Long considered an environmental problem, waste rock from mining could in fact help fight global warming by absorbing some of the greenhouse gases responsible for climate change. Greg DIPPLE, professor in the Department of Earth and Ocean Sciences at the University of British Columbia, studied the capacity of these rock residues to sustainably trap carbon dioxide (CO2).
According to him, this phenomenon, natural on a geological time scale, would appear much more rapidly on residues rich in magnesium silicates such as those from nickel, diamond, chrysolite, platinum mines and those from certain mines of 'gold. The process of mineral carbonation allows the CO2 dissolved in rainwater to react with the silica on the surface of the rock. DIPPLE believes that it is then possible to trap in this waste all the CO2 produced by mining 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.
The next step in the research is then to model the process and understand how to improve the rate of CO2 uptake, at a viable cost to mining operators. It would seem that the efficiency of the absorption of carbon dioxide varies according to the means implemented to treat the mining residues. Although initially skeptical, the mining companies are beginning to look with interest on the question.