Investigating the performance of a novel polyamine derivative for separation of quartz and hematite based on theoretical prediction and experiment

Abstract

This paper presents the effective design method for amine collectors in the reverse flotation of iron ore and a novel polyamine collector N, N-Dimethyl-N′-dodecyl-1,3-propanediamine (DPDA) was designed based on this method. The properties and flotation behaviors of DPDA were evaluated by Density Functional Theory (DFT) calculation and Molecular Dynamics (MD). The properties analysis indicated that DPDA had an excellent collecting ability, which was similar to N-dodecyl-1,3-diaminopropane (NDEA), but it had better selectivity than NDEA and dodecylamine (DDA). The flotation tests showed that DPDA had a strong collecting ability and good selectivity, it could realize the efficient separation of quartz and hematite under neutral and weak alkaline pulp conditions, which was consistent with the theoretical analysis. The analyses of fourier transform infrared spectroscopy (FTIR), zeta potential, and X-ray photoelectron spectroscopy (XPS) indicated that DPDA adsorbed on the surface of minerals mainly via electrostatic force and hydrogen bonding, which also could be noted from the computation calculation results. The excellent flotation performance of DPDA (especially in selectivity) could be ascribed to more active sites and larger polar group sizes. The results indicated that DFT calculation and MD simulation were an effective method to guide the design of the novel cationic collectors with high selectivity.