Abstract The rare earth elements are considered critical metals, due to the risk of supply interruption. The recycling of waste electrical and electronic equipment can be an alternative to supply the rare earth market. Several processes have been developed, and by aqueous media is the most prominent, which makes possible the extraction and separation of elements even in low concentration (traces). As an example of thermal processing, the use of thermodynamic simulations might benefit the metal extraction in hydrometallurgical processing. For this reason, the goal of this work is to evaluate the use of FactSage 7.2 software for the leaching of fluorescent lamp powders by sulfuric acid. The effect of concentration and temperature was evaluated. Results comprise that the thermodynamic software well-predicted the solid phase formed in all residues of leaching experiments – gypsum was predicted by the software and identified in XRD analyses. It demonstrates that FactSage software can be explored for metals extraction in aqueous media, being important for trace-elements extraction. Yttrium extraction reaches up to 95% at 45 °C using H2SO4 2 mol/L.

中文翻译：

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使用计算热力学从含稀土元素的残渣中回收钇

摘要 由于存在供应中断的风险，稀土元素被认为是关键金属。废旧电子电器设备的回收可以替代供应稀土市场。已经开发了几种工艺，其中最突出的是水介质，这使得即使在低浓度（痕量）中也可以提取和分离元素。作为热处理的一个例子，热力学模拟的使用可能有益于湿法冶金加工中的金属提取。出于这个原因，这项工作的目标是评估 FactSage 7.2 软件在硫酸浸出荧光灯粉中的使用。评价浓度和温度的影响。结果包括热力学软件很好地预测了在浸出实验的所有残留物中形成的固相 - 石膏由软件预测并在 XRD 分析中识别。它表明 FactSage 软件可用于在水性介质中提取金属，这对于微量元素提取非常重要。在 45 °C 下使用 H2SO4 2 mol/L 提取钇高达 95%。