Abstract: In a flotation recovery circuit which includes the steps of: a grinding stage wherein a predetermined quantity of ore is ground to a predetermined size while irrigating the ore with water including recovered process water thereby to form a ground ore portion; conveying the ground ore portion mixed with the recovered process water to a flotation recovery stage; applying flotation recovery to the ground ore portion thereby to extract a recovered metal portion from a mix of the recovered process water and the ground ore portion; returning at least a portion of the recovered process water to the grinding stage; a method of increasing recovery of the metal portion from the predetermined quantity of ore; said method comprising applying a magnetic field to the ground ore portion in a magnetic conditioning stage while it is contained in the recovered process water subsequent to the grinding stage.

Abstract: A metal or mineral compound collector for use in a froth flotation process so as to recover one or more desired minerals or metals; the collector comprising a functional group attached to a carbon chain; the functional group being a nitrile and the said chain having (11) or more carbon atoms. In a further form there is provided a method of recovering a metal or mineral compound from an ore comprising the steps of: wet grinding the ore to a desired particle size; adding water chemicals such as frothers or slurry-modifiers to the ground ore so as to prepare a slurry; adding an effective proportion of a collector comprising a functional group which has a carbon chain with a nitrile attached, said chain having (11) or more carbon atoms; supplying a gas stream to the slurry so as to generate a froth; and recovering the desired metal, mineral and/or sulphide thereof in the froth.