The present invention relates to a method for the flotation of silicates from ores in the presence of a collecting agent and an effective amount of a froth modifier/collecting booster comprising at least one of the compounds of general formula (I) or mixtures thereof: wherein X is C1-C3 alkyl; R′ is straight or branched hydrocarbyl group containing 8 to 22 carbon atoms; n is integer from 2-4; m can vary from 0 to 2 and R′ is X or —(CH2)n-N(X)2, with the proviso that when R′ is —(CH2)n-N(X)2, then m is 1.