Flotation collector lauryldiethanolamine: Adsorption configuration impact on collecting efficiency

Abstract

In the reverse flotation separation of apatite and its associated siliceous gangue minerals, the common collector dodecylamine (DDA) exhibits a poor selectivity. To remedy this issue, this study implements a change to DDA molecular structure by integrating two 2-hydroxyethyl groups at the N atom position, ultimately producing a freshly developed collector, lauryldiethanolamine (LDEA). Micro-flotation experiments reveal that, relative to DDA, LDEA showcases an enhanced selectivity in separating apatite from its associated siliceous gangue minerals quartz and K-feldspar through reverse flotation. This difference primarily stems from the weaker collecting ability of LDEA for apatite particles relative to DDA. Nevertheless, zeta potential measurements and X-ray photoelectron spectroscopic tests consistently show that, under identical dosage conditions, LDEA and DDA exhibit similar adsorption quantities on apatite surfaces. This observation implies that factors beyond its adsorption quantities inevitably influence the collecting ability of LDEA for apatite particles. First-principles calculations unveil markedly different adsorption configurations of LDEA and DDA on apatite surfaces, suggesting that the difference in the adsorption configurations of LDEA and DDA accounts for the significant variance in their collecting abilities for apatite particles.