To the untrained eye, a visit to Kovit Engineering’s lab in Sudbury looks like a number of adults playing with combinations of sand, silt and water.
On the surface, the lab might have a lot in common with a children’s playground.
But to Frank Palkovits, one of Kovit Engineering’s four co-owners, what goes on in the 3,500-square-foot laboratory is serious business.
Kovit Engineering consults with mines around the world to help them manage their on-surface tailings and backfill. The 30-employee company specializes in what it calls “paste technology” first developed by Inco in Sudbury, and later perfected by Golder Paste Technology in the mid-1990s.
Mining companies around the world mail their tailings samples to Kovit so the company’s researchers can concoct the perfect paste recipes with their ingredients.
The Kovits lab is full of high- and low-tech instruments to measure all the different properties of the pastes.
“We test them for how they thicken, how they filter, how they flow as a paste, how they get strength with cement or other types of binders,” Palkovits said.
Palkovits, who once worked for Inco and Golder, teamed up with Paul Rantala, Steve Reichle and Mark Wallgren to found Kovit in 2011. The company recently expanded to a 13,000-squarefoot facility.
The paste technology the firm develops in-house represents a natural extension of backfill and tailings management. In the early days of underground mining, miners moved on after a block of ore (stope) had been exhausted of its minerals.
Sometimes mining blocks would collapse over time, and limited the ability to safely extract material.
Companies filled exhausted ore zones with combinations of sand and water, and later added cement for structural integrity.
But the consistency of sand wasn’t always ideal, especially when large quantities of water were involved. Inco (now Vale) discovered it could create a paste, using the tailings it removed from its mines as the main ingredient, with a consistency similar to toothpaste.
Palkovits calls this a “Goldilocks” solution that consists of sand/silt size particles.
The paste can be transported in underground pipelines and has the right consistency to create a solid backfill as a foundation for mining beside, above, or even below.
It’s also a sustainable way to manage a mine’s tailings.
For surface tailings management, the company assesses opportunities to deposit the tailings paste in different areas where it is allowed to consolidate and be much safer and less prone to failure.
Once the initial layer is dry, the mine can add an additional layer of the paste on top. The saturated top-layer prevents oxygen from getting into the tailings, which in turn reduces the chances of acidification and metal leaching.
“You can layer quite reactive tailings in a very safe environment that is geotechnically and geochemically stable,” Palkovits said. Typically, reactive tailings were stored underwater, which meant depositing tailings into lakes. Paste disposal of reactive tailings has been proven as Best Available Technology (BAT) in Europe.
With his eye on expansion, Palkovits said he has made it a priority to bring in students from Sudbury’s three postsecondary institutions – Laurentian University, Cambrian College and Collège Boréal – to give them co-op opportunities, and potential spots on the company roster.
Palkovits said it’s important that students get to see the kinds of careers that are possible with a strong backing in geology. He added those opportunities were rare when he was a student.