WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Citation - WoS: 7Citation - Scopus: 7Separation of Mn and Fe From a Manganiferous Iron Ore Using Horse Dung as Reductant: A Zero Waste Approach(Springer, 2022-01-13) Top, Soner; Altiner, Mahmut; Kursunoglu, SaitThe separation of manganese and iron from a manganiferous iron ore using horse dung (biomass) as reductant was investigated in a sulfuric acid solution, and 99.80% Mn and 17.76% Fe were extracted into the solution under these leaching conditions: 1 M sulphuric acid concentration, 120 g/L biomass, 1/10 solid to liquid ratio, 300 rev/min stirring speed, 90 degrees C leaching temperature, and 3 h leaching time. In the first precipitation step, the iron and aluminum were first rejected from the solution at pH 5.04. Thereafter, 98.58% Mn was precipitated at pH 10 in the second step. The precipitate was identified as a pyrochroite mineral. After the leaching, the residue was subjected to a carbothermal reduction process conducted at 700 degrees C for 10 min in the presence of no extra reductant. The residue was converted to magnetite mineral, which can be easily recovered by magnetic separation. Based on the experimental results, a flowsheet has been proposed.Article Citation - WoS: 5Citation - Scopus: 5Selective Leaching of a Mixed Nickel-Cobalt Hydroxide Precipitate in Sulphuric Acid Solution With Potassium Permanganate as Oxidant(Taylor & Francis inc, 2020-10-12) Hussaini, Shokrullah; Ichlas, Zela Tanlega; Top, Soner; Kursunoglu, Sait; Kaya, MuammerSelective 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.Article Citation - WoS: 7Citation - Scopus: 7Recovery of Lithium From Spent Coin-Type Lithium Manganese Dioxide Cr Cells by Acidic Leaching in the Presence of Potassium Permanganate as Oxidant(Springer, 2022-09-20) Kursunoglu, Sait; Top, Soner; Altiner, Mahmut; Ozsarac, Safak; Kaya, MuammerThe selective leaching of lithium from spent coin-type lithium manganese dioxide CR cells by oxidative leaching and precipitation of Li2CO3 from Li-bearing 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.Article Citation - WoS: 7Citation - Scopus: 10Recovery of Lead and Zinc From a Citric Leach Solution of a Non-Sulfide Type Ore Flotation Tailing via Precipitation Followed by Solvent Extraction(Springer, 2023-01-12) Hussaini, Shokrullah; Tita, Angela Manka; Kursunoglu, Sait; Top, Soner; Kaya, MuammerThe 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 degrees 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.Article Citation - WoS: 17Citation - Scopus: 20Effects of Leaching Parameters on the Dissolution of Nickel, Cobalt, Manganese and Iron from Caldag Lateritic Nickel Ore in Hydrochloric Acid Solution(Taylor & Francis Ltd, 2020-06-18) Top, Soner; Kursunoglu, Sait; Ichlas, Zela TanlegaThe effects of leaching parameters on the metal dissolutions from Caldag laterite ore using hydrochloric acid at atmospheric pressure were investigated. The following leaching parameters were examined to understand their effects on the dissolution of the metals: hydrochloric acid concentration, solid/liquid ratio, particle size, leaching temperature and time. Extractions of 95.8%Ni, 94.5%Co and 94.3%Mn into the leach solution were obtained along with a substantial amount of iron (81.5%) under the following conditions: 3.0 M HCl concentration, 90 degrees C leaching temperature, 8 h leaching time, 1/5 solid/liquid ratio and -0.053 mm particle size. The hydrochloric acid consumption under these optimum conditions was found to be 543 kg t(-1)ore. The results indicated that hydrochloric acid concentration and leaching temperature were the most important parameters affecting metal dissolutions. It was found that the dissolution of nickel did not exhibit a good linear correlation to that of manganese, which suggested that considerable amounts of nickel were not hosted in asbolane phase but also in other mineral phases such as goethite, haematite and clays. It was, however, found that most of the cobalt appeared to be hosted in asbolane. The semi-quantitative mineral analyses revealed that mineral dissolution order was as follows: calcite > goethite > haematite > lizardite >= chlorite-serpentine > asbolane > albite > kaolinite.Article Citation - WoS: 2Citation - Scopus: 3Characterization of Nickel in Chromite Beneficiation Tailings by Mineral Liberation Analysis and Its Recovery by H2SO4 Leaching Followed by Oxalic Acid Precipitation(Springer, 2023-11-13) Altiner, Mahmut; Ibrahim, Ahmedaljaali Ibrahim Idrees; Kursunoglu, Sait; Top, Soner; Bayat, OktayThis study investigated the recovery of nickel from tailings (0.2% Ni) obtained in a chromite beneficiation plant using H2SO4 leaching followed by oxalic acid precipitation. The tailings were characterized using mineral liberation analysis. Ni was found as Fe-Ni, Fe-Ni-Co sulfide minerals, which were encapsulated in serpentine, olivine, pyroxene and clinochlore. Liberated fine chromite minerals benefited from magnetic separation followed by Falcon concentrator. A chromite product with a grade > 37% was obtained. The effect of leaching conditions including acid concentration, temperature, time and solid-to-liquid ratio on the leaching behavior of Ni was investigated based on the Taguchi approach. It was possible to extract Ni with a rate of > 98% from the tailings using the following conditions: H2SO4 concentration of 3 M, solid-to-liquid ratio of 1:20 and ambient temperature for 2 h. Finally, Ni was precipitated as an oxalate form with a precipitation rate of 72%. It is believed that implementing additional purification methods like solvent extraction may be essential to obtain a high-purity nickel product from the leach solution of oxalate precipitate. Experimental results indicate that the tailings used in this study are a good alternative as Ni resource in the near future.Article Citation - WoS: 7Citation - Scopus: 8Synergistic Effect of Organic Acid on the Dissolution of Mixed Nickel-Cobalt Hydroxide Precipitate in Sulphuric Acid Solution(Edp Sciences S A, 2019) Kursunoglu, Sait; Kursunoglu, SaitThe synergistic effect of an organic acid on the dissolution of nickel and cobalt from a mixed nickel-cobalt hydroxide precipitate (MHP) in sulphuric acid solution was studied. The effects of sulphuric acid concentration, the type of organic acid, leaching time, leaching temperature and stirring speed on the dissolution of the metals were experimentally investigated. It was observed that there is no beneficial effect of leaching temperature and stirring speed on the dissolution of the metals from the used MHP product which contains 37.7% Ni, 2.1% Co and 5.6% Mn. It was found that citric acid was more effective than oxalic acid for the dissolution of nickel and manganese, whereas oxalic acid was more effective than citric acid for the dissolution of cobalt. The addition of oxalic acid into the leaching system, however, affected the dissolution of nickel negatively because nickel precipitate as nickel oxalate. Therefore, the use of citric acid as synergist for sulphuric acid leaching of MHP product is more promising. After 60 min of leaching, 90.9% Ni, 84.2% Co and 98.1% Mn were dissolved under the following conditions: 0.75 M sulphuric acid, 2 g citric acid, 1/10 solid-to-liquid ratio, 400 rpm stirring speed and 30 degrees C temperature. The experimental results demonstrate that the addition of citric acid as a synergist for sulphuric acid leaching of a MHP product provides beneficial effect for the dissolution of nickel, cobalt and manganese.