Signature Series - Professor Jan Cilliers, Imperial College (London): The Electrostatic Travelling Wave for Dry Particle Transport and Separation

Topic: The Electrostatic Travelling Wave for Dry Particle Transport and Separation

Speaker: Professor Jan Cilliers FREng, Earth Science and Engineering, Imperial College London

Jan Cilliers is Professor of Mineral Processing at Imperial College London.

His current research focusses on water sustainability in mining. His team is developing techniques for waterless mineral processing. These systems have found application in lunar resource extraction. Previous research included flotation froths and hydrocyclones.

He serves on the International Mineral Processing Council, and is a Fellow of the Royal Academy of Engineering.

Presentation Abstract
Sustainable space exploration and habitation requires in-situ resource utilisation (ISRU). Technologies for terrestrial mining and mineral processing are not suited to the Moon’s environment. Innovative electrostatic methods are promising for both ISRU and dry terrestrial mineral processing.

The Electrostatic Travelling Wave (ETW) uses moving electric fields to transport particles. ETW fields influence particle trajectories differently at various frequencies: lower frequencies propel most particles forward, while higher frequencies increase transport in the opposite direction. This frequency-dependent behaviour allows both conveying of granular materials and performing particle size separation.

A model of the electrostatic field and simulating particle motion show the reason for, and effect of, frequency on particle trajectories. A critical crossover frequency, which decreases with particle size, enables effective separation. Particle transport and separation is demonstrated experimentally.

The application of the ETW for size classification marks a significant advancement in dry processing techniques, potentially enhancing the efficiency of mineral extraction and refinement in space and on Earth.