PREDICCIÓN DE DRENAJE ÁCIDO DE MINA, JALES DE LA MINA LA PRIETA, CHIHUAHUA, MÉXICO

Abstract

The La Prieta mine, Chihuahua, Mexico, was intensively exploited (silver, lead and copper) from colonial times until its closure; consequently, large quantities of tailings produced by metallurgical processing accumulated. These tailings can produce acid mine drainage due to oxidation and hydrolysis reactions. With the objective of predicting if tailings can generate acid drainage, tailings samples were characterized and the possibility of generating acidity was investigated. The pH values found were slightly alkaline (7.88.4). On the other hand, sulfates and total sulfur were determined by turbidimetric and infrared methods, respectively. It is worth mentioning that total sulfur was below the limit of detection of the Leco S-144DR equipment and sulfur concentrations in the form of sulfates were very low. The mineralogical characterization showed that pyrite was found in only three samples and in low percentages. The calcite and dolomite minerals present in the skarn type deposit were involved in the neutralization of acid mine drainage and the decreased mobility of most toxic metals and metalloids.