Calorimetric study of surface and interfacial properties of fine coal
In order to study the surface/interfacial properties of fine coal, heat flux calorimeter was used to make heat of immersion (..delta..H/sub imm/) measurements. These heats have been shown to be a valuable means of investigating the chemistry and surface properties of solids as they interact with adsorbate molecules. In addition, heats of immersion can be used to characterize a solid in terms of hydrophobicity/hydrophilicity and estimate its relative wetting tendency. The first phase of experiments that were performed served as a basis for comparison of coal components/characteristics immersed in deionized, distilled water. The results of these experiments were found to correlate well with reported flotation trends. In the second phase of experiments, the solids that were previously investigated were immersed in various wetting media. The solids were characterized in terms of hydrophobicity/hydrophilicity and their relative wetting tendency was also established. Heat of immersion measurements using surfactant solutions demonstrated that preferential adsorption of the surfactant molecule occurs on the coal surface, thereby altering its surface properties. This was supported by laboratory vacuum filtration tests. Using flotation agents as the wetting medium, the heat of immersion was found to vary with kerosene concentration, pH, kaolin addition and oxidation of the solid surface. The results of these ..delta..H/sub imm/ measurements were found to correlate very well with results obtained by independent flotation experiments performed under the same conditions.
- Research Organization:
- Pittsburgh Univ., PA (USA)
- OSTI ID:
- 5875483
- Resource Relation:
- Other Information: Thesis (Ph.D)
- Country of Publication:
- United States
- Language:
- English
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