Browsing by Author "Vapur, Hüseyin"

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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.
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.