The substance added in water in the froth flotation process is:

Sulphide ores respond best to this method. It is based on the various ways that water and pine oil wet the ore and gangue particles. Oil wets the ore, while water wets the impurities. The froth and ore particles rise to the surface after being adsorbed on potassium or sodium ethyl xanthate (as collector). The foam is stabilised using a froth stabiliser (cresols, aniline).