Women in Engineering Profile - Chemical Engineering PhD candidate Margaret Ekua Amosah (University of Newcastle)

PhD Student Margaret Ekua Amosah is Recovering Minerals from Mining Waste

ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals (COEMinerals) researcher, University of Newcastle PhD student Margaret Ekua Amosah travelled more than 16,000km to apply her minerals engineering experience and STEM skills in Australia, and to the challenging task of recovering ultrafine precious mineral and metal particles that are currently lost to tailings. 

Her PhD research is focused on recovering ultrafine tin particles that are suspended in liquid tailings’ reserves, because conventional technologies have been unable to recover them. Margaret’s work is finding a way. 

When Australia’s international borders closed during COVID, Margaret found herself unable to relocate and take up the chemical engineering research role with the Centre. It took more than a year for that journey to occur. Accepting and extending an internship as a trainee gold-metallurgist in Ghana filled the time-gap. She joined a team where — by her estimate — women represented, perhaps 1% of the department”. 

Despite the diversity gap, she thrived. Now in her ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals researcher (COEMinerals) role in Australia, Margaret actively champions engineering careers and STEM studies as a contribution to helping address the diversity gap in engineering studies and careers around the world. 

She shares: I have had the privilege of conducting engaging experiments for high school students with my COEMinerals colleagues. The experience provided valuable insights from the intellectually curious minds of the school students. The best part for me was seeing the surprise and excitement on the students’ faces during the experiments. Outreach events enables students to ask questions and learn more about engineering.”

Margaret strongly advocates for young people not to overlook the opportunity to embrace engineering study and careers, and to get into it”, adding it’s an esteemed profession, and it’s not as difficult as you may think”, and she is actively encouraging the next generation to consider STEM roles, and the importance of minerals to the world.

Applying academic learning to industry applications to improve mineral processing to help have a positive impact and to change the world,” is something Margaret is keen to embrace as her career in engineering progresses. Her motivation comes from a desire to recover, reuse and reprocess waste, or as she phrases it, turning waste into value”. 

Currently Margaret is recovering tin from cassiterite (a tin ore) from mining waste; she’s the first person in the Centre to work on the intractable problem of reprocessing low-grade cassiterite from tailings. 

Tin is a quiet achiever’ material that resists corrosion, so it’s been commonly used in cans for food preservation, as a coating for steel (tin-plating) for some time. However, Tin is increasingly being recognised as pivotal to the energy transition and the digital revolution,[1] given it is in everything electrical’ (predominantly in the solder and alloys). As such, it is an enabler for batteries and computing. 

With the arrival of the Internet of Things’ (IoT), and the growing interconnection of everyday objects embedded with technology (such as sensors, software, and processing units) that allow the exchange of data via the internet or other communications networks[2], tin is becoming a critical mineral for our future[3].

To achieve ultrafine tin particle separations, Margaret is working with new technology, The REFLUX Classifier (RC), invented by COEMinerals Director, who is also her PhD supervisor Laureate Professor Kevin Galvin of the University of Newcastle. Initially invented for other purposes, Marget has shown the RC is effective for reprocessing’ tailings using gravity separation as part of her research. 

Margaret’s approach enables fine and ultrafine dense tin particles to be separated; they sink to the bottom of the RC over time during processing. Without her work, the tin/​mineral particles do not get separated when they’re stored in the tailings dams’, but generally remain in a state of suspended animation. 

If we can get the strategy right for tin separations, we can test and apply the technique to recover other minerals, which hasn’t been done before.”

Beyond mineral recovery from waste, Margaret hopes her work will one-day impact, how processing circuits are set up on mine sites and reduce the initial fine particle mineral loss, and therefore reduce waste volumes”. A next step in her research is to turn lab-findings into reality with a mine site trial. 

[1] https://​www​.min​ing​-out​look​.com/​c​o​m​m​o​d​i​t​i​e​s​/​t​i​n​-​m​i​n​i​n​g​-​s​e​c​t​o​r​/​f​i​r​s​t​-​t​i​n​-​t​i​n​-​a​-​c​r​i​t​i​c​a​l​-​m​e​t​a​l​-​f​o​r​-​t​h​e​-​f​uture

[2] https://​www​.sta​tista​.com/​t​o​p​i​c​s​/​8724​/​i​n​t​e​r​n​e​t​-​o​f​-​t​h​i​n​g​s​-​i​o​t​-​i​n​-​a​u​s​t​r​a​l​i​a​/​#​t​o​p​i​c​O​v​e​rview

[3] https://​www​.min​ing​-out​look​.com/​c​o​m​m​o​d​i​t​i​e​s​/​t​i​n​-​m​i​n​i​n​g​-​s​e​c​t​o​r​/​f​i​r​s​t​-​t​i​n​-​t​i​n​-​a​-​c​r​i​t​i​c​a​l​-​m​e​t​a​l​-​f​o​r​-​t​h​e​-​f​uture