Fundamental Investigation of Microwave Pretreatment on the Flotation of Massive Ilmenite Ores

Abstract Microwave energy was used as a novel method to modify massive ilmenite surface properties and improve ilmenite flotation. Studies concentrated on an investigation into the effect of microwave radiation pre‐treatment on the flotation behaviour of a massive ilmenite ore sample from Norway. Experimental programmes were carried out in both Hallimond‐tube and Denver‐cell flotation devices. The experimental results indicate that the flotability of massive ilmenite was greatly improved after microwave‐induced thermal pretreatment. In comparison with conventional flotation, at the same optimised flotation conditions, massive ilmenite subjected to microwave heat treatments floated well in both the roughing and cleaning stages. Ilmenite recoveries were greatly increased over non‐treated samples. The major factors affecting ilmenite microwave‐pretreatment flotation are microwave power level and irradiation time. The investigation into the surface zeta potential indicates that microwave irradiation enhanced the adsorption of oleate ions in the Helmholtz layer of the ilmenite particles and resulted in ilmenite surface charge being more negative. Improved ilmenite flotation recovery was observed after microwave pretreatment.