TABLE OF CONTENTS Size analysis of the various products of a concentrator constitutes a fundamental part of laboratory testing procedure. It is of great importance in determining the quality of grinding and in establishing the degree of liberation of the values from the gangue at various particle sizes. In the separation stage, size analysis of the products is used to determine the optimum size of the feed to the process for maximum efficiency and to determine the size range at which any losses are occurring in the plant, so that they may be reduced.
It is essential, therefore, that methods of size analysis must be accurate and reliable, as important changes in plant operation may be made on the results of the laboratory tests. Since only relatively small amounts of material are used in the sizing tests, it is essential that the sample is representative of the bulk material and the same care should be taken over sampling for size analysis as for assay (Chapter 3).
Barbery (1972) derived an expression for the sample size necessary to meet the requirements of Gy's fundamental error in sampling (described also in Napier-Munn et al., 1996).
The primary function of precision particle analysis is to obtain quantitative data about the size and size distribution of particles in the material (Bernhardt, 1994; Allen, 1997). However, the exact size of an irregular particle cannot be measured. The terms "length", "breadth", "thickness", or "diameter" have little meaning because so many different values of these...
