Process for the regeneration of a nickel bath use for the coating of metal parts

The invention relates to a process for regenerating a spent nickel bath containing anionic compounds and cationic compounds including orthophosphites PO3 H2 ** -, hypophosphites H2 PO2 ** -, and Ni ions ** 2 + characterized in that it comprises a first phase separation of compounds in which a substantial amount of the anionic compounds in solution in said bath has separate cationic compounds under conditions allowing further retention solution an optimum amount of Ni ions ** 2 + a second phase separation of compounds in which a substantial amount of monovalent anionic compounds, anionic compounds included in separate cationic compounds during the first process step, is separated from the multivalent anionic compounds by creating a difference in valence between these compounds, particularly by the application of a pH enabling e create this difference of valence.