HR: 09:15h
AN: B31D-06    [Abstracts]
TI: Carbon Sequestration in Mine Residue
AU: * Dipple, G M
EM: gdipple@eos.ubc.ca
AF: Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T1Z4 Canada
AU: Southam, G
EM: gsoutham@uwo.ca
AF: Earth Sciences, University of Western Ontario, London, Ont N6A5B7 Canada
AU: Power, I
EM: ipower@uwo.ca
AF: Earth Sciences, University of Western Ontario, London, Ont N6A5B7 Canada
AU: Thom, J
EM: jthom@eos.ubc.ca
AF: Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T1Z4 Canada
AU: Wilson, S
EM: swilson@eos.ubc.ca
AF: Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T1Z4 Canada
AB: Mining of silicate rocks produces as waste a reactive, fine-grained residue that is an ideal feedstock for mineral sequestration of carbon. Natural weathering of Mg-silicate mine tailings is rapid because of the fine grain size, and produces mineral crusts that bind carbon. Stable and radiogenic carbon isotope fingerprinting on the minerals confirms an atmospheric carbon source. In active mines that produce Mg-rich tailings, the carbon sequestration capacity of annual tailings production exceeds annual mine greenhouse gas production by a factor of 5 to 10. Hardrock mines therefore represent an ongoing industrial activity that could serve as a net carbon sink. New cation release rates from inorganic and microbially-mediated mineral dissolution experiments indicate that individual large mining operations could be engineered to sequester carbon dioxide at a rate of 10E4 to 10E6 tonnes per year. Our laboratory experiments also suggest that cyanobacteria could be employed to catalyze precipitation of Mg-carbonate minerals. Mg-silicate tailings are abundant and distributed globally. The global sequestration capacity of annual tailings production from nickel, diamond, platinum group element, and asbestos mining is approximately half a gigatonne of CO2. Parallel, but less efficient mineral sequestration pathways in other silicate tailings increase the sequestration capacity by as much as an order of magnitude. Global implementation of mineral sequestration in mine tailings could contribute as much as one of the seven "wedges" of Pacala and Socolow (2004) that are required to stabilize atmospheric CO2 content over the next 50 years.
DE: 0412 Biogeochemical kinetics and reaction modeling (0414, 0793, 1615, 4805, 4912)
DE: 0419 Biomineralization
DE: 1039 Alteration and weathering processes (3617)
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 3612 Reactions and phase equilibria (1012, 8412)
SC: Biogeosciences [B]
MN: Fall Meeting 2005