Role of hydrophobicity and surface tension on shear flocculation and oil agglomeration of magnesite

This paper describes the role of hydrophobicity and surface tension on the shear flocculation and oil agglomeration of magnesite mineral. The experimental results have demonstrated that these processes were closely correlated with the particle hydrophobicity; however, they were not lowered by increasing the surface charge due to sodium oleate adsorption. Also, higher degrees of hydrophobicity were required to achieve the maximum aggregation in the oil agglomeration of magnesite fines in comparison to its shear flocculation. On the other hand, these aggregation processes decreased depending on the decrease in the contact angle with decreasing surface tension. Eventually the shear flocculation and oil agglomeration of fine particles in the suspension did not take place below a particular value of surface tension, corresponding the critical surface tension of wetting (γc) and the critical solution surface tension (γc-a) values, respectively.