Clean wastewater streams out of Raglan’s Mine Three
“If it wasn’t so cold, it would be fun to swim in”
Nunavik’s Raglan nickel mine is using a thrifty new process to reduce its amount of waste and, at the same time, retrieve marketable metals.
The processing plant is the first of its kind in the world, said Mike Bratty from Bioteq Environmental Technologies, a B.C.-based company that developed the process.
By simultaneously purifying leftover mine water and extracting metals, Bratty said Bioteq’s process contributes to a much better use of existing mines — and is an excellent example of what he calls “industrial ecology.”
“That’s the wave of the future,” Bratty said.
The idea is to find ways for industry to duplicate nature: materials and energy are recycled, as one organism’s waste becomes another organism’s food.
“The challenge is to apply the same process to industry. Mainly what we’re doing now is taking stuff up and throwing it away at the end, so if there are new technologies that come along, which allow you to recycle things, and this can be done economically, it’s really exciting,” he said.
Usually lime is used to treat acidic wastewater from operating or deserted mines. The lime neutralizes the water’s acidity, but this process leaves behind lime sludge filled with leftover metals that could be sold if extracted.
“In Raglan’s case, it’s probably hundreds of thousands of dollars of nickel just from their waste,” Bratty said.
An environmental advantage to Bioteq’s process is that it produces no sludge.
“Although the water that a lime plant would produce is perfectly acceptable, they have to husband those lime sludge pits and do long-term environmental monitoring,” Bratty said.
Bioteq’s method simply takes out the metals and leaves clean water behind.
“It’s very, very clean water. If it wasn’t so cold, it would be fun to swim in.”
Since last summer, Bioteq has been churning out clean water at Raglan’s Mine Three site, about five kilometres from Kattiniq.
The plant recovers nickel from the contaminated water to produce a high-grade concentrate. This is transported with other Raglan nickel concentrate for refining off-site.
Bioteq recently reported that its plant increased production by 20 per cent to reach a treatment capacity of approximately 550,000 cubic meters per year.
Due to the plateau’s harsh climate, water treatment is limited to only five or six months of the year.
Prior to the construction of the Bioteq plant, water from Mine Three was treated in a sludge lime treatment plant. Following a pilot project at the site during 2002, the plant was built and completed in November 2003. It started up at the beginning of the water treatment season in the spring of 2004.
Bioteq provided all capital and commissioning costs for the plant — about $1.8 million. The company charges Falconbridge Ltée., Raglan’s parent mining company, an annual capital fee of $300,000 until 2009 as well as an ongoing treatment fee of $1.06 per cubic metre of water treated.
In return, Falconbridge guarantees an average water volume for treatment each year of 530,000 cubic meters and pays Bioteq monthly treatment fees based on the quantity of water treated: a good deal all around.