Dust suppression: Vale's dust control measures an example for others.

• Author: Kelly, Lindsay
• Position: SUDBURY

Mining's a dusty job, but Vale has implemented a process for dust suppression that is proving to be effective at keeping the pesky substance at bay.

It doesn't pose any ill effects to human health, but the dust can be a nuisance, said Glen Watson, Vale's senior environmental specialist in Sudbury, which is why the company has worked over the decades to fine-tune its dust-control program.

"Years ago, if we weren't doing dust control properly, in a community like Lively or the highway stretch between Lively and Creighton Mine you could see the dust blowing across the highway on a windy day," Watson said. "That's a very rare event now We do a fine job of dust control up there and we get better at it all the time."

A fine, sandy dust is left after water drains through the waste slurry that is collected in tailings ponds as a result of the mining process, and it's this material that Vale strives to restrict to its property.

Dust control falls to a crew of eight seasonal employees working under Mark Palkovits, Vale's land reclamation supervisor. The team monitors conditions and applies dust-control measures when required.

In the "Cadillac" approach to dust control, which offers longer-term results, hay is distributed across the tailings field and then "crimped" into the surface of the tailings, Watson said. The crew uses regular farm equipment to distribute the hay, which is purchased from local farmers and delivered daily.

But under certain conditions, a product called Entac, manufactured by Hamilton-based Ens Solutions, offers a faster, more effective approach, such as when the weather forecast calls for high winds, or when tailings are due to be released and the crew knows that cover is needed.

Entac is a tall-oil pitch emulsion derived from the process of pulping pine trees. It's environmentally benign, non-toxic, and is good at keeping the dust down.

"If the wind's coming from a certain direction and we know we have to get in that area--and we know in a couple of days they're going to putting fresh tailings there--then we're going to use Entac because it's a lot faster, and it's a bit cheaper than the straw because there's a lot fewer resources required to do that," Watson said.

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