Improving X-ray technology for more sustainable mines

XRT ore sorting machine


Mining operations consume significant amounts of energy, not to mention water, chemicals and other resources. As ore grades continue to decline around the world, more and more of these resources are being used to process low-value rock that will ultimately be discarded. Removing this waste material before it is processed would go a long way towards boosting productivity and reducing the financial and environmental costs of the mining industry. 


Thanks to a generous contribution by Sacré-Davey, a Vancouver-based engineering and project management company, UBC’s Department of Mining Engineering is now better equipped to help advance this goal. The company has installed a laboratory-scale X-ray transmission (XRT) ore sorting machine in the department’s Coal and Mineral Processing Lab, enabling students and researchers to learn about and improve a technology that can prevent low-value rocks from being processed unnecessarily.


“We are grateful to Sacré-Davey for providing us ready access to this equipment, as well as funding through the Mitacs Accelerate grant program to allow us to pursue new research projects in the area of ore sorting,” says Dr. Maria Holuszko, PEng, an assistant professor of mining engineering at UBC who arranged the installation. “We are constantly working towards making mining operations cleaner and more effective, and Sacré-Davey’s support will really strengthen our ability to do so.”


Ore deposits are mixtures of valuable minerals and commercially worthless minerals known as gangue. After the ore is excavated and crushed, mines may divide the rocks into these categories using sensor-based ore sorting machines. Manufactured by COMEX, the XRT sorter provided by Sacré-Davey uses dual energy X-rays to determine the density of the ore particles it scans; generally speaking, the denser the ore, the more valuable it is.


“It’s a powerful tool for characterizing compositionally complex particles,” says Holuszko. “And when it is combined with texture analysis, the machine will allow us to recognize low-value rocks even more effectively. We look forward to improving this technology, which has to the potential to save substantial financial and natural resources, in partnership with the Sacré-Davey team.”


Why are some ore deposits more amenable to sorting than others? How can XRT ore sorting machines be made more robust? These are some of the questions that Holuszko and her team intend to explore. While XRT sorters are not widely used by the mining industry today, she expects that their popularity will eventually rise as more companies recognize the technology’s considerable advantages, including the fact that it does not require water and functions properly regardless how moist or dirty the rock surface is. 


“UBC has always been at the forefront of mining research,” said Brent Hilscher, Sacré-Davey’s principal engineer. “And with UBC’s long history of exceptional work in the area of ore sorting, it was an easy decision for us to set up this research facility there. We are pleased to provide funding for research focused on making mining more efficient and sustainable.”


A team of UBC researchers is beginning tests using the machine this month.