The behavior of N,N-dipropyl dodecyl amine as a collector in the flotation of kaolinite and diaspore

The flotation behaviors of N,N-dipropyl dodecyl amine (PN) on kaolinite and diaspore, PN exhibits more powerful collecting ability for kaolinite than diaspore. In the pH region of 2–8, the recovery difference values of kaolinite and diaspore are always remarkable, PN is expected to be a good cationic collector to separate kaolinite from diaspore in the pulp of pH < 8. [Display omitted] ► Maximum recoveries of kaolinite and diaspore were about 90% and 50% using PN collector. ► The interaction mechanism between PN and mineral surface was mainly electrostatic. ► PN collector can increase zeta potential of kaolinite a lot more than that of diaspore. The flotation behaviors of kaolinite and diaspore were investigated using N,N-dipropyl dodecyl amine (PN). Maximum recoveries of kaolinite and diaspore were about 90% and 50%, respectively. Both recoveries of kaolinite and diaspore increased with the increasing dosage of PN. On the basis of the zeta potential and FT-IR spectra, the ionization of surface hydroxyl and the isomorphic exchange of surface ions account for the charging mechanisms of surfaces of kaolinite and diaspore. The adsorption mechanism of PN on the surface of two minerals was mainly electrostatic. After reacting with PN, the zeta potential of kaolinite and diaspore both increased, and comparing with the original zeta potentials, potential of kaolinite increased much more than that of diaspore, this can explain why recovery of kaolinite is higher than that of diaspore.