Flotation behavior and mechanism of α-bromododecanoic acid as collector on the flotation separation of spodumene from feldspar and quartz

Abstract

The flotation behaviors of α-bromododecanoic acid (α-BDDA) on the separation of spodumene from feldspar and quartz with Ca(II) as activator were investigated through single mineral and artificial mixed ore flotation experiments. Under the condition of α-BDDA concentration of 1.79 mmol/L, Ca(II) concentration of 0.51 mmol/L and pH 7.1, the recovery of spodumene, feldspar and quartz was 83.44%, 7.83% and 1.38% respectively in single mineral flotation experiments, and a concentrate with recovery of 75.57% and Li2O grade of 5.77% was obtained in a ternary mixed ore (Li2O grade of 1.71%) flotation experiment. AFM, zeta potential measurements, FT-IR, XPS, species distribution and first-principles calculation were carried out to analyze the interaction mechanism between the reagents and the minerals. It was found that the amounts of α-BDDA adsorbed on spodumene were much higher than those on feldspar or quartz, which led to the higher recovery of spodumene. The main component of Ca(II) at pH 7.1 was Ca2+, which was adsorbed on spodumene, feldspar and quartz by both electrostatic attraction and chemical bond. The collector α-BDDA was adsorbed on Ca2+ activated spodumene, feldspar and quartz by chemisorption. Ca on the surface of the activated spodumene was the main active site to react with α-BDDA. In the presence of α-BDDA, the bond length of Ospodumene — Ca increased and was close to that of Oα-BDDA — Ca, indicating the conjugated effect among the O atom on spodumene, Ca2+ and the O atom in α-BDDA. The collector α-BDDA was an effective spodumene collector with high selectivity, which could effectively separate spodumene from feldspar and quartz.