| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for refining an Rh solution containing one or more kinds of impurities selected from heavy metals and alkaline-earth metals, and Ag. <P>SOLUTION: In the method for refining an Rh solution, alkali is added to a hydrochloric acid aqueous solution of Rh containing one or more kinds of impurities selected from heavy metals and alkaline-earth metals, and Ag, so as to regulate its pH to 7 to 12, the neutral precipitates in which Rh and the other components are precipitated is filtered away, the amount of the hydrochloric acid to be added is regulated in such a manner that Cl/Rh, the molar ratio of Cl to Rh upon redissolution with hydrochloric acid reaches 3 to 4, the solution heated at≥90°C is cooled and filtered, Ag is removed as precipitates, and thereafter, the same is extracted with DEHPA [Di(2-ethylhexyl)phosphonic acid]. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
