ABSTRACT
Foams formed by typical flotation frothers belong to transient unstable foams. In flotation, froth is the phase in which particles of a useful material is concentrated and then separated from the pulp by continuous skimming-off its top layer. Frothers applied in flotation should ensure formation of a foam layer just stable enough to enable the concentration and additional upgrading to occur without producing a concentrate which will not rupture quickly outside the flotation machine. Increase of the average water content in the whole foam volume is connected with the fact that when the gas velocity increases then the total volume of the foam formed under steady state conditions increases, too. Water content in foam is an important parameter that determines additional upgrading in froth layer and the amount of water skimmed-off with the concentrate. The direct method was elaborated for measurements of liquid content in wet foams formed from solutions of flotation frothers under steady state conditions.
