The University of Queensland has worked with Rio Tinto to create a new way to process bauxite ores.
According to the university, not only does the method add value to the ore, it also reduces the mine’s environmental footprint.
UQ’s Dr. Hong Peng, from the university’s School of Chemical Engineering, said the process utilises bauxite ore waste.
“Queensland is ideally placed to benefit from this technological improvement as bauxite is abundant in north Queensland and there are already processing facilities and experts established here,” Peng said.
“Now instead of wasting the bauxite ore by-products, we can recover most of the minerals, which also reduces the environmental impact of the mining activity.”
The new method will also make some previously uneconomical mines viable.
Bauxite contains between 30 and 54 per cent alumina, which is refined from bauxite ore using the Bayer process, which separates alumina from the mixture of various iron oxides, titanium dioxide and aluminosilicate, which is known as the desilication product (DSP).
Using the conventional Bayer process, the DSP crystallises to a fine powder intermingled through the residue, making separation of the components impossible.
“The red mud has to be chemically neutralised and maintained in long-term storage,” Peng said.
Peng’s method looks to control this crystallisation, instead yielding a coarser material, which can be separated and removed.
“The current process wastes a lot of these other minerals and creates bauxite residue,” he said.
“The new method we’re developing has environmental benefits and financial benefits, as the by-products can be sold.”
The research was supported by the Advance Queensland Research Fellowship, which is focused on aiding the mining industry in overcoming challenges.
Peng was one recipient, along with Dr. Pradeep Shukla – who is aiming to upscale new technology to produce cyanide on-site for gold and base metal mines – and Dr. Sergio-Andres Galindo-Torres, who aims to introduce new modelling and visualisation technologies