Role of shape properties of calcite and barite particles on apparent hydrophobicity

Shape properties of calcite and barite particles ground by ball, rod and autogenous mills were examined by using scanning electron microscope (SEM). Shape properties have been stated in terms of shape descriptors such as elongation ratio, flatness, roundness and relative width by measuring about 200 particles. The results were correlated with the critical surface tension (gamma(c)) of wetting determined by contact angle and micro-flotation methods. The correlations set between the shape properties and the wettability for the minerals studied are in the form of "gamma(c) = a (shape property) + b" type of equations (where a and b are constants). The results revealed that particles with higher flatness and elongation ratio had higher apparent hydrophobicity without being affected by the mill type