Crystal clear objective
by Vincent Ciccarello
Dr
Jun Li (pictured) is plain about her reason for wanting to solve
century-old problems with the Bayer process, the means of refining
bauxite to produce alumina.
"We want to solve these problems for the aluminium industry," she said. "It’s one of Australia’s largest export earners, generating more than $5.7 billion per year."
And given Australia is also one of the world’s largest producers of aluminium or alumina, Dr Li is probably in the right place.
A graduate of China’s Wuhan University, where she worked for 13 years before migrating to Australia, Dr Li was awarded a PhD in applied science from UniSA in 2000.
She became interested in Bayer process problems and crystallisation science during her undergraduate years.
"There are two main issues," Dr Li said. "One is that the aluminium hydroxide precipitation process of removing the alumina is very slow under Bayer conditions. The other is the production of fines (or tiny particles) in the final products, which affect the eventual smelter process."
She has been working on these problems and the mechanism of aluminium hydroxide crystallisation at UniSA for a number of years, initially as part of an Ian Wark Research Institute team led by Professor Andrea Gerson and Associate Professor Jonas Addai-Mensah.
Two years ago, she moved just across the way to become a research fellow at the Applied Centre for Structural and Synchrotron Studies (ACeSSS).
While the synchrotron has played an important role in chemical engineering for decades, its value in investigating the exact aluminium hydroxide crystallisation mechanism for solving the Bayer process problems has only been recognised recently.
Dr Li and ACeSSS Director Professor Andrea Gerson are about to publish the results of a breakthrough in using the synchrotron small angle X-ray scattering (SAXS) to follow the growth pathways of the aluminium hydroxide, a critical crystallisation process, which occurs during the Bayer process.
"We used SAXS in Japan and small angle neutron scattering in UK that weren’t able to detect the process," Dr Li said. "But an intense third generation synchrotron beam in Chicago did. It’s very exciting."
It is in what she describes as the "fuzzy layer" on the surface of growing aluminium hydroxide crystals that the solution to these problems probably lies, Dr Li said.
"If we can understand how to better control the Bayer process, we can increase the yield and quality of alumina. This will have an enormous impact on the alumina industry’s profitability."
Currently Dr Li is the team leader of a Nalco Alumina funded project. She is also part of a team at ACeSSS working on a $1 million ARC-AMIRA-funded project, led by Professor Roger Smart to critically evaluate reaction mechanisms and products in mining waste treatments.