Method and apparatus for on-line monitoring the quality of a purified metal sulphate solution.

摘要

A method and an apparatus for on-line monitoring the quality of a purified metal sulphate solution is disclosed. The method comprises the steps of depositing metal from the purified metal sulphate solution onto a working electrode submerged in the solution by passing constant current through the solution at a current density in the range of 25 to 150 mA/cm<2> for a predetermined time interval, dissolving the metal deposited on the working electrode by reversing the polarity of the potential applied between the working electrode and a counter electrode so as to pass a reverse current of the same current density through the solution until all zinc is removed from the working electrode as sensed by a sudden change in electrode potential, deriving the quality index of the solution by calculating the ratio of the dissolution time over the deposition time, and restoring the surface of the counter electrode by effecting the dissolution of the metal deposited on the counter electrode at the end of each measurement.