A novel surfactant O,O' -bis(2-butoxyethyl) ammonium dithiophosphate: Synthesis, selective flotation and adsorption mechanism towards galena

In this work, a novel surfactant, O,O'-bis(2-butoxyethyl) ammonium dithiophosphate (BEAT), was synthesized and first employed as a collector for the flotation separation of galena from sphalerite. Surface tension measurements elucidated that BEAT possessed a higher surface activity and stronger hydrophobicity than ADD due to the introduction of C-O-C groups. Compared to the conventional collector ammonium dibutyl dithiophosphate (ADD), BEAT exhibited both superior collecting ability and flotation selectivity for galena against sphalerite under approximately neutral or natural pH conditions from the results of micro-flotation and bench-scale flotation. Wettability experiments revealed that BEAT promoted the hydrophobicity of galena surfaces more markedly in comparison with sphalerite. The adsorption mechanism of BEAT on the mineral surface was uncovered by FTIR spectrum and X-ray photoelectron spectroscopy (XPS) measurements. The results of FTIR spectrum demonstrated that BEAT had a much stronger adsorption affinity towards galena than that towards sphalerite. Furthermore, XPS results recommended that BEAT might adsorb on the mineral surface through the reaction of P = S and P-S groups with galena to form metal complexes of P-S-Pb structure. This research provides significant implications for developing novel and efficient industrial chemical reagents for galena flotation.