The ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals (COEMinerals) is a collaborative research organisation focused on energy and water, mineral recovery and new generation.

This month, Emeritus Laureate Professor John Ralston from the University of South Australia will present a Signature Lecture Series on the critical nature of interfaces in the eco-efficient beneficiation of minerals.

The series is available online, or you can attend in person at the University of South Australia campus in Adelaide.

When: 16 September

Time: 10:00 – 11:00 AWST, 11:30 – 12:30 ACST, 12:00 – 13:00 AEST

Where: Lecture Theatre MM1-05, Building MM, University of South Australia, Mawson Lakes Campus, Adelaide

Register: Contact details below

About COEMinerals

The recovery and concentration of particles of high metallurgical value, known as beneficiation, is based on relatively mature paradigms.

While the industry has evolved over more than a century, the flotation processing rates per unit of vessel area have not increased during that period. The waste, which often requires massive tailings dams, results in excessive water consumption and risk of a catastrophic tailings breach.

With a projected global population of nine billion by 2050, and the demand for minerals set to soon outstrip supply, the industry faces an unprecedented challenge.

The key objectives of this new ARC Centre of Excellence are to:

• investigate the application of novel hydrophobic interactions utilising bubbles, emulsions, and foams, and the selective promotion of hydrophobicity at the mineral surface
• develop a separation strategy based on the processing of particles with a coarser size thus generating reductions in cost, energy requirements, water usage and environmental impact
• establish new engineered polymeric reagents for direct application in minerals processing, exploiting stimuli responsive features to control conformation and selectivity.

To achieve these objectives will require a blend of fundamental research embracing synthetic chemistry, physics, fluid mechanics, rheology and chemical engineering, along with engineering design combined with in and ex-situ characterization techniques.

Lecture content

In this lecture the role of interfaces is highlighted, especially aspects which are poorly understood yet which are central to the success or failure of mineral beneficiation processes.

“Hydrophobicity” can be interpreted in different ways, often incorrectly. Water structure at interfaces is very important. Bubbles and droplets have surfaces which may be mobile, immobile or somewhere in between. Polymers act in different ways and can respond to stimuli. Perhaps they also need to adapt to interfaces?

Particle surfaces may be rough at various length scales; are often patchy in terms of chemical and mineralogical composition; are frequently coated with tiny ‘particles’ to varying degrees; and rarely adsorb reagents uniformly. Many minerals comprise faces and edges whose structure and composition differ, along with their dielectric constants, and thus respond to reagents differently. Determining particle separation and fluid mechanical behaviour in opaque, multiphase systems with complex interfaces is therefore a great challenge. In addition, the aqueous phase may be highly saline.

What role might artificial intelligence and machine learning play in eco-efficient beneficiation? Specific interfacial concepts are explored, informed by experimental and theoretical studies.

Four practical examples drawn from the minerals industry – small particle dispersion, crystallization, coarse particle flotation and solvent extraction – will be discussed. In each example and in the overall lecture, important issues which are central to the research work of this new ARC Centre of Excellence are identified.

Registration and further details

Find out more about the COEMinerals