Bubble Attachment in Flotation

THE OBJECT of this paper is twofold: (1) To analyze the forces that cause air bubbles to spread on mineral surfaces in the flotation process; and (2) To develop a rational expression that will serve as a criterion of the floatability of minerals, to the end that the efficiencies of various flotation reagents can be accurately compared. Heretofore, the subject of the spreading of air bubbles has been dismissed with the statement that the surfaces of minerals on which bubbles spread are water-repellent. Imperfect understanding of the forces involved has led to the use, hitherto, of various erroneous formulas for the calculation of the comparative effectiveness of flotation reagents.