Flotation Behavior, Collector Adsorption Mechanism of Quartz and Feldspar-Quartz Systems Using PEA as a Novel Green Collector

A novel green cationic surfactant Poly (propylene glycol) bis (2-aminopropyl ether) (PEA) with multiple amine groups was utilized as a collector for flotation separation of quartz from feldspar-quartz associated ore (FQA) without acid (particularly, HF) and alkali. The collecting performances and the adsorption mechanisms of PEA on the quartz/FQA were investigated through flotation experiments, ICP-OES, XRD, Zeta potential, FTIR and XPS measurements. A remarkable separation of the quartz from FQA has been realized in an environmental friendly way. The froth flotation results show that the flotation recovery of quartz is 97.79% and that of FQA is 19.30% at pH 9.00–9.50 with 10−4 M PEA when the particle size ranges from 150 to 270 μm. The results of batch flotation, ICP-OES and XRD analyses show that the first flotation product is almost quartz, while more feldspar and little quartz exist in the sink product when compared with the FQA feed. The mechanism of PEA acting as the collector for the separation of quartz/feldspar has been investigated. The PEA is adsorbed on the quartz surface by electrostatic and hydrogen bonding interaction with ─NH3+ /─NH2 head groups, while is less adsorbed on the feldspar surface due to electrostatic repulsion between the K+ / Na+ ions and the positively charged ─NH3+/─NH2 head groups of PEA. A conceptual adsorption model of the PEA cationic collector on the quartz and the FQA surfaces has been proposed.