Tolga Depci

Effect of Microwave Radiation on Coal Flotation

Abstract Most low-rank coals are high in moisture and acid functional groups, therefore showing poor floatability. Drying, which removes the water molecules trapped in the pores and adsorbed at the surface of coal, decreases the hydrophilic character and improves the floatability. Microwave heating, whose simplest application is drying, was applied at 0.9 kW power level for 60 sec exposure time in the experiments to decrease the moisture content of coal in order to enhance the hydrophobicity. The flotation tests of microwave-treated coal by using heptanol and octanol lead to a higher flotation yield and ash removal than original coal.

Synthesis and thermoluminescence properties of rare earth oxides (Y, Ce-Lu) doped lithium triborate

Abstract Lithium triborate (LiB 3 O 5 ) was synthesized by high temperature solid-state reaction method, and then rare earth oxides were doped into LiB 3 O 5 to enhance its thermoluminescent (TL) properties. The identification and characteristics of the obtained compounds were determined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) analyses, differential thermal analyses (DTA) and scanning electron microscopy (SEM). The glow curves were obtained using a thermoluminescent (TL) reader. The results revealed that all the rare earth oxides were not good activators for lithium triborate and the obtained compounds could not be used for dosimetric applications.

Peat and lignite leaching process with tetralin in autoclave to produce oil

Instead of directly burning a lignite having low calorific value and peat, the Elbistan lignite (L) and the Adiyaman peat (P) were mixed and leached in an autoclave to obtain an oil to not only provide the demand for energy but also protect the environment. The effects of the peat ratio in the mixture on the properties of co-liquefaction products (oil, char, asphaltene, and preasphaltene) and oil yield were investigated in details. The products were characterized by XRD, FTIR, and elemental analysis. In addition, the composition of the oil was identified by GC/MS, showing that the peat ratio did not affect the chemical composition of the oil due to the high lignin content and the nearly same elemental compositions. On the other hand, the oil yield for a co-liquefaction process was found as 34.3% to be higher than the average value of oil yields obtained from the individual feeds (24.3% for lignite and 28% for peat), showing the synergistic effects between the lignite and peat. The obtained oil was paraffinic-low waxy oil with 5138.62 kcal/kg of calorific value and 0.94 g/cm3 density. Finally, it was suggested that the production of a more valuable product using the peat and the lignite having low calorific value will not only contribute more to the countrys economy in future but also be better for the environment, instead of directly burning them.