CHEN Guilan, SONG Xingfu, YU Jianguo. Effects of impurity ions on coupled reaction-extraction-alcohol precipitation process of MgCl2 and CO2[J]. CIESC Journal, 2017, (2): 702-707. DOI: 10.11949/j.issn.0438-1157.20161259.
CHEN Guilan, SONG Xingfu, YU Jianguo. Effects of impurity ions on coupled reaction-extraction-alcohol precipitation process of MgCl2 and CO2[J]. CIESC Journal, 2017, (2): 702-707. DOI: 10.11949/j.issn.0438-1157.20161259.DOI:
The preparation of nesquehonite (MgCO3·3H2O) and hydrogen chloride by MgCl2 and CO2 based on a coupled reaction-extraction-alcohol precipitation process is an effective way for the comprehensive utilization of brine. The effects of impurity ions Na+
K+ and Ca2+ in brine on the morphology of the solid product obtained in the coupled reaction-extraction-alcohol precipitation process are investigated systematically. The results indicate that Na+ and K+ have a similar influence on the coupled process. The products are rod-like high purity MgCO3·3H2O when Na+ and K+ are added. Moreover
Na+ and K+ can be selectively absorbed onto the axial face (101) of MgCO3·3H2O
that will hinder the growth along the (1 0 1) direction and resulting a decrease in the diameter of MgCO3·3H2O. Ca2+ shows a negative effect on the coupled process. The added impurity CaCl2 can react with CO2 and form spherical amorphous nano Mg/Ca-carbonate
which will decrease the purity of the solid products.