Flotation, << floh TAY shuhn, >> process is used to separate valuable minerals from each other or from other minerals with which they are mixed. In this process, the material that contains the minerals is first crushed and ground fine. It is then put into a tank called a flotation cell that contains water and certain chemicals called flotation reagents. These chemicals form a water-repellent film around the particles of one of the minerals, but not around the others.
To separate the minerals, the liquid in the flotation cell is stirred and air is piped in. Air bubbles cling to the water-repellent particles, causing them to rise to the top and float. For collection, the bubbles carrying the minerals must be trapped in a froth on the surface. A frothing agent, such as pine oil or eucalyptus oil, is added to create the froth. The froth with the mineral-laden bubbles can then be skimmed off. The other minerals or materials remain in the liquid.
