The potential for using concentrated seawater to fix CO2 by adding insoluble amine extractant was tested and verified. The experimental results showed that over 90% of Ca2+ ions could be converted to precipitation. Ammonia was chosen as regenerant to regenerate the extracting agent; the regeneration rate can reach 95%. On the basis of the analysis of MgCO3 precipitation properties, a new CO2 mineralization process was proposed in which CaO is employed to react with Mg2+ in solution. Mg(OH)(2) precipitation and Ca2+-rich aqueous solutions were produced, and both performed well in CO2 mineralization. This new process can produce different kinds of byproducts such as MgCO3, CaCO3, and NH4Cl. Since there is no energy consumption from phase separation, nor is there a heat requirement, it is therefore definitely less energy intensive. This approach has great application potential.