Moisture sorption characteristics of dehydrated pastirma were investigated at 15°C, 20°C and 30°C... more Moisture sorption characteristics of dehydrated pastirma were investigated at 15°C, 20°C and 30°C over a water activity (a(w)) range of 0.2-0.9. Sigmoidal (type-II) adsorption isotherms were observed for pastirma. The experimental sorption data obtained were applied to the Halsey, Harkins-Jura, Smith, BET, Henderson, Freundlich and GAB isotherm equations to test fitness of these equations to pastirma. The order of the best fit of sorption data obtained for pastirma at 15°C, 20°C and 30°C in all the range of a(w) studied (0.2-0.9) was Harkins-Jura>Halsey>BET>Smith>Freundlich>GAB>Henderson, respectively. In the range a(w) 0.2-0.55, BET model has a better fit than in the range a(w) 0.2-0.9. Isosteric heats of adsorption were evaluated by applying the Clausius-Clapeyron equation to experimental isotherms and decreased with increasing moisture content.
This study focused on the preparation, structural characterization and evaluation of some dynamic... more This study focused on the preparation, structural characterization and evaluation of some dynamic and rheological properties of a new type of mastic material, clay-mastic, which consists of bituminous binders mixed with mineral fillers. For this purpose, mastic samples were prepared by mixing conventional bitumen (50/70) with organo-montmorillonite (OMMT) in various proportions. X-ray powder diffraction (XRD) spectra and scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM) images of raw clay (MMT), organo-clay (OMMT) and raw bitumen with the prepared mastics were taken, and the changes in the crystallographic properties of the clay and its dispersion characteristics in the bitumen matrix as well as the changes in the morphological properties of the mastic samples were investigated comparatively. In addition, penetration, softening point, flash point, dynamic viscosity, dynamic shear rheometer (DSR) and Fraass breaking point tests were carri...
The adsorption of phosphate from aqueous solution on dolomite was investigated at 20 and 40 degre... more The adsorption of phosphate from aqueous solution on dolomite was investigated at 20 and 40 degrees C in terms of pseudo-second-order mechanism for chemical adsorption as well as an intraparticle diffusion mechanism process. Adsorption was changed with increased contact time, initial phosphate concentration, temperature, solution pH. A pseudo-second-order model and intraparticle diffusion model have been developed to predict the rate constants of adsorption and equilibrium capacities. The activation energy of adsorption can be evaluated using the pseudo-second-order rate constants. The adsorption of phosphate onto dolomite are an exothermically activated process. A relatively low activation energy and a model highly fitting to intraparticle diffusion suggest that the adsorption of phosphate by dolomite may involve not only physical but also chemisorption. This was likely due to its combined control of chemisorption and intraparticle diffusion. However, for phosphate/dolomite system chemical reaction is important and significant in the rate-controlling step, and for the adsorption of phosphate onto dolomite the pseudo-second-order chemical reaction kinetics provides the best correlation of the experimental data.
In this study, the adsorption of phosphate on gas concrete from aqueous solutions has been studie... more In this study, the adsorption of phosphate on gas concrete from aqueous solutions has been studied as functions of temperature, mixing rates and suspension pH. Over 99% of phosphate removal was found. The chemical composition of the gas concrete has been defined by X-ray analysis. Experimental data was fitted to the Langmuir equation in order to Langmuir coefficients. After calculating
Oil agglomeration is an effective technique for recovering and deashing coal fines. Conditioning ... more Oil agglomeration is an effective technique for recovering and deashing coal fines. Conditioning is the most important unit operation prior to agglomeration or size enlargement. In this study, the effects of the design and process parameters in the conditioning step, which markedly ...
In this study the effects of parameters such as coal loading (wt.%), the initial pH of mixture, t... more In this study the effects of parameters such as coal loading (wt.%), the initial pH of mixture, the addition of various electrolytes, surfactants and temperature on the viscosity and rheologic parameters of coalwater mixture (CWM) have been investigated. The apparent viscosity was ...
Moisture sorption characteristics of dehydrated pastirma were investigated at 15°C, 20°C and 30°C... more Moisture sorption characteristics of dehydrated pastirma were investigated at 15°C, 20°C and 30°C over a water activity (a(w)) range of 0.2-0.9. Sigmoidal (type-II) adsorption isotherms were observed for pastirma. The experimental sorption data obtained were applied to the Halsey, Harkins-Jura, Smith, BET, Henderson, Freundlich and GAB isotherm equations to test fitness of these equations to pastirma. The order of the best fit of sorption data obtained for pastirma at 15°C, 20°C and 30°C in all the range of a(w) studied (0.2-0.9) was Harkins-Jura>Halsey>BET>Smith>Freundlich>GAB>Henderson, respectively. In the range a(w) 0.2-0.55, BET model has a better fit than in the range a(w) 0.2-0.9. Isosteric heats of adsorption were evaluated by applying the Clausius-Clapeyron equation to experimental isotherms and decreased with increasing moisture content.
This study focused on the preparation, structural characterization and evaluation of some dynamic... more This study focused on the preparation, structural characterization and evaluation of some dynamic and rheological properties of a new type of mastic material, clay-mastic, which consists of bituminous binders mixed with mineral fillers. For this purpose, mastic samples were prepared by mixing conventional bitumen (50/70) with organo-montmorillonite (OMMT) in various proportions. X-ray powder diffraction (XRD) spectra and scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM) images of raw clay (MMT), organo-clay (OMMT) and raw bitumen with the prepared mastics were taken, and the changes in the crystallographic properties of the clay and its dispersion characteristics in the bitumen matrix as well as the changes in the morphological properties of the mastic samples were investigated comparatively. In addition, penetration, softening point, flash point, dynamic viscosity, dynamic shear rheometer (DSR) and Fraass breaking point tests were carri...
The adsorption of phosphate from aqueous solution on dolomite was investigated at 20 and 40 degre... more The adsorption of phosphate from aqueous solution on dolomite was investigated at 20 and 40 degrees C in terms of pseudo-second-order mechanism for chemical adsorption as well as an intraparticle diffusion mechanism process. Adsorption was changed with increased contact time, initial phosphate concentration, temperature, solution pH. A pseudo-second-order model and intraparticle diffusion model have been developed to predict the rate constants of adsorption and equilibrium capacities. The activation energy of adsorption can be evaluated using the pseudo-second-order rate constants. The adsorption of phosphate onto dolomite are an exothermically activated process. A relatively low activation energy and a model highly fitting to intraparticle diffusion suggest that the adsorption of phosphate by dolomite may involve not only physical but also chemisorption. This was likely due to its combined control of chemisorption and intraparticle diffusion. However, for phosphate/dolomite system chemical reaction is important and significant in the rate-controlling step, and for the adsorption of phosphate onto dolomite the pseudo-second-order chemical reaction kinetics provides the best correlation of the experimental data.
In this study, the adsorption of phosphate on gas concrete from aqueous solutions has been studie... more In this study, the adsorption of phosphate on gas concrete from aqueous solutions has been studied as functions of temperature, mixing rates and suspension pH. Over 99% of phosphate removal was found. The chemical composition of the gas concrete has been defined by X-ray analysis. Experimental data was fitted to the Langmuir equation in order to Langmuir coefficients. After calculating
Oil agglomeration is an effective technique for recovering and deashing coal fines. Conditioning ... more Oil agglomeration is an effective technique for recovering and deashing coal fines. Conditioning is the most important unit operation prior to agglomeration or size enlargement. In this study, the effects of the design and process parameters in the conditioning step, which markedly ...
In this study the effects of parameters such as coal loading (wt.%), the initial pH of mixture, t... more In this study the effects of parameters such as coal loading (wt.%), the initial pH of mixture, the addition of various electrolytes, surfactants and temperature on the viscosity and rheologic parameters of coalwater mixture (CWM) have been investigated. The apparent viscosity was ...
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