Abstract: The long-term storage of CO 2 using mineral sequestration is becoming increasingly interesting in many regions, especially where CO 2 underground sequestration is considered impossible or unfeasible. Despite the recognised and documented advantages of CO 2 mineral sequestration, twenty years of R&D work did not yet result in mature, economically viable technology that can be applied on a large scale. Lacking other CCS options while having access to large resources of suitable rock material, a route for carbonation of magnesium silicate mineral is currently being optimised in Finland. It involves the production of magnesium hydroxide, Mg(OH) 2 from the mineral followed by carbonation of this in a pressurised fluidised bed reactor. Although the Mg(OH) 2 production requires energy the consequent carbonation step is exothermic and the overall process could still be rendered energy neutral. Significant amounts of iron oxides are obtained as by-products. Carbonation levels of ~50% of several 100 µm diameter Mg(OH) 2 particles were obtained within 10 minutes at pressures > 20 bar and temperatures up to 500ºC. This paper reports on the latest developments of the work, addressing also process energy efficiency. Also, the large-scale application of this in Finland and at the locations of project partners abroad is briefly addressed
