DESCRIPTION: Flotation followed by shaker table concentration in open circuit grinding.
ORE TREATED: When the mineral in an ore is freed at a coarse mesh, this flowsheet gives high recovery and high capacity. The practice is limited in scope, as on ores requiring fine grinding, closed circuit is preferable, and on ores wherein the gold is free, amalgamation or cyanidation alone or with flotation, may give hotter results.
ADVANTAGES In this particular case, one product is desired in a good grade concentrate containing the gold and silver values which can be marketed profitably. The open circuit grinding allows maximum tonnage through the grinding mill, and the table following removes coarse heavy mineral. Dilution in the flotation machine may be high but efficiency can be sacrificed in order to handle the larger tonnage possible with this flowsheet. In cases wherein flotation necessitates a denser pulp, a dewatering device such as a thickener or sand cone could be installed ahead of the flotation machine.
COMMENTS The flotation machine is required to handle a coarse feed, and for this reason, the self aspirating flotation cell has been used as it is the only machine capable of this duty, yet retaining the ability to give high recovery, good grade of concentrate, low operating and maintenance costs.