Valorizing mine tailings

In October 2006 an important congress was held in Thetford Mines, Quebec regarding the valorization of mine tailings including the serpentine tailings from the chrysotile mines. (For information consult the site http://www.valorizationresidusminier.ca/).

Over the years since 1876, the chrysotile mines in the Thetford mines and Asbestos regions have accumulated mountains of serpentine tailings from which the chrysotile fibres have been extracted.
Several hundred million tonnes of these solid tailings represent an interesting potential for economic development.

The multinational Noranda (now part of  Xstrata) constructed the Magnola plant at Asbestos to recover magnesium metal from the serpentine tailings which contain 20% magnesium. The price of magnesium, Chinese competition, and technological problems forced the closure of Magnola in 2003.

Other companies like Minox and Nichromet are trying different methods to recuperate substances contained in the tailings : MgO, nickel, iron oxides, chrome, etc…

Construction Materials

For many years, serpentine tailings have been used as is for landscaping, building foundations, fill, etc… Once in place, the tailings are covered with earth and grass or asphalt.

Certain concerns about their content of nickel were confirmed to be unfounded. Analyses of the bio-disponibility of nickel showed it to be insoluble in a wet and acidic milieu.

It is therefore essential that regulations allowing the responsible use of tailings be maintained. Sustainable development which is based in part on the use of industrial residues must be made possible with realistic regulations.

Exploiting the Mine Landscape

The exploitation of chrysotile mines in our region for over 125 years has created a unique landscape with whitish tailings dumps and industrial buildings.

This mine heritage represents a unique potential which should be preserved and exploited for tourism and recreation.

Improvement projects like the "KBB" project put forward by Tourisme Amiante and the city of Thetford Mines must be supported financially by public, parapublic and private organizations to see the light of day.

That which some see as a problem (mine tailings and unused buildings) can become a source of socio-economic activities and pride for the greater Chaudière-Appalaches region and all of Quebec.