Formation Mechanism of Aragonite by Substitute of Mg2+ Ions |
Kyung-Sun Choi, Jin-Koo Park, Ji-Whan Ahn, Hwan Kim1 |
Korea Institute of Geoscience and Mineral Resources 1School of Materials Science and Engineering, Seoul National University |
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ABSTRACT |
Acicular type aragonite precipitated calcium carbonate was synthesized by carbonation reaction of $Ca(OH)_2$ slurry and $CO_2$ gas. As increasing the initial concentration of $Mg^{2+}$ ion, calcite crystal phase substantially decreased while that of aragonite crystal phase increased. According to XRD and EDS analysis, it was found that the addition of $MgCl_2$ induced the $Mg^{2+}$ ion to substitute in $Ca^{2+}$ ion site of calcite lattice then the unstabled calcite structure be resolved, consequently the growth of calcite structure is interrupted while the growth of aragonite structure is expedited. |
Key words:
Precipitated calcium carbonate, Aragonite, Carbonation process, Magnesium ion |
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