Preliminary assessment of spray coating, solution-immersion and dip coating to render minerals superhydrophobic

Achieving hydrophobic surfaces on mineral particles is an active research topic in mineral processing. The conventional technique for achieving good hydrophobicity is to mix mineral particles in solutions of organic salts (surfactants), briefly termed as conditioning. Alternatively, this paper presents three methods (spray coating, dip coating and solution-immersion) to render minerals superhydrophobic. The methods, as supported by the literature, can generate superhydrophobic mineral surfaces with water-repellent ability. Experimental results suggest that the spray-coated mineral particles can be separated with gravity concentration methods even if their densities are close. Also, the application of superhydrophobic coating techniques on fine particles yields an increase in the sedimentation rates. Therefore, superhydrophobic coating techniques have the potential to be used in mineral enrichment/dewatering.