Mineral composition of carbonatised products of CO2 liquidation determined by the recalculation of XRD and chemical analyses.

CO2 sequestration by artificial carbonatisation in a high-pressure reactor using appropriate minerals, rocks or waste materials provides a method of permanently binding the CO2 as carbonates. Laboratory tests were carried out to investigate the carbonitisation of two types of material, magnesite waste from the Jelsava plant and serpentinite from the Hodkovce outcrop in Slovakia. The magnesite waste sample contained 84.9% brucite, with 58.7% of the MgO bound in the brucite lattice, and 4.8% portlandite, with 3.62% free CaO in the lattice, both of which are suitable for reaction with CO2. The sample also contained 5.3% maghemite and 2.5% Si and Al oxides which are not appropriate for artificial carbonatisation. The carbonatised product contained hydromagnesite, brucite, calcite, maghemite, brugnatellite and an amorphous phase, with CO2 bound mainly in the lattices of hydromagnesite and to a lesser extent brugnatellite. The CO2 value of the product increased by 21.9% compared with the raw material. The serpentinite contained 81.1% lizardite together with olivine, both important minerals for CO2 sequestration, and a product containing 93.6% hydromagnesite could be obtained after carbonatisation in which CO2 was stable and securely bound in the lattice of the Mg carbonate mineral formed.
CO2 sequestration by artificial carbonatisation in a high-pressure reactor using appropriate minerals, rocks or waste materials provides a method of permanently binding the CO2 as carbonates. Laboratory tests were carried out to investigate the carbonitisation of two types of material, magnesite waste from the Jelsava plant and serpentinite from the Hodkovce outcrop in Slovakia. The magnesite waste sample contained 84.9% brucite, with 58.7% of the MgO bound in the brucite lattice, and 4.8% portlandite, with 3.62% free CaO in the lattice, both of which are suitable for reaction with CO2. The sample also contained 5.3% maghemite and 2.5% Si and Al oxides which are not appropriate for artificial carbonatisation. The carbonatised product contained hydromagnesite, brucite, calcite, maghemite, brugnatellite and an amorphous phase, with CO2 bound mainly in the lattices of hydromagnesite and to a lesser extent brugnatellite. The CO2 value of the product increased by 21.9% compared with the raw material. The serpentinite contained 81.1% lizardite together with olivine, both important minerals for CO2 sequestration, and a product containing 93.6% hydromagnesite could be obtained after carbonatisation in which CO2 was stable and securely bound in the lattice of the Mg carbonate mineral formed.