UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data grouped in the sections named "Externally Awarded" or "Internally Disbursed" (shown on the profile page) to your Research Finance Administrator. Your can find your Research Finance Administrator at http://www.ucl.ac.uk/finance/research/post_award/post_award_contacts.php by entering your department
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
The role of silicate surfaces on calcite precipitation kinetics
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Journal Article
  • Authors:
    Stockmann GJ, Wolff-Boenisch D, Bovet N, Gislason SR, Oelkers EH
  • Publication date:
    15/06/2014
  • Pagination:
    231, 250
  • Journal:
    Geochimica et Cosmochimica Acta
  • Volume:
    135
  • Status:
    Published
  • Print ISSN:
    0016-7037
Abstract
The aim of this study is to illuminate how calcite precipitation depends on the identity and structure of the growth substrate. Calcite was precipitated at 25°C from supersaturated aqueous solutions in the presence of seeds of either calcite or one of six silicate materials: augite, enstatite, labradorite, olivine, basaltic glass and peridotite rock. Calcite saturation was achieved by mixing a CaCl2-rich aqueous solution with a NaHCO3-Na2CO3 aqueous buffer in mixed-flow reactors containing 0.5-2g of mineral, rock, or glass seeds. This led to an inlet fluid calcite saturation index of 0.6 and a pH equal to 9.1. Although the inlet fluid composition, flow rate, and temperature were identical for all experiments, the onset of calcite precipitation depended on the identity of the seeds present in the reactor. Calcite precipitated instantaneously and at a constant rate in the presence of calcite grains. Calcite precipitated relatively rapidly on labradorite, olivine, enstatite, and peridotite (mainly composed of Mg-olivine) surfaces, but more slowly on augite and basaltic glass. Calcite precipitation rates, however, became independent of substrate identity and mass over time, and all rates approach 10-9.68±0.08mol/s for ~10day long experiments and 10-9.21±0.2mol/s for ~70day long experiments. Scanning Electron Microscope images showed olivine, enstatite and peridotite surfaces to be covered extensively with calcite coatings at the end of the experiments. Less calcite was found on labradorite and augite, and the least on basaltic glass. In all cases, calcite precipitation occurs on the mineral, rock or glass surfaces. Calcite precipitation on these surfaces, however, negligibly affects the dissolution rates of the silicate grains. These results support ultramafic and basalt carbonation as a long-term carbon storage strategy, as calcite readily precipitates on the surfaces of minerals contained in these rocks without inhibiting their dissolution. © 2014 Elsevier Ltd.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
There are no UCL People associated with this publication
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by