. Then the premixed CO2 and N2 with molar ratio of 3:10
were bubbled into the slurry through a column. The reaction should
be stopped as soon as the pH value of the suspension decreased to 7.0.
The obtained CaCO3 precipitates were rinsed firstlywith anhydrous ethanol
and hot distilledwater three times, respectively. Lastly, the product
was dried for at least 24 h in an oven at approximate 80 °C.