Yakup Cebeci

THE INVESTIGATION OF THE FLOATABILITY IMPROVEMENT OF YOZGAT AYRIDAM LIGNITE USING VARIOUS COLLECTORS

Abstract In this study, the floatability of Yozgat Ayridam lignite using kerosene, kerosene+emulsifier and kerosene+emulsifier+surfactant has been investigated. It was determined that the combination of both kerosene+emulsifier and kerosene+emulsifier+surfactant were stable (except anionic), easily dispersible in water and formed very small oil droplets compared to the kerosene. It was concluded that all of the collectors except kerosene investigated in this study increased the floatability of Yozgat Ayridam lignite. However when the combustible recovery and flotation efficiency index were considered, the best results were obtained from the combination of both keresone+Acorga M5640 and keresone+Acorga M5640+Flotigol CS (non-ionic). It was based on the high binding and spreading tendency of both collectors over the coal surface. The concentrates having a relatively low ash content were obtained with the kerosene+Acorga M5640+Flotigol CS. Consequently, the floatability improvement of Yozgat Ayridam lignite was achieved by using the combination of both kerosene+emulsifier and kerosene+emulsifier+surfactant.

Determination of bridging liquid type in oil agglomeration of lignites

Abstract The aim of this study was to determine the appropriate bridging liquid for lignites at selective agglomeration. Kerosene, diesel-oil, fuel-oil, spindle oil, heavy neutral, bright stock, light neutral and various surface active components were used. The best results were obtained with a mixture of 70% fuel-oil + 15% Acorga M5640 + 15% 2-ethyl hexanol or other alcohol type of reagents. It was determined that a clean coal having an ash content of 17% with a combustible recovery more than 90%, was produced from a coal with an ash content of 35.27%.

Investigation of kinetics of agglomerate growth in oil agglomeration process

Abstract In this study, the kinetics of agglomerate growth in a batch oil agglomeration process has been studied using bituminous coal. The effect of operating variables such as kerosene concentration, pulp density and speed of agitation on the agglomeration process was investigated. It has been found that the second-order kinetic equation describes the growth of agglomerates adequately. The growth of the agglomerates in the oil agglomeration process shows a self-preserving growth. Using this, a characteristic curve has been developed. For the prediction of the size distribution of the agglomerates, the d 50 values of the agglomerates must be known. Therefore, a model has been developed by using the kinetic equation for estimation of d 50 values of agglomerates for this coal. It was shown that the size distribution of the agglomerates for any levels of the process variables studied can be predicted using the equation of characteristic curve and d 50 values. Knowledge obtained from this study will be helpful for technological advancement of this kind of study.

Fundamental aspects of spherical oil agglomeration of calcite

Abstract In this study, concentration of calcite particles was investigated using oil agglomeration. For this purpose, effects of operating parameters were investigated and also zeta potential measurements and Fourier transform infrared spectrophotometer (FTIR) analyses have been carried out. In the experiments, effects of operating parameters such as pH, stirring speed, amount of Na–oleate as a collector and kerosene as a bridging liquid, solid ratio, suspension conditioning time, collector stirring time and agglomeration time were investigated to obtain optimum conditions. Zeta potential measurements were carried out depending on pH values and amount of Na–oleate. FTIR analyses were investigated to determine the adsorption type of Na–oleate on calcite surface. By the evaluation of the experimental results, optimum oil agglomeration conditions of calcite were determined as follows: pH 10; stirring speed, 1600 rpm; amount of kerosene, 180 l t−1; amount of Na–oleate, 10 kg t−1; solid ratio, 5 wt.%; suspension conditioning time, 2 min; collector stirring time, 1 min and agglomeration time, 5 min. In the optimum conditions, calcite was concentrated with recovery of 94.13 wt.%.

A study on spherical oil agglomeration of barite suspensions

Abstract In this study, the recovery of barite particles was investigated by using oil agglomeration. For this purpose, effects of operating parameters were investigated and also, zeta potential measurements and Fourier Transform Infrared Spectrophotometer (FTIR) analyses have been carried out. In the experiments, effects of operating parameters such as; pH, stirring speed, amount of Na-Oleate as a collector, and kerosene as a bridging liquid, solid concentration, suspension conditioning time, collector stirring time and agglomeration time were investigated to obtain optimum conditions. Zeta potential measurements were carried out depending on pH values and amount of Na-Oleate. FTIR analyses were investigated to determine the adsorption type of Na-Oleate on the barite surface. By the evaluation of the experimental results, optimum oil agglomeration conditions of barite were determined as follows; pH: 10, stirring speed: 1500 rpm, amount of kerosene: 80 l/t, amount of Na-Oleate: 3 kg/t, solid concentration: 5 wt.%, suspension conditioning time: 2 min, collector stirring time: 1 min and agglomeration time: 2 min. In the optimum conditions, barite was concentrated with recovery of 98.07 wt.%.

Using float–sink data in simple equations to predict sulfur contents

Abstract In this study, the interpretation of float–sink test data by simple equations on coals of different origins with respect to sulfur content has been investigated. Primarily, the cumulative weight and sulfur content of the floating fraction have been determined for each coal in all relative densities tested. For deriving of the equations, the recoveries of both non-sulfur and sulfur compounds in cumulative floating part have been calculated. Then, the relationship between the recoveries and relative densities has been stated as simple equations and the calculated values from equations have been compared with the experimental results. Furthermore, it has been found that these types of equations are suitable for the interpolation of sink–float data. The results reveal that the float–sink test results can be stated by simple equations relating to the sulfur content.