Abstract:Bayan Obo Mine in Inner Mongolia is the world""s largest iron-niobium-rare earth polymetallic co-associated deposit, and the prospective rare earth reserves rank first in the world. However, during mining process of the deposit, valuable elements such as rare earth cannot be effectively extracted and enter into the slag to form important secondary rare earth resources. In order to recover rare earth resources, based on the main component of Bayan Obo metallurgical slag and taking the ternary basic system of CaO-SiO2-La2O3 as the research object, firstly, the best rare earth enrichment phase of the system was identified as CaxLa4.67-x(SiO4)3O1-0.5x phase. Subsequently, a supergravity force field was introduced to separate CaxLa4.67-x(SiO4)3O1-0.5x rare earth phase from slag phase online at G=1 000, time of 10 min and temperature of 1 350 ℃, and high purity rare earth phase crystals were obtained. Finally, the obtained rare earth crystals were characterized and refined by Rietveld, and the specific chemical formula is identified as Ca1.11La3.56Si3O12.36, and the crystal structure and crystal data of rare earth phase were obtained, which further improves the basic physical and chemical data of the earth phase and provides a theoretical basis for the recovery and utilization of rare earth resources.