Mineralogical properties of ludwigite and the effects of microwave radiation on its particle characteristics and mineral liberation properties

To effectively separate the valuable minerals in ludwigite, this study investigated the mineralogy of ore, particle-size distribution and mineral liberation characteristics. Most of the magnetite was intergrown with ascharite and serpentine. Nearly half of the serpentine existed in a dense, massive body. Most of the ascharite was encased in magnetite, and a small amount was embedded in the serpentine phase. After the microwave radiation, some intergranular and through cracks were formed to improve mineral liberation during the grinding process. The mass fractions for the +75 μm range decreased from 43.16 wt% for untreated samples to 24.31 wt% for treated samples with a microwave power of 3 kW for 40 s. By contrast, the mass fractions of particles in the −75 μm range increased from 56.84 wt% for untreated samples to 75.69 wt% for treated samples. D50 decreased from 53.54 µm for the untreated sample to 21.58 µm for the treated sample. The liberation degrees after the treated samples clearly improved and increased by 26.64% for magnetite, 18.92% for ascharite and 14.10% for serpentine.