disclosed is a process for the concentration of sulfide ore wherein an aqueous slurry of sulfide ore particles are subjected to sulfide ore froth flotation under sulfide ore froth flotation conditions . the improvement in process comprises using an effective amount of a frothing agent selected from the group consisting of : the reaction product of a c 5 - c 10 diol and a c 1 - c 7 carboxylic acid ; the reaction product of a c 5 - c 10 diol and an acrylonitrile ; the reaction product of a c 2 - c 4 alkylene oxide and a c 1 - c 7 carboxylic acid ; the reaction group of a c 2 - c 4 alkylene oxide and a c 5 - c 10 diol ; the reaction product of a c 2 - c 4 alkylene oxide and an acrylonitrile ; and mixtures thereof , the resulting modified alcohol frothing agents have at least one hydroxyl group thereon . the modified alcohol frothing agents of the present invention provide improved flotation kinetics and selectivity in the sulfide ore float .