Flotation

Flotation, industrial process used to separate valuable mineral compounds from low-grade ores. The ore is pulverized into minute particles and mixed with water. Then special chemicals, called flotation reagents, are added to prevent the water from wetting those substances to be extracted. When air is sprayed into the mixture a foam develops and carries to the surface the dry particles, which are then easily removed. The waste materials sink to the bottom of the mixture.