The use of centimicron bubbles

Because of strong surface retardation of centimicron bubbles, there is unlikely to be detachment of attached particles. 

Because of strong retardation of centimicron bubbles, a substantially lower amount of cationic surfactant of high surface activity is needed (cf. Section 10.13). 

It is difficult to produce centimicron bubbles. Flotation machines generate mainly larger size bubbles, and bubbles of smaller size are obtained in air-dissolved flotation and electroflotation. 

Because of strong surface retardation and weak hydrodynamic pressing forces cationic surfactants are required. 

An evaluation of the possibility of overcoming the electrostatic barrier by hydrodynamic pressing forces in the transient hydrodynamic regime has not been carried out, but it is clear that the situation will be much better at strong surface retardation than in the Stokes regime (cf. Section 10.5.2). 

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