Building a better metals test.

• Author: Huhtala, Sari
• Position: SPECIAL REPORT: MINING

Scientists at an analytical lab in Sudbury believe they have hit the mark with a proposed research project utilizing the Canadian Light Source synchrotron, Canada's super microscope at the University of Saskatchewan, to improve metals analysis methods in the mining industry.

Testmark Laboratories Ltd. is planning to embark on a large-scale project utilizing the synchrotron to identify species of metals and the oxidation state of various metals in the environment.

A refined acid base accounting method that measures acid-generating capacity will provide the mining industry with more accurate accounts of toxic metals, said John Scollard, PhD, director of research and development at Testmark.

"This is specific to the mining industry," Scollard said. "We're looking at better ways of doing acid base accounting (ABA) by using the synchrotron. One of the things to figure out is the oxidation state of sulfur--whether it is sulfide or sulfate. Currently, the techniques used to determine the amount of sulfur versus sulfide (in metals) don't give reliable, reproducible results."

Considering environmental regulations are based on a total amount of a specific metal, being able to identify the toxic compounds could mean the difference between a mining project falling within environmental regulations or not, he explained.

Arsenic

"If you look at the toxicity of arsenic, some forms are more toxic than others, so while the environmental regulations are based on a total amount of arsenic, you can argue that if you can properly identify the arsenic species that you're working with, you may actually have a lower arsenic number when you take away the non-toxic compound," Scollard said.

But differentiating the species is only one aspect of improving ABA processes, Scollard pointed out. Quantifying the species is also vitally important, and that is where Testmark scientists believe they have hit the mark.

"That's the secret," Scollard said. "We know how to do it. We can put a number on it."

Scollard is in the midst of writing up proposals to submit to the Industrial Research Assistance Program (IRAP) for funding assistance to enable Testmark scientists to work with the synchrotron to improve on ABA methods, both in identifying and quantifying metals.

The synchrotron is a powerful microscope that projects brilliant and intense beams of light to allow matter to be viewed at atomic scales. Canadian Light Source Inc., housed at the University of Saskatchewan, operates...