Treatability Study of Acid Mine Drainage at Morro da Mina Mine, Brazil

摘要

Jar testing was conducted on mining influenced water (MIW) collected from Ipe Lake at the Morro da Mina mine to determine the most effective and efficient way to remove contaminants of concern (COCs) from the Ipe Lake. The COCs from the lake water include: pH, total dissolved solids (TDS), sulfate, copper, manganese, and nickel. The bench scale studies were performed at the Colorado School of Mines (CSM) and the pilot scale phase was performed at mine site. Pilot scale plant was constructed to scale up the results obtained from bench scale work. The laboratory scale results demonstrated that the most effective and efficient way to remove the majority of the COCs from the lake water should be by using lime addition system, with subsequently treatment of this water by an open crushed channel filled up with pyrolusite (MnO_2) for metal polishing. Jar test result shown that added a Lime dose of 0.3 grams/L to the Lake Water for a minimum mixing time of 15 minutes, and a settling time of 72 hours, all of the COCs, with the exception of sulfate were decrease to levels below Brazilian maximum concentration for receiving waters. These results have been confirmed in pilot scale.