Flotation employs “collector” chemicals and surface properties of various minerals to render them hydrophobic and separable into an air-based froth phase. It is very common in the recovery of precious and base metals, and industrial minerals, and is generally applied in a rougher-cleaner-scavenger configuration. Unfortunately, this configuration often leads to excessive circulation of valuable minerals in various sub-streams in a plant, which frequently results in them being “over-processed” and rejected to tails. Peacocke & Simpson often applies innovative thinking to flotation process testing, for example flotation in association with gravity concentration or ultrafine grinding, to add the edge to a widely applied process, and to recover particles from circulating loads.
Gravity can also be applied as a scavenger process on flotation tails, to recover mixed grains or enclosed minerals that are not sufficiently hydrophobic for flotation, but that do have sufficient particle mass to be “recognised” by enhanced gravity devices.
Whilst undertaking batch flotation tests for the optimisation of the reagent suite to be used at Zimplats SMC platinum complex in Zimbabwe, Peacocke & Simpson developed an interactive spreadsheet that allowed the client to predict platinum flotation plant performance by selecting various permutations and combinations of reagent types and dosages from 56 separate bench tests conducted in Peacocke & Simpson’s laboratory.