Coeur Manquiri, a wholly owned subsidiary of the US-based Coeur d’Alene Mines Corporation, recently purchased three MC Press filter presses for its San Bartolome mine in Potosi, Bolivia. Located at the base of the Cerro Rico Mountain (Andes Mountains) near Potosi, Bolivia, the San Bartolome mine is one of the world’s newest and largest pure silver mines. With a projected 14-year mine life, San Bartolome has proven and probable reserves of 120 million ounces of silver within gravel deposits at the base of the mountain. The mine produced 7.5 million ounces of silver in 2009, its first year of production. Its mountaintop location and limited available land for dewatered material made dry stacking the most viable storage option. The dewatering filter presses will allow improved dry stacked tailings management on site. Mechanical and chemical processes are used to extract the desired product from the run of the mine ore and produce a waste stream known as tailings. Dewatering tailings to higher degrees than paste produces a dry cake. These unsaturated tailings are usually hauled by truck or via conveyor to a tailings deposit where they are spread and compacted. Known as “dry stacking”, this stable form of storage requires a smaller footprint, is ideal for sloped terrain, and is generally easier to reclaim at the end of mine life. Coeur Manquiri also uses J-Press filter presses from Siemens at the silver recovery plant. They were installed years ago as part of the Merrill-Crowe process, which is a zinc dust precipitation method used to separate silver from a cyanide solution.
