Flotation separation of ilmenite against titanaugite using a novel collector in a highly acidic environment

Abstract

Functional mechanism of a new high-efficiency collector was studied in ilmenite flotation. Microflotation experiment showed that flotation recovery of ilmenite remained above 80 % using 50 mg/L dodecyl dimethyl benzyl ammonium chloride (DDBAC) collectors at a pH range of 1.0 ∼ 10.0, while the recovery of titanaugite decreased from 67.06 % at pH 6.0 to 19.92 % at pH 1.5. Contact angle and AFM analyses revealed that DDBAC exhibited high adsorption on ilmenite surfaces at pH 6.0 and 1.5 and on titanaugite surfaces at pH 6.0. However, its adsorption on titanaugite surfaces diminished at pH 1.5. FTIR and XPS analyses revealed that DDBAC could chemisorb with Mg sites on titanaugite surfaces, but it mainly adhered to ilmenite and titanaugite surfaces through physical adsorption. In a highly acidic environment, the surface activity diminished and hydrophilicity rose in comparison to a weakly acid environment, along with a lower Mg content on titanaugite surfaces. This led to a decline in both physical and chemical adsorptions of DDBAC on titanaugite surfaces, reducing the floatability of titanaugite. Actual mineral flotation tests displayed that the TiO₂ grade of the coarse flotation concentrate rose by 2.37 % to 40.65 % using 420 g/t DDBAC collectors, in contrast to the benchmark that utilized an efficient reagent system (300 g/t Pb(NO₃)₂ activators and 1500 g/t TW-705 collectors). Taken together, the DDBAC collector held significant potential for industrial applications.