Coarse spherical crystals

The particle size affects the value of the active surface, as is clearly shown in Table 7.1. The surface area also depends on the particle s shape — the smallest specific surface is encountered with spherical particles, the largest specific surface being characteristic for particles of plate shapes in the given fraction. In the more coarse fractions, spherical particles are prevalent. In colloidal dispersions flat and needle-shaped particles are predominant, this is connected with the stratified character of the crystal lattice of clay minerals forming the major portion of the colloidal fraction. 

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