Electroosmotically enhanced dewatering/deliquoring of fine-particle coal: Final report, January 1--December 31, 1988

Abstract

This research is an investigation of the use of electroosmosis to dewater/deliquor ultrafine coal. Post-beneficiation dewatering/deliquoring methods for ultrafine coal are inadequate and generally require subsequent thermal drying. Thermal drying is not only expensive and time consuming, it also does not recover liquids for reuse in beneficiation processes. The degree of difficulty associated with dewatering increases as surface forces become more important than gravimetric forces. Electroosmotic flow has advantages for dewatering because it is much less sensitive to pore size than hydraulic gradient flow for the 1 to 75 ..mu..m ultrafine size range. The first year of this project focused upon preparation of ultrafine coal samples, development of test equipment and test cells, identification of variables affecting electroosmosis, and trial runs. Techniques and procedures not previously used by researchers of electroosmotic dewatering have revealed important information about the dynamics of the electroosmosis process. The identification of the first few millimeters of the cathode region of the cell as the sink for most of the energy input into the process provides the potential for improving efficiency by concentrating the second year effort on intervention in that region. Information gathered about differences in FTIR spectra as a function of location in themore » dewatering cell will be investigated. Changes in pH with temperature and by the application of electroosmotic current flow will receive attention, as well. 178 refs., 16 figs.« less