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ABSTRACT The adsorption of o-cresol, which is commonly used in coal flotation as frother, on two lignites and a bituminous coal has been studied. Coal samples used for the adsorption experiments were: fresh; oxidized, demineralized;... more
ABSTRACT The adsorption of o-cresol, which is commonly used in coal flotation as frother, on two lignites and a bituminous coal has been studied. Coal samples used for the adsorption experiments were: fresh; oxidized, demineralized; demineralized then oxidized. The oxidation processes were conducted by dry (in air at 100, 150 and 200°C) and wet (with 15% H2O2) methods. The extent of the coal oxidation was quantified by determining the amounts of the two principal oxygen-containing functional groups, carboxylic and phenolic, in the coal samples. The UV spectrophotometric technique was used for the analysis of o-cresol in solution. The adsorption for the lignites was found to increase by oxidation, but to decrease by demineralization, implying that o-cresol is adsorbed by hydrophilic interactions at the coal surface. In contrast, for the bituminous coal, the adsorption was increased by demineralization while it was decreased by slight oxidation, indicating that the adsorption occurs predominantly through hydrophobic interactions between the frother molecule and the coal surface. However, further oxidation of the bituminous coal resulted in an increase in the extent of adsorption in comparison with the fresh coal sample. Among the coal samples used, the adsorption on the bituminous coal samples conformed to the Langmuir equation, and adsorption free energies for these samples were found to be in the range −22.6 to −29.3 kJ mol−1.
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Research Interests: Chemistry, Food Science, Food Engineering, Kinetics, Vacuum Drying, and 15 moreOptimization, Model, Retention, Food Quality, Activation Energy, Degradation, Temperature Dependence, Dehydration, Ascorbic Acid, First Order Logic, Air Temperature, Moisture Content, Food Sciences, Reaction Rate, and Air Drying
The thermal decomposition of Şaphane alunite from Kutahya, Turkey, has been studied using ambient- and high-temperature X-ray diffraction analysis, differential thermal analysis, and thermogravimetric analysis. The alunite content in the... more
The thermal decomposition of Şaphane alunite from Kutahya, Turkey, has been studied using ambient- and high-temperature X-ray diffraction analysis, differential thermal analysis, and thermogravimetric analysis. The alunite content in the ore was about 47.5%. The first endothermic peak at about 545 °C is due to the dehydration of the structural water and the transformation of alunite into KAl(SO4)2 and amorphous Al2O3. The small exothermic peak at about 712 °C is probably caused by the recrystallization of KAl(SO4)2 into K3Al(SO4)3 and Al2(SO4)3. So far, no work has reported this new phase, K3Al(SO4)3, resulting from the exothermic reaction of alunite. Moreover, the d and I values of unidentified peaks in the previous literature gave reflections that were surprisingly identical to those of the K3Al(SO4)3 peaks. The second endothermic peak at about 810 °C is due to the desulfurization by which K3Al(SO4)3 and amorphous Al2(SO4)3 decompose into K2SO4 (arcanite) and two polymorphic varieties of Al2O3 (κ and γ)...
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Research Interests: Mechanical Engineering, Chemical Engineering, Scanning Electron Microscopy, Phosphorus, Raw materials, and 12 moreFuel, Fluidized Bed, Surface Area, Particle Size, Flue Gas, Phosphate Rock, Low Temperature, Fluidized Bed Reactor, Fluidized Bed Combustion, Flue Gas Desulfurization, X ray powder diffraction, and pore structure
The effects of temperature, CO2 concentration and particle size on simultaneous calcination/sulfation of Mardin–Mazıdagı phosphate rock in fluidized-bed reactor were investigated. For this, a raw sample was exposed to calcination and... more
The effects of temperature, CO2 concentration and particle size on simultaneous calcination/sulfation of Mardin–Mazıdagı phosphate rock in fluidized-bed reactor were investigated. For this, a raw sample was exposed to calcination and sulfation processes in a fluidized-bed reactor to determine the effects of parameters by using a model gas mixture similar to the flue gas composition. The calcination ratio increased with
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It has been suggested that iodine plays an important role in gastric cancer. Gastric cancer ranks first among the cancers in the north-eastern Anatolia region, Turkey, where iodine deficiency is common. In this study, iodine levels were... more
It has been suggested that iodine plays an important role in gastric cancer. Gastric cancer ranks first among the cancers in the north-eastern Anatolia region, Turkey, where iodine deficiency is common. In this study, iodine levels were determined in gastric cancer and surrounding normal tissues in 19 patients with gastric cancer. Tissue iodine levels were determined by the Foss method based on the Sandell-Kolt-hoff reaction. Tissue iodine levels were lower in gastric cancer tissue (17.8±3.4ngI/mg protein, mean±SEM) compared with surrounding normal tissue (41.7±8.0ngI/mg protein) (p<0.001). There was positive correlation between the iodine levels in gastric cancer tissue and surrounding normal tissue (r=0.845, p<0.001). There was no significant difference in iodine levels in cancer and surrounding normal tissue between male and female subjects. The iodine deficiency in our region may be one of the factors for increased gastric cancer prevalence. Our results support the hypothe...