Abstract: A method of sequestering carbon dioxide comprises reacting the carbon dioxide with aqueous magnesium ions at elevated pH to form magnesium carbonate-containing salts. The carbon dioxide is preferably reacted with alkali to form carbonate and/or bicarbonate anions at elevated pH, and the carbonate and/or bicarbonate anions are subsequently reacted with aqueous magnesium cations to form the magnesium carbonate-containing salts. A preferred alkaline material for use in elevating the pH of the aqueous solution in the present invention is Cement Kiln Dust (CKD), and a preferred source of aqueous magnesium ions is reject water from a desalination plant.

Abstract: A method for producing an activated nesquehonite includes activating one or more nesquehonites by heating. The one or more nesquehonites may be formed by the reaction of carbon dioxide with aqueous magnesium ions at elevated pH, and may include barringtonite, nesquehonite, dypingite, hydromagnesite, and/or artinite and/or lansfordite. The activated nesquehonite may be useful in a building material, and have advantageous cementitious properties.

Abstract: A method for producing calcium sulfoaluminate cement comprises the steps of providing thermal energy by combustion of sulphur and/or a sulphur-containing compound, reacting sulphur oxides produced by combustion of the sulphur and/or sulphur-containing compound with a mixture of calcium oxide and/or carbonate, and alumina and/or its hydrates to form a sulphur-containing mixture, heating the sulphur-containing mixture using the thermal energy to produce a clinker, and reacting remaining sulphur oxides produced by combustion of the sulphur and/or sulphur-containing compound with lime. The sulphur and/or sulphur-containing compound preferably comprises elemental sulphur, sour crude, sour gas or calcium sulfate.

Abstract: A method of sequestering carbon dioxide comprises reacting the carbon dioxide with aqueous magnesium ions at elevated pH to form magnesium carbonate-containing salts. The carbon dioxide is preferably reacted with alkali to form carbonate and/or bicarbonate anions at elevated pH, and the carbonate and/or bicarbonate anions are subsequently reacted with aqueous magnesium cations to form the magnesium carbonate-containing salts. A preferred alkaline material for use in elevating the pH of the aqueous solution in the present invention is Cement Kiln Dust (CKD), and a preferred source of aqueous magnesium ions is reject water from a desalination plant.