Process for metallurgy and separating rare earth concentrate using combination method

A process for metallurgy and separating a rare earth concentrate using a combination method, the process comprising:

• (1) decomposing the rare earth concentrate by roasting under a certain roasting atmosphere to obtain a roasted concentrate, wherein the roasting atmosphere during the roasting includes one or more of a water vapor atmosphere, N2, CO, CO2, air, and inert gases;
• (2) adding the roasted concentrate with a hydrochloric acid to leach rare earth, and collecting a leaching liquor of rare earth and a leach residue respectively after solid-liquid separation;
• and
• (3) dehydrating the leach residue, then adding the dehydrated leach residue with a concentrated sulfuric acid, roasting, collecting a roasted product, leaching the roasted product with water, and neutralizing to remove impurities to obtain a rare earth sulfate solution, and separating the obtained rare earth sulfate solution by extraction, or transforming the obtained rare earth sulfate solution by extraction or transforming the obtained rare earth sulfate solution by precipitation to obtain a rare earth chloride solution;
• wherein in step (2), the obtained leaching liquor of the rare earth is aged at 60° C. to 90° C. for 1 to 5 hours, and solid-liquid separation is performed to obtain a rare earth chloride solution and a rare earth fluoride powder product;
• and the obtained rare earth chloride solution is combined with the rare earth chloride solution obtained by transforming the rare earth sulfate solution in step (3), and separating the combined solution by extraction to obtain a single rare earth compound.