Gravity is used by spiral concentrators when particles of different densities are to be separated. It should not be confused with separating particles of different sizes, which is done using a Spiral Classifier.
Helical profiled troughs supported on a central column are the main parts of the spiral concentrator. Low and high particles are separated and stratified with the help of adjustable splitters at the end of the spiral. This is done as the slurry travels down the spiral.
Click here to read more on separation using dense media, also known as dense media separation.