Flotation (flotation of materials using foam) is a process for separating hydrophobic from hydrophilic materials, which was first used in the mining industry, but nowadays it is also widely used in the recycling and wastewater treatment industries. Flotation has played a very important role in the processing and extraction of sulfide ores and it has made it possible to economically recover precious metals from minerals with a much lower grade than in the past, in addition to mechanized extraction.