Innovative flotation for the utilisation of carbonate-bearing (siderite) iron ore using MS-2 as a dispersant

Abstract

MS-2, a novel dispersant, was employed to improve the innovative dispersion flotation of carbonate-bearing refractory iron ore. High quality iron concentrates (TFe grade of 67.04% and recovery of 75.57%) were achieved by the locked-cycle flotation tests and analyzed by X-ray diffraction and scanning electron microscopy to investigate the surface morphology, which show the siderite slime coatings on hematite and quartz surfaces were effectively dispersed by MS-2. The dispersal mechanism was investigated via Zeta potential measurements and Fourier-transform infrared (FTIR) spectroscopy, which confirmed that MS-2 chemically adsorbed onto hematite surfaces, while physically adsorbed on quartz surfaces. Molecular dynamics simulations revealed the adsorption configurations of MS-2 onto both mineral surfaces, further confirming that the functional groups –COO‐ in MS-2 molecules interacted strongly with the Fe atoms on the hematite surface. Derjaguin-Landau-Verwey-Overbeek (DLVO) theory calculations indicated that the repulsive force between siderite and quartz or hematite became stronger after MS-2 was added, which weakened the siderite slime coatings on quartz and hematite. Therefore, MS-2 effectively dispersed the siderite or carbonate slime coatings from hematite and quartz surfaces and then restored the regular reverse anionic flotation for carbonate-bearing refractory iron oxide ores.