Production of rare earth compounds

摘要

A method for preparing high-density particles of rare earth carbonate comprises precipitating rare earth ions with aqueous carbonate or bicarbonate ions, in the presence of rare earth carbonate crystals, and separating the resulting precipitate. The method can be conducted to prepare individual batches or, alternatively, a continuous precipitation method can be used, wherein rare earth and carbonate or bicarbonate ions are mixed at a controlled rate to maintain an optimum pH condition. High-density rare earth oxide is obtained by calcining the precipitate.