Method for preparing large-particle-size barium carbonate by four-tower serial carbonization method

The invention provides a method for preparing large-particle-size barium carbonate by a four-tower serial carbonization method, which comprises the following steps: (1) adding a BaS solution into a first tower and a second tower, introducing CO2 into the first tower, and introducing H2S gas generated by the first tower into the second tower; (2) when BaS hydrolysis in the second tower is finished, adding a BaS solution into the third tower, and enabling H2S gas generated by the first tower to enter the third tower through the second tower; and (3) when all the liquid in the third tower is the Ba (HS) 2 solution, adding the BaS solution into the fourth tower, introducing H2S gas generated by the first tower, the second tower and the third tower into the fourth tower, and discharging by the first tower. The invention also provides the prepared large-particle-size barium carbonate. The method provided by the invention better meets the particle size requirement of the product, and meanwhile, the four-tower series