In this research, a recycling process for palladium using “dry aqua regia,” which consists of iron(III) chloride–potassium chloride, was proposed. Palladium was dissolved in “dry aqua regia,” and the dissolved palladium was recovered by leaching with potassium chloride solution with added ammonium chloride and nitric acid. Palladium was almost completely dissolved in 3 h at 600 K, and the recovery ratio of dissolved palladium was up to 80%. In addition, the dissolution of palladium in coexistence with platinum and the dissolution of platinum-palladium alloy by “dry aqua regia” were also tested. The dissolved palladium and platinum were separated and recovered by solid–liquid separation technique using the difference in solubility of their compounds in potassium chloride and sodium chloride solutions. As a result, pure compounds of each element were recovered. This result suggested the possibility of using “dry aqua regia” for the separation of platinum-group metals.

Graphical Abstract

中文翻译：

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考虑到用过的自动催化剂的回收利用“干水族”的钯回收基础研究

在这项研究中，提出了一种使用“干王水”的钯回收工艺，该干王水由氯化铁（III）-氯化钾组成。将钯溶解在“干燥王水”中，并通过添加氯化铵和硝酸的氯化钾溶液浸出，回收溶解的钯。钯在600 K下3 h几乎完全溶解，溶解钯的回收率高达80％。另外，还测试了钯与铂共存的溶解以及“干王水”对铂-钯合金的溶解。通过固液分离技术分离溶解的钯和铂，并利用其化合物在氯化钾和氯化钠溶液中的溶解度差异来进行回收。因此，回收了每种元素的纯净化合物。该结果表明使用“干王水”分离铂族金属的可能性。

图形概要