ON THE KINETICS OF FROTH FLOTATION

The problem of froth flotation kinetics is treated as a transport phenomenon. Two coupled equations of balance are formulated which concern the particles attached upon the bubbles and the free particles in the pulp. The combined equations are solved and an analytical expression for the recovery as a function of time is obtained. The correctness of the theoretical derivation is checked by way of laboratory flotation experiments with glass ballotini (160-200 μm) in a wide pH range (pH 3-13) and collector dodecylamine hydrochloride (C12H25NH2, HCL). The authors demonstrate that the recovery of glass possesses a well-defined maximum at pH 11.2. The cause of this maximum is sought for in the strong dependence of the three-phase contact (TPC) rate of expansion on pH. The role of the kinetic characteristics: time of TPC formation and TPC expansion rate are discussed with the help of the well-known criterion of floatability "attachment forces greater than the detachment forces" which is applied locally in any moment of the particle-bubble interaction. © 1990.