The classification
The classification of materials is intended to:
- produce particle sizes for marketing (limestone aggregates, carbon sizes, plastic granules, wood pellets, etc.),
- prepare material for downstream treatment based on their particle sizes (for instance granulation of fine particles and grinding of coarse fragments),
- prepare material for processing requiring fine separation (dust removal) or conversely the elimination of excessively large elements.
In the case of mixed materials, this process also enables an initial stage of separation or concentration to be performed for one of the components, mainly through certain waste recycling processes.
The choice of classification techniques is mainly dictated by the particle sizes of the material to be dealt with: for particle sizes greater than 500 µm, screening is performed (dry or wet method), while for smaller particle sizes, pneumatic classification or hydraulic classification may be used.
