A PROCESS OF SMELTING MONAZITE RARE EARTH ORE RICH IN Fe

摘要

A process of smelting monazite rare earth ore rich in Fe in particular comprises the following steps: mixing Fe-rich monazite rare earth ore containing 8-40% Fe with concentrated sulphuric acid and adding the mixture into a calcining kiln; calcining at 231-600ºC, wherein rare earth reacts with sulphuric acid to produce rare earth sulphate which dissolves in water or a solution with a H+ concentration less than 1.5mol/L and Fe is transformed into at least one of iron sulphate, iron phosphate and iron pyrophosphate; leaching the calcined ore with water or a solution with a H+ concentration less than 1.5mol/L and filtering to obtain a solution of rare earth sulphate containing Fe and P; neutralizing the solution to recover Fe and P and to obtain pure solution of rare earth sulphate; producing single or mixed rare earth compound by extracting and separating the pure solution directly, or producing mixed rare earth carbonates by precipitation process. The process could avoid the influence of Fe on extracting rare earth. The process is simple, continuous, easy to control, low in consumption of chemical engineering materials, high in recovery ratio of rare earth and suitable for large-scale production.