| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for recovering a heavy rare earth element, which enables recovery of the element with high efficiency and at high recovery rate. <P>SOLUTION: The method includes adding to a solution containing the heavy and light rare earth elements, an alkali metal sulfate so as to become 27 g/l or more in terms of a sulfate ion concentration, and coprecipitating the heavy rare earth element and the double sulfate of the light rare earth element to recover. It is preferable to control the temperature of the solution to ≥55°C but ≤100°C, and also preferable to agitate for 20 min or more after addition of the alkali metal sulfate. Furthermore, the solution is preferably conditioned so that the molar ratio of the light rare earth element to the heavy rare earth element becomes 3 or more. <P>COPYRIGHT: (C)2013,JPO&INPIT |
