Measurement of polarization parameters impacting on electrodeposit morphology. II: Conventional zinc electrowinning solutions

A new technique for measuring effects of polarization modifiers on nucleation potential and plating potential in polycrystalline electrodeposition was presented in Part I of this series (J. Appl. Electrochem. 32 (2002) 1101-1107). This paper presents the results of application of the proposed technique to conventional zinc electrowinning. Strong correlations are observed between deposit metallographic structure and the polarization characteristics. The results demonstrate that the new galvano-staircase method can be used to predict long-term (i.e. substrate-independent) deposit morphology, based on relatively rapid electrochemical measurements. With sufficient knowledge of the system, beneficial changes can be specified for additives, particularly long term averages. However even interactive, control on an hourly basis should be possible.