A FLOW-SHEET APPROACH TO THE ISSUE OF PYRITE-RICH TAILINGS

The present work is meant to evaluate the effect of separation of pyrite-rich fractions of tailings for both economic and environmental benefit. The project was focused on two tailing dumps in the former mining and processing site of Reps (Northern Albania). In-situ and laboratory investigations were conducted (i) to outline the main environmental characters of the selected dumps with an emphasis on heterogeneities within and between dumps and (ii) to evaluate the concentration potential of commodities, namely pyrite, from the waste materials. Mineralogical and geochemical data were collected and the Acid-Base account procedure was performed in order to evaluate the Acid Drainage (AD) potential of the selected tailing dumps. A quantitative flowsheet was devised in order to relate quantitatively the available information on processing and the collected data. Gravity separation tests were performed by a water shaking table method and the re-processing potential was evaluated through mineralogical and geochemical analyses. The site is subject to long-lasting (103 years) AD processes with significant release of Potentially Toxic Elements into the local environment. Two different classes of tailings have been recognized, based on the sulfide S content. The high- sulfide (S>10%) content material (hS) accounts for about 82% of the total potential H2SO4 production, despite it represents less than 20% of the whole tailing discard. On the contrary, the remnant low- sulfide (S