Quartz crystal microbalance with dissipation (QCM-D) was used to study the zinc sulfide activation with silver, copper and lead. The interactions between calcium sulfate and minerals and gypsum nucleation on functional surfaces were investigated using a QCM-D, surface forces apparatus (SFA), and atomic force microscope (AFM).;This study is the first of its kind to apply the QCM-D technique to investigate sphalerite activation, which indroduces a new in-situ approach to investigate surface adsorption and activation in many mineral processes and surface modifications. The fitting of adsorption of copper and lead species to sphalerite at pH 6.5 and 9 with kinetic models indicates that the activation in this pH range is a chemisorption process. Gypsum was found to grow on functional surfaces following the growth rates as -COOH>-OH>-CH3, but not on sphalerite. The uptake of copper and adsorption of xanthate on sphalerite could be retarded in the presence of calcium sulfate. |