CHARACTERIZATION AND STOICHIOMETRY OF THE CYANIDATION REACTION IN NaOH OF ARGENTIAN WASTE TAILINGS OF PACHUCA, HIDALGO, MEXICO

摘要

The argentian resources of Pachuca, Hidalgo, Mexico have suffered an extensive exploitation, resulting in more than 100 million tons of waste tailings located in several sites around the city of Pachuca and surrounding municipalities. Chemical, mineralogical and granulometric characterization of the waste tailings of Pachuca, Hidalgo, Mexico, was carried out in this work. Characterization results indicate that these argentian wastes contain 56 g Ag ton~(-1), and the silver is present in the forms of metal, argentite and argentian jarosite in a quartz matrix. Stoichiometry of the cyanidation reaction in NaOH media was analyzed, and the following conclusions were obtained: 1) both metal silver and silver present in the form of argentite can be quickly cyanidation, 2) Alkaline decomposition of argentian jarosite is the rate-control step in the cyanidation reaction.