Praseodymium-containing ultrafine high-precision rare earth polishing powder and its preparation method

The invention discloses a praseodymium-containing ultrafine high-precision rare earth polishing powder and its preparation method. The polishing powder is used as a grinding material and contains cerium oxide, lanthanum oxide and praseodymium oxide, and the total rare earth content TREO is more than 92wt%. CeO2/TREO=60-70%, La2O3/TREO=30-35%, Pr6O11/TREO=2-7%, and Nd2O3/TREO is less than or equals to 0.1%. In order to raise the polishing effect, the fluorine element which has chemical effects is added during the wet synthesis process. Thus, the prepared rare earth polishing powder can be endowed with good polishing grinding surface. Through deposition, fluorination, wet grinding and roasting of mixed rare earth chloride, the praseodymium-containing rare earth polishing powder is obtained. The grain diameter D50 of the rare earth polishing powder is 0.3-1micron. The rare earth polishing powder has advantages of good suspensibility, dispersibility, narrow particle size distribution and high polishing grinding surface smoothness, and is especially suitable for polishing of high-precision elements.