Vanning

[1] Typically, a powdered sample of orestuff is swirled with water on the blade of a shovel and then given a series of upward flicking motions.

The heavier ore is tossed up through the water and appears as a crescent shaped patch at the top of the charge with the lighter gangue below.

It was invented in 1874,[3] by W. B. Frue, Superintendent of the Silver Islet Mine, Ontario, Canada, who spent two years developing the system.

As it travelled upwards, it met with small jets of water which gradually washed the gangue off the bottom of the belt.

One machine could treat 6 tons per 24 hours of stuff passing a 40 mesh screen, or 2 vanners to 5 stamps.

End, side and overhead views of a Frue Vanner
Vanner room, Treadwell gold mine , 1887. These vanners served a 120 stamp mill battery. Note railroad tracks in aisle.