Froth flotation process is used to separate hydrophobic materials from hydrophilic materials. Apart from its major application in processing ores containing sulfides, carbonates and oxides prior to further refinement for extracting metals, the froth flotation process is used in industries like waste water treatment and paper recycling etc. Oil is removed from the waste water effluents of oil refineries, petrochemical and chemical plants and natural gas processing plants etc. by using this technology. Similarly hydrophobic contaminants like printing ink and stickies are removed from the recycled paper by froth flotation process.