The invention provides a method for manufacturing a nano-grade
calcium carbonate from high-concentration
carbon dioxide industrial exhaust gases, which comprises the following steps: (1) adding a
crystal nucleus forming accelerator into a suspension of a
calcium hydroxide; (2), introducing a gas containing 50 to 100
volume percent of a
carbon dioxide, adding a dispersant when a
carbonization rate is over 80 percent, and continuously introducing the gas for 10 to 20min when the pH value of the suspension is reduced to between 6.5 and 7.0, wherein the final temperature of a reaction
slurry liquid is 45 to 70 DEG C; and (3) adding the
aqueous solution of a cladding agent into the suspension of the
calcium hydroxide, wherein a cladding and activating time is 1 to 2h, and then collecting the nano-grade activated
calcium carbonate from the
reaction product. The method of the invention greatly reduces the equipment and operation costs, quickens the
carbonization reaction, saves the time of the
carbonization reaction and energy, reduces the
energy consumption, increases the oversaturated concentration of the
calcium carbonate, and finally generates narrowly distributed nano-grade
calcium carbonate particles the grain size of which is uniform.