Process Research and Mechanism Analysis of Pellet Roasting and Monazite Decomposition

The concentrated sulfuric acid roasting method and caustic soda method, as the main processes for treating Bayan Obo mixed rare earth concentrate, have been operating normally for decades. However, due to their serious pollution, high cost, and waste of accompanying resources, relevant rare earth enterprises are facing severe environmental and cost pressures. The sodium carbonate roasting method is a clean method for treating rare earth minerals, but due to the phenomenon of “ring formation” in the rotary kiln during the reaction process, this process has not been widely promoted. Based on the above facts, this article proposes a decomposition method for sodium pelletizing to decompose monazite, which effectively alleviates the related technical problems caused by the “ring formation” problem. Moreover, the rare earth leaching rate is 86.87%, and the recovery rates of F, P, and Th are 98.64, 13.87, and 88.96%. It is a potential rare earth mineral cleaning production process and can provide certain technical references for relevant rare earth enterprises.