In September 2021, AngloGold Ashanti’s Serra Grande mine became the first mine in Brazil to implement a 100% filtered tailings disposal system. This means that, at the end of ore processing, all the tailings generated go through a drying process after which it is placed in filtered tailings stacks. Wet tailings are no longer sent to the tailings storage facilities.
“These pioneering interventions are a source of great pride for the entire Serra Grande team,” says Vinicius Assis, Serra Grande’s Senior Manager of Metallurgy. “It took a great deal of dedication and hard work to reach this goal, and we are pleased to offer peace of mind to our local communities and leave a positive, lasting legacy for future generations.”
Filtered tailings have the same volume requirements as conventional TSFs, but don’t have a water reservoir. This greatly improves their stability.
In order to dry the tailings, the team had to restore an old vacuum filter area in Serra Grande’s metallurgical plant. By the end of 2021, an additional three new filters had been acquired and installed in the new filtration plant, which will help to enhance the project in the future.
The internal basin of the retired Serra Grande TSF will be filled with dried tailings and soil before it is closed entirely. “The TSF basin will go through this transition over a period of four years, and will later be integrated into the surrounding environment through rehabilitation and revegetation processes,” explains Geotechnics Specialist Lilian dos Santos.