Study on flotation separation of barite fluorite by citric acid under new collector system

Barite and fluorite have similar physical and chemical properties and floatability, and traditional flotation reagents are difficult to effectively separate these two minerals. In order to realize the effective separation of the two minerals, a new system with high selectivity and strong collecting ability, α-BLA ( bromododecanoic acid) system, was selected in this paper. The system can be applied at a wide range of pH values and can greatly eliminate the interference of metal ions. Therefore, this study selected this stable system to explore the effect of citric acid on barite fluorite flotation, in order to more objectively explain the adsorption mechanism of the agent. The results show that the floatability of the two minerals is quite different under the action of citric acid. Barite concentrate with grade of 81.12% and recovery of 87.74% can be obtained by micro-flotation experiment. On this basis, the interaction mechanism between citric acid and mineral surface was further studied by contact angle test, Zeta potential test, Fourier transform infrared ( FTIR), X-ray photoelectron spectroscopy ( XPS) and density functional theory ( DFT) calculation. The results show that when citric acid reacts on the surface of barite, its adsorption energy increases with the increase of bond number. The reaction on the surface of fluorite produces 3-hydroxyglutaric acid, which transfers a certain amount of electrons to Ca1 and Ca2 ions on the surface of fluorite, enhancing the chemical adsorption of citric acid on the surface of fluorite. This paper provides a theoretical basis and effective guidance for the flotation separation of barite fluorite.