Abstract: This is an essay in the field of mineral processing engineering. In this study, sodium palmitate, sodium oleate and sodium linoleate were applied as collectors for the flotation of Ca²⁺-activated quartz. Results indicate that the three different sodium fatty acids have different flotation performances for Ca²⁺-activated quartz. It was found that the sodium linoleate was a better collector for collecting Ca²⁺-activated quartz than sodium oleate and sodium palmitate. To understand the different flotation behaviors of the three fatty acids, a comprehensive investigation has been conducted through zeta-potential measurements, FTIR characterization, free Ca²⁺ concentration measurement, surface tension measurement, and quantitative adsorption determination. It was found that the addition of sodium fatty acids decreased (more negatively charged) the zeta potentials of Ca²⁺-activated quartz, suggesting the adsorption of sodium fatty acids occurred on the collophanite surfaces. Characterization by FTIR spectra indicates that the calcium fatty acids are generated in the mineral pulp. The free Ca²⁺ concentration measurement and the surface tension measurement show that the sodium linoleate is not as sensitive to Ca²⁺ as sodium oleate and sodium palmitate, the good ability of resistance to hard water of sodium linoleate should be the reason that the sodium linoleate could float Ca²⁺-activated quartz better.