Le Geotop - Dr. Greg Dipple: Sulfur in magmas... (01-12-2017)

Dr. Greg Dipple: Sulfur in magmas... (01-12-2017)

 

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Dr. Greg Dipple, University of Brtish Columbia

Carbon Dioxide Capture, Utilization and Storage in Mine Wastes

Vendredi 1er décembre 2017 à 15h30 / Friday, December 1, 2017, 3:30 pm

Redpath Museum Auditorium, 859 Rue Sherbrooke O, Université McGill

Résumé / Abstract :

Ultramafic igneous rocks and serpentinites are out of chemical equilibrium with the carbon dioxide content of Earth’s atmosphere and represent an important potential reservoir to offset anthropogenic carbon emissions. Ultramafic mine tailings react spontaneously with atmospheric carbon dioxide via kinetically controlled mineral-microbe-fluid-gas reactions to precipitate carbon in solid mineral form that is stable and easily monitored. The capacity of ultramafic mine tailings to sequester carbon is about ten times greater than greenhouse gas (GHG) emissions of associated mining and mineral processing. If even a small fraction of this capacity is tapped, it provides an opportunity to generate significant GHG offsets or even create mines with a net GHG benefit. Rates of accidental carbon mineralization, however, are slow and controlled by (1) the nature of ore, gangue and alteration mineralogy, (2) mineral processing and mine design, (3) tailings handling and storage procedures, and (4) local climate. Laboratory and field experiments have confirmed that mineralization can be significantly accelerated at ambient (i.e., Earth’s surface) conditions with modest intervention using existing technologies, and can also produce co-benefits such as tailings stabilization, deleterious metal encapsulation, and dust control. Acceleration approaches in the form of a technology ladder, which matches technologies with carbon value based on their affordability, provides a means to consider industrial intervention in the context of carbon pricing.