A multidisciplinary team of engineers from the University of Nottingham and Teledyne e2v have received this year’s Colin Campbell Mitchell Award from the Royal Academy of Engineering for developing MicroHammer, a revolutionary process for extracting copper from its ore using microwave technology. The team were presented with the award at the Academy’s AGM in London on 18 September.
The team, which includes Professor Sam Kingman and Dr Chris Dodds from the University of Nottingham and Dr Ewan Livingstone, Paul Burleigh and David English from Teledyne e2v, combined their skills in microwave technology and engineering to develop the largest microwave processing system ever constructed, capable of processing up to 3000 tonnes of rock per hour.
Copper is one of the world’s most widely used metals, playing an integral role in many sectors from construction to power generation and transmission. Although global demand is increasing rapidly, with copper a vital material for nearly all electrical devices, the quality of copper reserves is in decline with both the percentage of copper and the size of grains found in ores decreasing.
Current extraction techniques require enormous amounts of energy, with an estimated 5% of the world’s electricity used to fine grind rocks in mineral processing plants. MicroHammer, which uses microwave energy to separate copper grains from the ore, reduces the energy needed to extract copper by over 20% and boosts production by almost a third.
By exposing rocks to powerful microwave energy for a fraction of a second, MicroHammer heats and expands the copper grains, causing them to split from the encasing rock. The microfractures, which are smaller than the width of a human hair, weaken the host rock and make it possible to extract the copper without completely grinding the ore.
Using microwaves to create fractures in mineral ores has been a topic of academic study for several years, but presented real challenges in demonstrating it was possible at a commercial scale in a mining environment.
Working with one of the world’s largest metals and mining corporations, Rio Tinto, who funded the project, the team have designed a system that contains and focuses hundreds of kilowatts of microwave energy and can be safely used in the harsh operating conditions of a mine. The demonstration system processes over 150 tonnes of rock per hour, and, using numerical simulation and experimental validation, the team have demonstrated this can be expanded to thousands of tonnes per hour – the scale needed for sustainable commercial use.
Professor Sam Kingman, the project’s academic lead, and Pro-Vice-Chancellor for the Faculty of Engineering at the University of Nottingham, said: “Our collaboration with Teledyne e2v has been the key to unlocking the potential that this technology has offered for decades, but no one has been able to access due to significant technical challenges. It is a great honour to receive this award which recognises the contributions of a significant number of people both at the University of Nottingham and at Teledyne e2v. We are now well placed to take this technology to market and deliver one of the most significant impacts to mineral processing since the development of froth flotation”
Paul Burleigh, project lead at Teledyne e2v, said: “It’s exciting to be part of a team that has developed a technological solution that will make a real difference in creating sustainability in the supply of materials that underpin economic and social development across the globe. Though receiving the award in person, it’s important to remember that this is on behalf of the wider team who have delivered the innovative steps and engineering solutions to the challenges that have been overcome.”
Professor Raffaella Ocone FREng FRSE, Chair of the Royal Academy of Engineering Awards Committee, said: “The tremendous amounts of electricity needed to extract copper from low grade sources has left the mining industry in an unsustainable position and in desperate need of a new technological solution. The MicroHammer process developed by the team from the University of Nottingham and Teledyne e2v is a tremendous breakthrough, not just in saving energy but in helping to ensure that copper supply meets global demand. The achievements of the team make them worthy winners of the Royal Academy of Engineering’s Colin Campbell Mitchell Award.”
The Colin Campbell Mitchell award is awarded annually to an engineer or small team of engineers who have made an outstanding contribution to the advancement of any field of UK engineering.