A novel sulfur-containing ionic liquid collector for the reverse flotation separation of pyrrhotite from magnetite

Abstract

To improve the quality of the iron concentrate, the efficient separation of pyrrhotite from magnetite has always been an important beneficiation objective. In this paper, a novel collector of sulfur-containing ionic liquid (SCIL) was synthesized by using the isobutyl xanthic acid with N-tetrabutyl quaternary ammonium salt, and its molecular structure was characterized by 1H NMR, 13C NMR and FTIR analysis. The SCIL was used as a flotation collector for the first time to selectively separate pyrrhotite from magnetite by reverse flotation. Its flotation performance and adsorption mechanism on pyrrhotite or magnetite were investigated by microflotation tests, FTIR spectra, zeta potential measurement, XPS analysis and MDS. The microflotation results demonstrated that the SCIL has excellent collecting ability and selectivity for pyrrhotite against magnetite, compared with the traditional collector of sodium butyl xanthate (SIBX). Specifically. the flotation test results of mixed mineral shown that the S grade was reduced from 25.72 % of feed to 2.92 % of concentrate using SCIL as the collector, confirming its high efficiency. The analyses of zeta potential measurement and FTIR spectra indicated that SCIL was chemisorbed onto the pyrrhotite surface. The XPS results further confirmed that the CS bond of SCIL could be associated with S sites of the pyrrhotite surface, and Fe sites of the pyrrhotite surface might react with the CN or the CS bonds of SCIL. MDS further indicated that the adsorption of SCIL onto the pyrrhotite surface was much stronger than the SIBX.