| 摘要 |
<p>PURPOSE:To aim at cost reduction in an electron tube by separating a scandium ion selectively through ion exchange after dissolving the residue of an electron emission solution left unapplied to the cathode, and refining it for recovery. CONSTITUTION:The residue of an electron emission solution (a) inclusive of alkaline earth carbonate powder, scandium oxide powder, dust and the like being collected in a vessel 16 of a sprayer 10 is dissolved in nitric acid, and after that, if cation exchange resin is added, a scandium ion is firmly stuck to it, and an alkaline earth metal ion is selectively separated in a state of being weakly stuck. First, the alkaline earth metal ion being weakly stuck to the cation exchange resin is eluted, then the scandium ion is eluted, converting the elute into scandium nitrate, and furthermore into scandium exalate, and this scandium oxalate is refined and converted into scandium oxide. The recovered scandium oxide is reusable as raw material for an electron emission.</p> |
