Method for preparing anhydrous rare-earth chloride based on spray drying-melting dehydration

The invention discloses a method for preparing anhydrous rare-earth chloride based on spray drying-melting dehydration. The method comprises the following steps: S1, preparing a rare-earth chloride heptahydrate into a rare-earth chloride solution with a concentration of not less than 200 g/L; S2, performing spray drying on the rare-earth chloride solution at a temperature of 110-120 DEG C so as toobtain a rare-earth chloride trihydrate; S3, heating and melting the rare-earth chloride trihydrate so as to obtain molten liquor and impurity liquid, wherein in the heating and melting process, thetemperature is 850-1000 DEG C, and the vacuum degree is 50-100mm mercury column; and S4, separating and cooling the molten liquor, thereby obtaining the anhydrous rare-earth chloride. According to themethod disclosed by the invention, the operation of preparing the anhydrous rare-earth chloride from the rare-earth chloride heptahydrate is realized by adopting the spray drying-melting dehydration.The method is simple in process, pollution-free, low in equipment requirement and capable of easily realizing industrialized production; and compared with a general dehydration method in the prior art, the method disclosed by the invention has the advantages that a protective atmosphere is not needed, organic matters or other heavy metals do not need to be introduced, and production of hydrogen chloride or ammonia and other toxic gases is avoided.