The present study examined a process for precious metal recovery (silver and gold) from difficult minerals which exhibit refractory characteristics to cyanidation and ammonium thiosulfate leaching (low extraction and high consumption of leaching agent). It is well known that mangano-argentiferous minerals are mainly composed of manganese, silver, gold, and iron. In this research, a mineral sample from Monte del Favor mine, located in Hostotipaquillo, Jalisco, Mexico, was physically and chemically characterized by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), fire assay, and atomic absorption spectroscopy (AAS). Two-stage leaching was carried out: first to eliminate manganese from the sample using sodium sulfite (Na 2 SO 3 ) as a reductive reagent and sulfuric acid (H 2 SO 4 ) and a second stage to dissolve silver and gold with sodium hypochlorite (NaClO) and hydrochloric acid (HCl); the results show extraction around 96% for Mn and 98.73% and 83% of Ag and Au, respectively. The usefulness of high acidity and Na 2 SO 3 to obtain good results in Mn and Ag leaching is discussed along with the roles that HCl and NaClO play in the dissolution of Ag and Au values.

中文翻译：

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用次氯酸钠和盐酸溶解难熔矿物（锰-含银）中的银和金

本研究考察了一种从难处理的矿物中回收贵金属（银和金）的工艺，这些矿物表现出对氰化和硫代硫酸铵浸出（浸出率低，浸出剂消耗量高）的难处理特性。众所周知，锰银矿物主要由锰、银、金和铁组成。在这项研究中，来自位于墨西哥哈利斯科州 Hostotipaquillo 的 Monte del Favor 矿的矿物样品通过 X 射线粉末衍射 (XRPD)、扫描电子显微镜 (SEM)、能量色散 X 射线光谱学进行了物理和化学表征(EDS)、火分析和原子吸收光谱 (AAS)。进行了两阶段浸出：首先使用亚硫酸钠 (Na 2 SO 3 ) 作为还原剂和硫酸 (H 2 SO 4 ) 从样品中去除锰，然后使用次氯酸钠 (NaClO) 和盐酸 (HCl) 溶解银和金; 结果表明，Mn 的萃取率约为 96%，Ag 和 Au 的萃取率分别为 98.73% 和 83%。讨论了高酸度和 Na 2 SO 3 在 Mn 和 Ag 浸出中获得良好结果的有用性以及 HCl 和 NaClO 在 Ag 和 Au 值溶解中的作用。