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Öğe A Study on Characterization and Use of Flotation to Separate Unburned Carbon in Bottom Ash from Cayirhan Power Plant(TAYLOR & FRANCIS INC, 2011) Ucurum, M.; Toraman, O. Y.; Depci, T.; Yogurtcuoglu, E.In this study, bottom ash from the Tuncbilek power plant has been characterized by X-ray fluorescence, X-ray diffraction, and infrared analysis. The bottom ash sample is potentially of class C type and has unburned carbon. The unburned carbon was separated from the bottom ash in a laboratory flotation cell. In the flotation experiment, sodium silicate (as a potential dispersant and depressant), butanol (promoter), kerosene oil (collector), and pine oil (frother) were used and the optimization of these flotation reagents were done through statistical modeling using a full two-level factorial design in order to evaluate the main and interaction effects of variables in flotation of unburned carbon; the evaluation of the results was done by Yates' notation. Test results showed that a product with 45.41% combustible grade at 40.0% recovery and 94.86% ash rejection was obtained at 1.98 g/kg sodium silicate, 1.38 g/kg promoter, 4.95 g/kg collector, and 2.41 g/kg frother.Öğe A study on the effect of process parameters in stirred ball mill(ELSEVIER SCIENCE BV, 2011) Toraman, O. Y.; Katircioglu, D.An experimental study on the fine grinding of calcite powder (d(50) = 62.16 mu m) using a 0.75 I laboratory stirred ball mill has been carried out. The effects of various operating factors, such as grinding time (min), stirrer speed (rpm), slurry density (wt.%) and ball filling ratio on fine grinding was studied under batch wet conditions using alumina balls, 95% purity with diameters 3.5-4.0 mm. A series of laboratory experiments using 24 full factorial designs was conducted to determine the optimum grinding parameters. The test results showed that the stirrer speed and grinding time have strong effects on the grinding efficiency, based on the value of specific surface area (m(2)/g). (C) 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.Öğe Dry Fine Grinding of Calcite Powder by Stirred Mill(TAYLOR & FRANCIS INC, 2013) Toraman, O. Y.The demand for fine powder is increasing in many fields such as chemical, pharmaceutical, and material industries. Therefore, research in fine grinding has gained in importance. In this study, the effects of various operating parameters, such as grinding time (min), stirrer speed (rpm), feed quantity (% of ball weight), and ball filling ratio (%) on fine grinding of calcite powder (CaCO3) (d(50)=34.04 mu m) were studied using a laboratory vertical stirred mill under dry conditions. A series of laboratory experiments using 2(4) full factorial designs was conducted to determine the optimum grinding parameters. The main and interaction effects on the volumetric surface area (S-v) (m(2)/cm(3)) of the ground product were evaluated using Yates' analysis. The grinding time, media filling ratio, and stirrer speed play distinct roles (positive) in product surface area and fineness.Öğe Effect of chemical additive on stirred bead milling of calcite powder(ELSEVIER SCIENCE SA, 2012) Toraman, O. Y.The effect of liquid additive on the dry ultrafine grinding of calcite powder (CaCO3) was investigated by using a stirred bead mill. The experiments were carried out by a batch operation, and the change in particle size distribution (PSD) and volumetric surface area (S-v) (m(2)/cm(3)) of calcite. The results show that the chemical additive promotes the fine grinding of calcite and that the maximum volumetric surface area of calcite obtained with additives 0.2%. (C) 2012 Elsevier B.V. All rights reserved.Öğe Effect of Various Operating Factors on Wet Stirred Mill Performance(TAYLOR & FRANCIS INC, 2011) Toraman, O. Y.; Katircioglu, D.In this study, the effects of various operating factors, such as initial particle size, feed quantity, filling volume of the ball, and ball size distribution on fine grinding of calcite powders (CaCO3) were studied using a laboratory stirred mill under wet conditions. A series of laboratory experiments using 24 full factorial designs was conducted to determine the optimum grinding parameters. The main and interaction effects on the specific surface area (m2/g) of the ground product were evaluated using Yates' analysis. The test results showed that the main factors that influence the mill grinding performance are the feed quantity and the ball size distribution.Öğe Predicting Los Angeles abrasion loss of rock aggregates from crushability index(SPRINGER, 2008) Kahraman, S.; Toraman, O. Y.Predicting Los Angeles abrasion loss of aggregate material from some simpler tests will be useful for especially preliminary studies. For this reason, to investigate the possibility of predicting the Los Angeles abrasion loss from the crushability index, Los Angeles abrasion, crushability, density and porosity tests were performed on 11 different rock types collected from different areas of Turkey. The results of the tests were analysed using simple and multiple regression analyses. Generally significant correlations were obtained from both simple and multiple regression analyses. The correlation coefficients and estimation capabilities of the two multiple regression equations are slightly higher than that of the simple regression equation. It was concluded that the simple regression equation is practical and reliable enough for estimation purposes. However, the two multiple regression equations can be used for a more accurate estimation.Öğe Predicting the crushability of rocks from the impact strength index(PERGAMON-ELSEVIER SCIENCE LTD, 2010) Toraman, O. Y.; Kahraman, S.; Cayirli, S.To investigate the possibility of predicting the crushability of rocks from impact strength index, twenty-four different rock types were tested in the laboratory. The crushability results were correlated with the results of impact strength test and regression analysis was performed. A strong inverse linear relation between the crushability index and the impact strength index was found. The effect of porosity and density on the correlation was also shown. In addition, multiple regression analysis including porosity and density was carried out. The significances of the derived models were statistically tested. It was concluded that the crushability of rocks can practically be estimated from the impact strength index using the simple regression model. (C) 2010 Elsevier Ltd. All rights reserved.Öğe Predicting the strength and brittleness of rocks from a crushability index(SPRINGER HEIDELBERG, 2018) Kahraman, S.; Toraman, O. Y.; Cayirli, S.Uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), and brittleness are widely used in rock engineering applications. However, preparing the test samples for the standard tests may not always be possible for weak or soft rocks. On the other hand, only rock fragments may be available to estimate the rock strength in some cases such as drilling. Therefore, developing some models for estimating the rock strength and brittleness from rock fragments will be useful. In this study, a crushability index (CI) was described from the crushing test, and the possibility of predicting UCS, BTS, and brittleness from this index was investigated. Strong and significant linear correlations were found between the CI and UCS, BTS, and one of the brittleness concepts. It was concluded that the UCS, BTS, and some brittleness concepts of rock could be estimated from the CI. The suggested method is especially useful for the drilling industry and for the cases where there are not enough samples for the standard tests. However, the study is a preliminary study on limited rock types and further study is required by including the number of different rock types.Öğe Preparation of submicron calcite particles by combined wet stirred media milling and ultrasonic treatment(TAYLOR & FRANCIS INC, 2017) Toraman, O. Y.; Inal, H.This paper investigates the grindability of calcite powder (D-50 = 6.68 mu m) to submicron particle sizes using stirred media mill (0.75 l) and ultrasonic generator (400 W, 24 kHz). The present study focuses directly on the comminution of calcite powder in water media by combined stirred milling and ultrasonic treatment and effects of some operational parameters such as grinding time (10-30 min), ultrasonic power (40-100% mu m as amplitude settings), and solid ratio (10-30% w/w) on comminution. Experimental results have been evaluated on the basis of product size and width of particle size distribution.Öğe Production of Submicron Particles by Mechanical Treatment: Width of Particle Size Distribution and Fineness of Product(TAYLOR & FRANCIS INC, 2015) Toraman, O. Y.Calcium carbonate (CaCO3) powders commonly used as a functional filler in paints, inks, papers, plastics, cosmetics, and so on, are generally produced by mechanical treatment (milling). This research was aimed to produce calcium carbonate submicron particles by stirred milling in wet conditions. The experiments were carried out by a batch operation, and determined the change in particle size distribution (PSD) of calcium carbonate. The product size (fineness) and PSD were used in the evaluation of the test results. The results showed that wet grinding in a stirred bead mill using the smaller grinding media (500 mu m) is an effective method for reduction of product size (approximate to 500nm) of the CaCO3 powder.Öğe The Effect of High Power Microwave Energy on the Grindability of Turkish Cayirhan Lignite(TAYLOR & FRANCIS INC, 2010) Toraman, O. Y.In this study, the effect of microwave radiation on grindability of Turkish lignite has been investigated. Turkish lignite (-15 mm, 500 g) was treated by microwave (at a frequency of 2.45 GHz) in a Te010 single mode cavity using a pneumatic system to control the residence time of each sample in the cavity with high-electric-field-strength microwave energy at different power settings (in the range of 5-20 kW) for a short residence time (2 sec). In order to determine the grinding resistance of Turkish lignite samples treated by microwave ovens, the Hardgrove Grindability Test was applied for each treated and untreated sample and also the amount of fine product (-74 m) was evaluated and compared with each other. Experimental results have shown that significant increases in grindability were achieved when the lignite samples were exposed to microwave radiation. The Hardgrove Grindability Index of samples and the amount of fine product increased up to 123 and 117%, respectively.Öğe The Influence of Microwave Preheating on Grindability of Low Rank Turkish Coal Using Impact Strength Index (ISI)(TAYLOR & FRANCIS INC, 2015) Toraman, O. Y.; Delibalta, M. S.In this study, the effect of microwave treatment on grindability of low rank Turkish coal has been investigated. Coal samples (-9.52 + 3.18 mm) was treated by microwave at a frequency of 2.45 GHz with different residence time (15-180 sec). In order to determine the grinding resistance of lignite samples treated by microwave oven, the impact strength index test was applied for each treated and untreated sample and compared with each other. Experimental results have shown that significant increases in grindability without damaging the coal structure were achieved when the coal samples were exposed to microwave radiation. The impact strength index of samples decreased up to 265%.Öğe Use of Wet Grinding and Aging to Produce Narrow Particle Size Distribution(TAYLOR & FRANCIS INC, 2011) Toraman, O. Y.An experimental study on the improvement of particle size distribution of calcite powder (d(50) = 3.23 mu m) was carried out. Ultrafine grinding of calcite powder was studied under batch wet conditions in a laboratory stirred mill. After grinding, the suspension was allowed to age at 30 degrees C for 12 and 24 h. The results indicated that the fineness narrow particle size distribution is influenced to a small extent by altering some operating parameters, such as suspension temperature and aging time. Further increase in the fineness narrow particle size distribution is likely with additional optimization work on the operating parameters of aging process.Öğe WET FINE GRINDING IN A LABORATORY STIRRED BALL MILL(INT SCIENTIFIC CONFERENCE SGEM, 2010) Toraman, O. Y.; Katircioglu, D.Fine grinding involves a large number of parameters in its operation. In this study, the effect of some parameters such as initial particle size, filling volume of the ball and ball size distribution on fine grinding of calcite powders (-200, -150 and -100 mu m) using a laboratory stirred ball mill was studied under wet conditions. Zirconia beads (ZrSiO4) were used as grinding media with 1.0-1.2, 2.0-2.2 and 2.8-3.0 mm. A series of batch experiments using 2(3) full factorial designs was conducted to determine optimum grinding parameters. The main and interaction effects on specific surface area (m(2).g(-1)) in fine grinding were evaluated using Yates' analysis. The test results showed that the ball filling ratio is the most important effect.
