Abstract: The present work deals with the effect of N(2aminoethyl)dodecanamide on the flotation behavior of aluminosilicates(including kaolinite, illite and pyrophyllite). It was found that the N(2aminoethyl)dode canamide made the recovery of pyrophyllite more than 97.7％. The collecting power of N(2aminoethyl) dodecanamide for kaolinite and illite are relatively weak, generally, the recovery does not go beyond 82％. The pulp pH has less effect on the recovery of aluminosilicate. In the acidic range,the surfactants were adsorbed on mineral surface mainly by electrostatic forces, while, in the alkaline pulp, they were adsorbed mainly by way of hydrogen bond. The FTIR spectra give a proof of hydroxyl groups on the aluminosilicates surface. The Zeta potential is negative over a wide pHrange. SEM photographs(×15000) of aluminosilicate particles show that pyrophyllite particle take the shape of thin slice, but kaolinite and illite are particles with irregular appearance.

Key words: N-(2-aminoethyl)-dodecanamide, Aluminosilicate, Flotation, 　Hydrogenbond, Adsorption