title: Carbon sequestration kinetic and storage capacity of ultramafic mining waste.
abstract: Mineral carbonation of ultramafic rocks provides an environmentally safe and permanent solution for CO(2) sequestration. In order to assess the carbonation potential of ultramafic waste material produced by industrial processing, we designed a laboratory-scale method, using a modified eudiometer, to measure continuous CO(2) consumption in samples at atmospheric pressure and near ambient temperature. The eudiometer allows monitoring the CO(2) partial pressure during mineral carbonation reactions. The maximum amount of carbonation and the reaction rate of different samples were measured in a range of experimental conditions: humidity from dry to submerged, temperatures of 21 and 33 °C, and the proportion of CO(2) in the air from 4.4 to 33.6 mol %. The most reactive samples contained ca. 8 wt % CO(2) after carbonation. The modal proportion of brucite in the mining residue is the main parameter determining maximum storage capacity of CO(2). The reaction rate depends primarily on the proportion of CO(2) in the gas mixture and secondarily on parameters controlling the diffusion of CO(2) in the sample, such as relative saturation of water in pore space. Nesquehonite was the dominant carbonate for reactions at 21 °C, whereas dypingite was most common at 33 °C.
authors.affiliation: Département de géologie et génie géologique & GEOTOP, Université Laval, 1065 avenue de la Médecine, Québec (QC), Canada G1V 0A6.
authors.forename: Julie
authors.initials: J
authors.lastname: Pronost
authors.forename: Georges
authors.initials: G
authors.lastname: Beaudoin
authors.forename: Joniel
authors.initials: J
authors.lastname: Tremblay
authors.forename: Faïçal
authors.initials: F
authors.lastname: Larachi
authors.forename: Josée
authors.initials: J
authors.lastname: Duchesne
authors.forename: Réjean
authors.initials: R
authors.lastname: Hébert
authors.forename: Marc
authors.initials: M
authors.lastname: Constantin
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry; D057965:Carbon Sequestration; D007700:Kinetics; D008276:Magnesium Hydroxide / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008906:Mining; D013052:Spectrometry, X-Ray Emission; D013696:Temperature
chemical_list: D002245:Carbon Dioxide; D008276:Magnesium Hydroxide