Spiral Concentrators

are sorting devices which separate by sorting the material according to its different densities. They can be used for a grain size range from approx. 0.04 to 4 mm, with a capacity per single spiral of approx. 1 to 4 t/h.

If an even higher throughput is to be treated, 2 or 3 spirals must be combined to form a column. Several spiral col-
umns can be joined to form banks of 2, 4, 6 or 8 with distri-
butors for the inlets and collector chutes for the outlets.

Fields of application:

• Separating of ores and minerals

• Coal processing

• Decoaling of silica sands

• Soil remediation by soil washing

• Processing of municipal residues

Functioning:

The solids suspension (10 to 40 % solids, depending on application) is fed into the spiral from the top. Spread on the spiral bottom it moves down by gravity. A transverse flow which is directed inwards on the sluice bottom or out-
side on the slurry surface is superimposed on the main flow.
This combination results in a separation of the particles contained in the slurry, depending on their density. Parti-
cles with a lower specific gravity, such as wood, coal or organic matter, are concentrated in the outer areas of the flow. Particles with a higher specific gravity are transported towards the spiral axis. Two adjustable splitters on the end of the spiral enable the extraction of three fractions: heavy-, middle- and light-density fractions.

There are different spirals available depending on the raw material (heavy or light material) to be processed.

Flyer Spirals