Abstract: The invention relates to a method and an apparatus for preparing a mother plate of a permanent cathode to be used in a process for electrolytic recovery of metal such as metal electrorefining or metal electrowinning. The apparatus comprises a holder for releasably holding the permanent cathode, a measurer for measuring a shape of the mother plate to obtain measurement data, a calculating device functionally connected with the measurer and configured for calculating geometric deviation of the mother plate in comparison to a predefined reference shape by using the measurement data, and a presser functionally connected with the calculating device and configured for automatically locally pressing the mother plate in accordance with the calculated geometric deviation of the mother plate to plastically deform the mother plate.

Abstract: The invention relates to a method and an apparatus for preparing a mother plate (1) of a permanent cathode (2) to be used in a process for electrolytic recovery of metal such as metal electrorefining or metal electrowinning. The apparatus comprises a holding means (8) for releasable holding the permanent cathode (2), a measurement means (4) for measuring a shape of the mother plate (1) to obtain measurement data, a calculating means functionally connected with the measurement means (4) and configured for calculating geometric deviation of the mother plate (1) in comparison to a predefined reference shape by using said measurement data measured by said measurement means (4), and a pressing means (3) functionally connected with the calculating means and configured for automatically locally pressing the mother plate (1) in accordance with the calculated geometric deviation of the mother plate (1) to plastically deform the mother plate (1).