Explain hydraulic washing with a neat diagram.

Explanation

Hydraulic (Gravity separation) method:
Principle:
(i) The difference in the densities or specific gravities of the ore and gangue is the main principle behind this method.
(ii) Oxide ore are purified by this method.
(iii) E.g. Haematite `Fe_2O_(3)` the ore of iron.
Method:

(i) Ore is poured over a sloping , vibrating corrugated table with grooves and a jet of water is allowed to flow over it .
(iii) The denser ore particles settle down in the grooves and lighter gangue particles are washed down by water .