SWIRLFLOW, a mixing technology used in mineral processing, celebrated its 25-year milestone of operations in Australia and is expected to save millions in capital and production costs.
Developed by Australia’s national science agency CSIRO with Queensland Alumina Limited (QAL), SWIRFLOW units have successfully trialled in a gold tailings neutralisation tank in Australia and a gold leach tank in Guinea.
SWIRLFLOW is a leading example of CSIRO innovation and science, CSIRO Research Program director Andrew Jenkin said.
“SWIRLFLOW was invented to overcome severe production losses caused by scale build-up on the sides of mixing tanks experienced during the alumina refinery process,” Jenkin said.
SWIRLFLOW sits at the top of the mixing tank and produces a tornado-like swirl throughout the fluid, mixing and dispersion of solids in thick slurries.
The swirling flow picks up solids from the tank’s base and lifts them to the upper regions, where the solids continue to spiral downward along the tank wall routing back to its base.
The swirling motion also creates a cleansing effect against the tank walls, reducing scale.
“Our fluids engineering team worked with QAL to create a technology solution that increases the overall efficiency of the process by reducing scale, increasing yield and reducing costs,” Jenkin said.
Many mineral processing procedures rely on keeping solids in suspension in large tanks.
“It involves a different impeller system – a long shaft that goes all the way down into the mixing tank, with multiple blades spinning the system,” he said.
“SWIRLFLOW is revolutionary in terms of the mixing pattern – it picks material up off the floor of the tank easily and gets a well-mixed system in place.”
Inefficient processing through uneven mixing and build-up of solids around the tank wall can reduce the amount of metal extracted, causing frequent downtime for equipment maintenance and increasing energy consumption.
According to Jenkin, SWIRLFLOW is expected to have cost savings in maintenance, with the tanks of SWIRFLOW running longer without being stopped and cleaned.
“Capital cost is around erosion on the actual tanks themselves, so there are some cost savings there,” he said.
“We estimate an average alumina refinery can save between five-to-ten million dollars a year in capital and production costs.”
SWIRLFLOW technology has allured attention from processors of other minerals, including those in magnetite, uranium, and gold industries.
CSIRO has installed around 30 SWIRLFLOW units and is influencing the global alumina industry – operating in China, Germany, and Vietnam.
“We’ve now got a commercialisation partner for the Chinese market called SAMI and are in negotiation with another company,” he said.
“We’re looking to commercialise the system, and CSIRO would benefit from licence fees the more that are installed.”