Browsing by Author "Kaya, Muammer"

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Critical review on secondary zinc resources and their recycling technologies
(ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2020) Kaya, Muammer; Hussaini, Shokrullah; Kursunoglu, Sait; 0000-0002-1680-5482; 0000-0003-0287-0061; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
In a race to save the earth of its rapidly depleting natural resources, the use of Secondary Raw Materials (SMRs) as alternative replacements in several processes is currently intensively pursued. The valorization of SMRs is consistent with the sustainable circular economy, where resource efficiency is maximized for the benefit of both the economy and green environment. In line with this mandate, this article focuses on investigating recent studies on secondary zinc (Zn) resources and describing state-of-art Zn recycling technologies. Globally, some of the main Zn-containing secondary raw materials are mine/concentrator/smelter tailings, wastes, slags, scraps, dust, etc. Although the pyrometallurgical process has been dominant in the secondary metal recycling processes, there has been growing interest and pressure to achieve sustainable and greener recycling methods to remediate the environmental problems caused by emissions of toxic heavy metals and sulfur oxides in the traditional smelting process. In the last decades, many sustainable and environmentally friendly novel hydrometallurgical processes for Zn extraction were developed to overcome tougher legislation and meet cost competitiveness. Secondary Zn recycling focuses on the development of selective Zn-rich but Pb, Fe, As-lean recovery processes.
Dissolution of lateritic nickel ore using ascorbic acid as synergistic reagent in sulphuric acid solution
(ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2018) Kursunoglu, Sait; Ichlas, Zela Tanlega; Kaya, Muammer; 0000-0002-1680-5482; 0000-0003-2550-5948; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
The dissolution of nickel and cobalt from Caldag lateritic nickel ore using the combination of sulphuric and ascorbic acids was investigated. The use of other organic acids, namely citric, maleic and stearic acids, as synergistic reagents was studied for comparison. The results revealed that the use of ascorbic and citric acids markedly improved the dissolution of cobalt compared to the other two organic acids that only showed slight synergistic effect on the leaching rate. In terms of nickel dissolution, ascorbic acid is the most effective synergist, followed by citric, maleic and stearic acids in descending order. Under the most optimized conditions found in this study, i.e., using 1 mol/L of sulphuric acid with the presence of 4 g/L of ascorbic acid at 80 degrees C and solid-to-liquid ratio of 1/10, more than 99% and 98% leaching rates of cobalt and nickel, respectively, can be achieved within 4 h of leaching. In addition, the leaching performance is relatively insensitive to the change of ascorbic acid concentration from 2 to 4 g/L which is highly desirable from operational perspective.
DISSOLUTION OF MIXED ZINC-CARBON AND ALKALINE BATTERY POWDERS IN SULPHURIC ACID USING ASCORBIC/OXALIC ACID AS A REDUCTANT
(JOHN WILEY & SONS, 2012) Kaya, Muammer; Kursunoglu, Sait; 0000-0002-1680-5482; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait
The aim of this study was to investigate the effectiveness of ascorbic (C6H8O6) / oxalic (C2H2O4) acid as a reductant for the simultaneous recovery of zinc and manganese from a spent and mixed zinc-carbon and alkaline battery powder in sulphuric acid leaching. The effects of sulfuric acid concentration, ascorbic/oxalic acid dosages, reaction temperature and leaching time on the zinc and manganese dissolutions were investigated according to 2(k) full factorial experimental design; then, a simple optimization study was carried out for the best reductant. The optimum reductive acid leaching conditions were determined at 3 hours leaching time, 70 degrees C leaching temperature, 0.5M sulfuric acid concentration, 13 g/L ascorbic acid dosage, 1/20 g/mL solid/liquid ratio and 200 rpm stirring speed. Under these conditions, the dissolution efficiencies were 99.9% for Zn and 99.3% for Mn. When our results were compared with the previous results, our findings were better than previous studies. In addition, the manganese dissolution kinetics was undertaken, and the activation energy was found to be 7.04 kJ/mol. Selective precipitations of Zn and Mn from acid solutions were carried out using NaOH and KOH. Using 3M NaOH as precipitating agent at room temperature and at pH 8; 95.4% of Zn and at pH 10; 93.7% of Mn were precipitated from the leaching solution. Under the same conditions, using 3 M KOH at pH 8; 91.6% of Zn and at pH 10, 96.4% of Mn were precipitated. Based on the experimental results obtained, an appropriate flow sheet was proposed to recover zinc and manganese.
HYDROMETALLURGICAL PROCESSING OF NICKEL LATERITES- A BRIEF OVERVIEW ON THE USE OF SOLVENT EXTRACTION AND NICKEL/COBALT PROJECT FOR THE SEPARATION AND PURIFICATION OF NICKEL AND COBALT
(TMMOB Maden Mühendisleri Odası/The Publication of the Chamber of Mining Engineer of Turkey, 2019) Kursunoglu, Sait; Kaya, Muammer; 0000-0002-1680-5482; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait
In this study, a brief overview of the solvent extraction (SX) application for the separationand purification of nickel and cobalt in hydrometallurgical processing of laterite nickel ores ispresented. This paper consists of two parts: firstly, the SX of nickel and cobalt from sulphateleach solutions is described; and secondly, the development of hydrometallurgical plants forthe processing of laterite nickel ores that involve solvent extraction technique is discussed. Themost important extractants are shortly given in the first part of the study. It is seen that theextraction and separation of nickel and cobalt from the impure leach solution of laterite nickelores can be performed by either using a single extractant system that is called as a direct solventextraction (DSX) or a mixture of two or more extractant which is known as a synergistic solventextraction system (SSX). Mixed sulphide precipitation (MSP) and mixed hydroxide precipitation(MHP) processes are mentioned. This paper is also addressed advantage and disadvantages ofeach extraction system. It is shown that capital investment expenditure, operational investmentexpenditure and mineralogical content are the most important factors that can affect the selectionof the appropriate hydrometallurgical process for lateritic nickel ore.
Laterit Liç Çözeltisinden Sinerjik Solvent Ekstraksiyon (SSX) Yöntemi Kullanılarak Nikel ve Kobalt Kazanımı
(TUBİTAK, 2019) Kursunoglu, Sait; Kaya, Muammer; 0000-0002-1680-5482; 0000-0002-1680-5482; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait; Kaya, Muammer
Bu çalışmada, nikel sülfat (NiSO4.6H2O), kobalt sülfat (CoSO4.7H2O), manganez sülfat (MnSO4.H2O), magnezyum sülfat (MgSO4.7H2O) ve kalsiyum klorür (CaCl2.2H2O) tuzları deiyonize su ile çözündürülerek sentetik bir liç çözeltisi hazırlanmıştır. Sentetik çözelti içerisinde seçimli olarak nikel ve kobalt kazanımı için sinerjik solvent ekstraksiyon (SSX) ve direkt solvent ekstraksiyon (DSX) yöntemleri uygulanmıştır. Organik ekstraksiyon çözeltisi olarak Cyanex 272 (bis (2,4,4-trimethylpentyl) phosphonic asit, Versatic 10 (neodecanoic asit) ve DEHPA/D2EHPA (di (2-ethylexyl) fosforik asit) n-Hexan içerisinde seyreltilerek kullanılmıştır. Organik çözelti içerisine ekstraksiyon esnasında oluşabilecek üçüncül fazları ve yerel çökmeleri engellemek için ayarlayıcı olarak TBP (tributyl phosphate) kullanılmıştır. Kobalt Cyanex 272 solvent ekstraksiyon ünitesinde yaklaşık pH 5,7’de manganez ile beraber ekstrakte edilmiştir. Yüklü organik çözelti temizleme devresinde asitliği ayarlanmış deiyonize su ile pH 5,5’de üç aşama temizleme işlemi görmüştür. Temizlenmiş yüklü organik 2 kademe 10 g/L Co çözeltisi ile tekrar temizlenmiştir. Temizlenmiş yüklü çözelti pH 0,5’de 2 kademe sıyırma işlemine tabi tutularak kobalt ve manganez yüklü çözelti elde edilmiştir. İkinci solvent ekstraksiyon ünitesinde organik ekstraktant olarak Versatic 10 kullanılmıştır. Cyanex 272 ünitesi sonunda kalan atık çözelti ikinci üniteye beslenmiştir. Bu ünitede nikel yaklaşık pH 6,9’da organik faza yüklenmiştir. Yüklü organik pH 6,5’de asitliği ayarlanmış deiyonize su ile 2 kademe temizlenmiş ve ardından 2 kademe 10 g/L Ni çözelti kullanılarak tekrar temizlenmiştir. Temizleme işleminden sonra pH 0,5’de 1 kademe sıyırma işlemi gerçekleştirilerek yüklü nikel çözeltisi elde edilmiştir. Çalışma sonunda, ilk ekstraksiyon kademesinde manganez sentetik liç çözeltisinden tamimiyle uzaklaştırılamamıştır. SSX çalışmalarında %15 Cyanex 272+%5 Versatic 10+%5 TPB, %15 Versatic 10+%5 Cyanex 272+%5 TPB, %15 Cyanex 272+%5 Versatic 10+%5 DEHPA+%5 TBP ve %15 Cyanex 272+%5 DEHPA+%5 TBP sistemleri test edilmiştir. %15 Cyanex 272+%5 Versatic 10+%5 TBP sisteminin Ni-Mg-Ca’yı Co’dan ayırmada kullanılabileceği belirlenmiştir. %15 Versatic 10+%5 Cyanex 272+%5 TPB sistemi kullanılarak Ca ve Mg arasında büyük bir seçimlilik olduğu ve bu iki metal iyonunun liç çözeltisinden seçimli olarak ayrılabileceği görülmüştür. Aynı zamanda %15 Cyanex 272+%5 Versatic 10+%5 DEHPA+%5 TBP sistemi kullanılarak düşük pH değerlerinde Mn’nin Co’dan uzaklaştırılabileceği belirlenmiştir.
Leaching method selection for Caldag lateritic nickel ore by the analytic hierarchy process (AHP)
(ELSEVIERRADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2017) Kursunoglu, Sait; Ichlas, Zela Tanlega; Kaya, Muammer; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait
Leaching is an important process in hydrometallurgical operations. This process is used to extract metals from the ores by dissolving them in a lixiviant. It is desired that the leaching method is able to provide high extraction rate at minimal capital and operational costs. There are many parameters that can affect the leaching efficiency and thus, the process of selecting a leaching method is complex. In this study, the use of Analytic Hierarchy Process (AHP) method to select an appropriate leaching method for Caldag lateritic nickel ore has been performed. The application of AHP is assisted with the use of ExperChoice 2000 (R) Software. The results shown that heap leaching (HL) is the most attractive leaching method with a rating of 0.592, followed by atmospheric leaching (AL), and high pressure acid leaching (HPAL) with ratings of 0.293 and 0.115, respectively. In addition, sensitivity analyses have been applied to investigate the impact of the main criteria on the alternative leaching methods. It was found that HPAL can be selected when economical main criteria decreased from 76.1% to 16.3%.
Leaching of yahyali non-sulphide PB-ZN flotation tailing using organic acids
(Baski, 2019) Hussaini S.; Kursunoglu, Sait; Kaya, Muammer; 0000-0002-1680-5482; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait
The laboratory scale leaching of Kayseri-Yahyali non-sulphide lead (Pb)-zinc (Zn) flotation tailing using two organic acids was experimentally investigated. The effect of citric and oxalic acid on the dissolution of Zn, Pb, iron (Fe) and arsenic (As) was individually investigated under the following conditions: citric or oxalic acid concentration of 0.5-1.0M, temperature of 60-80°C and leaching time of 30-180 min. at 1/10 solid-to-liquid (S/L) ratio. 90.1% Zn dissolution was achieved using 0.5 M citric acid at 80°C leaching temperature for 180 min leaching time. The Fe, Pb and As dissolutions were determined as less than 20% under the conditions tested. 95.5% Fe and 68.8% As were removed from the flotation tailing along with less than 5% of Zn and Pb using 1.0 M oxalic acid for 180 min. leaching time at 60°C leaching temperature. It was found that citric acid is more prominent than oxalic acid for the selective leaching of zinc from the flotation tailing whereas a substantial amount of iron and arsenic removal can be achived by oxalic acid leaching. The use of NaCl along with citric acid was not useful for higher Zn dissolution. Based on the experimental results, an appropriate process will be improved for the selective leaching of valuable metals from the Pb-Zn non-sulphide flotation tailing in the near future. Copyright
Pb-Zn recovery from a malic leach solution of a carbonate type ore flotation tailing by precipitation and solvent extraction
(ELSEVIERRADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2021) Hussaini, Shokrullah; Tita, Angela Manka; Kursunoglu, Sait; Top, Soner; Ichlas, Zela Tanlega; Kar, Umut; Kaya, Muammer; 0000-0002-1680-5482; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait; Top, Soner
The recovery of zinc and lead from a malic leach solution of a carbonate type ore flotation tailing by precipitation with sulfuric acid followed by solvent extraction using di(2-ethylhexyl)phosphoric acid (D2EHPA) as extractant was investigated. The separation of lead via precipitation was essentially complete from the malic acid leach solution by adding sulphuric acid to reach a pH of 0.25 at 25 degrees C. The precipitate product was identified by XRD as anglesite (PbSO4). The pregnant leach solution after lead precipitation was then subjected to solvent extraction using D2EHPA. The optimum solvent extraction conditions were determined as 10% D2EHPA concentration, 25 degrees C temperature, 10 min contact time and phase ratio of unity. Under these conditions, 99.3% of zinc was extracted into the organic phase at a pH of 4.2 in a single contact alongside a substantial amount of Ca (76.6%), and minor amounts of Fe (19.2%) and Mg (18%). Complete stripping of zinc and calcium from the loaded organic solution along with 47.8% of Mg was achieved at a pH 0.5 under room temperature. No iron stripping was observed from the loaded organic. The zinc content in the loaded strip solution could be enriched and then sent to the electrowinning (EW) stage. It is noted that the calcium and magnesium impurities in the loaded strip solution had no adverse effect on the zinc EW process. Based on the experimental results, a flowsheet was proposed for the recovery of Pb and Zn from the malic acid leach solution. With the proposed precipitation and solvent extraction process, two different material streams are produced.
Production of mixed rare earth oxide powder from a thorium containing complex Bastnasite ore
(ELSEVIERRADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2021) Kursunoglu, Sait; Hussaini, Shokrullah; Top, Soner; Ichlas, Zela Tanlega; Gokcen, Hasan Serkan; Ozsarac, Safak; Kaya, Muammer; 0000-0002-1680-5482; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait; Top, Soner
The production of mixed rare earth oxide powder from a thorium containing bastnasite ore by sulfuric acid bake water leaching followed by precipitation with oxalic acid and thermal decomposition of the oxalates was investigated. The sulfuric acid baking was performed at 250 degrees C and the optimum baking time was found to be 3 h. Using deionized water as lixiviant, 92.6% La, 86.8% Ce, 86.9% Pr, 82.3% Nd, 95.4% Th and 31% Y were dissolved from the baked ore at 25 degrees C after 30 min of leaching. The effect of solid-to-liquid ratio on the dissolution of the rare earth elements and thorium shows that when the solid ratio in the water increased from 1:10 to 1:3, the dissolution percentage decreased. The final mixed rare earth oxide powder contained 88.54% REO and 6% ThO20 together with small amounts of other impurities. The SEM mapping results revealed that the produced REO has an irregular crystal shape. Based on the experimental results obtained from the current study, a flowsheet was proposed for the production of mixed rare earth oxide powder from a specific complex bastnasite ore. (C) 2020 Elsevier B.V. All rights reserved.
Recovery of Lead and Zinc from a Citric Leach Solution of a Non-sulfide Type Ore Flotation Tailing via Precipitation Followed by Solvent Extraction
(SPRINGER, 2023) Hussaini, Shokrullah; Tita, Angela Manka; Kursunoglu, Sait; Top, Soner; Kaya, Muammer; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
The recovery of zinc (Zn) and lead (Pb) from a citric leach solution of a non-sulfide type ore flotation tailing was examined utilizing sulfuric acid precipitation followed by solvent extraction using di(2-ethylhexyl) phosphoric acid (D2EHPA) as the extractant. Following lead precipitation (98.9%) with sulfuric acid, the pregnant leach solution was sent to solvent extraction stage with D2EHPA for the separation of zinc from the other impurities such as Ca, Mg and Fe. The best solvent extraction conditions were determined to be a concentration of 20% D2EHPA, temperature of 25 °C, contact time of 10 min and phase ratio of unity. Under the optimum conditions, 98.3% Zn was extracted into the organic phase in a single contact at a pH of 3.6, along with a significant amount of Ca (79%) and minor amounts of Mg (14.7%) and Fe (8.6%). At pH 4.5, the loaded organic solution was carried to the scrubbing stage, where 20 g/L zinc solution was used to remove approximately 91% Ca and 34% Mg from the organic solution. At a pH of 0.25, the loaded organic solution was almost completely stripped of zinc and 27% of calcium in two steps.
Recovery of Lithium from Spent Coin-Type Lithium Manganese Dioxide CR Cells by Acidic Leaching in the Presence of Potassium Permanganate as Oxidant
(SPRINGER LINK, 2023) Kursunoglu, Sait; Top, Soner; Altiner, Mahmut; Ozsarac, Safak; Kaya, Muammer; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
The selective leaching of lithium from spent coin-type lithium manganese dioxide CR cells by oxidative leaching and precipitation of Li2CO3 from Libearing leach solution has been experimentally and theoretically investigated. The oxidative leaching experiments were carried out using sulfuric acid in the presence of potassium permanganate (KMnO4). The dissolutions of lithium, manganese, nickel, and cobalt were found to be 84.8%, 0.9%, 46.6%, and 9.7%, respectively. The results demonstrated that a considerable amount of manganese and cobalt remained in the leach residue. The Li-bearing leach solution was fed to an impurity removal stage. It was observed that a substantial amount of lithium loss, along with manganese, nickel, and cobalt, was determined at pH 10. At standard temperature and pressure, the species of lithium as a function of pH, lithium concentration, and carbonate concentration was evaluated for the generation of Li2CO3 from the oxidative leach solution. The results revealed that the precipitation of lithium as lithium carbonate is thermodynamically feasible from the solution at high pHs.
Recovery of Manganese from Spent Batteries Using Activated Carbon Powder as Reductant in Sulfuric Acid Solution
(ASIAN JOURNAL OF CHEMISTRY, 11/100 RAJENDRA NAGAR, SECTOR 3,, SAHIBABAD 201 005, GHAZIABAD, INDIA, 2013) Kursunoglu, Sait; Kaya, Muammer; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü;
Recovery of manganese from spent batteries was investigated using activated carbon powder as a reducing agent in sulfuric acid solution. The effects of four different leaching parameters (sulfuric acid concentration, amount of activated carbon powder, temperature and time) on the leaching of manganese from spent batteries were investigated using central composite design technique. The maximum manganese recovery conditions were determined as 1 M of sulfuric acid concentration, 3 g of activated carbon powder, 80 degrees C of temperature and 3 h of leaching time. Under these conditions, the recovery of manganese was 86.39 % and pH value of the solution was 0.77. According to the reductive acid leaching results, an empirical second order equation for manganese recovery based on four investigated parameters was calculated. The observed values of manganese recoveries using model equation were found to be in a good agreement with the predicted values (R-2 = 0.92).
Recovery of zinc and lead from Yahyali non-sulphide flotation tailing by sequential acidic and sodium hydroxide leaching in the presence of potassium sodium tartrate
(ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2020) Kursunoglu, Sait; Top, Soner; Kaya, Muammer; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
The recovery of zinc and lead from Yahyali non-sulphide flotation tailing using sulfuric acid followed by sodium hydroxide leaching in the presence of potassium sodium tartrate was experimentally investigated. In the acidic leaching stage, the effects of pH, solid-to-liquid ratio and temperature on the dissolution of zinc from the tailing were explored. 82.3% Zn dissolution was achieved at a pH of 2, a temperature of 40 degrees C, a solid-to-liquid ratio of 20% and a leaching time of 2 h, whereas the iron and lead dissolutions were determined to be less than 0.5%. The sulfuric acid consumption was found to be 110.6 kg/t (dry tailing). The leaching temperature had no beneficial effect on the dissolution of zinc from the tailing. The acidic leach solution was subjected to an electrowinning test. The cathode product consisted of 99.8% Zn and 0.15% Fe. In the alkaline leaching stage, the Pb dissolution increased slightly in the presence of potassium sodium tartrate. More than 60% of Pb was taken into the leach solution when the leaching temperature increased from 40 to 80 degrees C. The final leach residue was analyzed by XRD and XRF. The XRD results indicated that the major peaks originated from the goethite and quartz while minor peaks stem from smithsonite and cemssite. The XRF analysis demonstrated that the residue contained 70.3% iron oxide. Based on the sequential leaching experiments, the zinc and lead were excellently depleted from the flotation tailing, leaving a considerable amount of iron in the final residue.
Selection of an appropriate acid type for the recovery of zinc from a flotation tailing by the analytic hierarchy process
(ELSEVIER SCI LTDTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND, 2021) Kursunoglu, Sait; Kursunoglu, Nilufer; Hussaini, Shokrullah; Kaya, Muammer; 0000-0003-1765-9015; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait
The selection of acid type for metal dissolution from minerals is an important issue in leaching operations. Acids are used to recover valuable elements from the minerals by dissolving them in a solution. The acid must offer a high recovery at marginal cost and a low environmental effect. Many parameters can affect the acid type selection for high leaching recovery and low environmental effect and thus, the selection of an acid type is complex. In this study, based on the experimental results obtained from the bench-scale laboratory studies, the selection of acid type for the recovery of zinc from a flotation tailing was investigated using the analytic hierarchy process (AHP). The utilization of AHP was supported by the use of ExpertChoice (R) 2000 software. The outcomes demonstrated that sulfuric acid is the most desirable acid type with a ranking of 0.541, tracked by citric acid, and oxalic acid with scoring of 0.282 and 0.177, respectively. Furthermore, analyses of sensitivity were performed to examine the influence of the main criteria on the different acid type. It emerged that citric acid can be used when the environmental main criterion ascended from 7.8% to 75.3%. (C) 2020 Elsevier Ltd. All rights reserved.
Selective leaching of a mixed nickel-cobalt hydroxide precipitate in sulphuric acid solution with potassium permanganate as oxidant
(TAYLOR & FRANCIS INC, 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA, 2020) Hussaini, Shokrullah; Ichlas, Zela Tanlega; Top, Soner; Kursunoglu, Sait; Kaya, Muammer; 0000-0003-3486-4184; 0000-0002-1680-5482; 0000-0003-0287-0061; 0000-0003-2550-5948; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
Selective leaching of a mixed nickel-cobalt hydroxide precipitate was investigated using potassium permanganate as oxidant in sulfuric acid solution. 94.9% Ni, 50% Co and 0.6% Mn were dissolved under the following conditions: sulfuric acid concentration of 0.75 M, potassium permanganate of 5 g/L, temperature of 30 degrees C, leaching duration of 60 min, solid-to-liquid ratio of 1/10, and stirring speed of 400rpm. The pregnant leach solution was subjected to a solvent extraction process. 98% Co and 99% Mn were extracted at pH 4.84 with 30% (v/v) Cyanex 272, leaving essentially all nickel in the raffinate. Based on the experimental results, a flowsheet is proposed.
Solvent extraction process for the recovery of nickel and cobalt from Caldag laterite leach solution: The first bench scale study
(ELSEVIERRADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2017) Kursunoglu, Sait; Ichlas, Zela Tanlega; Kaya, Muammer; 0000-0002-1680-5482; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait
A solvent extraction application consisting of two-sequential solvent extraction circuits to separate the nickel and cobalt from a synthetic sulphate leach solution which simulates a typical Caldag lateritic leach solution was conceived and experimentally explored. The first circuit allowed the simultaneous extraction of most of the nickel (98%), cobalt (98%) and manganese (94%) with 20% neodecanoic acid (Versatic 10) and 5% tri-n-butyl phosphate (TBP) in ShellSol 2046 at pH 72 together with substantial amounts of calcium (65%) and magnesium (12%). Three stages of scrubbing at pH 5.6 using diluted sulphuric acid solution allowed the removal of most of the magnesium (90%) and substantial amount of calcium (16%). Complete stripping of nickel, cobalt, manganese, magnesium and calcium was achieved at pH 0.75. This loaded strip solution was the feed for the second circuit. The use 15% bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272) and 5% TBP in ShellSol 2046 allowed the extraction of most of the cobalt (94%) and manganese (98%) at pH 5.0 but with substantial co-extraction of magnesium (41%) and calcium (40%) and a minor amount of nickel (3%). A two-stage scrubbing of this loaded organic with cobalt (20 g L-1) solution was performed. Magnesium, calcium and nickel were completely displaced with cobalt. Most of the manganese (93%) was removed from the organic. Complete stripping of the cobalt and manganese in the scrubbed organic phase was achieved at pH 1.0. Therefore, nickel (94%) and cobalt (91%) were totally separated from the feed solution. In addition, slope analyses were carried out to determine the nature of the extracted complexes of the nickel and cobalt with each extractant. Based on the experimental results, a flowsheet for the separation process is presented. (C) 2017 Elsevier B.V. All rights reserved.
Testing of 17-different leaching agents for the recovery of zinc from a carbonate-type Pb-Zn ore flotation tailing
(PERGAMON-ELSEVIER SCIENCE LTDTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND, 2021) Hussaini, Shokrullah; Kursunoglu, Sait; Top, Soner; Ichlas, Zela Tanlega; Kaya, Muammer; 0000-0002-1680-5482; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Kursunoglu, Sait; Top, Soner
The recovery of zinc from a flotation tailing using 17-different leaching agents, including inorganic and organic acids, alkaline solutions and chelating agents, was investigated. The effects of the lixiviant type, acid concentration, leaching temperature, leaching time, and solid-to-liquid ratio on the metals dissolution were studied. The use of sulfuric acid resulted in 91% of zinc extraction with a high selectivity against lead. The major impurities of lead, iron, calcium and arsenic precipitated during the leaching process as a segnisite, beudantite, gypsum, and goethite in this lixiviant. It was seen that the addition of oxidants in sulfuric acid solution slightly increased zinc dissolution. The citric acid dissolved 90.1% of zinc along with 9.1% lead. 90% of zinc dissolution was achieved by using malic acid, and high selectivity between zinc and lead dissolutions was also observed. The citric and malic acid leach residues contained a substantial amount of segnitite, beudantite, and quartz as the major phases. In term of zinc and lead dissolution selectivity, the best inorganic agents were determined in the following order: sulfuric acid > hydrochloric acid > perchloric acid > nitric acid. With organic agents, the best zinc and lead selectivity was achieved in the following order: sulfosalicylic acid > citric acid > malic acid > formic acid > tartaric acid > ascorbic acid. The best simultaneous zinc and lead dissolutions were achieved using sodium hydroxide agent. Using 5 M sodium hydroxide at 80 degrees C and 1/10 solid-to-liquid ratio for 180 min. leaching time, 81.4% of zinc and 47.4% of lead were dissolved while leaving a considerable amount of iron in the residue. When the ammonium chloride was used as a lixiviant, the silver and zinc were taken into the leach solution. 61.3% of zinc dissolution was obtained by using 50% ammonia as lixiviant, whereas no iron and lead dissolutions were observed. Using 0.37 M EDTA at 80 degrees C, 1/10 solid-to-liquid ratio for 180 min. leaching time, more than 90% of zinc dissolved along with a substantial amount of iron, arsenic and lead co-dissolutions. 47.4% of zinc dissolution was obtained at 80 degrees C and 1/10 solid-to-liquid ratio for 180 min. leaching time when sodium citrate was used as lixiviant, whereas less than 20% of zinc dissolved using ammonium oxalate at similar leaching condition. 39% zinc was dissolved using 3 M ammonium acetate at 80 degrees C, 1/10 solid-to-liquid ratio for 180 min., while 23.1% of zinc dissolution was achieved when the ammonium acetate was tested under similar experimental conditions. As a result, sulfuric, citric, malic, sulfosalicylic and formic acids were deemed to be the most promising leaching agents for the selective recovery of zinc from the lead-zinc flotation tailing.