Rosin-Rammler Particle Size Distribution

The Rosin-Rammler distribution is frequently used to describe the particle size distribution of various types and sizes of coal. The function is particularly suited to representing particles generated by grinding, milling and crushing operations. This will allow you to predict the percentages of material at sizes not measured and to estimate what the particle size will be when a coal is crushed.

The conventional Rosin-Rammler function is calculated through:

Where:
R is the retained weight fraction of particles with a diameter greater than D
is the particle size
is the mean particle size
n is a measure of the spread of particle sizes

For a graph template for the Rosin-Rammler proces specifically created by SGS for your convenience.

Source:
Graphical form for applying the Rosin and Rammler equation to the size distribution of broken coal
Author: W S Landers
Source: United States Department of the Interior, Bureau of Mines (1946)