Objective It is an effective path for carbon emission reduction by CO₂ mineralization technology utilizing metal ions to solidify CO₂ into carbonate. The anions migration in the process of CO₂ mineralization coupled with organic amine extraction is investigated to provide theoretical reference for further design of mineralization process.

Methods CO₂ mineralization coupled with organic amine extraction could continuously precipitate metal ions with carbonate ion(CO₃^2-) from dissolved CO₂ by using of organic amines as the extractant to transfer hydrogen ion(H⁺) and anion into organic phase. The anion mobility during the CO₂ mineralization were investigated in magnesium-based and calcium-based systems. The effects of time, reaction temperature, and organic phase-water volume ratio on the anion mobility were tested.

Results The anion mobility in magnesium-based system states as: y_I^- > y_NO3^- > y_Br^- > y_Cl^- > y_SO4^2-. The anion mobility in calcium-based system states as: y_I^- > y_NO3^- > y_Br^- > y_Cl^-. The anions mobility in calcium-based system is higher than that in magnesium-based system. The mobility rate of nitrate ions is higher than that of chloride ions. The mobility of NO₃^- and Cl^- decreases with the increase of temperature.

Conclusions The anion mobility increases with the acidity of anions and H⁺ increasing. After acid extraction with organic amines, R₃N…H-O turns to R₃NH⁺…O-H. Lower temperature and higher organic phase-water ratio are favorable for the anions migration in CO₂ mineralization coupled with organic amine extraction reaction.