Flotation performance and adsorption mechanism of a new collector 2-(carbamoylamino) lauric acid on quartz surface

To investigate the effect of an amide group on the flotation performance of a fatty acid collector, a novel surfactant, 2-(carbamoylamino) lauric acid (2-CLA), was synthesized by introducing an amide group to the alpha-C position of lauric acid (LA). Flotation tests on pure quartz indicated that under suitable flotation conditions, pH of 11.5, 50 mg/L of CaCl2, and 100 mg/L of 2-CLA, the quartz recovery of 2-CLA flotation was above 98% and almost unaffected by pulp temperatures between 10 degrees C and 40 degrees C. For comparison, the quartz recovery of LA flotation was only 80% at high temperatures above 35 degrees C. The adsorption mechanisms of 2-CLA on the quartz surface were investigated using Fourier transform-infrared spectra, zeta potential measurements, and X-ray photoelectron spectroscopy analysis, which demonstrated that 2-CLA was adsorbed onto the surface of activated quartz by strong chemisorption and hydrogen bonding. This study also revealed that an additional amide group at the a-C position of fatty acids enhanced both the chemical bonding interaction and hydrogen bonding synergy during the adsorption of 2-CLA on the activated quartz surface.