Spiral Concentrators

General introduction of Spiral Concentrators:

A spiral concentrator uses gravity to separate particles of different densities. It is used globally in the mineral processing industry, consists of an open trough that twists downward in helix configuration about a central axis. Particles fed to the top of the concentrator are separtated radially on the basis of density and size as the slurry gravitates downward.

Working Principle of Spiral Concentrators:

In order to have a good separation, there should be a difference in Specific Gravity's of at least 1.0. One main benefit of spiral concentrators is they have no moving parts. The feed range, in percent solids, to a spiral ranges from 20% solids up to 40% solids. Depending upon the material characteristics, a maximum efficiency will usually be reached somewhere in this range. All that is required are some slurry pumps, the slurry to be separated and the banks of spirals with a feed distributor.

Slurry is pumped to the top of the spiral (typically 13' to 15' from the floor), and it enters a feed distributor that evenly distributes the feed to each spiral concentrator. The design and shape of the spiral make it work, when combined with gravitational acceleration. As the slurry travels the spiraling path down the spiral, mineral grains settle and start sorting according to size, density and to a lesser extend shape. Low density particles are carried with the bulk of the water towards the outside of the spiral (perimeter), while particles with the greatest density migrate towards the inside of the spiral.

Main Features and Benefits of Spiral Concentrators: