Hydraulic classification by size. Classification by sedimentation

The unit operations implemented in separative techniques are usually preceded or coupled with classification phases into various batches of different particle sizes. In fact, gravimetric concentration equipment only performs well on materials with well-defined particle size ranges. Similarly, aggregate producers supply sands and gravels specifically defined by their particle size ranges. They therefore carry out preliminary washing which, among other things, eliminates fractions below 60 or 100 μm.

Hydraulic size classification refers to all processes used to separate solid particles from a suspension (or pulp) in a liquid medium into two or more fractions of different granularity, solely by the action of the gravitational (sedimentation) [J 3 131] or centrifugal [ [J 3 132] ] acceleration field.