A Comparison of Alternative Reagents to Cyanide as Lixiviants Gold: A review

El oro es un metal de gran interés en áreas como la ingeniería, la joyería y las finanzas, es por ello por lo que hay un gran interés en la investigación de técnicas de recuperación de oro de diversas fuentes, como los minerales o los desechos electrónicos. Existen múltiples solventes que son capaces de formar complejos con el oro, como por ejemplo el iodo, tiourea, tiosulfato, tiocianato, glicina y el cianuro; este último siendo el más utilizado a escala industrial. En el presente artículo se revisan los reactivos más utilizados para la lixiviación del oro analizando su panorama mediante herramientas de mapeo bibliográfico en los últimos 5 años, usando estas herramientas se concluye que a pesar la relevancia con la que cuentan los sistemas libres de cianuro para la disolución de oro, el cianuro seguirá siendo relevante tanto industrialmente por sus ventajas operativas y económicas como en materia científica buscando formas de mitigar sus efectos dañinos.Gold is a metal of great interest in areas such as engineering, jewelry and finance, which is why there is great interest in research into gold recovery techniques from various sources, such as minerals or electronic waste. There are multiple solvents that are capable of forming complexes with gold, such as iodine, thiourea, thiosulfate, thiocyanate, glycine and cyanide; the latter being the most used on an industrial scale. In this article, the most used reagents for gold leaching are reviewed, analyzing their panorama using bibliographic mapping tools in the last 5 years. Using these tools, it is concluded that despite the relevance of cyanide-free systems for the dissolution of gold, cyanide will continue to be relevant both industrially due to its operational and economic advantages and in scientific matters seeking ways to mitigate its harmful effects

Leaching Chalcopyrite with an Imidazolium-Based Ionic Liquid and Bromide

The unique properties of ionic liquids (ILs) drive the growing number of novel applications in different industries. The main features of ILs are high thermal stability, recyclability, low flash point, and low vapor pressure. This study investigated pure chalcopyrite dissolution in the presence of the ionic liquid 1-butyl-3-methylimidazolium hydrogen sulfate, [BMIm]HSO4, and a bromide-like complexing agent. The proposed system was compared with acid leaching in sulfate media with the addition of chloride and bromide ions. The results demonstrated that the use of ionic liquid and bromide ions improved the chalcopyrite leaching performance. The best operational conditions were at a temperature of 90 °C, with an ionic liquid concentration of 20% and 100 g/L of bromide

Analysis of the Behavior of As and Pb during the Pretreatments Applied to a Jarosite Residue for the Recovery of Gold and Silver

The recovery of valuable metals from jarosites is a topic of great relevance regarding the implementation of the circular economy; however, these materials also contain metals such as arsenic and lead, which are harmful to health and the environment. Considering these factors, it is important to monitor these metals at each stage of treatment used to recover the valuable metals. In the present work, the behavior of As and Pb was assessed during the pretreatment conducted on a jarositic residue using direct zinc leaching (DLR), as well as leaching in cyanide and cyanide media with glycine. It was found that when no DLR pretreatment was performed, As and Pb naturally dissolved in the cyanide-leaching medium at concentrations of 34.08 mg/L and 99.12 mg/L, respectively. When an alkaline treatment was conducted on the residue (DLR-AH), it was found that there was no presence of As and Pb in the cyanidation solution, while in the case of the cyanide solution with glycine, we observed 83.35 mg/L of As and 213.63 mg/L of Pb. During the oxidizing alkaline hydrothermal treatment (DLR-AHO), 27.5 mg/L of As and 106.78 mg/L of Pb were detected in the cyanide solution. In the cyanide solution with glycine, there was less dissolution of As and Pb (11.68 and 66.75 mg/L), respectively. Finally, when desulfurization of the DLR was conducted prior to the DLR-AHO treatment, the dissolution of As and Pb increased due to the elemental sulfur covering the arsenopyrite and galena particles, so that, when removed, these were more susceptible to pretreatment and cyanidation

Memoria del primer foro sobre logros, problemas y propuestas de los cuerpos académicos de educación y humanidades de la Universidad Autónoma del Estado de México

Motivados por el interés de dialogar nuestras preocupaciones cotidianas en torno al quehacer académico en la Universidad, e impulsados por la inquietud de compartir puntos de vista y apreciaciones acerca de la forma en que organizamos colectivamente el trabajo académico (en especial, de investigación) en los diferentes espacios de especialización disciplinaria e interdisciplinaria en los campos de las Ciencias de la Educación y las Humanidades, asistimos a la convocatoria para reflexionar qué tanto hemos avanzado como verdaderos equipos de trabajo (sobre todo en lo relativo a la investigación) y cuánto aún nos queda por hacer, a fin de coordinar esfuerzos individuales y sumar capacidades en proyectos y actividades comunes a cada cuerpo académico