Abstract
To establish an evaluation system of coals for CWM, attempts were made with twenty kinds of coal from various countries and locations to study the relations of the rank of coal as bulk material to viscosity characteristics in CWM, in addition to surface-chemical properties such as water vapor adsorption and zeta potential.
Various parameters of viscosity described in Fig. 2-b, such as φ0, α and φ1000, show almost the same tendency of reaching a constant level above about 85% carbon content in coal (Fig. 12 Curve a)—an outstanding feature of viscosity characteristics.
The same tendencies were also observed in zeta potential, quantities of adsorption of water on coal surface, φAD, and of water occluded within aggregates of coal particles, φOC.
The results on various parameters are rather scattered, and it is presumed necessary to study coal not only as bulk material but also on the basis of surface chemistry.
