CSIRO's SWIRLFOW technology hits 25-year operating milestone

Industrial mixing technology SWIRLFLOW, developed by CSIRO in partnership with Queensland Alumina Limited (QAL), is celebrating its landmark 25-year milestone of operations in alumina processing in Australia.

Looking like a supercharged stick blender, SWIRLFLOW sits at the top of the mixing tank and generates a tornado-like swirl throughout the fluid, which delivers mixing and dispersion of solids in thick slurries.

CSIRO Research Program Director Andrew Jenkin says SWIRLFLOW is a leading example of CSIRO innovation and science in response to industry challenges.

“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,” he said.

Many mineral processing procedures rely on keeping solids in suspension in large tanks. Inefficient processing through uneven mixing and build-up of solids (scale) around the tank wall can reduce the amount of metal extracted, cause frequent downtime for equipment maintenance and increase energy consumption.

“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,” said Jenkin. “We estimate an average alumina refinery can save between five and 10 million dollars a year in capital and production costs.”

The swirling flow created by SWIRLFLOW picks up solids from the base of the tank and lifts them to the upper regions, where the solids continue to spiral downward along the tank wall en route back to the base, to be lifted again. The swirling motion also creates a cleansing effect against the tank walls, reducing scale.

CSIRO has now installed around 30 SWIRLFLOW units and is making an impact on the global alumina industry, operating in China, Germany and Vietnam. SWIRLFLOW technology has also attracted attention from processors of other minerals including those in the magnetite, uranium and gold industries.

To date, SWIRLFLOW units have been successfully trialled in a gold tailings neutralisation tank in Australia and in a gold leach tank in Guinea.

Image: SWIRLFLOW creates a tornado-like swirling action to deliver mixing and dispersion of solids in thick slurries.