TABLE OF CONTENTS Ore sorting is the original concentration process, having probably been used by the earliest metal workers several thousand years ago. It involves the appraisal of individual ore particles and the rejection of those particles that do not warrant further treatment.
Hand sorting has declined in importance due to the need to treat large quantities of low-grade ore which requires extremely fine grinding. Hand sorting of some kind, however, is still practised at some mines, even though it may only be the removal of large pieces of timber, tramp iron, etc. from the run-of-mine ore.
Electronic ore-sorting equipment was first produced in the late 1940s, and although its application is fairly limited, it is an important technique for the processing of certain minerals (Sassos, 1985; Salter and Wyatt, 1991; Sivamohan and Forss-berg, 1991; Collins and Bonney, 1998; Arvidson, 2002).
Sorting can be applied to pre-concentration, in which barren waste is eliminated to reduce the tonnage reporting to the downstream concentration processes, such as in uranium or gold ore sorting, or to the production of a final product, such as in limestone or diamond sorting. The ore must be sufficiently liberated at a coarse size (greater than 5 10 mm) to allow barren waste to be discarded without significant loss of value. Preconcentration by sorting is seen as a method of improving the sustainability of mineral processing operations by reducing the consumption of energy and water in grinding and concentration, and achieving more benign tailings disposal (Cutmore and...
