Hyperspectral Imaging Technology for Mining
Mineral resources are essential to Australia’s national security as well as to economic prosperity. There is an increased thrust towards a green industry and cities like Queensland are well-positioned to play a lead role in this regard. Growth in demand for critical minerals, now referred to as ‘green minerals’, is being stimulated by the move towards a renewable economy, and this calls for innovative approaches in mining. One such innovative technology is hyperspectral imaging. So, what is hyperspectral imaging, and can it be even more useful to miners?
Overview Of Hyperspectral Imaging
Hyperspectral imaging, or imaging spectroscopy, combines the power of digital imaging and spectroscopy. Digital imaging has applications in the medical industry via steel fabrication and hyperspectral cameras scan an item or area, collecting the light intensity of each pixel across the electromagnetic spectrum. The light striking each pixel is broken down into many different bands of colours. This provides thousands more colours than what our eyes can see or what a RGB camera in a smart phone for example, can capture. Humans can only see or collect three colour bands: red, green, and blue, whereas a hyperspectral camera collects and analyses a wide spectrum of light instead of just three colours. This provides an enormous amount of data which results in three-dimensional image cubes comprising two spatial dimensions and one spectral dimension.
Hyperspectral Imaging in Mining
HySpex NEO hyperspectral cameras are advancing the use of spectral imaging in the mining sector for identifying minerals. One example is analysing the reflected light scanning from a drill core sample. Broken down into hundreds of different wavelengths, the unique spectral signatures for each mineral can be recognised — enabling geologists to identify rock types in a core sample. This process is so valuable to geologists that CSIRO has developed a ‘spectral library’ or database of sample types to help with fast identification of mineral types. Modern exploration techniques from multiple platforms — for example spaceborne and airborne — to detect and map the spectral characteristics of the materials, require spectral libraries as an essential reference.
Mineral resource exploration using mining plant and equipment is an essential part of today’s high-tech industries and elements such as rare-earth elements (REEs) and copper are in especially high demand. Rare-earth elements are necessary components of more than 200 products in a wide range of applications. They are used in high-tech consumer products, such as cell phones, computer hard drives, electric and hybrid vehicles, and even flat screen monitors and televisions.
Challenges Involved
Reference libraries of spectral data such as the CSIRO’s on its site (and app) called MyLogger are needed to improve hyperspectral scanning of large areas of Australia. A research team was involved in gathering predictive information about ore grades from the outcrop of a former gold, copper, and pyrite mine in Cyprus using hyperspectral data gathered from cameras on the ground and from UAV scans. In mapping the distribution of surface minerals, the team tested ’spectral libraries’. However, compiling, interpreting, and analysing the hyperspectral data requires significant expertise. It can also be time-consuming and extend the turnover rate required for proactive intervention. This is not ideal for on-site mining and steel fabrication operations.
To meet this challenge, HySpex NEO have joined forces with a consortium of European partners and the Sustainable Minerals Institute in Queensland, enabled by AusScope, in a project called M4Mining. The challenge for this group is to deliver a hyperspectral camera mounted on a drone that can provide calibrated, corrected, and even interpreted data from a scan within 24 hours, making decisions at mine sites far more useful as well as far more economical.
Closing Thoughts
It can be observed that hyperspectral imaging has the potential to add a layer of dynamism to on-site mining operations and production. It is a cutting-edge technique which can be quickly used to identify mineral types, however efficient data analyzing methods need to be incorporated to ensure that hyperspectral imaging is effective. Expect Australia’s mining industry to gravitate towards this technique – we will be hearing a lot more about hyperspectral imaging soon!