Zincor experienced significant losses of metallic zinc to dross during
the melting of zinc cathode plates. In this study five factors affecting
the formation of dross are identified from literature. Dross from both
the plant and that produced in the laboratory is characterized using
XRD. An empirical model, based on laboratory-scale investigations,
was developed to quantify the effect these factors on their own or in
combination with each other has on the amount of zinc loss to dross.
The predictive capability of the model is evaluated based on the
laboratory-scale investigations. Predictions are made on the effects
that heat treating the cathode plates prior to melting, increasing the
cathode plate thickness, washing and drying prior to melting, and
loading the furnace in a controlled manner have on the amount of
zinc loss to dross.