Australian Nuclear Science and Technology Organisation to aid mining exploration with it's nuclear scanning technique.
Gouri J S
credits: ANSTO
Australian Nuclear Science and Technology Organisation (ANSTO) is set to enhance the mining industry by detecting the presence of precious metals and strategic minerals in a core sample using its nuclear scanning technique. Dingo, the neutron tomography instrument at ANSTO's Australian Centre for Neutron Scattering, has been enhanced suitably for the development of this technology.
Primarily, a rig was made to hold the core under study and parallelly scanned. The cartridges of the device can hold four cores up to 1.5 metres long with a maximum diameter of 80mm each. The cores were supplied by Aurelia Metals (ASX:AMI) and were extracted from the Hera gold-lead-zinc-silver mine in New South Wales.
Dingo uses neutrons to generate images which are similar to those of an x-ray CT scan. The neutron particles are produced by the Open pool Australian Light water Reactor (OPAL). This produces the 3D images of the drill cores by rotating the cores in a neutron beam thereby acquiring thousands of shadow radiographs which are later converted to 3D visualisation of the drill cores.
The radiographs can be suitably used to extend 2D surface mineral maps to accurately report the mineral content within entire drill cores.
Our collaborators at Macquarie University were satisfied that the images were viable for mineralogical assessments and are developing new methods to explore and integrate these datasets into geological and geochemical analyses.- Joseph Bevitt, One of the researchers involved in the experiment.
According to researchers, non destructive neutron CT scanning of a one metre core length can be completed in around one hour depending on the scan resolution required.
At present, inspection and analysis of drill cores are conducted by using X-ray techniques. However, this has limitations as X-rays cannot penetrate heavy metal samples such as lead without losing the image contrast. Neutrons are expected to overcome this limitation as a number of commonly occurring minerals like lead, that are problematic to X-rays are more transparent to neutrons.
The researchers are also planning to install an X-ray source to produce bi-modal neutron and X-ray tomographic images of drill cores. This can enhance the holistic 3D mineral mapping by combined aspects of both x-rays and neutron CT scanning.