Magnesium Leachability of Mg-Silicate Peridotites: The Effect on Magnesite Yield of a Mineral Carbonation Process

Abstract

The aim of this study was to increase feedstock availability for mineral carbonation. Acid dissolution and carbonic acid dissolution approaches were used to achieve higher Mg extractions from peridotites. Acid dissolution studies of raw dunite, heat-activated dunite, heat-transformed dunite, and twin sister dunite have not been reported in the literature. Heat-activated dunite is more reactive as compared to heat-transformed dunite, raw dunite, and twin sister dunite. The fraction of magnesium extracted from heat-activated dunite was 57% as compared to 18% from heat-transformed dunite, 14% from raw dunite, and 11% from twin sister dunite. Similarly, silicon and iron extractions were higher for heat-activated dunite compared to that of heat-transformed dunite, raw dunite, and twin sister dunite. Materials rich in forsterite (twin sister dunite and heat-transformed dunite) showed preferential Mg release and exhibited incongruent dissolution similar to that of forsterite. Heat-activated dunite (amorphous magnesium silicate rich) on the other hand behaved differently and showed congruent dissolution. Olivine did not dissolve under carbonic acid dissolution (with concurrent grinding) and acidic conditions. Under carbonic acid dissolution with concurrent grinding conditions, olivine was partially converted into nanometer sized particles (d10 = 0.08 µm) but still provided 16% Mg extraction during 4 h of dissolution.

Testing and Validating Instruments for Feedstocks of Mineral Carbonation

“…Table 4 shows the analysis. Please refer to earlier publications [2,10,13,14,18,19] for detailed description of methods. TGA-MS curves are presented in Figure 14.…”

“…Few of these results are presented graphically in Figure 17. For already published results, please refer to [2,19] and [10,18] and [13,14]. Soaked dunite especially heatactivated provided the highest yields.…”

“…Experimental methods, acid dissolution, regrinding, single-stage carbonation, acrylic reactor testing without temperature and pressure, concurrent grinding both in situ and in operando and two-stage carbonation are discussed. Please refer to these publications for further details [2,10,13,14,18,19].…”

How Ph.D. Students Start a Research

“…Materials, Methods and experimental set-up is already discussed and shown in earlier publications [1,9,12,13,15,16].…”

“…Initially a gradual mass increase was observed. Which can be attributed to water mass loss or bit later to brucite decomposition material [1,9,12,13,15,16].…”