Variables in the shear flocculation of galena

Like froth flotation the shear flocculation is governed by the physical, chemical and geometrical variables. Among the important factors which influence the particle aggregation are the particle size, hydrophobicity, charge and the intensity of agitation. The present paper investigates the effect of different variables on the shear flocculation of (1). galena and (2). synthetic PbS. Since flocculation is influenced both by the charge and the hydrophobicity of the particle the zeta potentials were measured for different experimental conditions. The reaction mechanisms of PbS surfaces in aqueous solutions are examined based on the results; of electrokinetic- and potentiometric titration- studies. In comparison to conventional flotation, higher recoveries were obtained with shear flocculated aggregates. The results are discussed.