Understanding the species of nickel in samples is important because some species of nickel are carcinogenic and others aren’t.
“Nickel subsulphide, a product of the smelting process and an intermediate in the formation of final nickel, is a known inhalation carcinogen,” said Dutton. “Nickel oxide is as well, whereas nickel metal, or pure nickel is not, so if you want to understand both workplace and environmental exposures, it’s important to do nickel speciation.”
The Canadian Light Source synchrotron, the only facility of its kind in Canada, cost $174 million and was commissioned in 2004. Described as a racetrack for electrons, it’s the size of three or four hockey rinks and includes a so-called storage ring with a circumference of 170 metres.
“We start by producing electrons using an electron gun, which is basically a really big TV tube, except we put 220,000 volts through it,” explained Canadian Light Source communications coordinator Matthew Dalzell. “That produces a stream of electrons which we then accelerate to about 99 per cent of the speed of light in a linear accelerator. Then we use magnets to steer that beam into a circular accelerator, which is what the synchrotron is.
That increases the energy of the electrons 1,000 times. From there, we shoot them into a storage ring, a big outer ring with electromagnets inside it, which keep the electrons going around in a circle.”
As the electrons whiz around, energy emitted in the form of light is directed through gaps in the ring to so-called beam lines – steel pipes containing optics.
The light –x-rays, in this case – shine on a sample in a holding chamber at the end of the beam line, and detectors measure the energy absorption signatures, which are unique for each nickel species.
The synchrotron light is tunable, which means different wavelengths of light can be produced and used, depending on the application.
According to Dalzell, Canadian Light Source is a world leader in applying synchrotron technology to the mining industry. Aside from nickel speciation, it’s also used to identify other metal species, including arsenic, some of which are inert, while others are water soluble and therefore mobile in the environment.
Pharmaceutical research and work on advanced materials is also carried out at the facility.
“We’re very pleased with the results we’re getting from the synchrotron,” said Vale Inco’s Dutton. “We haven’t decided what we’re going to do going forward, but I think we’re going to use it for more research – not only for nickel, but for lead and silica as well.”
Armed with a better understanding of metal species, mining companies can take steps to mitigate potential health and safety or environmental risks through improved ventilation or the use of specialized personal protective equipment.
The synchrotron can also be used to learn more about how exposure to metals affects organisms at the cellular level.
“You can actually look at the sub-cellular distribution of metals – where they end up in the cells,” said Dutton.
Earlier this year, the Sudbury-based Mining Innovation, Rehabilitation and Applied Research Corporation (MIRARCO) signed a Memorandum of Understanding with Canadian Light Source to collaborate on research projects focusing on resource extraction, processing and waste management.
“MIRARCO prides itself on building bridges between researchers from a variety of institutions and industry,” said Steve Hall, president of MIRARCO. “This collaboration will undoubtedly be of tremendous benefit, not only to us, but to the entire resource sector.”