Acid-dissolution of antigorite, chrysotile and lizardite for ex situ carbon capture and storage by mineralisation

Abstract

Serpentine minerals serve as a Mg donor in carbon capture and storage by mineralisation (CCSM).The acid-treatment of nine comprehensively-examined serpentine polymorphs and polytypes, and the subsequent microanalysis of their post-test residues highlighted several aspects of great importance to the choice of the optimal feed material for CCSM. Compelling evidence for the nonuniformity of serpentine mineral performance was revealed, and the following order of increasing Mg extraction efficiency after three hours of acid-leaching was established: Al-bearing polygonal serpentine (<5%) ≤ Al-bearing lizardite 1T (≈5%) < antigorite (24-29%) < well-ordered lizardite 2H 1 (≈65%) ≤ Al-poor lizardite 1T (≈68%) < chrysotile (≈70%) < poorly-ordered lizardite 2H 1 (≈80%) < nanotubular chrysotile (≈85%).It was recognised that the Mg extraction efficiency of the minerals depended greatly on the intrinsic properties of crystal structure, chemistry and rock microtexture. On this basis, antigorite and Albearing well-ordered lizardite were rejected as potential feedstock material whereas any chrysotile, non-aluminous, widely spaced lizardite and/or disordered serpentine were recommended.The formation of peripheral siliceous layers, tens of microns thick, was not universal and depended greatly upon the intrinsic microtexture of the leached particles. This study provides the first comprehensive investigation of nine, carefully-selected serpentine minerals, covering most varieties and polytypes, under the same experimental conditions. We focused on material characterisation and the identification of the intrinsic properties of the minerals that affect particle's reactivity. It can therefore serve as a generic basis for any acid-based CCSM pre-treatment.

Determination of the Carbon Dioxide Sequestration Potential of a Nickel Mine Mixed Dump through Leaching Tests

“…On the other hand, the low extraction efficiencies of Mg reported can be attributed to the competing presence of Fe and Al in the sample. This phenomenon observed was similar to that reported by Lacinska et al [42], in which they cited the presence of Al 3+ ions as the hindering factor in the release of Mg + , primarily due to the promotion of layer-to-layer linkage by H-bonding, which kept the Mg + ions bound to the solid. The preferential leaching of Fe 3+ in comparison to Mg + has also been observed in samples where both ions are present, such as in antigorites, thus contributing to low Mg extraction rates [37].…”

“…In addition, the presence of rod-shaped particles in Figure 4b suggests the presence of lizardite in the sample as verified by the spike of Mg in the EDX elemental analysis. The presence of silicon is also verified for both samples, particularly for the region bearing spherical particles and is consistent with existing data related to wastes and ores derived from mines [12,[41][42][43][44].…”

Influence of physicochemical properties of Brazilian serpentinites on the leaching process for indirect CO2 mineral carbonation

“…However, the Al 3+ level reported by Daval et al (2013) was 0.88% in the form Al 2 O 3 . According to Lacinska et al (2016), lizardite 1T with low Al 2 O 3 (1%) levels, lead to higher Mg extraction than lizardite 1T with high Al 2 O 3 levels (2.36%). Since the lizardite used by Daval et al (2013) had low Al 2 O 3 levels, the low extraction could be caused by the large particle size of the material used (500-800 μm).…”

“…While there have been many studies in this field, there is still a discrepancy regarding CO 2 capture potential of silicate rocks. In order to get a better understanding of whether or not silicate rocks are adequate, recently Gadikota et al (2014b); Lacinska et al (2016); Lavikko and Eklund (2016); Styles et al (2014) have suggested that silicate rocks must be characterized more carefully because their mineralogy varies widely. The characterization must consider pore structure, surface area (S BET ), origin, subsequent metamorphic changes, and crystal structure of the minerals in the rocks.…”

CO2 Absorption and Magnesium Carbonate Precipitation in MgCl2–NH3–NH4Cl Solutions: Implications for Carbon Capture and Storage

“…Among the many materials tested, magnesium-rich materials are thought to be good candidates for carbonation due to their natural abundance [14] and relatively higher unit mass binding efficiency (e.g., as compared to calcium). For example, physical activation (grinding [15][16][17] or heating [18,19]), chemical leaching (acid [20][21][22], recyclable ammonium salt [23,24] or non-acidic ionic solutions [25]), bioleaching [26,27] were applied to Mg rich minerals to dissolve and concentrate Mg. However, the other CO 2 absorption and carbonate precipitation steps have been less explored.…”