There are a number of key reasons for the control of particle size distribution when processing minerals and at different stages of the mineral process route.
This may be to enable undersized material to bypass the crushing or grinding circuit and to retain oversized particles for further size reduction, and also to provide an optimum particle size material for efficient processing in the downstream separation and concentration systems.
Of course the primary objective in mineral processing is to prepare the material for the market, ie. to meet a range of desired specifications be they physical or chemical. Therefore, the target market application of the mineral will also dictate its particle size distribution.
There are two distinct methods for separation of particles based on size: screening and classification.
Classification techniques take advantage of the principle that particles of the same density but of different sizes settle in a fluid at different...