Bauxite is a sedimentary rock that is rich in alumina, the base for making aluminum. It is generally easy to mine because it is found near the surface of terrain. However, the process for separating the alumina from the other base elements in bauxite can be environmentally unfriendly.
For bauxite refining the Bayer process—that separates the valuable alumina from the surrounding materials involves caustic materials, high temperatures, and pressure. The resulting waste stream, especially from bauxite, is a slurry generally known as “red mud,” that must be kept in holding ponds until the toxicity of the solution is neutralized. Red mud can have a severe environmental impact if holding ponds fail and the solution is released into local waterways.
To minimize the production of red mud and extract more alumina at the beginning of the process, ST Equipment & Technology’s tribo-electrostatic belt separator can be used prior to the Bayer process to remove silicates from bauxite, and increase available alumina from finely ground bauxite. The result is the recovery of a greater amount of alumina, lower use of expensive caustic soda, a reduced need for red mud holding ponds, and a reduction in the amount of energy needed during the Bayer process to heat and pressurize the mined materials.
ST Equipment & Technology’s belt separator is also extremely energy efficient, can process a large amount of feed material per hour, and is small enough to be used on-site at refining operations, reducing shipping costs.
In other words, you’ll be saving money on processing, making more money on the additional alumina you’ll be pulling from the feed material, and you can present your mining company as an eco-friendly operation, which goes a long way toward building a good reputation with the locals.