Grant: Engage Plus Grants Program

This project aims to characterize and quantify the roughness of zinc electrodeposits produced at Teck Resources Limited (operations in Trail BC, Canada). In the typical industrial method of producing high-purity zinc, electrowinning is used to recover the metal at an aluminum cathode under large current densities and high-deposition rates. With these conditions, electrowinning is economical but the zinc deposits are often non-uniform and may cause cell short-circuits if the growing zinc layer makes contact with another electrode in the cell. To avoid this, a variety of organic leveling agents may be added to the zinc feed to produce smoother deposits. However, short-circuits are still a problem faced in many electrwinning operations and a better understanding of how the additives interact with the metal surface is required.In this proposal, Atomic Force Microscopy (AFM) and Scaling Analysis will be used to monitor the surface structure of zinc electrodeposits as a function of electrolyte composition. Zinc deposits will be prepared on an aluminum cathode using a standard zinc electrolyte donated by Teck Resources in a manner that was developed in our previous NSERC Engage grant with the company. In the current approach, three dimensional images of the zinc deposits will be acquired with AFM and the features of the surface including roughness, periodicity and aspect ratio will be quantified as a function of electrolyte composition. This approach will allow for a better understanding of the role that these leveling agents play in the electrowining process.