Spiral separator

Spiral separators of the wet type, also called spiral concentrators, are devices to separate solid components in a slurry, based upon a combination of the solid particle density as well as the particle's hydrodynamic properties (e.g. drag).

Conversely, light particles stay towards the outside of the spiral, with the water, and quickly reach the bottom.

At the bottom, a "cut" is made with a set of adjustable bars, channels, or slots, separating the low and high density parts.

The device consists of a tower, around which is wound an inwardly inclined flight.

Round particles roll at a higher speed than other objects, and so are flung off the inner flight and into the collection funnel.