| 摘要 |
<p>PURPOSE:To recover efficiently a fluorescent substance and high-quality glass from parts coated with a fluorescent coating compound, by grinding the parts of waste household electric appliance, coated with the fluorescent coating compound, treating the ground material with an acid, extracting rare earth elements, adding successively an alkali, nitric acid, and oxalic acid to the extracted solution prepared by solid-liquid separation and precipitating the fluorescent substance and the high-quality glass again. CONSTITUTION:Waste electric appliances are roughly disassembled, parts coated with a fluorescent coating compound (e.g., panel glass of Braun tube, etc.) are selected, and ground. Then, the parts are treated with an acid such as nitric acid, to extract rare earth elements. The extracted solution is subjected to solid-liquid separation, and an alkali is added to the extracted solution, to precipitate the rare earth elements. The solution is further subjected to solid-liquid separation, precipitate is redissolved in nitric acid, precipitated again with oxalic acid and dehydrated to recover a fluorescent substance.</p> |
