Effect of Tween 80 on flotation separation of magnesite and dolomite using NaOL as the collector

Dolomite is difficult to be separated from magnesite by sodium oleate (NaOL) because of their same crystal structure, similar chemical composition, and high solubility. The work investigated the effect of Tween 80 as the accessory reagent on the flotation of magnesite and dolomite using NaOL as the collector by flotation tests, solution chemical calculations, surface tension measurements, Zeta potential measurements, contact angle measurements, FTIR spectra measurements, and XPS measurements. Flotation experiments and contact angle analysis showed that the addition of Tween 80 strengthened the floatability of magnesite and weakened that of dolomite when NaOL was used as a collector. Surface tension analysis, Zeta potential analysis, and MR spectra analysis revealed that Tween 80 could strengthen the adsorption of NaOL on mineral surface by promoting the dissolution and dispersion of NaOL solution. Solution chemical calculations, Zeta potential analysis, and MR spectra analysis also indicated that Ca2+ and CaOH+ were the active components of dolomite in flotation, and Tween 80 had a specific inhibitory effect on dolomite. XPS and Ca2+ dissolution tests further indicated that Tween 80 inhibited dolomite by binding Ca2+ with its EO groups. This action reduced the adsorption of Ca2+ with NaOL and improved the separation of magnesite and dolomite. (C) 2020 Elsevier B.V. All rights reserved.