Mineral Carbonation

An integrated process for carbon dioxide capture, sequestration and utilisation, which comprises:

• a) providing an aqueous slurry comprising an aqueous liquid and a particulate solid comprising an activated magnesium silicate mineral;
• b) in a dissolution stage, contacting a CO2-containing gas stream with the aqueous slurry to dissolve magnesium from the mineral to provide a slurry comprising a magnesium ion enriched carbonated aqueous liquid and a magnesium depleted solid residue;
• c) subjecting at least part of the magnesium depleted solid residue from step b) to a particle size classification process that separates the magnesium depleted solid residue into a fine particle size fraction and a coarse particle size fraction;
• d) subjecting at least part of the coarse particle size fraction from step c) to a particle size reduction process to provide a particle size reduced fraction;
• e) providing an aqueous slurry comprising particle size reduced fraction from step d) and repeating step b), wherein this step e) does not include using fine particle size fraction from step c);
• and
• f) in a precipitation stage, precipitating magnesium carbonate from magnesium ions dissolved in b) and e).