This study is focused on the extraction and recovery of gold and silver from thiourea acid leaching ore liquors. In a first step, extraction is performed using di(2-ethylhexyl)dithiophosphoric acid (D2EHDTPA). The extraction of gold and silver takes place simultaneously, allowing the removal of both metals in a single equipment under the same operational conditions. Each metal is then recovered by selective stripping, using NH₄SCN/H₂SO₄ solutions to separate the silver from the D2EHDTPA. Such treatment is followed by a second stripping system, where a (NH₄)₂S₂O₃ solution is used to recover gold. A mathematical model is developed to represent all the operations in the process flowsheet. Through this model, it is predicted that, for properly selected operating conditions, recoveries higher than 99.9% for silver, gold and thiourea (to be recycled) can be obtained. The data predicted by the model has a good fit with previously reported experimental data. The proposed process is a more sustainable approach, in comparison with the traditional process involving cyanide, and has potential to be economically feasible.

这项研究的重点是从硫脲酸浸矿液中提取和回收金和银。在第一步中，使用二（2-乙基己基）二硫代磷酸（D2EHDTPA）进行萃取。金和银的提取同时进行，因此可以在同一操作条件下在一台设备中同时去除两种金属。然后使用NH ₄ SCN / H ₂ SO ₄溶液通过选择性汽提来回收每种金属，以从D2EHDTPA中分离出银。这样的处理之后是第二汽提系统，其中（NH ₄）₂ S ₂ O ₃溶液用于回收黄金。建立了数学模型来表示过程流程图中的所有操作。通过该模型，可以预测的是，对于适当选择操作条件下，回收率高于为银，金和硫脲（被回收）99.9％可以得到。该模型预测的数据与先前报告的实验数据非常吻合。与涉及氰化物的传统工艺相比，该工艺是一种更具可持续性的方法，并且具有经济上的可行性。