Browsing by Author "Top, Soner"

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Assessment of Rock Aggregate Quality Through the Analytic Hierarchy Process (AHP)
(SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS, 2020) Koken, Ekin; Top, Soner; Ozarslan, Ahmet; 0000-0003-0178-329X; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
The present study aimed to assess rock aggregate quality through the Analytic Hierarchy Process (AHP). In the context of the AHP analyses, four rock types (i.e., andesite, basalt, granodiorite, and gabbro), five evaluation criteria, and several technical requirements/suggestions for coarse aggregates related to bituminous paving mixtures were considered. In order to set over the evaluation criteria, detailed laboratory studies were conducted. For this purpose, various mineralogical, physical, and mechanical aggregate properties were determined for each rock type concerning their weathering grades. As a result of the laboratory studies, it was determined that the rock weathering processes have substantial negative impacts on the rock aggregate properties considered in this study. The AHP analysis results indicated that that different rock types have several advantages concerning various evaluation criteria. Based on the general evaluation point (EP) of the rocks, the gabbros were found to have the highest rock aggregate quality (EP = 0.393). In contrast, the andesites had the lowest quality (EP = 0.069). Besides, the basalts (EP = 0.271) and granodiorites (EP = 0.267) presented approximately the same quality for their use in bituminous pavement mixtures. It was also demonstrated that the AHP, with its specific methodology, can be utilized to represent different environmental and mechanical conditions by changing the relative weight of the evaluation criteria. In this way, the pros and cons of different rock types could be revealed quantitatively, which enables related engineers to select proper rock types for their use under different environmental and mechanical conditions. From this point of view, the present study could be declared a case study noted for combining theoretical and practical approaches on bituminous paving mixtures as a sign of rock aggregate quality.
Characterization of Nickel in Chromite Beneficiation Tailings by Mineral Liberation Analysis and Its Recovery by H2SO4 Leaching Followed by Oxalic Acid Precipitation
(SPRINGER, 2024) Altiner, Mahmut; Ibrahim, Ahmedaljaali Ibrahim Idrees; Kursunoglu, Sait; Top, Soner; Bayat, Oktay; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
This 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.
Concentration study of a specularite ore via shaking table, reverse flotation, and microwave-assisted magnetic separation
(Taylor and Francis Ltd., 2023) Al-Dhubaibi, Ammar Mahdi Ahmed; Vapur, Hüseyin; Top, Soner; Sivrikaya, Osman; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
Despite the difficulties in pelletizing specularite-type refractory iron ores, the utilization of these resources is indispensable for the steel industry due to the increasing need for iron. This study investigated Fe recovery from a refractory iron ore using gravity separation, reverse flotation, and two-stage magnetic separation. Tilt angle and particle size had a significant effect on the grade and recovery of concentrates in shaking table tests. Gravity concentration at optimum conditions resulted in an iron concentrate with 64.47% Fe grade and 90.73% Fe recovery. In the reverse flotation tests, the frother and depressant substantially affected the Fe grade of concentrates while the collector influenced the Fe recovery. A 90% Fe recovery with 64.69% Fe grade was obtained within optimum flotation conditions. The Fe grades were raised to >67.5% in products after the first magnetic separation. The tailings of the first magnetic separation were subjected to the second magnetic separation after microwave-assisted roasting to increase the magnetic susceptibility. In the second magnetic separation, a concentrate containing 66.06% Fe was separated from the microwave-roasted non-magnetic material with 82.23% Fe recovery. To the best of our knowledge, the microwave-roasting method has been applied to a specularite-type refractory iron ore for the first time
A distinctive determination of circular nozzles in downcomer for column flotation
(Taylor and Francis Ltd., 2023) Vapur, Hüseyin; Top, Soner; Altiner, Mahmut; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
This study aims to recover clean coal from valuable hard coal tailings (HCT), which have been used as solid fuels in a thermal power plant, through convenient conditions. The effective diameters of circular nozzles on the recovery of HCT were investigated by using the Jameson cell (JC) as the main purpose. Preliminary tests were conducted to determine the type and dosages of the collector and frother. The JC test results were evaluated by Yates and Box Behnken based on ANOVA analysis, statistically. It was observed that 3,000 g/ton of diesel oil, 300 g/ton of MIBC, 100 g/ton of Na2SiO3, and 60 cm of downcomer depth were found applicable levels of parameters. The decrease of the diameter increased the venturi effect of downcomer which provided the best recovery ratio of 97.79%. Besides, the results of kinetic models were obtained with desired efficiencies (CR∞ = 94.77%, k coal = 1.20, R 2 = 0.98 and SI = 2.40). The best diameter was 5 cm supplied a short time and high carrying capacity (CC) for concentrate.
Effective Processing of Specularite Ore by Wet Magnetic Separation and Reverse Flotation Techniques
(HİTİT ÜNİVERSİTESİ, 2019) AL DHUBAIBI, Ammar mahdi; Vapur, Hüseyin; Top, Soner; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
The aim of this study was to obtain a high grade and yield percentage of iron concentratefrom a specularite ore by using wet magnetic separation and reverse flotation techniques.The processing a specularite sample using wet magnetic separation and reverseflotation method was studied. During the magnetic separation process, particle size was-2000 μm and magnetic field applied at 0.25 T and 0.85 T which were performed at asolid-liquid ratio of 10% and 20% by weight, respectively. In the reverse flotation tests,experimental design (DOE) was applied, statistically. Depressant dosage, collector dosageand flotation time were selected as main parameters. PH value, frother dosage (MIBC) andparticle size were constant parameters. The results showed that particle size and magnetic fieldintensity had a significant effect on the iron concentrate grade and yield for wet magneticseparation. The optimum value of iron concentrate grade was 98.75% at 0.25 T andparticle size of -150 μm while the highest value of iron concentrate yield was 67% at 0.75T and particle size of -74 μm. In the flotation tests, depressant dosage had the greatestinfluence on the iron concentrate grade while the effect of the collector dosage and frothcollection time were less. Froth collection time had the greatest effect on iron concentrateyield.The maximum iron concentrate grade was 90.13% for the following conditions:5250 g/ton depressant, 1000 g/ton collector and 2-minute froth collection time. Themaximum iron concentrate yield was 98.96% for the following conditions: 5250 g/tondepressant, 1500 g/ton collector and 1 min froth collection time under fixed conditions.
Effects of leaching parameters on the dissolution of nickel, cobalt, manganese and iron from Caldag lateritic nickel ore in hydrochloric acid solution
(TAYLOR & FRANCIS LTD, 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND, 2020) Top, Soner; Kursunoglu, Sait; Ichlas, Zela Tanlega; 0000-0003-3486-4184; 0000-0003-2550-5948; 0000-0002-1680-5482; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
The 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.
Investigation of the beneficiation of low grade manganese ores
(Chamber of Mining Engineers of Turkey, 2013) Bayat, O.; Altiner, M.; Top, S.; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
In this study, beneficiation of low grade manganese ores was investigated by applying high intensity dry magnetic separation, MGS (Multi Gravity Separator) and flotation methods. Manganese grades of the ores were 25.65% Mn and 13.96% Mn taken from Antalya and Kayseri regions, respectively. Flotation and magnetic separation recoveries of both tested samples were low and the grades of the concentrates were less than 45% Mn. Similar results were also observed using a lab-type MGS but a concentrate could be obtained with 41.24% Mn and 78.71% recovery for manganese ores taken from Antalya region.
JİPS ARTIĞINDAN TAGUCHİ YAKLAŞIMI KULLANILARAK ÇÖKTÜRÜLMÜŞ KALSİYUM KARBONAT (ÇKK) ÜRETİMİ
(Eskişehir Osmangazi Üniversitesi, 2022) Top, Soner; Altıner, Mahmut; Kaymakoğlu, Burçin; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; TOP, Soner
Bu çalışmada, desülfürizasyon ünitesinden elde edilen jips (DJ) taneciklerinin çöktürülmüş kalsiyum karbonat (ÇKK) taneciklerine direk mineral karbonatlaştırma yöntemi ile dönüştürülmesi sırasında ultrasonik güç uygulama, sıcaklık, karbondioksit (CO2) besleme hızı deneysel parametrelerinin etkileri Taguchi yaklaşımı kullanılarak araştırılmıştır. Deneylerde venturimetre ünitesi karbonatlaştırma zonu olarak kullanılmıştır. Elde edilen ürünlerin karakterizasyonu XRD, SEM ve tane boyutu analiz yöntemleri ile belirlenmiştir. Ayrıca ürünlerin özellikleri ASTM standartları dikkate alınarak değerlendirilmiştir. Sonuç olarak; üretim şartlarına bağlı olarak iğnemsi, kübik veya delikli yapıda kalsit kristallerinden oluşan ÇKK tanecikleri elde edilmiştir. ASTM standartlarına göre endüstriyel bir artıktan üretilen bu ürün, boya ve plastik sektörlerinde değerlendirilebilmesi için gereken özellikleri sağlamaktadır.
Leaching of a complex Pb-Zn ore in sulfuric acid solution
(Niğde Ömer Halisdemir Üniversitesi, 2024) Ozsarac, Safak; Kursunoglu,Sait; Top, Soner; Altiner, Mahmut; Hussaini,Shokrullah; Gokcen, Hasan Serkan; Kaya,Muammer; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
In this study, the leaching behavior of a Gazipasa-Aydap complex Zn-Pb ore sample in sulfuric acid solutions was investigated. Firstly, the chemical and mineralogical compositions of the ore sample were determined by AAS, ICP-OES, XRF, and XRD analyses. The ore seemed to be very complex, containing major amounts of zinc (16.4%), lead (10.6%), iron (2.6%), and a minor amount of copper (0.2%). The leaching experiments demonstrated that 86.7% Zn, 90% Cu, and 25.2% Fe could be taken into the leach solution under the following conditions: 2 M sulfuric acid concentration, 25 °C leaching temperature, 1/10 solid-toliquid ratio, and 125 rpm shaking rate. The effects of the leaching temperature on the metal dissolutions were also tested. The experimental results revealed that increasing the leaching temperature had no beneficial effect on zinc dissolution, but increased iron dissolution significantly. Overall, it was determined that zinc could be extracted from the complex ore using a short leaching time (30 min), a low leaching temperature (25 °C), a relatively low sulfuric acid concentration (2 M), and a relatively high solid-to-liquid ratio (2/10).
Lead Blast Furnace Dust Recycling
(SPRINGER LINK, 2023) Top, Soner; Altiner, Mahmut; Kurşunoğlu, Sait; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
The recycling of lead (Pb), which has a limited reserve in the world, has great importance in terms of sustainable and efficient use of resources. Currently, more than half of the lead, which is the softest of base heavy metals, is recovered by recycling. In addition to the insulation of the cables and its use as a radiation shield, lead is mostly used in the manufacture of lead-acid batteries (LABs). Generally, lead smelting flue dust, also known as lead smelting fly ashes, formed during the smelting stage in secondary Pb production is fed back into the smelter. However, the impurities contained in this dust and the other required specifications for feeding into the furnace prevent dust from being fed back into the furnaces. Therefore, it is essential to evaluate these by-products with an effective process and to obtain valuable content from them. In this chapter, firstly the characterization of lead smelting flue dust has been investigated. Afterwards, the processes that can be applied to obtain contents such as Pb, Sb, Zn, and As from these materials were compiled from the literature and a comprehensive review study was presented.
Manganlı demir cevherinden manganın çözündürülmesinde farklı indirgeyicilerin etkisi
(TMMOB Maden Mühendisleri Odası/The Publication of the Chamber of Mining Engineer of Turkey, 2022) Top, Soner; Altıner, Mahmut; Kurşunoğlu, Sait; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
Bu çalışmada, bir manganlı demir cevherinden manganez çözünmesi indirgeyici liç yöntemiyle incelenmiştir. Sülfürik asit (H2SO4) çözeltisi içerisinde cevherden seçimli olarak manganez çözünümü için indirgeyici ajan olarak çeşitli kimyasallar kullanılmıştır. Öncelikle indirgeyici kullanılmadan seçimli mangan çözünmesi için optimum çözünme değerleri belirlenmiştir. Cevherden manganezin seçimli çözünümü hedeflendiğinden indirgeyici liç testleri, %11.54 Mn ve %2.16 Fe çözünme değerlerinin elde edildiği optimum parametreler altında (1 saat liç süresi, 300 rpm karıştırma hızı, 70 °C sıcaklık ve 1 M sülfürik asit konsantrasyonu) indirgeyici eklenerek gerçekleştirilmiştir. Çeşitli organik bileşikler kullanılarak (tartarik asit (C4H6O6), oksalik asit (C2H2O4), sitrik asit (C6H8O7), glikoz (C6H12O6), sükroz (C12H22O11) ve maleik asit (C4H4O4)) %97,46’ya varan yüksek verimlerde mangan çözünümü sağlanmıştır.
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 Alpha-Alumina from Black Aluminum Dross Using NaOH Leaching Followed by Calcination
(SPRINGER, ONE NEW YORK PLAZA, SUITE 4600, NEW YORK, NY, UNITED STATES, 2020) Turk, Murat; Altiner, Mahmut; Top, Soner; Karaca, Serkan; Bouchekrit, Chafia; 0000-0003-3486-4184; 0000-0002-7428-5999; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
The aim of this work is to produce alpha-alumina particles from aluminum (Al) dross via leaching-precipitation-calcination processes. In the leaching test, the effects of parameters such as the temperature, NaOH concentration, and time were investigated based on the Taguchi approach. In addition, the effect of the particle size on the Al extraction rate was determined. The Al extraction rate ranged from 78.64% to 93.11% and from 78.35% to 91.99% for ground dross and as-received dross, respectively. In the precipitation test, the pH of the leachate solution was decreased using HCl to remove Al ions as Al hydroxide precipitate. The precipitate was calcined at 1000 degrees C to 1200 degrees C for 270 min. The morphological and polymorphic properties of the products were characterized by scanning electron microscopy, atomic force microscopy, and x-ray diffraction analysis. The experimental findings indicated that the calcination temperature and stabilization time were critical for producing alpha-alumina particles rather than other polymorphs.
Production of high-grade antimony oxide from smelter slag via leaching and hydrolysis process
(ELSEVIER, 2025) Ibrahim, Ahmedaljaali Ibrahim Idrees; Aboelgamel, Muhammed; Soylu, Kartal Kaan; Top, Soner; Kursunoglu, Sait; Altiner, Mahmut; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
This study aimed to investigate the recovery of antimony (Sb) from slag generated in an antimony smelting plant using leaching followed by hydrolysis processes. The leaching behaviors of rare earth elements (REEs) were also examined. The physicochemical properties of the slag were determined using various analytical techniques. The slag (4.12 % Sb) was mainly composed of quartz and minor minerals, including microline, magnetite, heden-bergite, and stibiconite. The Sb types in the slag determined by XPS were found to be in the oxide form. The concentrations of REEs (La, Y, Ce, and Nd) in the slag were 169.21 g/t. Preliminary leaching experiment results indicate that (i) HCl was selected rather than other acids due to its high extraction ability on the Sb from the slag, (ii) a sample with a d50 of <25 mu m should be used, (iii) the slurry should be mixed at 300 rpm. In the following leaching tests, the effects of leaching parameters (HCl acid concentration, amount of tartaric acid, solid-to-liquid ratio, reaction temperature, and time) on the extraction rates of Sb, impurities, and REEs were investigated. At the best leaching conditions (HCl: 8 M, amount of tartaric acid: 1 g/L, stirring speed: 300 rpm, reaction tem-perature: 75 C-degrees, and time: 180 min), the extraction rates of Sb from the slag were determined to be 91.19 %, but the extraction rates of REEs were measured to be <= 50 %. The activation energy (Ea) for Sb leaching was found to be 46.75 kJ/mol, indicating that the reaction was governed by the chemically controlled mechanism. In particular, it was understood from the additional experimental results that the leaching procedure should be carried out for 20 h to extract La with an extraction rate of >90 %. However, the extraction rate of Sb was negligible in extended times. It was determined that using tartaric acid positively affected La's leaching mech-anism, and the required leaching time for La decreased to 180 min from 20 h with the increase of tartaric acid from 1 g/L to 6 g/L. Hydrolysis tests were conducted using the Taguchi approach (L32, 2<^>1 4<^>3). The effects of the alkaline type (NH4OH and NaOH), stirring speed (100, 200, 300, and 400 rpm), temperature (50, 60, 70, and 80 C-degrees), and pH (1.5, 2, 2.5, and 3) on the precipitation of Sb from the PLS were investigated. NH4OH was suggested for use in the hydrolysis test to obtain precipitates with higher purities. The product obtained under the optimal conditions comprised 81.43 % Sb, 16.23 % O, and 2.34 % Fe. The product was identified as antimony oxide by XRD
Production of high-grade antimony oxide from smelter slag via leaching and hydrolysis process
(ELSEVIER, 2024) Ibrahim Idrees Ibrahim, Ahmedaljaali; Aboelgamel, Muhammed; Kaan Soylu, Kartal; Top, Soner; Kursunoglu, Sait; Altiner, Mahmut; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
This study aimed to investigate the recovery of antimony (Sb) from slag generated in an antimony smelting plant using leaching followed by hydrolysis processes. The leaching behaviors of rare earth elements (REEs) were also examined. The physicochemical properties of the slag were determined using various analytical techniques. The slag (4.12 % Sb) was mainly composed of quartz and minor minerals, including microline, magnetite, hedenbergite, and stibiconite. The Sb types in the slag determined by XPS were found to be in the oxide form. The concentrations of REEs (La, Y, Ce, and Nd) in the slag were 169.21 g/t. Preliminary leaching experiment results indicate that (i) HCl was selected rather than other acids due to its high extraction ability on the Sb from the slag, (ii) a sample with a d50 of < 25 µm should be used, (iii) the slurry should be mixed at 300 rpm. In the following leaching tests, the effects of leaching parameters (HCl acid concentration, amount of tartaric acid, solid-to-liquid ratio, reaction temperature, and time) on the extraction rates of Sb, impurities, and REEs were investigated. At the best leaching conditions (HCl: 8 M, amount of tartaric acid: 1 g/L, stirring speed: 300 rpm, reaction temperature: 75 °C, and time: 180 min), the extraction rates of Sb from the slag were determined to be 91.19 %, but the extraction rates of REEs were measured to be ≤ 50 %. The activation energy (Ea) for Sb leaching was found to be 46.75 kJ/mol, indicating that the reaction was governed by the chemically controlled mechanism. In particular, it was understood from the additional experimental results that the leaching procedure should be carried out for 20 h to extract La with an extraction rate of > 90 %. However, the extraction rate of Sb was negligible in extended times. It was determined that using tartaric acid positively affected La's leaching mechanism, and the required leaching time for La decreased to 180 min from 20 h with the increase of tartaric acid from 1 g/L to 6 g/L. Hydrolysis tests were conducted using the Taguchi approach (L32, 2^1 4^3). The effects of the alkaline type (NH4OH and NaOH), stirring speed (100, 200, 300, and 400 rpm), temperature (50, 60, 70, and 80 °C), and pH (1.5, 2, 2.5, and 3) on the precipitation of Sb from the PLS were investigated. NH4OH was suggested for use in the hydrolysis test to obtain precipitates with higher purities. The product obtained under the optimal conditions comprised 81.43 % Sb, 16.23 % O, and 2.34 % Fe. The product was identified as antimony oxide by XRD.
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.
Production of Mn3O4 nanoparticles from a manganiferous iron ore via reductive leaching, precipitation, and calcination
(ELSEVIER, 2022) Altiner, Mahmut; Bouchekrit, Chafia; Top, Soner; Kursunoglu, Sait; 0000-0003-3486-4184; 0000-0002-1680-5482; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner; Kursunoglu, Sait
The synthesis of Mn3O4 nanoparticles from a manganiferous iron ore through reductive leaching, precipitation, and calcination was investigated. The reductive leaching results showed that Mn (99.9%) was almost completely extracted into the leaching solution along with a substantial amount of Mg (99.9%), Al (99.5%), Ca (80%), and Fe (22.9%) under the following conditions: 30 g/L tartaric acid as a reducing agent, 1 M HCl solution, leaching temperature of 90 ◦C, and leaching duration of 3 h. In the first precipitation step, Fe and Al were expelled from the pregnant leach solution by the addition of NaOH prior to conducting the precipitation experiments for the production of manganese carbonate (MnCO3) particles from the purified solution. In the second precipitation step, MnCO3 particles were produced using sodium carbonate (Na2CO3) as the precipitating agent. The effects of parameters such as reaction temperature, Na2CO3 concentration, and experimental duration were investigated using the Taguchi approach. Manganse(II) was precipitated in the form of MnCO3 particles (97.4%) under the following conditions: a temperature of 30 ◦C, Na2CO3 concentration of 0.014 mol/L, and duration of 30 min. The precipitate was observed to have a structure similar to that of rhodochrosite (MnCO3). Thermogravimetric/ differential thermal analyses were subsequently performed in three different atmospheres (air, oxygen, and nitrogen) to select a suitable atmosphere for calcination. The experimental results indicated the formation of hausmannite (Mn3O4) with a purity of 97.5% Mn3O4, 0.42% MgO, 1.66% CaO, and 0.34% FeO. The specific surface area, particle size, Curie temperature, magnetisation, coercivity, and remanence ratio of the final product obtained via 3 h of calcination at 350 ◦C were estimated to be 133.3 m2 /g, <142.2 nm, 56 K, 10.10 Am2 /kg, 0.35 T, and 0.19, respectively. The characterisation results revealed the excellent low-temperature ferromagnetic properties of the produced Mn3O4 nanoparticles.
Production of precipitated calcium carbonate particles from gypsum waste using venturi tubes as a carbonation zone
(ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND, 01.01.2019) Altiner, Mahmut; Top, Soner; Kaymakoglu, Burcin; Seckin, Ismail Yigit; Vapur, Huseyin; 0000-0002-7428-5999; 0000-0003-3486-4184; 0000-0003-4438-3982; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
In this study, we investigated the production of precipitated calcium carbonate (PCC) particles from desulfurization gypsum (DG) waste using a new experimental apparatus that is divided into two main parts: carbonation and stabilization zones. The solution was circulated via a pump from the stabilization zone to the carbonation zone where different types of Venturi tube were used for the reaction of CO2 with solution to produce PCC particles. The effects of CO2 flow rate, circulation rate, and Venturi types on the properties of the produced PCC particles were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size analyses. The conductivity and pH values of the solution were monitored during the carbonation. In addition, the reactivity of selected PCC was determined to evaluate its use as a sorbent in a desulfurization unit. The experimental results indicate that the Venturi tube had a strong effect on the reaction time and properties of PCC particles. The use of a Venturi tube resulted in a decrease in the time required for producing PCC particles, which were smooth, well-crystallized, and nano-sized cubic crystals. However, when no Venturi tube was used, hollow spherical crystals formed along with cubic crystals. It was found that the reactivity of selected PCC particles produced using Venturi tube was rather higher (52x10(-4) min(-1)), indicating that the PCC can be used as a sorbent in the desulfurization unit.
Properties of alkali-activated lightweight concrete
(ELSEVIER, 2021) Top, Soner; Altiner, Mahmut; Vapur, Hüseyin; 0000-0003-3486-4184; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Top, Soner
This chapter presents a brief overview of the properties of alkali-activated lightweight concrete. Nowadays, the production of lightweight concrete has great attentions due to its extraordinary advantages such as reduced mass, improved sound and thermal insulation properties. Furthermore, the low gas emissions and the utilization of waste materials increase the importance of alkali-activated lightweight concrete. In this chapter, the strengths of lightweight concrete were examined by considering the aggregate type and density, the alkali activator type and concentration, the type of fiber reinforcements and foaming agents, which are the factors that have the most impact on the strengths. Thermal conductivity, fire resistance, acoustic performance, and durability properties have been explained considering the key points in the literature. In addition to porosity, it has been determined that one of the most important factors directly affecting the fire resistance is the precursor type. It has been concluded that the fire resistance of the concrete prepared by using K-based precursors is higher. Acoustic performances of alkali-activated lightweight concrete vary. It is necessary to use a high amount of aggregate in order to obtain concretes with wide frequency ranges and high absorption coefficient. Contrary to concrete produced from Portland cement, alkali-activated concrete is more resistant to acid and sulfate attacks, since the formation of gypsum and strength is less.
Properties of fly ash-based lightweight geopolymer concrete prepared using pumice and expanded perlite as aggregates
(ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2020) Top, Soner; Vapur, Huseyin; Altiner, Mahmut; Kaya, Dogan; Ekicibil, Ahmet; 0000-0003-3486-4184; 0000-0002-6313-7501; 0000-0002-7428-5999; 0000-0003-4438-3982; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
The present paper aims to utilize the fly ash wastes with lightweight aggregates for geopolymer concrete production process in which sodium hydroxide (NaOH) and sodium metasilicate (Na2SiO3) were used as alkali activators, respectively. The designed experiments were examined by the Yates Analyses and so the productions of geopolymer concrete were investigated depending on curing temperature, solid/liquid rate and concentration of alkali activators. The curing temperature and alkali activator concentration were revealed as effective parameters in geopolymerization. The effects of expanded perlite (EP) and acidic pumice (AP) aggregates were discovered for the production of lightweight geopolymer concretes. The microstructural properties of each produced geopolymer concrete were characterized using SEM, EDS and laser particle size analyses. The specifications of the concrete were evaluated based on their uniaxial compressive strength (UCS), point load strength (PLS), sonic speed (SS), Mohs hardness (MH), and water absorption (WAR) ratio results. In addition, the effects of pre-wetting of EP aggregates, which have hydrophilic nature, were examined. To the best of our knowledge, this is the first time that pre-wetted lightweight EP aggregates were used to produce lightweight GP concretes. As a result of pre-wetting, chemical usage decreased by 32.5%. The UCSs of the lightweight geopolymer concretes were in a range of 10-50MPa and their unit weights changed between 1250 and 1700 kg/m(3). Lighter concretes were obtained by the addition of EP aggregates rather than AP ones. (C) 2019 Elsevier B.V. All rights reserved.