Green gold from the tailings of mining

Long considered an environmental problem, waste rock from mining could in fact help fight global warming by absorbing part of the greenhouse gases responsible for climate change. Greg DIPPLE, professor at the Department of Earth and Ocean Sciences at the University of British Columbia, has studied the ability of these rock residues to permanently trap carbon dioxide (CO2).

According to him, this phenomenon, natural on the scale of geological times, would manifest itself much more quickly on residues rich in magnesium silicates such as those from the mines of nickel, diamonds, chrysolite, platinum and those from certain mines of 'gold. The mineral carbonation process allows the CO2 dissolved in rainwater to react with the silica on the surface of the rock. DIPPLE thinks that it is then possible to trap in this waste all the CO2 produced by the mining operation itself, thus transforming this industry into a clean industry in terms of greenhouse gas emissions. is very fast on some sites, it is barely noticeable on others.

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The next step in the research is then to model the process and understand how to improve the rate of absorption of CO2, at a viable cost for mine operators. Indeed, it seems that the efficiency of carbon dioxide absorption varies depending on the means used to treat mine tailings. Although skeptical at the outset, mining companies are starting to take an interest in the matter.

- UBC Public Affairs:
Sources: University of British Columbia reports, 10/01/2005
Editor: Delphine Dupre, VANCOUVER,

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