| 摘要 |
<p>PURPOSE:To realize a decrease in cost of an electron tube by utilizing difference between the quantity of alkaline earth metallic ions dissolving into an organic solvent solution and that of scandium ions dissolving into the organic solvent solution so that recovery of scandium oxide is performed. CONSTITUTION:After residues of an electron emission material solution, with which a cathode has not been coated, are dissolved, a solvent extraction means by an organic solvent solution is used to reversely extract scandium nitrate from the organic solvent solution. Thereafter, scandium oxalate converted from this scandium nitrate is further purified into scandium oxide and recovered. Scandium oxide which is especially expensive, out of residues of the electron emission material solution with which the cathode has not been coated, can be separated and recovered to be reusable as a raw material of the electron emission matter, and so a large decrease in cost of the electron tube can be realized.</p> |
