Hydraulic Washing

Hydraulic washing is the simplest of the concentration techniques, and it relies on nothing more exotic than density difference — it is a form of gravity separation.

How it works

• The ore is first powdered.
• A stream of running water is passed upward through the powder.
• Because the ore particles are denser (heavier) than the gangue particles, the flowing water is strong enough to carry the lighter gangue away while the heavier ore settles and stays behind. …