35 Carbon Mineralization Potential of Ultramafic and Ophiolitic Units (Posters)

Friday, 4 April 2025
8:00 AM - 4:00 PM
Sierra Ballroom

DEMONSTRATION OF ENHANCED CARBON MINERALIZATION WITHIN ULTRAMAFIC MINE TAILINGS

Paper number: 35-1
Program: Theme Sessions
Time: 8:00 AM – 4:00 PM

Authors

Abstract

Enhanced mineralization is a recognized carbon dioxide (CO2) removal pathway whereby atmospheric CO2 is captured through chemical reactions during the weathering of alkaline wastes, such as mine tailings. CO2 in air reacts with cations from alkaline mine tailings (Mg2+, Ca2+) to form carbonate minerals that are isolated from the atmosphere and stored over geological time scales. Mine tailings from ultramafic ore passively captures CO2 after being deposited from a slurry at very slow rates, but the capture rates of CO2 can be enhanced through the manipulation of the surface of the tailings storage facility.

Here we report on a hectare-scale demonstration of enhanced mineralization from the Arca Climate Technologies feasibility pilot of integrated Smart Churning technology with continuous monitoring of CO2 capture. The tailings surface is roughened using physical manipulation techniques in a multi-hectare plot to increase the rate of CO2 capture from air. CO2 removal is directly measured at a point-scale using commercially available dynamic closed chambers, and at a larger-scale with eddy covariance monitoring. The two independent methods measure similar CO2 removal rates. Results demonstrate that the rate of capture from Smart Churning is significantly increased over baseline passive air capture rates. Mineral trapping is confirmed with electron microscopy imaging of the carbonate mineral cements that bind milled tailings grains. This process has been formalized in a methodology that has been independently validated as ISO compliant (ISO14064-2:2019).

Geological Society of America Abstracts with Programs. Vol. 57, No. 4

doi: 10.1130/abs/2025CD-410154

© Copyright 2025 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.