Synergistic Flotation Mechanism of Apatite Using Lauric Acid-Lauryl Alcohol Combined Collector

Abstract

To investigate the synergistic effect of fatty alcohols on the flotation performance of fatty acid collectors, a novel combined collector comprising lauric acid and lauryl alcohol was prepared. Flotation results of apatite indicated that the combined collector with 30% lauryl alcohol exhibited the best flotation performance. Under the conditions of pH 9 and a combined collector dosage of 50 mg/L, the flotation recovery of apatite exceeded 99% in the temperature range of 5–45 °C. In contrast, lauric acid alone produced a lower flotation recovery and exhibited strong temperature dependence. Thermogravimetric analyses (TGA) revealed that single lauryl alcohol did not adsorb on the apatite surface, whereas its combined use with lauric acid significantly promoted the adsorption of lauric acid onto apatite. Zeta potential and FT-IR analysis confirmed that the combined collector was strongly adsorbed on the apatite surface. This adsorption process did not involve electrostatic interaction, but attributed to chemical adsorption and hydrogen bonding. Meanwhile, XPS results clearly revealed that intense chemical adsorption occurred between the combined collector and apatite via the formation of Ca–O bonds. Accordingly, the combined collector composed of fatty acid and fatty alcohol achieved efficient flotation of apatite through the synergistic effect of chemical adsorption and hydrogen bonding. The research findings provided a valuable reference for the development of novel combined collectors for apatite flotation.