Abstract:In order to find out the effect of Ca2 on the flotation behavior and adsorption characteristics of coarse-fine molybdenite. The mechanism of Ca2 and coarse-fine molybdenite was explored by means of pure mineral flotation tests combined with Zeta point test, Ca2 solution chemical and XPS analysis. The results show that the Ca2 in ore slurry will significantly weaken the molybdenite flotation effect, and the influence of fine grain is more obvious；In the concentration of 1.0x10-2mol/L Ca2 solution, when pH<12.39, it exists mainly in the form of calcium ion and calcium hydroxide ion，Further exclusion of the factors affecting the decrease of molybdenum recovery due to Ca(OH)2 sedimentation on the surface of pure minerals；The absolute value of the surface potential of molybdenite that has been treated with Ca2 has become significantly smaller, demonstrating that Ca2 has a strong adsorption on the molybdenite surface. In addition, the peak content of Ca-MoO4 on the surface of fine-grained molybdenite was 1.15 times higher than that of coarse particles by the peak separation treatment of XPS spectrum. Compared with the coarse particles, the calcium ions are more obvious for the reduction of the floatable ore of the fine particles of molybdenite. It is due to the chemical adsorption of Ca2 on the “edge” surface of molybdenite，forming a hydrophilic film of CaMoO4 on the surface, which reduces the floatability of the minerals.