The University of Newcastle, Australia

A surprise opportunity

When Dr Kim van Netten sat for an undergraduate industry scholarship interview at the start of her degree, she definitely didn’t expect the outcome to lead her to where she stands today.

“The interview went terribly, it was horrible.”

“But Professor Kevin Galvin was on the panel and he must have seen something in me because he offered me an ongoing research scholarship instead.”

Throughout her Bachelor’s degree at UON, Kim spent one day a week conducting research with Kevin’s chemical engineering team.

“Before that I had never even considered research.”

“I just thought combining study with work might be a good thing to do. But working in the lab really introduced me quite early on to what the research environment is like and I really enjoyed it.”

“So I stuck with it. I gave my first national conference presentation as a second year undergraduate.”

Research alongside industry

Once she had completed her Bachelor and Honours degrees, Kim was all set to start her PhD in the field of particle separation.

“My project was based on an idea Kevin had just before I started, so I was the first one to work on it.”

“We work closely with industry - that's one of Kevin's strengths, he makes sure that we're moving in the same direction that the industry needs.”

In the process of mining for minerals, the ore is first taken from the ground and crushed to liberate the minerals of interest. The mixture of minerals and low-value materials then needs to be separated.

Traditionally, froth flotation is used, which firstly requires the valuable mineral particles to be hydrophobic, to repel water, then air bubbles are added to extract the particles. The valuable particles float upwards, joined to the air bubbles, for easy removal.

However, due to the falling quality of mineral deposits and increased demand for metals, this highly effective technology is starting to reach its limit.

“In our research, we have replaced the air bubbles with a selective binder which has a hydrophobic surface. It’s actually more like a gel than a bubble, and is 95% water.”

“With intense mixing, we see large agglomerates of the hydrophobic particles form in seconds.”

Following each experimental separation, Kim runs her final product over a screen to recover the agglomerates for further analysis.

“It probably took me about six months to figure out what I was doing!”

“Since then I have been able to optimise the binder – I would try different things to see their effect on the final product until I found the combination of conditions that was the most successful.”

“It’s not a complex process at all – but it turns out the mechanisms behind it are very complicated. We can do it but we are only just learning now how it works.”

As she now has a doctorate student to help her with this fundamental study, Kim is focussing on streamlining the process so it can be used in industry.

“Everything I have done in the lab up until now has been on a batch scale, but if it’s going to be used in industry then it needs to be part of a continuous process.”

International collaboration and recognition

Kim started working on this part of the challenge just before she completed her thesis, when she was invited to a platinum mine in South Africa to test out her process on their real feeds.

“The work was really good and I really enjoyed it.”

“But one of the main things I took away from that experience was there was still a lot to be done!”

Kim’s work has also been recognised internationally – she won the first Australian Falling Walls Lab competition run by the Australian Academy of Science, with her three-minute presentation on her research. This took her to Berlin to compete with other finalists from all over the world.

“I nearly went insane trying to prepare my speech.”

“You have to appeal to a general audience, describe the problem, present the solution in terms of the science, and outline the way ahead, all in about 300 words.

“I think that's a valuable exercise for any researcher to do because it teaches you to communicate science to an audience.”