Abstract Tungsten, considered a specialty metal, plays a remarkable role in the development of new tools for aerospace, defense, and other trending technological applications. However, due to its high supply risk index, extensive research on alternative sources for recycling has been conducted. In this contribution, the recovery of tungsten from spent electroless nickel solutions as a secondary metal source for this element is described for the first time. Laboratory experimental procedures are presented, involving the acid-promoted tungstite precipitation where the oxidizing properties of nitric acid demonstrated to play a key role in the tungsten oxide product formation. Further reaction with calcium hydroxide allows the rapid isolation of high-purity scheelite (>98%) in good yield. This protocol serves as a model for a tungsten recovery pilot plant scale-up, where other reactions for the preparation of additional tungsten derivatives, employing scheelite as starting material, can be implemented.

中文翻译：

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用废化学镍溶液生产白钨矿作为替代钨回收源

摘要 钨，被认为是一种特殊金属，在航空航天、国防和其他趋势技术应用的新工具的开发中发挥着显着的作用。然而，由于其高供应风险指数，已经对回收的替代来源进行了广泛的研究。在这篇文章中，首次描述了从废化学镍溶液中回收钨作为该元素的二次金属来源。介绍了实验室实验程序，涉及酸促进钨石沉淀，其中硝酸的氧化特性证明在氧化钨产品形成中起关键作用。与氢氧化钙的进一步反应允许以良好的收率快速分离高纯度白钨矿 (>98%)。