Conference paper
Understanding natural analogues of mineral carbonation to inform the development of industrial CO2 storage
Conference Handbook and Abstracts, pp.99-99
Curtin University, Western Australian Organic and Isotope Geochemistry Centre
19th Australian Organic Geochemistry Conference, 19 (Fremantle, Australia, 04/12/2016–07/12/2016)
2016
Abstract
Natural examples of mineral carbonation, the conversion of Mg-silicate to Mg-carbonate and silica, are common in ultramafic rocks throughout the world and reflect the thermodynamic instability of Mg-silicate minerals in the presence of CO2. However, the industrial implementation of mineral carbonation as a means of safely storing CO2 in the form of carbonate minerals is hampered by slow kinetics and the cost associated with heat-activation and carbonation reactors at high pressures and temperatures.
In the Great Serpentinite Belt, New South Wales, Australia, natural carbonation occurs in the form of weathering derived magnesite deposits, carbonate crust on ultramafic mine tailings and hydrothermal silica-carbonate alteration. At Attunga, low temperature (10 to 50 °C) meteoric waters have altered serpentinite to typical cauliflower-like magnesite nodules and veins, usually accompanied by late stage amorphous silica. Consistently low δ13C and small radiocarbon contents point to overlying soil as the source of carbon in the magnesite. Textural observations suggest carbonation progressed via fractures and porosity created by weathering of the host-rock, producing intermediate phases with decreased Mg/Si ratios in the process. For the mine tailings of the Woodsreef Asbestos Mine a relationship between textures, mineral content and isotopic fingerprint indicates that carbonate crusts covering the tailings formed from evaporating meteoric fluids, which absorbed CO2 directly from the atmosphere. Rate estimates based on the carbonate content and time since closure of the mine indicate that carbonation of the mine tailings proceeds at much higher rates than background uptake of CO2 by chemical weathering. Lensoid masses of silica-carbonate rock and magnesite veins at the Piedmont magnesite deposit formed by hypogene replacement of serpentinite at temperatures between 165 and 225 °C. The magnesite is usually Fe-rich, indicating reducing conditions during formation, and often accompanied by dolomite and quartz with alteration fluids ascribed to hydrothermal and magmatic sources.
Each of the above processes created a distinct set of textures, minerals and isotope-geochemical signatures which reflect conditions and mechanisms favourable for carbonation, but also the associated limitations that need to be overcome for industrial implementation. A better understanding of natural analogues to mineral carbonation informs the development of accelerated carbonation processes for large scale industrial storage of CO2 in carbonate minerals.
Details
- Title
- Understanding natural analogues of mineral carbonation to inform the development of industrial CO2 storage
- Authors/Creators
- Hans C. Oskierski - Murdoch UniversityBogdan Z. Dlugogorski
- Publication Details
- Conference Handbook and Abstracts, pp.99-99
- Conference
- 19th Australian Organic Geochemistry Conference, 19 (Fremantle, Australia, 04/12/2016–07/12/2016)
- Publisher
- Curtin University, Western Australian Organic and Isotope Geochemistry Centre
- Identifiers
- 991005560464007891
- Murdoch Affiliation
- Centre for Water, Energy and Waste; Harry Butler Institute
- Language
- English
- Resource Type
- Conference paper
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