Abstract: The flotation behavior of cervantite with dodecylamine (DDA) was studied. The results show that the recovery rate of cervantite reaches more than 90% in the pH range of 2. 0 to 8. 0. But it sharply decreases in the pH range of 8. 0 to 10. 0. When pH〉 10, DDA has little collecting capacity on cervantite. The flotation solution chemical analysis of dodecylamine indicates that dodecyl-amine cations are the main components of the cervantite collector. The electronic structures of cervantite crystals and dodecylamine ions and molecules were studied using the density functional theory. The adsorption behaviors of dodecylamine ions, dodecylamine mole-cules, and water molecules were simulated. It is found that the adsorption energy order of these adsorbents on cervantite surfaces is DDA 〉 H₂ O 〉 DDA⁺. DDA⁺ can remove hydration films on cervantite surfaces to make cervantite hydrophobic. DDA⁺ adsorbs on cer-vantite surfaces mainly by physical adsorption.