The objective of this project was to compare the effect of a selective flotation frother (MIBC) and powerful frothers (DEMPH and DF-1012) on bubble size and foamability in water and in brine. In water, the bubble size is clearly reduced by flotation frother which prevent bubbles from coalescing. The present study shows that the bubbles do not coalesce in brine and, therefore, frothers do not affect the sized of bubbles in brine. The dynamic foamability index measured in brine is much lower than that in water for weak frothers (e.g. MIBC); for both tested strong frothers the foamability measurements in brine reveal formation of meta-stable foams.