Separation of emulsifiable oil from a flotation solution by surface tension control

The oil flotation behaviour of emulsifiable oil was studied using N-octyl-N -benzyl-N-mcthylglycine (OBM) as the collector and heavy alkylate naphthale ne sulphonates (HNS) as the Je-emulsifier. The study showed that the surfac e tension has an effect on oil recovery. The interfacial tension at the air /water interface was controlled by the use of an alcohol such as ethanol, n -propanol and n-butanol and compared with the collector when used alone in froth flotation. The adsorption of the collector from the aqueous solution was investigated by measuring the surface tension as a function of concentr ation at different temperatures. Surface properties, in particular the crit ical micelle concentration (CMC), the effectiveness of surface tension redu ction (ITCMC), efficiency (P-C20), the maximum surface excess (Gamma (max)) and the minimum surface area (A(min)), were measured at temperatures of 25 , 35 and 45 degreesC, respectively The results were discussed in terms of t he adsorption isotherm and surface properties of the collectors at the solu tion/air interface.