Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

© 2016 Elsevier Ltd Acid leaching of ultramafic rocks to produce Mg2+- and Ca2+-rich solutions for mineral carbonation may inadvertently leach toxic trace metals. This study investigates the capacity of nesquehonite (MgCO3·3H2O), a common product of mineral carbonation at Earth's surface conditions, to sorb Cr, Ni, Mn, Co and Cu from solution. Our results demonstrate that upon precipitation, nesquehonite rapidly sequesters transition metals present in solution at concentrations from 10 to 100 mg/L. Trace metal uptake appears to occur by substitution for Mg2+ in the nesquehonite crystal structure, and also by incorporation into minor, metal-rich phases, such as Fe-oxyhydroxides. This indicates that first row transition metals will likely be trapped and stored within Mg-carbonate minerals produced in industrial mineral carbonation reactors and in landscapes modified to capture atmospheric CO2 via enhanced weathering. Thus, it is unlikely that trace metals will pose an environmental risk in the event of accidental release of wastewater.

Original publication

DOI

10.1016/j.ijggc.2016.11.006

Type

Journal article

Journal

International Journal of Greenhouse Gas Control

Publication Date

01/12/2016

Volume

55

Pages

73 - 81