A novel way of separating granular material during mineral processing could help overcome binding, a costly and frustrating problem, especially at iron ore operations.
A team of scientists at CSIRO Manufacturing and Infrastructure Technology has developed a new type of sorting machine, named the Rotary Classifier.
The classifier separates granular material by tumbling material in a tilted vessel at various speeds, causing avalanches in the surface. This moves particles of a smaller size or higher density towards the centre and particles of larger size or lower density radially outward, which allows different materials to be extracted at selected locations.
The classifier is being investigated by mineral processor RCR Tomlinson, which plans to have a pilot tumbler in operation by early 2007, before scaling up a full system.
RCR Tomlinson Bunbury operation general manager John Noordhoek says blinding is a huge problem.
“Once a screen becomes blocked, it reduces screening efficiency and increases processing time,” Noordhoek says.
He says the Rotary Classifier development can overcome this problem and improve production efficiencies.
“Building a commercial scale pilot plant will allow us to prove the technology works. Early testing looks positive, so the potential out there for a screen-replacement product is huge.”
Co-inventor of the classifier, Dr Guy Metcalfe, says the unit’s dry separation ability is becoming important.
Metcalfe says the technology will be of immediate importance to the iron ore industry, where more minerals are obtained in an environment where limited or no water is available.
“If we can prove that dry separation works, industry could be clamouring to use it,” he says.