The essential physical characteristics of the distinction of particles are size, shape and surface roughness.
Particle shape and surface roughness are considered important parameters in the prediction of the behavior
of particles individually or collectively. These parameters are of great importance to industries employing
various materials in a powder form. These parameters have not been currently reviewed satisfactory in the
mineral processing field. Therefore, this research is concerned with the different methods used to estimate
the particle shape and surface roughness and also to relate these parameters with the behavior of some
mineral processing operations, especially comminution and flotation processes.
The surface roughness of mineral particle influences the fundamental processes of particle–bubble
attachment and the other sub-processes in froth flotation. The contact angle is dependent on the surface
roughness. The modification of the wettability due to surface roughness can be greatly enhanced in the
fractal surface; that is the fractal surface will be superrepellen (superwettable) to a liquid when the contact
angle is greater (less) than 90°. Correlations were found between the shape properties, surface roughness
values and wettability.
The dry grinding produces relatively rough particle surfaces with a high concentration of microstructural
defects while the wet grinding produces smoother cleaner surfaces. The dry ground samples exhibited more
stable, higher loaded froths and faster flotation kinetics.