Impedance studies of the adsorption of hydrophobic and hydrophylic species on mineral pulps

Physical adsorption of dodecylamine on galena (PbS) and on fluorite (CaF2) does not change the dielectric permittivity of pulps at 10 MHz while a chemical adsorption of xanthate on PbS and of oleate on CaF2 leads to significant variations. Physical adsorption is observed for hydrophylic species such as nickel hydroxide for PbS and quebracho for CaF2 which are used for limiting the flotation of the minerals. Their co-adsorption with xanthate and oleate can be studied by dielectric methods.