Chemistry of novel hydrophobic and selective interactions

About Program 2

For the last 100 years, high value minerals have been ground to a fine particle size and then separated by adsorbing reagents, known as collectors, onto the mineral surface to make the minerals hydrophobic, and attraced to bubble interfaces. New approaches are needed to exploit the full potential of hydrophobic interactions for i) separating coarser particles, ii) ultrafast and selective separations, and iii) separating almost all the liquid from the mineral particles at the end of the separation process.

Minerals of high value are rendered hydrophobic through the specific adsorption of reagents known as collectors. This has been the predominant methodology for 100 years, generally achieved through flotation. However, there is a need for new approaches to advance selectivity, and to properly exploit the full-potential of hydrophobic interactions in effecting i) coarser separations, ii) ultrafast and selective separations, and iii) a step change in solid-liquid separation. For example, our recent work shows that a 10 – 100-fold increase in the process intensification can be realised, so we know there exists a tremendous upside via our strategy to further exploit hydrophobic interactions.

Program 2 investigates the application of novel hydrophobic interactions utilising bubbles, emulsions, and foams, and the selective promotion of hydrophobicity at the mineral surface to support more robust, faster and more efficient separation technologies. This research seeks to extend the conventional notion of flotation into a far broader concept. Hydrophobic interactions are powerful, can be made selective, and potentially support very fast separations.

Program 2 consists of three sub-programs

The first is related to understanding how novel polymers (developed in Program 3) can be applied to selectively and efficiently recover both coarse and fine particles by froth flotation and agglomeration. Such advances will reduce the degree of fine grinding required via the introduction of early gangue rejection and reduce the loss of fine valuable product to tailings.

The second seeks to develop novel systems to deliver reagents to the surfaces of particles in order to control their hydrophobicity for collection via flotation, or the ultrafast agglomeration in Program 1. The novel delivery systems will reduce the amount of reagent required and enable faster recovery of valuable particles, resulting in reduced processing costs. 

The third will develop understanding of how the use of the polymers developed in Program 3, and the novel delivery systems developed in our second sub-program can be applied to improving solid liquid separations, to end the practice of using tailings dams.