A novel macromolecular depressant for reverse flotation: Synthesis and depressing mechanism in the separation of hematite and quartz

Abstract

Abstract In this paper, a novel macromolecular depressant of hematite, polymaleic anhydride-triethylenetetramine (PMTA) with multiple carboxyl and amine groups, has been synthesized and used for cationic reverse flotation separation of quartz from hematite. The structure is characterized by Fourier transform infrared spectroscopy (FT-IR). The depression performance and adsorption mechanism of PMTA onto hematite and quartz surface are investigated by micro-flotation tests, FT-IR, zeta potential and X-ray photoelectron spectra (XPS). The micro-flotation results indicate that PMTA exhibits a good depression performance compared to starch. We find that 98.29% of hematite is depressed with a grade of 65.24% at pH 11 with 12 mg/L dosage. The FT-IR spectra, zeta potential and XPS analysis demonstrate that PMTA may mainly chemisorb on the hematite surface by Fe O bonds, and mainly adsorb on the quartz surface by hydrogen bond interaction. PMTA could be a good depressant of hematite in the separation from quartz.