Production of magnesium hydroxide from magnesium silicate for the purpose of CO2mineralization – Part 2: Mg extraction modeling and application to different Mg silicate rocks

Mineral carbonation of Mg silicates via a gas/solid carbonation of magnesium hydroxide, Mg(OH)2in a fluidized bed (FB) reactor process route is the most actively investigated route of carbon capture and stor- age by CO2mineralization (CCS) research in Finland. This paper reports Mg extraction behavior and pro- duction of magnesium hydroxide, Mg(OH)2from different Mg-silicate rocks from worldwide locations (Finland, Lithuania, Australia and Norway). Magnesium hydroxide, the reactive material for gas/solid mineralization of CO2can be produced from different Mg-silicate minerals via a staged solid/solid reac- tion with ammonium sulfate (AS) salt followed by precipitation in aqueous ammonia solution. A compar- ison is made for five different minerals. The kinetics of Mg extraction from Mg-silicate minerals and the possible effects of iron by-products on reactivity and kinetics were studied and modeled as well.