The method utilizing frothers as a flotation reagent, emulsified in water by means of ultrasonic waves of a suitable frequency and intensity, was investigated. The object is to obtain high selectivity for the differential flotation with the lowest economical comsumption of the flotation reagents. By this process, the ore minerals to be required can be collected with high efficiency which is due to the increase of the floating action, even if the reagents are hardly mixing with water, the emulsion can be readily intermixed into the pulp
