Pre-concentration of gold ore for characterization of forms of occurrence and mineral associations

The technological and mineralogical characterization of gold ores faces several obstacles due to the low contents, occurrence in micrometric grains, possible nugget effect and anomalous occurrence. In order to increase the concentration in content and mass of the phases of interest and gold-bearing minerals, pre-concentration operations have been applied in studies to characterize the forms of occurrence and associations of gold by analyzing scanning electron microscopy images. The use of mineral separation using heavy liquids and hydroseparation systems, such as the Mozley table and elutriation, allows the concentration of high specific weight minerals in a more agile operation, with high recovery of the minerals of interest and with greater ease of standardization and control operational. In this study, the densitary pre-concentration was evaluated for three samples of gold ores of different grades by elutriation, heavy liquid and Mozley table. Elutriation was the procedure that presented the best performance in relation to gold recovery and enrichment in the five granulometric ranges studied. (author)