Flotasyon

Flotasyon, or flotation, is a separation process in which hydrophobic materials are separated from hydrophilic ones. In mineral processing, finely ground ore is mixed with water to form a slurry. Air bubbles are introduced, and surface modifiers render target minerals hydrophobic so they attach to the bubbles and rise to the surface as froth, which can be skimmed off; the remaining material stays in the slurry.

Historically developed in the early 20th century, froth flotation became a central method for concentrating ores, especially sulfide and oxide minerals. The concept has since been extended to other separations, including dissolved air flotation for wastewater treatment and industrial effluents.

Equipment and process: Flotation is carried out in cells, ranging from mechanical to column types. The process includes grinding, slurry conditioning with pH control and reagents, air introduction to form bubbles, and froth removal. Column cells can offer higher purity for fine particles.

Chemistry: The main reagents are collectors (to promote hydrophobicity), frothers (to stabilize bubbles), and modifiers (depressants, activators, and pH-adjusting agents). Common collectors include xanthates for sulfides, while MIBC or similar compounds act as frothers.

Applications: Flotation is used to separate metal sulfides (such as copper, lead, and zinc minerals), various oxides, and coal. It also has roles in recycling and wastewater treatment via dissolved air flotation.

Limitations: Flotation efficiency depends on particle size and mineralogy and may require significant reagents and energy. Environmental considerations include chemical use and tailings management.