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Öğe An improvement on selective separation by applying ultrasound to rougher and re-cleaner stages of copper flotation(Mdpi, 2020) Hassanzadeh, Ahmad; Sajjady, Sayed Ali; Gholami, Hamed; Amini, Saeed; Özkan, Şafak GökhanIt has been known that the power ultrasound is used as a pretreatment and rarely applied as a simultaneous method to improve grade and recovery during froth flotation processes. This work aimed at investigating the impact of simultaneously used ultrasonic waves under variant operating configurations on the flotation of representative porphyry copper ore during rougher and re-cleaner stages. For this purpose, four different operating outlines were examined as (I) conventional flotation, (II) homogenizer, (III) ultrasonic bath, and (IV) combination of a homogenizer and an ultrasonic bath. The ultrasonic vibration was generated by the homogenizer (21 kHz, 1 kW) in the froth zone and ultrasonic bath (35 kHz, 0.3 kW) in the bulk zone. The rougher and re-cleaner flotation experiments were conducted using Denver-type mechanically agitated cells with 4.2 and 1 L capacities, respectively. The results showed that using the homogenizer (at 0.4 kW) slightly affected the selectivity separation index of chalcopyrite and pyrite, although it positively increased the grade of chalcopyrite from 21.5% to 25.7%. The ultrasonic-assisted flotation experiments with the ultrasonic bath and its combination with the homogenizer (0.4 kW) (i.e., configurations III and IV) led to an increase of approximately 16.1% and 26.9% in the chalcopyrite selectivity index compared to the conventional flotation, respectively. At the cleaning stage, a lower grade of aluminum silicate-based minerals was obtained desirably in every ultrasonic-treated configuration, which was supported with the water recoveries. Finally, applying the homogenizer and its combination with the ultrasonic bath were recommended for re-cleaner and rougher stages, respectively. Further fundamental and practical knowledge gaps required to be studied were highlighted.Öğe Artificial intelligence versus natural intelligence in mineral processing(Physicochemical Problems of Mineral Processing, 2023) Özkan, Şafak GökhanThis article aims to introduce the terms NI-Natural Intelligence, AI-Artificial Intelligence, MLMachine Learning, DL-Deep Learning, ES-Expert Systems and etc. used by modern digital world to mining and mineral processing and to show the main differences between them. As well known, each scientific and technological step in mineral industry creates huge amount of raw data and there is a serious necessity to firstly classify them. Afterwards experts should find alternative solutions in order to get optimal results by using those parameters and relations between them using special simulation software platforms. Development of these simulation models for such complex operations is not only time consuming and lacks real time applicability but also requires integration of multiple software platforms, intensive process knowledge and extensive model validation. An example case study is also demonstrated and the results are discussed within the article covering the main inferences, comments and decision during NI use for the experimental parameters used in a flotation related postgraduate study and compares with possible AI use.Öğe Effect of chloride salt Ions onto coal flotation based on contact angle and bubble-particle attachment time(2022) Özkan, Şafak Gökhan; Güngören, Can; Baktarhan, Yasin; Özdemir, Orhan; Şahpaz, Orhan; Kurşun, İlginThis study was aimed to reveal the effect of K+, Na+, Ca2+, and Mg2+ ions on the bubble-particle interactions of high-rank coal with contact angle and bubble-particle attachment time studies. The results for the contact angle experiments indicated that the contact angle of the coal, which was 62° in the absence of ions, increased slightly in the presence of mono- and divalent ions and reached a maximum (67°) in the presence of 1?10-1 mol/dm3 Mg2+, and the effect of K+ ions on the contact angle was minimal. Furthermore, the results for the bubble-particle attachment time experiments showed that the bubble-particle attachment time of coal, which was measured as 4.5 ms in the absence of ions, decreased as a function of ion concentration from 1?10-2 mol/dm3 to 1 mol/dm3. While the bubble-particle attachment times of coal particles in the presence of K+/Na+ and Ca2+/Mg2+ at low concentrations were around 2-3 ms and 1-2 ms, respectively, the increase in the concentration slightly changed the attachment time which decreased to less than 1 ms except for K+ ions. Overall, it can be concluded from this study that the effect of these dissolved ions in water was more prominent on the bubble-particle attachment time of the coal particles rather than the contact angle which showed no significant change. Also, the specific ion effect was determined as “Mg2+ > Ca2+ > Na+ > K+” in terms of the bubble-particle interactions in the presence of these ions.Öğe Effect of conventional and microwave thermal treatments on floatability of low- and high-rank lignites(Energy Sources Part A-Recovery Utilization and Environmental Effects, 2020) Özkan, Şafak Gökhan; Baktarhan, Yasin; Demir, İsmail; Güngören, CanThermal treatment is one of the well-known methods used before froth flotation to remove the polar groups from coal surfaces to make them more hydrophobic. In this study, the effect of conventional and microwave thermal treatments on the wettability of low and high-rank lignite was investigated using flotation experiments, zeta potential, and bubble-particle attachment time measurements, as well as hydrophilicity index analyses. The results showed that both of the thermal treatments increased hydrophobicity, and therefore floatability of the coal samples. The optimum results were achieved with conventional and microwave thermal treatment for the low and high-rank coals, respectively.Öğe Effect of operating parameters on the breakage process of calcite in a stirred media mill(Mining, Metallurgy & Exploration, 2019) Özkan, Şafak Gökhan; Katıcıoğlu-Bayel, Diler; Toraman, Öner YusufOne of the most energy-intensive processes for producing submicron range calcite is stirred media mill. In the present work, numerous operating parameters such as solid mass fraction, grinding media size, media filling ratio, and grinding time have been investigated using a vertical type stirred media mill. The results are evaluated on the basis of mean particle size, specific surface area, and specific energy consumption. After conducting this study, optimum experimental conditions found to be as 70% media filling ratio, 25% solid mass fraction, 1 mm grinding media size, and 120 min grinding time. Besides, energy savings up to 22% were achieved with the choice of proper media size.Öğe Effect of power ultrasound on wettability and collector-less floatability of chalcopyrite, pyrite and quartz(MDPI-Multidisciplinary Digital Publishing Institute, 2021) Hassanzadeh, Ahmad; Gholami, Hamed; Özkan, Şafak Gökhan; Niedoba, Tomasz; Surowiak, AgnieszkaNumerous studies have addressed the role of ultrasonication on floatability of minerals macroscopically. However, the impact of acoustic waves on the mineral hydrophobicity and its physicochemical aspects were entirely overlooked in the literature. This paper mainly investigates the impact of ultrasonic power and its time on the wettability and floatability of chalcopyrite, pyrite and quartz. For this purpose, contact angle and collectorless microflotation tests were implemented on the ultrasonic-pretreated and non treated chalcopyrite, pyrite and quartz minerals. The ultrasonic process was carried out by a probe-type ultrasound (Sonopuls, 20 kHz and 60 W) at various ultrasonication time (0.5-30 min) and power (0-180 W) while the dissolved oxygen (DO), liquid temperature, conductivity (CD) and pH were continuously monitored. Comparative assessment of wettabilities in the presence of a constant low-powered (60 W) acoustic pre-treatment uncovered that surface of all three minerals became relatively hydrophilic. Meanwhile, increasing sonication intensity enhanced their hydrophilicities to some extent except for quartz at the highest power-level. This was mainly related to generation of hydroxyl radicals, iron-deficient chalcopyrite and elemental sulfur (for chalcopyrite), formation of OH and H radicals together with H2O2 (for pyrite) and creation of SiOH (silanol) groups and hydrogen bond with water dipoles (for quartz). Finally, it was also found that increasing sonication time led to enhancement of liquid temperature and conductivity but diminished pH and degree of dissolved oxygen, which indirectly influenced the mineral wettabilities and floatabilities. Although quartz and pyrite ultrasound-treated micro-flotation recoveries were lower than that of conventional ones, an optimum power-level of 60-90 W was identified for maximizing chalcopyrite recovery.Öğe Effects of ultrasound on desliming prior to feldspar flotation(Mdpi, 2019) Malayoğlu, Ufuk; Özkan, Şafak GökhanIn this study, the effects of ultrasound on removal of impurities from raw feldspar were investigated by testing with a newly developed flotation cell with various frequency and power intensities prior to multistage feldspar flotation. Particularly, the quality of feldspar concentrates, the volume of removed slimes and the content of impurities were taken into account to reveal the impacts. Two representative feldspar ore samples taken from the Milas-Mugla region in Turkey were separately tested for desliming and flotation by conventional and ultrasonic methods under similar conditions and the results were compared to each other in terms of the quantity and the quality of the removed slimes and the final feldspar flotation concentrate. As a result, during desliming stage by using ultrasound, the volume of removed slimes was reduced by approximately 45% when compared to the conventional slime removal methods. Moreover, the impurity contents were doubled inside slimes when ultrasound was used. These outcomes lead to significant success in terms of reducing losses during the desliming stage and production of high quality feldspar concentrates by froth flotation assisted by ultrasound.Öğe Enhancement of galena-potassium ethyl xanthate flotation system by low power ultrasound(Elsevier, 2020) Güngören, Can; Baktarhan, Yasin; Demir, Ismail; Özkan, Şafak GökhanThe objective of this study is to investigate the improvement possibilities of the floatability of galena with ultrasonic application in the presence of potassium ethyl xanthate (KEX). For this purpose, micro-flotation experiments were carried out in addition to surface chemistry studies including zeta potential, contact angle, and bubble-particle attachment time measurements at various ultrasonic power levels and conditioning time. The results showed that, the maximum micro-flotation recovery of 77.5% was obtained with 30 W ultrasound power and 2 min conditioning time. In addition, more negative zeta potential values were obtained with ultrasound as well as higher contact angle and lower bubble-particle attachment time, which indicated the increased hydrophobicity of galena with ultrasound.Öğe Investigation of the effect of polymer-based novel grinding aids on cement grinding efficiency(Wiley, 2021) Özcan, Ebru Dengiz; Çinku, Kenan; Özdamar, Şenel; Ergin, Hasan; Özkan, Şafak GökhanGrinding aids, primarily amine group chemicals, are used to reduce agglomeration and increase concrete strength in order to ensure an efficient comminution process in the modern cement industry. This paper aims to investigate polymer-based novel grinding aids on cement grinding efficiency. It is hereby conventional grinding aids such as triethanolamine, triisopropanolamine, and other polymer-based novel chemicals are examined to reveal their effects on cement grains in grinding process. The physical, chemical, and mechanical properties of the final product in concrete were also compared to each other within the study. The experimental results showed that using polymer-based grinding aids (A1-A2-A3) increased the fineness of the cement by up to 15%, the cement strength by up to 5% and reduced the water requirement by up to 8%. In the grinding process, the polymer-based grinding chemicals (A1-A2-A3) also reduced agglomeration and surface energies on cement grains. Furthermore, the energy consumption was reduced by 7%-9% while the grinding performance was increased by 30%-32%. The flocculation on the mill's internal walls was also observed, resulting in a decrease in ball surface area. Finally, these results suggest that polymer-based chemical additives may outperform conventional grinding chemicals in the cement comminution process.Öğe Kritik madenlerin kullanıldığı ürünler ülke ekonomisine katkı sunar(2024) Özkan, Şafak GökhanGeleceğin katma değerli ekonomisinde belirleyici unsurlar arasında sadece lityum, grafit, kobalt ve nikel değil bor, nadir toprak elementleri, bakır, altın, gümüş, manganez, titanyum, demir, silisyum ve alüminyum içeren mineraller de giderek daha kritik bir rol oynamaktadır. Bu tip madenler, enerji dönüşümü, sürdürülebilirlik, yüksek teknoloji üretimi ve stratejik ekonomik avantajlar açısından büyük öneme sahip olmakla birlikte lityum, kobalt, nikel ve grafit, elektrikli araçlar (EV'ler) ve yenilenebilir enerji depolama sistemlerinin bataryalarında kullanılmaktadır. Elektrikli araç bataryaları ve enerji depolama çözümleri, enerji verimliliğini artırarak ve karbon emisyonlarını azaltarak önemli ekonomik değer sağlamaktadır. Nadir toprak elementleri, bor, bakır ve silisyum içeren mineraller ise rüzgâr türbinleri ve güneş panelleri gibi yenilenebilir enerji teknolojilerinde kullanılmakta ve bu teknolojiler, zaman içinde fosil yakıtların yerini alarak sürdürülebilir ekonomik büyümeye katkıda bulunmaktadır.Öğe Öğe Ultrasound supported flocculation of borate tailings with differently charged flocculants(Journal of Boron, 2021) Özkan, Şafak Gökhan; Demir, İsmail; Güngören, Can; Baktarhan, Yasin; Yücel, Melike; Çinku, İlgin; Kurşun, İlginMining activities are followed by mineral processing and wet beneficiation methods which generate a significant amount of tailings. Slime fractions are discharged to the tailing ponds with associated process water and this causes storage and disposal difficulties and creates severe environmental problems. Therefore, dewatering these tailings is necessary for both economic and environmental aspects. In this study, the flocculation behaviors of the boron tailings from Agildere and Hisarcik (Turkey) were studied in the presence of anionic, cationic, and non-ionic flocculants. The results showed that the free settling condition was optimum for the Agildere sample. On the contrary, the settling rate of the Hisarcik sample increased considerably by the use of flocculants with a significant decrease in the turbidity of the suspension. Flocculation experiments indicated that the effect of the flocculant type on the flocculation of the Hisarcik sample can be generally ordered as anionic>cationic>non-ionic>no-flocculant. Furthermore, ultrasound was used as a supporting application. The results indicated that although the ultrasound application decreased the settling rate of both samples, lower sediment bed heights were obtained for the Hisarcik sample with ultrasound because of the formation of a more compact sediment bed in the presence of ultrasound.Öğe Use of ultrasound in physical and chemical mineral processing operations(Springer Nature Switzerland AG, 2024) Özkan, Şafak Gökhan; Özdemir, Orhan; Güngören, Canhis Series covers the advances and developments in a wide range of materials such as energy materials, optoelectronic materials, minerals, composites, alloys and compounds, polymers, green materials, semiconductors, polymers, glasses, nanomaterials, magnetic materials, superconducting materials, high temperature materials, environmental materials, Piezoelectric Materials, ceramics, and fibers.
