Froth flotation is a process using air bubbles to separate materials based on their relative affinity to water. Bubbles carry reagent and hydrophobic materials to the top of a tank where they can be removed. The process also widely used in medical science. In some schools of alternative medicine, flotation therapy may be used as a tool to help clients achieve specific goals, and people also use flotation tanks more generally for meditation and relaxation.
In Medical Treatments
Researchers believed that the brain would sink into a state of semi-consciousness if the body was suspended in warm water in a dark, soundproofed room. Originally, flotation tanks were designed for sensory deprivation experiments in the 1950s. Early studies seemed to suggest that this was, in fact, the case. As research subjects relaxed in the flotation tanks, their brain waves changed, until they ultimately reached a state of deep relaxation which is very close to unconsciousness.
In a flotation therapy session, the client will be asked to strip and shower before entering the tank. Many clients like to wear swim suits for modesty. The therapist may discuss the experience with the client before he or she enters the tank, and the client is usually asked to remove all jewelry and other distractions. Ear plugs may be provided to keep water out of the client’s ears and to keep sound pollution to a minimum.
Air bubbles are introduced at the base of the tank. The tendency of the hydrophobic materials to adhere to the bubbles carries them up to the surface of the tank. At the top, the bubbles carrying their load of minerals, or froth, are skimmed off. The segregated compounds, which are solid, go through a further processing step to separate them from the air bubbles and the reagent residue. The residual hydrophilic material mixed with water in the tank, also known as gangue, is drained away. Potassium amyl xanthatre is a most powerful chemical reagent used as collector of Xanthate, widely used in the flotation treatment of sulfide ores,especially for the flotation treatment of Cu-Ni compound sulfide ore.
Many factors affect the quality of separation; these include the rate of flotation, the size of the ore particles, the density of the ore and water mixture, and the amount of air used. A recent use of the process separates ink from recycled paper. The mining uses of froth flotation include the separation of many different types of compounds including sulfides, silicates, phosphates, coal, and iron ore. Reagents or surfactants are carefully chosen to produce exactly the separation effect desired for a particular ore or combination of ores.