An investigation into the flotation of muscovite with an amine collector and calcium lignin sulfonate depressant

• Zeta potential measurements of muscovite and gangue measured.
• Effect of flotation reagent addition analyzed.
• Separation of muscovite from gangue through flotation was related to zeta potential.

Muscovite mica is a naturally occurring phyllosilicate mineral with a wide range of industrial applications. This work investigated the separation of muscovite from unwanted gangue minerals in a mica ore. Electroacoustic zeta potential measurements and single mineral flotation tests were used to determine the effect of Custamine 8113 (collector) and Norlig-H (depressant) on muscovite. These results were then compared to those of gangue minerals (feldspar and quartz). Muscovite showed an isoelectric point (IEP) at pH 3.5. Feldspar and quartz did not have an IEP, having negative zeta potentials over the pH range investigated (pH 3–10). This suggests that effective separation using a cationic amine collector, which relies on electrostatic attraction as the basic mechanism of adsorption onto mineral surfaces, would not be possible without the use of a depressant. Zeta potential measurements and single mineral flotation tests in the presence of both Custamine 8113 and Norlig-H indicate that reagent adsorption is controlled by Custamine 8113 in the case of muscovite and by Norlig-H in the case of feldspar and quartz. This suggests that effective separation of muscovite from the gangue minerals present in the mica ore is possible. These results were used to determine optimal flotation conditions of the ore. Concentrates from the ore flotation were examined by QEMSCAN analysis, which showed that muscovite was effectively separated from gangue minerals.