Mean elementary particle diameter and specific surface

According to the LEA & NURSE method, air permeability of a pressed tablet is the method used to measure elementary particle size (dp); the results obtained closely correlate with electronic microscopy results

For non-isometric particles the dp is equal to the smallest dimension; for aragonitic or scalenohedral- calcitic SOCAL®, the ratio between the biggest and smallest dimensions is typically from 5 to 10.

BLAINE surface (see formula below) is a good match for the B.E.T. surface.

with p = 2,71 for calcite

and p = 2,94 for aragonite

Remark: dp = median diameter [mm] (Blaine); S = specific surface [m²/g] (Blaine]

Size of agglomerates | Brightness and lightness | Volatile components | Organic coating content | Yield stress and viscosity