The mechanism of fine-grained actinolite flocculation enhancing reverse flotation desilication of hematite

Actinolite is often associated with hematite and tends to form fine-grained particles during grinding, which makes the recovery and separation of hematite through flotation challenging. This study innovatively used polyethylene oxide (PEO) as a flocculant and, in a reverse flotation system with dodecylamine (DDA) as the collector, increased the recovery rate of actinolite by 40.59 %, the desilication rate of the binary artificial mixed ore by 25.23 %, and that of the ternary artificial mixed ore by 4.62 %. The study also investigated the effect of PEO on the structure of actinolite during flocculation and the relationship between the structure of actinolite flocs and their floatability. Laser particle size and turbidity tests indicated that PEO significantly increased the particle size of fine actinolite, causing it to aggregate into flocs while reducing its settling velocity and apparent density. Optical microscopy and scanning electron microscopy observations revealed that the low density of the flocs was due to PEO flocculating fine actinolite into porous and irregular spherical shapes with high surface roughness and specific surface area. Energy dispersive spectroscopy analysis and wrapping angle analysis demonstrated that the flocs have a large specific surface area, apparent volume, and are subject to greater buoyancy, making them more likely to attach onto the surface of bubbles and be carried by them. Therefore, PEO can be used as a flocculant for the flotation of actinolite, increasing the floatability of fine-grained actinolite and thereby enhancing the flotation removal rate of actinolite in hematite. The mechanism of fine-grained actinolite flocculation enhancing reverse flotation desilication of hematite.