Abstract: <FONT face=Verdana>Hydrochloric acid was adopted as leaching agent to take out calcium from calcium slag of phosphogypsum at first.Then refined CaCl2 solution would obtained through the secondary purification.Finally,high-quality precipitated calcium carbonate was prepared by carbonizing refined CaCl2 solution.Processes of acid-leaching and refining were studied in detail and the optimum process parameters were obtained.Under the optimum process conditions,product was prepared,which had reached high-grade standard of Industrial Precipitated Calcium Carbonate,HG/T 2226—2000,tested and approved by Guizhou Provincial Quality Supervision and Inspection Station for Chemical Products.Product was also characterized by scanning electron microscopy (SEM) and results showed product particles were uniform and rod-like with good dispersion.</FONT>