Froth Flotation Process

The method is extensively employed for the concentration of Sulphide ores. The process is based on the principle of preferential wetting of ore particles by the oil and gangue by water.

The impure crushed ore is taken in the big tank provided the resulting mixture is agitated vigorously by passing compressed air through a perforated pipe. The ore particles are preferentially wetted by oil which rises up to the surface with froth or foam formed by the oil and air. The gangue impurities being wetted by water settle to the bottom of the tank. The foam gets transferred to the other side of the tank where it slowly subsides. It is transferred to another tank and is repeatedly washed with water to recover are particles free from impurities. Sometimes other substance known as Collectors are also added. These substance increases the binning properly of ore particles and foam. The commonly used collectors are Ethyl Xanthate and Potassium Ethyl Xanthate.