and a linear relationship between rate and inverse particle size support the reaction controlled dissolution mechanism. Hydrogen peroxide addition accelerated the reaction compared with nitric acid alone. It was concluded that the dissolution process is favourable, since the acid consumed for oxidation of galena can easily be regenerated in the same reactor by means of hydrogen peroxide. (c) 2007 Elsevier B.V. All rights reserved.Öğe Koyulhisar sfalerit konsantresinin asidik ferrik klorürlü ortamda liçing şartlarının belirlenmesi(Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2003-08-28) Aras, Ali; Aydoğan, SalihBu tezde Sivas - Koyulhisar yöresinde bulunan Cu - Pb - Zn kompleks cevherinden flotasyon yoluyla zenginleştirilmiş sfalerit konsantresinin asidik ortamda ferrik iyonları etkisinde çözündürülme şartlan ve kinetiği araştırılmıştır. Fe+3 kaynağı olarak ferrik klorür (FeCI3.6HbO) kullanılmıştır. Deneyler, sıcak su banyosunda 1 lt'lik beherlerde karıştırma liçi yapılarak gerçekleştirilmiştir. Araştırmalarda; karıştırma hızı, Fe+3 derişimi, katı/sıvı oranı, sıcaklık ve tane boyutunun çinko çözünmesine olan etkisi incelenmiştir. İncelenen koşullarda elde edilen sonuçlara göre sfalerit konsantresinden ferrik iyonları etkisinde çinko çözünmesinin; karıştırma hızından hemen hemen bağımsız, Fe+3 derişimi ve sıcaklık ile doğru orantılı, katı sıvı/oranı ve tane iriliği ile ters orantılı olduğu tespit edilmiştir. 600 dev/dak karıştırma hızında, 1.0 M Fe+3 derişiminde, 10/500 g/ml katı/sıvı oranında, 80 ° C sıcaklıkta ve -212 um tane iriliğinde % 82 Zn çözünmesi sağlanmıştır. Kinetik değerlendirme sonucunda sfalerit konsantresinden ferrik iyonları etkisinde Zn çözünmesinin küçülen partikül modeli (1-(1-X) ) 'ne uyduğu belirlenmiştir. Buradan; aktivasyon enerjisi 46.13 kJ/mol hesaplanmıştır. Zn çözünmesinin ferrik iyonlarına bağımlılığının [Fe+3]0,42, katı/sıvı oranına bağımlılığının (katı/sıvı)0,48 olduğu tespit edilmiştir.Öğe LEACHING OF CHALCOPYRITE CONCENTRATE IN HYDROGEN PEROXIDE SOLUTION(OFICYNA WYDAWNICZA POLITECHNIKI WROCLAWSKIEJ, 2014) Ağaçayak, Tevfik; Aras, Ali; Aydoğan, Salih; Erdemoğlu, MuratThe leaching conditions of chalcopyrite (CuFeS2) concentrate in a hydrogen peroxide medium were investigated by studying the effects of its leaching parameters, such as stirring speed, temperature, hydrogen peroxide concentration and the particle size of the concentrate on Cu extraction. It was found that stirring speed has no effect on the leaching. Copper extraction from chalcopyrite is directly proportional to hydrogen peroxide concentration, but the extraction decreases at temperatures above 60 degrees C. The maximum copper extraction was obtained with the following conditions without stirring: 240 min of leaching time, 3.0 M hydrogen peroxide concentration, 40 degrees C leaching temperature and 53-75. m particle size fraction.Öğe Leaching of zinc and manganese from spent zinc–carbon batteries in acetic acid solution(Selçuk Üniversitesi Mühendislik Fakültesi, 2016) Taner, Hasan Ali; Ağaçayak, Tevfik; Aras, AliIn this study, extraction of Zn and Mn from spent zinc–carbon batteries in acetic acid solution was studied. Leaching tests were carried out to evaluate the leaching behaviour of Zn and Mn under different conditions. Experimental parameters used were; stirring speed, acetic acid concentration, temperature and particle size. The zinc and manganese extraction were obtained as 83.59% and 52.47%, respectively. The maximum Zn and Mn extraction were obtained in 240 min of leaching time with the following conditions; 600 rpm stirring speed, 2.0 M acetic acid concentration, -53 ?m particle size and 60°C leaching temperature.Öğe Optimization of nickel extraction from lateritic ore in hydrochloric acid solution with hydrogen peroxide by Taguchi method(Selçuk Üniversitesi Mühendislik Fakültesi, 2017) Aras, Ali; Ağaçayak, TevfikTaguchi optimization method was used to determine optimum conditions for the extraction of nickel from lateritic ore in hydrochloric acid solution with hydrogen peroxide. Leaching time, stirring speed, temperature, hydrochloric acid concentration and hydrogen peroxide concentration were chosen as parameters. The optimum conditions for dissolution were found as leaching time of 240 min, a temperature of 70°C, hydrochloric acid concentration of 3 M, hydrogen peroxide concentration of 0.1 M and without stirring. The experimental results under optimum leaching conditions, showed that the extraction of nickel from lateritic ore was 90.66%. Analysis of variance (ANOVA) was applied to experimental results. Percentage contributions of each factor for the extraction of nickel were determined.Öğe Oxidative ammonia leaching of sphalerite concentrate(Selçuk Üniversitesi Mühendislik-Mimarlık Fakültesi, 2005) Aydoğan, Salih; Aras, Ali; Canbazoğlu, MehmetThis paper presents a study of kinetics of leaching of sphalerite concentrate in ammonia solutions. The effects of ammonia concentration, oxygen partial pressure, reaction temperature and particle size on the leaching rate were investigated. The shrinking core model was applied to the results obtained from these experiments. Reaction order with respect to PO2 (1-10 atm.) and NH3 concentration (1.05-5.20 M) were 0.22 and 0.63 and the activation energy was determined to be 43.59 kj/mol in the temperature range of 90-130 °C. In addition, the apparent rate constant is in inverse relationship with the mean initial particle radius. The results of this study showed that the leaching of sphalerite was a reaction controlled process.
