There are three major goals of this research project. The first is to develop methodologies and data on mechanical properties of crushed and finely ground low-rank coals and their mineral residues, relevant to their behavior and handling problems in gasification, liquefaction, and slurry transport applications. These properties include: shear strength, compressibility and permeability of dry, free-sliding coal; abrasiveness of finely ground coal and mineral residues in slurries; viscosity of coal and residue slurries in water and in coal-derived liquid products; porosity, defined as size distribution and continuity of pores and their variation through processing steps; mechanical and thermal friability; and shear and compressive strength of cokes or chars formed by devolatilization of coals. The second research goal is to relate observed mechanical or physical properties, such as elasticity, plasticity, or internal friction, to the three-dimensional structural arrangement of the coal macromolecules via the theories and models of polymer science. The third research goal is to determine the distribution and modes of incorporation of water in low-rank coals, and develop approaches for the measurement of ''moisture''which can be interpreted in ways meaningful for low-rank coal utilization. 64 figs., 4 tabs.