New technology for recovering valuable minerals from waste rock

Researchers report discovery of a completely new technology for more efficiently separating gold, silver, copper, and other valuable materials from rock and ore. Their report on the process, which uses nanoparticles to latch onto those materials and attach them to air bubbles in a flotation machine, appears in the ACS journal Langmuir.

Robert Pelton and colleagues explain that companies use a technique termed froth flotation to process about 450 million tons of minerals each year. The process involves crushing the minerals into small particles, and then floating the particles in water to separate the commercially valuable particles from the waste rock. The water contains "collector" substances that can attach to the valuable particles, causing them to repel water and rise to the bubbling top of the water where they can be easily skimmed off.

The researchers demonstrated an entirely new type of collector technology, consisting of water-repelling nanoparticles. In laboratory experiments using glass beads to simulate actual mineral particles, they showed that the nanoparticles attached so firmly to the beads that flotation produced a recover rate of almost 100 per cent.

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That's interesting. I've been a bit of a lurker the past two months and I wanted to share some "technology" updates.

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His Royal Highness The Duke of Edinburgh visited The University of Western Australia today to inspect the progress on the development of advanced aerial mining exploration technology with the potential to discover minerals in new locations.

VK1 is a highly sensitive gravity mapping tool, or airborne gravity gradiometer, which has been developed as a joint venture between Rio Tinto's Exploration and Technology & Innovation teams and UWA and which is now in commercial trials with Rio Tinto.

When flown at altitudes of just 80 metres above the ground, VK1 measures tiny changes (or gradients) in the Earth's gravity field, indicating the potential presence of mineral ore bodies beneath the surface.

The original vision for the device came from UWA's Dr Frank van Kann in 1979. It took its first flight onboard a light aircraft on 21 August 2010.

Targeted to operate at an accuracy and sensitivity that outperforms existing technologies, VK1 has been designed to help discover otherwise invisible, buried orebodies and expand Rio Tinto's knowledge of existing mineral resources. VK1 will also provide a much needed mineral data set.

UWA Vice-Chancellor Professor Alan Robson said the university was delighted to be showcasing some of its leading research to His Royal Highness.

"The University is honoured to be hosting His Royal Highness on his visit to Western Australia and to have the chance to demonstrate our particular expertise in developing advances in technology that are leading the world," Professor Robson said.

Dr van Kann described the 30-year development and production of VK1 as having been a long, fascinating and challenging project.

"The collaboration between UWA and Rio Tinto has made significant progress and I am looking forward to the next steps in the development of my original concept," Dr van Kann said.

Rio Tinto expects the technology will undergo further modifications before a detailed testing program starts next year.

Source: The University of Western Australia